eduagarcia/scielo_abstracts · Datasets at Hugging Face

scl/1516-1439/S1516-14392022000100379.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100379

10.1590/1980-5373-mr-2022-0310

ENGINEERING, CHEMICAL

Annamalai University

null

Tribological and Viscoelastic Behaviour of Jute, Prosopis Juliflora Bark, and Kenaf Fibers Reinforced Polyester Hybrid Composites for Engineering Applications

Muthalagu, R.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Utilizing biomaterials for every conceivable purpose area, such as automobiles, sporting goods, medical, civil, and textile industries, is the aim of the research field. Applications of Natural Fiber (NF) reinforced polymer composites in structural and tribological engineering are rapidly expanding. For the first time in this work, Prosopis juliflora bark and two different types of NF (jute and kenaf) were reinforced with polyester matrix by the hand layup method. The objective of the work is to determine the wear performance and viscoelastic properties of the new hybrid bio-composite. Under dry contact conditions, the tribological performance of the proposed hybrid composite material was evaluated using a range of process parameters, including sliding distance (1000-2000 m), applied load (10-50 N), and sliding velocity (1-5 m/s). The wear behaviour of the fabricated NF composite was greatly enhanced (17.5 x10-8 mm3 /N-mm) by the higher composition of kenaf fibers has been observed. The dynamic mechanical analysis (DMA) showed that the manufactured composites had high storage modulus (4.1 GPa) and loss modulus (3.8 GPA). SEM was used to investigate and propose a potential wear mechanism for the developed composites by evaluating the exterior geomorphology of samples after wear tests. AFM provided details on the fiber surface properties of hybrid composites.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100379&lng=en&tlng=en

47

scielo_articles/scl/1516-1439/S1516-14392022000100379.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Muthalagu, R.", "Srinivasan, V.", "Kumar, S. Sathees", "Krishna, V. Murali" ]

null

[ "DMA", "juliflora", "kenaf", "Polyester", "Wear" ]

null

[ "Annamalai University", "B.V. Raju Institute of Technology", "Institute of Aeronautical Engineering" ]

scl/1516-1439/S1516-14392022000100372.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100372

10.1590/1980-5373-mr-2022-0156

ENGINEERING, CHEMICAL

University of Jeddah

null

Ag/SeO2/C Avalanche Type Resonant Tunneling Schottky Barriers

Al Garni, Sabah E.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Herein, the design and characterization of Ag/SeO2/C avalanche type resonant tunneling devices are reported. Thin pellets of SeO2 nano-powders pressed under hydraulic pressure of 1.0 MPa which is used as the active material are characterized. They showed tetragonal structure refereeing to space group of P 4 2 m b c and lattice parameters of a = b = 7.866 Å and c =5.336 Å. The current-voltage characteristic curves have shown that SeO2 can perform as active media to produce resonant tunneling diodes when forward biased and as avalanche type diode when reverse biased. The peak to valley current ratios of these diodes reached 18.3. In addition, the impedance spectroscopy measurements have shown that the device works in the low impedance mode when operated in the microwave range of frequency near 1.50 GHz. Negative conductance effect is observed in that frequency domain. The features of the Ag/SeO2/C nominate them for use as signal amplifiers and microwave oscillators.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100372&lng=en&tlng=en

26

scielo_articles/scl/1516-1439/S1516-14392022000100372.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Al Garni, Sabah E.", "Qasrawi, A.F.", "Khusayfan, Najla M." ]

null

[ "Ag/SeO2/C", "tetragonal", "microwave cavity", "Esaki diodes", "negative conductance" ]

null

[ "University of Jeddah", "Arab American University", "Istinye University" ]

scl/1516-1439/S1516-14392022000100362.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100362

10.1590/1980-5373-mr-2022-0060

ENGINEERING, CHEMICAL

Chang’ an University

null

Compression Behavior of 3D Printed Polymer TPU Cubic Lattice Structure

Zhang, Chenfan

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Based on the face-centered cubic structure, several different types of cubic lattice structures are designed in this paper, the quasi-static compression behavior of the lattice structure is thoroughly investigated by finite element simulation and experimental testing, in which mechanical properties and energy absorption capacities are summarized. The experimental specimens made from thermoplastic polyurethane TPU are additively manufactured using the fused deposition technology. Effects of strut style, strut distance, arrangement form, curvature, and several honeycomb lattice structures are considered. The results show that: under the condition of the same relative density, the selection of sinusoidal struts with larger curvature, the arrangement of 45°/135°, and the inward gradient of the strut distance can all improve the energy absorption characteristics of the structure. Compared with the traditional face-centered cubic structure (specimen L-1), the SEA of the structure with the strut curvature of 0.25, the 45°/135° arrangement of the sinusoidal struts, and the inward gradient of the strut distance is improved by 64% , 190%, and 107%; the introduction of a honeycomb structure with a high relative density can effectively resist the buckling deformation of the structure, and the SEA of the triangular, re-entrant and hexagonal honeycomb structures are 354%, 603% and 548% higher than that of the basic structure, respectively. In addition, reducing the lattice height also resists destabilization.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100362&lng=en&tlng=en

40

scielo_articles/scl/1516-1439/S1516-14392022000100362.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Zhang, Chenfan", "Li, Teng", "Deng, Qingtian", "Li, Xinbo" ]

null

[ "Cubic lattice structure", "Energy absorption", "Strength", "Honeycomb structure" ]

null

[ "Chang’ an University" ]

scl/1516-1439/S1516-14392022000100347.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100347

10.1590/1980-5373-mr-2022-0161

ENGINEERING, CHEMICAL

PSNA College of Engineering and Technology

null

Evaluation of Abrasive WearRate and Machining Behaviors of Synthesized Nitinol Composite

Sridhar, S.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

The present investigation deals with wear and machining behaviors of manufacture nitinol composite through Vacuum Induction Melting (VIM). The major composition of nickel and titanium was reinforced with tungsten carbide (WC). Scanning Electron Microscopy (SEM) was employed to investigate the morphology of the synthesized nitinol composite. For investigating the topography of the surface of the nitinol composite was analyzed by scanning force microscopy or atomic force microscopy. Spark erosion machining has been applied to explore the machining behavior of the nitinol composite. Abrasive Wear Rate (AWR) is evaluated by using abrasion tester. Machining and wear parameters are optimized by applying taguchi approach. The contribution and the effect of input constraints on the responses are investigated by analysis of variance.Optimal abrasive wear rate was attained at 900 rpm of disc speed, 12 gm/min of abrasive flow rate and 400m of sliding distance. Disc speed was a dominant factor and it has developed 43.86% effect on abrasive wear rate. Optimal rate of metal removal was achieved at 45A of current, 200µs of pulse on time and 35V of Volts. The current was the leadingfactor and it has produced 86.38% effect on the rate of metal removal.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100347&lng=en&tlng=en

34

scielo_articles/scl/1516-1439/S1516-14392022000100347.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Sridhar, S.", "Marichamy, S.", "Subbiah, Ram" ]

null

[ "Nitinol composite", "abrasive wear rate", "machining characteristics", "Surface topography", "Taguchi approach" ]

null

[ "PSNA College of Engineering and Technology", "Sri Indu College of Engineering and Technology", "Gokaraju Rangaraju Institute of Engineering & Technology" ]

scl/1516-1439/S1516-14392022000100346.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100346

10.1590/1980-5373-mr-2021-0579

ENGINEERING, CHEMICAL

Muğla Sıtkı Koçman University

null

A Study on Physical, Morphological and Antibacterial Properties of Bio Polymers Reinforced Polyvinyl Acetate Foams

Yildirim, Nadir

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

In this study, foaming-agent free novel polyvinyl acetate (PVAc) foams reinforced with bio polymers were manufactured through freeze-drying technique. The physical, morphological and antibacterial properties of foams which were reinforced with different ratio of zinc borate and water-soluble chitosan were investigated according to relevant standards. The PVAc foams showed low densities (0.12 g/cm3 – 0.21 g/cm3) and high porosity rates (87.50% - 79.05%). The results showed that although the foams have no antibacterial character against Escherichia Coli, they have antibacterial character against Staphylococcus Aureus bacteria. This study mainly focusses on physical and morphological properties of the foams. However, researchers also performed accelerated weathering tests to determine its usability in different industries. The effects of accelerated weathering on the surface of foams were investigated by measuring surface color. The highest color difference was determined 8.09. This foam can be used as a low-density packaging material and/or medical box with its promising physical and morphological properties with hazardous-chemical free structure.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100346&lng=en&tlng=en

100

scielo_articles/scl/1516-1439/S1516-14392022000100346.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Yildirim, Nadir", "Ozen, Ertan", "Ergun, Mehmet Emin", "Dalkilic, Berk" ]

null

[ "Antibacterial effect", "bio polymers", "freeze-drying", "polyvinyl acetate (PVAc) foam" ]

null

[ "Muğla Sıtkı Koçman University", "Alaaddin Keykubat University", "Hamad Bin Khalifa University", "Sinop University" ]

scl/1516-1439/S1516-14392022000100348.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100348

10.1590/1980-5373-mr-2022-0041

ENGINEERING, CHEMICAL

Universidade do Estado do Rio de Janeiro

null

Production of low-Sn Cu-Sn Alloy Coatings onto Steel Substrate Using Sodium Citrate Bath – Part 1: the Effect of Current Mode (DC or SPC) and Applied Current on the Chemical, Morphological, and Anticorrosive Properties of the Coatings

Zhou, Nathalia Xiaohui

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstratc This work reports the production of low-tin Cu-Sn alloy coatings on carbon steel substrates using a bath containing CuCl2, SnCl2, and sodium citrate. In the first part of this study, the coatings were electrodeposited by direct and simple pulse current processes (DC and SPC, respectively). Different current density values were used, while the pulse frequency and duty cycle remained constant. Independent of the current mode used, low-tin Cu-Sn coatings, showing globular surface morphology and Cu6Sn5 as the main compositional phase, were produced. Both the current mode and the applied current density affected the anticorrosive properties of the coatings. The most protective DC and SPC coatings, showing Sn content < 3 wt.% and compact morphology, were prepared using j = 80 A m-2 and jc = 167 A m-2, respectively. High charge transfer resistance values were verified even after immersion for 24 h in 0.5 mol L-1 NaCl solution.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100348&lng=en&tlng=en

59

scielo_articles/scl/1516-1439/S1516-14392022000100348.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Zhou, Nathalia Xiaohui", "Silva, Priscila Santos da", "Braga, Antônio Vitor de Castro", "Lago, Dalva Cristina Baptista do", "Pimenta, André Rocha", "Senna, Lilian Ferreira de" ]

null

[ "Cu-Sn alloy", "cyclic voltammetry", "DC process", "SPC process", "sodium citrate", "anticorrosive coatings" ]

null

[ "Universidade do Estado do Rio de Janeiro", "Instituto Federal de Educação Ciência e Tecnologia do Rio de Janeiro" ]

scl/1516-1439/S1516-14392022000100378.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100378

10.1590/1980-5373-mr-2022-0315

ENGINEERING, CHEMICAL

Universidade de São Paulo

null

Low Cycle Fatigue Behavior of Al-Mg-Si Alloys Extruded Parts

Nascimento, D.F.L.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Over the past years, Al-Mg-Si alloys have been largely applied in automotive industry, which has required a deep knowledge of their mechanical properties and the influence of precipitates distribution on their mechanical behavior. This work evaluated the main mechanical properties of AA6005, AA6063, and AA6351 alloys by means of tensile and low cycle fatigue tests with 0.005 seg-1 deformation rate and 0.3% < εat <1.2% strain amplitudes. Besides, the hysteresis loop and internal stress analysis were investigated to analyze hardening and softening phenomena and to evaluate the friction and back stresses, respectively. Macro and microstructural were performed focusing in intermetallic distribution. Concerning the low cycle fatigue behavior, AA6351 presented shorter lives for strain amplitudes higher than 0.5%, and AA6005 showed the highest fatigue strength and fatigue ductility. AA6063 showed the lowest fatigue strength due to the presence of coarse particles (Fe,Mn)SiAl. During internal stress analysis, the highest value of friction stress for AA6351 indicates the effect of hardener precipitates are the most relevant role for cyclic loadings and the lowest back-to-friction stress ratio indicating that deformation is controlled by particles. In the other hand, AA6063 showed the lowest friction stress due to low amount of fine precipitates.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100378&lng=en&tlng=en

34

scielo_articles/scl/1516-1439/S1516-14392022000100378.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Nascimento, D.F.L.", "da Silva-Antunes, A.M.B.", "Paes, M.", "Baptista, C.A.R.P." ]

null

[ "Al-Mg-Si alloys", "low cycle fatigue", "internal stress", "cyclic hardening", "cyclic softening" ]

null

[ "Universidade de São Paulo", "Universidade de São Paulo", "Faculdade de Tecnologia de Cruzeiro Prof. Waldomiro May" ]

scl/1516-1439/S1516-14392022000100349.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100349

10.1590/1980-5373-mr-2022-0057

ENGINEERING, CHEMICAL

Swinburne University of Technology

null

Lateral Crushing of Square Aluminium Tubes Filled with Different Cores

Hussein, Rafea Dakhil

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Thin-walled tubular structures are widely used in industries such as automotive, aerospace and military because of their lightweight and excellent performance under different loading conditions. This study aimed to investigate the lateral crushing performance of square aluminium tubes filled with different cores (honeycomb, polyurethane foam and mixed of these two fillers). Different failure modes of tested structures have been observed and they are progressive failure with plastic hinges formed in the middle of the tube wall, cracks at the corners of some tested tubes and fractures in the mixed foam and honeycomb core. Results show that the lateral crushing performance of aluminium tubes was significantly improved when using mixed filler (honeycomb and foam). The average load, energy dissipation and specific energy absorption of mixed core filled tubes increased up to 638%, 451% and 177% respectively when compared to those for hollow tubes.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100349&lng=en&tlng=en

42

scielo_articles/scl/1516-1439/S1516-14392022000100349.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Hussein, Rafea Dakhil", "Naeem, Haider Tawfiq", "Atiyah, Hasanain", "Ruan, Dong" ]

null

[ "Aluminium", "Honeycomb", "Polyurethane foam", "lateral crushing", "square tube" ]

null

[ "Swinburne University of Technology", "Al-Muthanna University" ]

scl/1516-1439/S1516-14392022000100350.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100350

10.1590/1980-5373-mr-2022-0186

ENGINEERING, CHEMICAL

Universidade Federal de Pernambuco

null

Green Polyethylene in Harsh Environments: Gamma-irradiation Effects

Medeiros, Pablo R. de

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Bio-based linear low-density polyethylene (green LLDPE) composites are used as electrical jackets/insulator for cables. Assessments of gamma-irradiation (Co-60) effects on these materials are of interest as they might be used in nuclear power plants (NPPs). Brazilian sugarcane juice-based green LLDPE composite electrical jackets were irradiated until 1000 kGy and analyzed for thermal stability and mechanical characteristics. Thermogravimetry analysis (TGA) showed increasing of pyrolysis activation energy (Ea) (under N2) from 42.7 ± 4.2 kJ/mol in unirradiated samples to 72.8 ± 4.6 kJ/mol after 60 kGy dose, as resulted of radiation-induced effects. FTIR spectra evidenced radiation-induced formation of conjugated C=C bonds after 250 kGy dose. Tensile stress and Young modulus did not change significantly until 150 kGy dose, whereas elongation at break decreased and reached 50% at 91 kGy dose. These results suggest that green LLDPE might withstand radiation damage through a NPP operating life (~ 40 years).

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100350&lng=en&tlng=en

50

scielo_articles/scl/1516-1439/S1516-14392022000100350.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Medeiros, Pablo R. de", "Araujo, Patricia L. B.", "Aquino, Katia A. S.", "Araujo, Elmo S." ]

null

[ "bio-based plastics", "gamma radiation", "LLDPE thermal properties", "LLDPE mechanical properties", "nuclear power plants" ]

null

[ "Universidade Federal de Pernambuco", "Universidade Federal do Pernambuco", "Universidade Federal de Pernambuco" ]

scl/1516-1439/S1516-14392022000100360.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100360

10.1590/1980-5373-mr-2022-0137

ENGINEERING, CHEMICAL

Centro Universitário Católico de Santa Catarina

null

Percolation Threshold and Depression in Properties of Polymer Nanocomposites

Barnasky, Ricardo Ritter de Souza

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Percolation threshold is an important phenomenon to be addressed when producing nanocomposites, especially because the literature suggests a depression of properties near this region. In this study, epoxy matrix nanocomposites were produced with different volume fractions of multi-walled carbon nanotubes and were characterized according to their electrical, thermal, and mechanical properties. In addition, digital image correlation (DIC) was used to measure the strain of nanocomposites and to show how it behaves in different percolation states. Electrical conductivity indicated a percolation threshold near 0.22% v/v of nanoparticles. Differential scanning calorimetry analysis showed a depression followed by an increase in glass transition temperature near the percolation threshold. Tensile strength tests presented a depression followed by an increasing near percolation threshold. DIC images showed that nanocomposites present a different behavior when near the percolation threshold, with a more distributed strain over the surface of the sample under stress and fracture toughness decreased near the percolation threshold.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100360&lng=en&tlng=en

57

scielo_articles/scl/1516-1439/S1516-14392022000100360.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Barnasky, Ricardo Ritter de Souza", "Frankowiak, Juliana Cristina", "Opelt, Carlos Vinícios", "Coelho, Luiz Antonio Ferreira" ]

null

[ "Percolation Threshold", "Carbon nanotubes", "Interphase", "Nanocomposites" ]

null

[ "Centro Universitário Católico de Santa Catarina", "Universidade do Estado de Santa Catarina" ]

scl/1516-1439/S1516-14392022000100377.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100377

10.1590/1980-5373-mr-2022-0167

ENGINEERING, CHEMICAL

Bairrimoldes

null

Experimental and Numerical Assessment of the Impact Test Performance Between Two UHSS Toe Cap Models

Peixinho, Nuno

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract This paper presents an integrated approach for an ultimate high-performance safety toe cap with significant milestones in slim design and weight saving. The study of crashworthiness properties was performed through impact-crash test conditions exploring the potential of applicant solutions by the combination of an advanced high-strength steel and enhanced geometric stiffening models. The structural response for a significant thickness reduction was assessed and it provides an evolved discussion for improvements in energy absorption capacity. The present case study focuses on two geometric models from the S3 slim toe cap development by prototypes made of a martensitic 1200 steel alloy. The comparison of results is complemented using numerical simulation models with mathematical description of the dynamic plasticity behaviour by applying a constitutive Cowper-Symonds equation with fundamental parameters for material strain-rate dependence.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100377&lng=en&tlng=en

21

scielo_articles/scl/1516-1439/S1516-14392022000100377.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Peixinho, Nuno", "Costa, Sérgio", "Mendonça, João" ]

null

[ "High strength steel", "numerical simulation", "impact", "safety toe cap" ]

null

[ "Bairrimoldes", "Universidade do Minho" ]

scl/1516-1439/S1516-14392023000100221.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100221

10.1590/1980-5373-mr-2022-0232

ENGINEERING, CHEMICAL

Universidade Federal do Piauí

null

Thermal and Acoustic Performance of Green Polyethylene/Cork Composite for Civil Construction Applications

Vasconcelos, Gabriela Celso Melo Soares de

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract In this study, green high-density polyethylene (GHDPE) composites with 5, 10 and 15% natural powdered cork (CP) with and without 5% maleic anhydride (PE-g-MA) were developed in order to evaluate the potential of these materials for civil construction applications. The composites were produced in a co-rotating twin-screw extruder and injection molded. An impedance tube was used to determine the acoustic behavior of the composites, which were then used as ceiling tiles in prototypes of provisional constructions in order to study ascertain their performance with respect to thermal comfort in the City of Teresina, PI - Brazil. Our data indicates that composites sound absorption coefficient values are good between 500 and 1200 Hz, especially for those with a higher percentage of cork, with the lowest absorption rate observed for composites containing PE-g-MA. The composites used in the prototypes provided a decrease in the internal temperature of the built structure.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100221&lng=en&tlng=en

42

scielo_articles/scl/1516-1439/S1516-14392023000100221.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Vasconcelos, Gabriela Celso Melo Soares de", "Carvalho, Laura Hecker", "Araújo, Frederico H.", "Pinto, Fernando A. N. C.", "Barbosa, Renata", "Santos, Maria do Socorro Ferreira dos", "Alves, Tatianny Soares" ]

null

[ "Green polymer", "sound absorption", "thermal comfort" ]

null

[ "Universidade Federal do Piauí", "Universidade Federal do Piauí", "Universidade Federal do Piauí", "Universidade Federal de Campina Grande", "Universidade Federal do Rio de Janeiro" ]

scl/1516-1439/S1516-14392022000100375.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100375

10.1590/1980-5373-mr-2022-0219

ENGINEERING, CHEMICAL

Universidade do Estado de Minas Gerais

null

DFT Calculations for Structural, Electronic, and Magnetic Properties of ZnFe2O4 Spinel Oxide: The Role of Exchange-Correlation Functional

Rezende, Anivaldo Ferreira de

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

In this study, quantum-mechanical calculations in the framework of the Density Functional Theory (DFT) were performed to investigate the role of exchange-correlation functional in describing structural, electronic, and magnetic properties of ZnFe2O4. Herein B3LYP, PBE0, B1WC, and WC1LYP functionals implemented in the CRYSTAL17 code were considered due to the different amounts of the exact Hartree-Fock exchange fraction. In particular, the role of HF fraction on ZnFe2O4 properties was addressed for the first time. Indeed, structural, electronic, and magnetic properties indicate the dependence upon the exchange fraction, where WC1LYP with a 16% exact HF exchange exhibits the best performance compared to the other hybrid functionals. The obtained results reveal an excellent agreement for bandgap, local magnetic moment, long-range magnetic ordering, and unit-cell lattice parameters, overcoming previous theoretical studies based on local/semilocal exchange-correlation treatments. These results confirm the importance of hybrid HF/DFT with controlled HF term contribution to describe the essential features of strongly correlated materials.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100375&lng=en&tlng=en

54

scielo_articles/scl/1516-1439/S1516-14392022000100375.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Rezende, Anivaldo Ferreira de", "Oliveira, Marisa Carvalho de", "Ribeiro, Renan Augusto Pontes", "Mesquita, Weber Duarte", "Marques, Jakelini de Jesus", "Magalhães, Nilva Fernanda dos Santos", "Lemes, Jorge Henrique Vieira", "Longo, Elson", "Gurgel, Maria Fernanda do Carmo" ]

null

[ "ZnFe2O4", "Antiferromagnetic", "DFT", "Exchange-correlation functional", "WC1LYP" ]

null

[ "Universidade do Estado de Minas Gerais", "Universidade Federal de Catalão", "Universidade Federal de São Carlos", "Universidade Federal de Catalão" ]

scl/1516-1439/S1516-14392022000100374.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100374

10.1590/1980-5373-mr-2022-0406

ENGINEERING, CHEMICAL

School of Mechanical Engineering

null

Investigation of TiO2 Nano Filler in Mechanical, Thermal Behaviour of Sisal/Jute Fiber Reinforced Interpenetrating Polymer Network (IPN) Composites

Gopal, Kumar Vijayendra

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

In this work, various proportionate (0%, 1%, 3% 5% & 7%) of titanium di-oxide nano-filler was utilized as particulate matter along with the sisal/jute fiber reinforcement, in the view to increase the physical properties of the composite materials. Beside, as matrix material the mixture of Epoxy (E) and Polyurethane (PE) was chosen with the proportionate of 70 and 30 wt.% respectively, in order to extract the specific qualities of both the matrices to achieve the interpenetrating polymer networks (IPNs). Moreover, to exactly find out the thermo-mechanical characteristics of the sisal/jute fiber reinforced IPN composites, tests like thermo-gravimetric analysis (TGA), tensile, flexural, Impact, short beam strength and water absorption tests were carried out as per standards. It was found that, incorporation of 5% of TiO2, increases the mechanical properties such as tensile, flexural, impact and short beam strength. Similarly, incorporation of TiO2 into IPN matrix enhances the thermal stability and water absorption resistance. All the obtained values of various filler weight % of TiO2 were compared with each other against with and without particulate incorporated IPN laminate in the purpose of using the same in construction industries.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100374&lng=en&tlng=en

44

scielo_articles/scl/1516-1439/S1516-14392022000100374.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Gopal, Kumar Vijayendra", "Kumar, Kuttynadar Rajammal Vijaya", "Suresh, Gopi", "Rajasekharan, Vezhavendhan", "Nagarajan, Prasumanna Krishnamurthy", "Meenakshi, Chinathambi Muthukaruppan" ]

null

[ "Epoxy", "polyurethane", "TiO2", "thermo-gravimetric analysis", "mechanical properties" ]

null

[ "School of Mechanical Engineering", "Bharath Institute of Higher Education and Research", "Dr. M. G. R. Educational and Research Institute", "Rajalakshmi Institute of Technology" ]

scl/1516-1439/S1516-14392022000100373.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100373

10.1590/1980-5373-mr-2022-0245

ENGINEERING, CHEMICAL

Pontifícia Universidade Católica do Rio Grande do Sul

null

TiO2 Antireflection Coating Deposited by Electro-Beam Evaporation: Thin Film Thickness Effect on Weighted Reflectance and Surface Passivation of Silicon Solar Cells

Model, José Cristiano Mengue

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Titanium dioxide was extensively used in solar cell industry and currently has been studied to produce passivated contacts in PERC/PERT and TOPCon solar cells. The aim of this paper was to analyze the impact of the thickness of TiO2 thin films deposited by electro-beam evaporation on the weighted reflectance and the surface passivation on silicon solar cells. Thin films with different thicknesses were deposited to produce PERT solar cells, varying from 50 to 90 nm. The surface passivation was enhanced as the thickness was increased. For instance, at 400 nm, the internal quantum efficiency increased from 71% to 76% when the thickness of the TiO2 was augmented from 50 nm to 90 nm. The lowest weighted reflectance was obtained in samples with 80 nm thick TiO2 films. Considering the compromise between antireflection properties and surface passivation, the highest efficiency solar cells were produced with 80 nm thick TiO2.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100373&lng=en&tlng=en

29

scielo_articles/scl/1516-1439/S1516-14392022000100373.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Model, José Cristiano Mengue", "Moehlecke, Adriano", "Zanesco, Izete", "Ly, Moussa", "Marcondes, Tatiana Lisboa" ]

null

[ "Silicon solar cells", "titanium dioxide", "antireflection coating", "surface passivation" ]

null

[ "Pontifícia Universidade Católica do Rio Grande do Sul" ]

scl/1516-1439/S1516-14392022000100370.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100370

10.1590/1980-5373-mr-2022-0304

ENGINEERING, CHEMICAL

Universidad Nacional Autónoma de México

null

Optoelectronic Properties of Bismuth Sulfide Thin Films Grown by PVD

Cruz-Gómez, J.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Bismuth (III) sulfide thin films are prepared on glass substrates by physical vapor deposition technique. Then, the films are annealed at different temperatures from 150 to 350°C with nitrogen and nitrogen-sulfur atmospheres, respectively. The effect of annealing temperature on the optoelectronic properties is investigated. The layers were characterized using ultraviolet-visible spectroscopy, XRD, Raman spectroscopy, EDS analysis and Hall effect. The film annealed at 250°C in a nitrogen-sulfur atmosphere exhibited the best condition with an initial thickness of 106 nm and band gap of 1.37 eV. Also, Bismuthinite phase was obtained, close to the stoichiometry with 59.95 and 40.05 at % for bismuth and sulfur, respectively. The charge carrier concentration of 6.9x1019 cm-3 with a n-type conductivity, the resistivity of 0.19 Ω-cm, and mobility of 0.44 cm2V-1s-1 are obtained.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100370&lng=en&tlng=en

19

scielo_articles/scl/1516-1439/S1516-14392022000100370.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Cruz-Gómez, J.", "Cruz-Díaz, E.B.", "Santos-Cruz, D.", "Chettiar, Aruna-Devi Rasu", "Mayén-Hernández, S. A.", "Moure-Flores, F. de", "Vega-González, M.", "Pérez-García, C.E.", "Centeno, A.", "Santos-Cruz, José" ]

null

[ "Bismuth sulfide", "Physical vapor deposition", "Thermal Annealed", "Optoelectronic Properties" ]

null

[ "Universidad Nacional Autónoma de México", "Universidad de Guadalajara", "Universidad Autónoma de Querétaro", "Cinvestav-IPN" ]

scl/1516-1439/S1516-14392022000100363.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100363

10.1590/1980-5373-mr-2022-0118

ENGINEERING, CHEMICAL

Centro Federal de Educação Tecnológica de Minas Gerais

null

Effect of the Heat Input and Ageing Treatment on Microstructure and Mechanical Properties of AISI 317L Stainless Steel Dissimilar Welded Joints

Antunes, Pedro Duarte

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

The present work investigated the influence of heat input and aging time on the microstructural characteristics and the mechanical properties of dissimilar AISI 317L austenitic stainless steel welded joints. The AWS ER2209 wire-electrode was used as filler metal, and two different heat input levels were applied (4 and 8 kJ/cm), aiming to verify the influence of this parameter on the deleterious phases precipitation. An aging heat treatment (AHT) was carried out at 700 °C for two different exposure times: 50 and 100 hours. It was observed that aging promoted a refinement of the base metal region, and all delta ferrite was transformed into the sigma phase. The microstructure of the fusion zone (without AHT) presented a significant amount of austenite that precipitated in three different morphologies: allotriomorphific of grain boundary, Widmanstätten, and intragranular. For all the thermally treated samples, it was possible to identify the presence of the σ and χ phases. Additionally, the highest concentration of the χ phase was identified in the samples submitted to 50 hours of AHT. The welding condition and AHT that presented joints with higher mechanical resistance and remarkable toughness were those welded with 4 kJ/cm heat input and with 100 hours of AHT. All welded joints showed an increase in the hardness profile after AHT. The microhardness values showed a good correlation with the microstructure and the mechanical tests so that the highest values of microhardness were observed in welded joints with heat input of 4 kJ/cm and 100 hours of AHT

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100363&lng=en&tlng=en

43

scielo_articles/scl/1516-1439/S1516-14392022000100363.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Antunes, Pedro Duarte", "Silva, Cleiton Carvalho", "Corrêa, Edmilson Otoni" ]

null

[ "AISI 317L Steel", "Electrode AWS ER2209", "Aging heat treatment", "Microstructure", "mechanical properties" ]

null

[ "Centro Federal de Educação Tecnológica de Minas Gerais", "Universidade Federal do Ceará", "Universidade Federal de Itajubá" ]

scl/1516-1439/S1516-14392022000100369.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100369

10.1590/1980-5373-mr-2022-0132

ENGINEERING, CHEMICAL

Universidade Federal de Ouro Preto

null

Effect of Niobium on Microstructure and Mechanical Properties of a Hypereutectoid Steel

Pessoa, Ricardo Amorim

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

High-carbon steels have been used to high-strength steel wire and strands for prestressing concrete. The necessity of high-strength levels at increasingly larger diameters of wire rods is a technological challenge. Two steels with and without Nb were obtained in a steel mill, submitted to detailed microstructural (previous austenitic grain size, pearlite interlamellar spacing and colony size) and mechanical characterization through tensile tests and hardness. Hot torsion and dilatometry tests were performed to simulate steels processing and to verify the influence of Nb on phase transformation. Adding Nb to steel resulted in a refinement in austenitic grain size and pearlite colonies but had no effect on pearlitic interlamellar spacing. There was a decrease at the start transformation temperature austenite/pearlite and therefore an increase in the hardenability of the Nb-added steel. Finally, Nb addition proved to be a technical and economical way to increase tensile strength and to reduce the variability of the mechanical properties.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100369&lng=en&tlng=en

27

scielo_articles/scl/1516-1439/S1516-14392022000100369.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Pessoa, Ricardo Amorim", "Porcaro, Rodrigo Rangel", "Cândido, Luiz Claudio", "Pereda, Beatriz", "Lopez, Beatriz" ]

null

[ "High-carbon steel", "Niobium", "Microstructure", "Mechanical properties", "Wire rod" ]

null

[ "Universidade Federal de Ouro Preto", "Ceit-BRTA" ]

scl/1516-1439/S1516-14392022000100368.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100368

10.1590/1980-5373-mr-2022-0365

ENGINEERING, CHEMICAL

PSN College of Engineering and Technology

null

Surface and Wear Investigation on Microwave Sintered Nitinol Composite

Hariprasad, P.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

The present research of the article is used to describe the microwave sintering of nitinol composite and its surface topography analysis by atomic microscopy (AFM). Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) technique is used to analyze the characterization and alloying composition of the composite. Silicon carbide is the reinforcing particle between nickel and titanium. Wear test is conducted to investigate the worn surface morphology of the sintered specimen. The synthesized composite has exceptional material properties such as ultimate tensile strength of 1020MPa, 16% of elongation to fracture, 7.51 g/cc of density and hardness of 310 HV. Low wear rate of 0.01 mg/m is perceived at minimum load and minimum sintering time. Surface roughness is varied from 22.87 to 54.05nm at different sintering time. Maximum roughness height of 327.6 nm is observed in the surface profile of the composite.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100368&lng=en&tlng=en

29

scielo_articles/scl/1516-1439/S1516-14392022000100368.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Hariprasad, P.", "Kumaresan, K.", "Vijayakumar, M.", "Kumaresan, G." ]

null

[ "Nitinol composite", "Characterization", "Microwave sintering", "Surface topography", "Silicon carbide", "Wear" ]

null

[ "PSN College of Engineering and Technology", "KIT-Kalaignar Karunanidhi Institute of Technology", "Park College of Engineering and Technology", "Bannari Amman Institute of Technology" ]

scl/1516-1439/S1516-14392022000100367.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100367

10.1590/1980-5373-mr-2022-0309

ENGINEERING, CHEMICAL

Instituto Federal de Educação, Ciência e Tecnologia de Minas Gerais

null

Effects of Sodium Octaborate on AISI 4140 Steel Machined by Die-sinking EDM

Lima, Daniel de Moraes

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Researchers are constantly developing processes aiming to improve the properties of metal surfaces, especially related to the wear resistance of components, as in the case of the nitrided layer obtained by die-sinking electrical discharge machining (EDM). Following this line of research, this work investigated the effects of sodium octaborate (Na2B8O13.4H2O), mixed into deionized water as a dielectric fluid on AISI 4140 steel surfaces machined by die-sinking EDM. An adapted EDM machine was employed in the process using electrolytic copper as tool. The effects on AISI 4140 steel-machined surfaces were evaluated by optical microscopy, Vickers microhardness, X-ray diffraction, and energy dispersion X-ray spectroscopy (EDS) analyses. The results showed a hardness gain of approximately 146.8% in the modified layer when compared to the AISI 4140 steel (base material). This suggests the formation of a borided layer, such as the Fe2B phases identified on sample surfaces, which can be explained by the boron element decomposed from the dielectric solution.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100367&lng=en&tlng=en

46

scielo_articles/scl/1516-1439/S1516-14392022000100367.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Lima, Daniel de Moraes", "Silva, Sinval Pedroso da", "Nascimento, Claudinei Alfredo do", "Silva, Ernane Rodrigues da" ]

null

[ "AISI 4140 steel, Boriding, Dielectric solution", "Die-sinking EDM, Sodium octaborate" ]

null

[ "Instituto Federal de Educação, Ciência e Tecnologia de Minas Gerais", "Centro Federal de Educação Tecnológica de Minas Gerais" ]

scl/1516-1439/S1516-14392022000100351.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100351

10.1590/1980-5373-mr-2022-0204

ENGINEERING, CHEMICAL

Kongu Engineering College

null

Effect of Silicon Carbide and Alumina Reinforcement of Different Volume Fraction on Wear Characteristics of AL 7075 Hybrid Composites Using Response Surface Methodology

Gukendran, R.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

This study investigates the wear performance of Hybrid composite of Aluminium Al 7075 (SiC/Al2O3). The Reinforcements used for the Hybrid composite preparation are Silicon Carbide (SiC) and Aluminium Oxide (Al2O3). Reinforcements are added in 5%, 10% and 15% in volume percentage in to aluminium alloy for composite preparation. The wear performance of the developed composites was analysed using dry sliding test apparatus. The effect of wear study parameters such as load, sliding distance, sliding velocity on the response of wear rate were predicted. This study revealed that Wear rate was influenced by the load significantly. The addition of reinforcement in hybrid composite increases the wear rate up to 10% of addition and reduces the wear rate at 15% of addition. Scanning Electron Microscope (SEM) study displays the wear mechanism clearly. This study concludes that the introduction of reinforcements into the aluminium enhances the wear confrontation of the composites considerably. The developed composite may be used in high wear prone zones effectively.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100351&lng=en&tlng=en

35

scielo_articles/scl/1516-1439/S1516-14392022000100351.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Gukendran, R.", "Sambathkumar, M.", "Sasikumar, K. S. K.", "Karupannasamy, D. K." ]

null

[ "Al 7075", "SiC", "Al2O3", "Wear", "RSM" ]

null

[ "Kongu Engineering College" ]

scl/1516-1439/S1516-14392022000100366.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100366

10.1590/1980-5373-mr-2022-0202

ENGINEERING, CHEMICAL

Pontifícia Universidade Católica do Rio de Janeiro

null

A Simple Method for Low-temperature Sintering of Titania

Miguel, Anna Luísa W. R.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract A low-temperature sintering process was used to produce pellets at different temperatures using TiO2 anatase (Vetec) and P25 (Evonik) commercial powders. The initial powder was mixed with 75% acetic acid aqueous solution and pressed under 375 MPa. The temperature was applied after the pelletization in a conventional furnace for 4 hours. The best sintering temperature for anatase was 800°C, which is higher than typical cold sintering temperatures but below conventional ones. However, the optimal temperature was 450 °C for P25 due to its density and SEM results. The sintered pellets' maximum densities were 70% (anatase, 800oC) and 66% (P25, 450oC). It was not possible to measure the anatase pellets treated under 800oC because they disintegrated in water. This work studied the effects of the applied pressure, solvent concentration, particle size, and sintering temperature on the properties of sintered pellets, such as integrity, density, and presence of porous. It also evaluated the electrochemical activity measured by cyclic voltammetry (CV), which indicated that the sintered TiO2 pellets are porous with a partial capacitive response.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100366&lng=en&tlng=en

54

scielo_articles/scl/1516-1439/S1516-14392022000100366.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Miguel, Anna Luísa W. R.", "de Avillez, Roberto R.", "Pedrozo-Peñafiel, Marlin J.", "Aucélio, Ricardo Q.", "Letichevsky, Sonia" ]

null

[ "titanium oxide", "low-temperature sintering", "anatase", "P25", "cyclic voltammetry" ]

null

[ "Pontifícia Universidade Católica do Rio de Janeiro", "Pontifícia Universidade Católica do Rio de Janeiro" ]

scl/1516-1439/S1516-14392022000100365.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100365

10.1590/1980-5373-mr-2022-0090

ENGINEERING, CHEMICAL

Bipin Tripathi Kumaon Institute of Technology

null

Oxide Ion Conductivity of Mechanically produced Calcia Stabilised Zirconia for Oxygen Sensing Applications

Kannan, M.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Cryo-milling was used to make calcia stabilized zirconia (CSZ) powders with 9 mol%, 12 mol%, and 15 mol% of calcia. Powder X-ray diffraction was done to examine the phase growth in prepared powders over the course of 80h of mechanical alloying (MA) in cryogenic environment at 300rpm. The calcined powders were hydraulically pressed into cylindrical shaped sensor elements in a uniaxial press and then sintered for 4h at 1400°C. The microstructure of sintered pellets were studied using Scanning Electron Microscope (SEM). Electrical Conductivity measurements of the prepared stabilized zirconia at various temperatures over a temperature range of 200°C to 500°C using a dual-probe impedance analyzer is carried out and the effects of composition and temperature on the grain boundary impedance of CSZ were analyzed. Conductivity is discussed in terms of ionic vacancies in the bulk due to calcium ion substitution and available grain boundary paths. Ionic Conductivity of prepared CSZ is compared for suitability in oxygen sensing applications.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100365&lng=en&tlng=en

33

scielo_articles/scl/1516-1439/S1516-14392022000100365.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Kannan, M.", "Singh, Satyendra", "Prasad, R.R." ]

null

[ "Calcia-Stabilized Zirconia", "Conductivity", "Mechanical Alloying", "Cryo-Milling" ]

null

[ "Bipin Tripathi Kumaon Institute of Technology", "BSM College of Engineering", "Uttarakhand Technical University" ]

scl/1516-1439/S1516-14392022000100364.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100364

10.1590/1980-5373-mr-2022-0234

ENGINEERING, CHEMICAL

Pamukkale University

null

Preparation of Diatom-Doped Bio-Nanocomposite Materials for Bone Tissue Scaffolds

Gönenmiş, Dicle Erden

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Naturally sourced materials have an important place in bone tissue engineering due to their biocompatibility and biodegradability. Non-diatom, diatom-doped chitosan/hydroxyapatite (CS/HAp) and collagen/chitosan/hydroxyapatite (Col/CS/HAp) as three-dimensional tissue scaffolds were produced by freeze drying technique. It was determined by SEM analysis that CS/HAp, CS/HAp/Di, Col/CS/HAp, Col/CS/HAp/Di scaffolds have 160 μm, 130 μm, 390 μm and 340 μm pores, respectively. The diatoms in the structure have approximately 9-16 μm in length, 8-20 μm in diameter and nanopore sizes of 260-330 nm. Cell culture studies were performed using the 3T3 cell line to study the non-toxic nature of biocomposite scaffolds that support cell attachment and proliferation. The cells in the scaffolds without diatom proliferate in a reticulated manner, whereas in the scaffolds containing diatom the cells were wrapped around the scaffold like a cover. The suggested scaffolds have the potential to meet the basic requirements in biocompatibility, cytocompatibility and interconnected pore structure.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100364&lng=en&tlng=en

64

scielo_articles/scl/1516-1439/S1516-14392022000100364.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Gönenmiş, Dicle Erden", "Özcan, Yusuf" ]

null

[ "Bio-nanocomposite", "Bone-tissue", "Diatom", "Scaffold", "Tissue engineering scaffold" ]

null

[ "Pamukkale University" ]

scl/1516-1439/S1516-14392022000300208.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300208

10.1590/1980-5373-mr-2022-0136

ENGINEERING, CHEMICAL

Universidade Federal do Rio de Janeiro

null

Superhydrophobic and Low Reflectance Carbon Nanotubes Buckypapers

Campos, Rodrigo Bezerra Vasconcelos

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract In this paper, carbon nanotube (CNT) buckypapers (BPs) were produced by vacuum filtration of CNT water suspensions prepared by sonication using 0.5 wt % of Triton X-100 dispersing agent. The as-produced BPs were efficiently dispersed and presented very low optical reflectance, with an average reflectance of 1.30% in the visible range and hydrophilic/oleophilic properties, readily absorbing water or oil liquid drops through their network of pores. Plasma treatment with 1, 1, 1, 2 tetrafluoroethane (C2H2F4) turned the BPs superhydrophobic with water contact angles (CA) greater than 140°, while still maintaining their oleophilic properties unchanged. This effect is attributed to the combination of the decrease of surface energy and modification of the surface structure with micro/nanopores due to the coating with a fluorocarbon film. After only 1 minute plasma treatment, the BPs presented high hydrophobicity (CA = 145°) while keeping their oleophilicity and the very low optical reflectance essentially unaffected. These results indicate that a good combination of low reflectance and a superhydrophobic/oleophilic behavior can be achieved which is of importance for technological applications that require super black surfaces and prevent water from being absorbed, improving the handling of optical signals and increasing the useful life of materials.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300208&lng=en&tlng=en

59

scielo_articles/scl/1516-1439/S1516-14392022000300208.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Campos, Rodrigo Bezerra Vasconcelos", "Rocha, Tiago Damasceno da", "Wysard Jr., Mauro Meliga", "Camargo Jr., Sergio Alvaro de Souza" ]

null

[ "Carbon nanotubes", "buckypaper", "superhydrophobic", "surface treatment", "reflectance" ]

null

[ "Universidade Federal do Rio de Janeiro", "Universidade Federal do Rio de Janeiro" ]

scl/1516-1439/S1516-14392022000100376.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100376

10.1590/1980-5373-mr-2022-0312

ENGINEERING, CHEMICAL

Universidade Estadual Paulista

null

The Effect of EDTA Functionalization on Fe3O4 Thermal Behavior

Fumis, Daniel B.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The surface of Fe3O4 nanoparticles is very reactive and can oxidize to γ-Fe2O3 (maghemite) and α-Fe2O3 (hematite) structures. Based on this, the oxidation process of Fe3O4 nanoparticles must be prevented, and one of the strategies is surface functionalization with organic or inorganic molecules. Thus, this study analyzed the thermal behavior of Fe3O4 and Fe3O4-EDTA nanoparticles using X-ray diffraction (XRD), simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC). Results showed that γ- Fe2O3 was obtained as an intermediate in Fe3O4 and Fe3O4-EDTA decomposition, as confirmed by TG-DTA and DSC curves. Moreover, Fe3O4-EDTA exhibited a temperature peak (Tp = 573.5°C) of phase transformation (γ-Fe2O3 → α-Fe2O3) higher than that of Fe3O4 (Tp = 533.0°C), confirming that EDTA molecules stabilized the nanoparticles efficiently. The kinetic behavior of samples changed, and the activation energy for functionalized samples decreased.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100376&lng=en&tlng=en

48

scielo_articles/scl/1516-1439/S1516-14392022000100376.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Fumis, Daniel B.", "Silveira, Maria L.D.C", "Gaglieri, Caroline", "Ferreira, Laura T.", "Marques, Rodrigo F.C.", "Magdalena, Aroldo G." ]

null

[ "Magnetite", "Maghemite", "Hematite", "Non-isothermal kinetics" ]

null

[ "Universidade Estadual Paulista", "Universidade Estadual Paulista" ]

scl/1516-1439/S1516-14392022000100361.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100361

10.1590/1980-5373-mr-2021-0584

ENGINEERING, CHEMICAL

Instituto Federal de Educação, Ciência e Tecnologia Baiano

null

Influence of Nonionic Surfactant Hydrophobicity on the Tribological Properties of Microemulsion Systems Aimed at Cutting Fluid Applications

Santos, Erinéia da Silva

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The development of new environmentally-friendly cutting fluids is an important technological advancement. The aim of this study was to assess the tribological behavior of microemulsions (W/O) developed with epoxidized soybean oil and nonionic surfactants with different degrees of ethoxylation (NP4EO, NP6EO and NP9.5EO). The tribological performance of the microemulsion systems was assessed in a High Frequency Reciprocating Rig (HFRR) tribometer. Microemulsions showed Newtonian fluid behavior, with viscosities compatible with conventional cutting fluids. In addition, contact angle values above 90º indicate spherical-shaped drops on the surface on which they are deposited, due to their hydrophobic nature. The microemulsions formulated using surfactants with lower ethoxylation numbers and 20% concentration exhibited greater stability, lower viscosity and better friction reduction during tribological contact between surfaces, given that the average wear scar diameter was 118 µm with smooth surfaces exhibiting slight slippage wear caused by abrasion, as identified by SEM/EDS analyses.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100361&lng=en&tlng=en

39

scielo_articles/scl/1516-1439/S1516-14392022000100361.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Santos, Erinéia da Silva", "Uchôa, Igor Micael Alves", "Melo, Ricardo Paulo Fonseca", "Lopes, Francisco Wendell Bezerra", "Silva, Alfredo José Ferreira da", "Duarte, Lindemberg de Jesus Nogueira", "Barros Neto, Eduardo Lins de" ]

null

[ "Tribological performance", "Microemulsion", "Nonionic surfactant" ]

null

[ "Instituto Federal de Educação, Ciência e Tecnologia Baiano", "Université de Sherbrooke", "Universidade Federal do Rio Grande do Norte", "Universidade Federal do Amazonas", "Universidade Federal do Rio Grande do Norte", "Universidade Federal Rural do Semi-Árido" ]

scl/1516-1439/S1516-14392022000200205.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200205

10.1590/1980-5373-mr-2021-0520

ENGINEERING, CHEMICAL

Universidade Federal do Rio de Janeiro

null

Evaluation of Flow Accelerated Corrosion in Typical Recovery Boiler Environments of Energy Production Industries

Moreira, Rogaciano M.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Flow accelerated corrosion (FAC) is a steel degradation that occurs in heat recovery steam generators in the power industry. The mechanism of this corrosion comprises an electrochemical dissolution of the semi-protective magnetite layer (Fe3O4) that is formed within the pipes employed in the boilers. The FAC is influenced by different factors such as fluid velocity, pH and dissolved oxygen concentration. In this context, Rotating Cage tests were used to evaluate the influence of pH and dissolved oxygen content on FAC of A210, P11 and P22 steels. General corrosion was lower for P11 and P22 steels, an effect consistent with the presence of chromium in their compositions. General corrosion was most critical at pH 8.5. The corrosion intensity decreased for the three steels when the dissolved oxygen concentration increased, at 2 m/s. This behavior is coherent considering the most effective precipitation of Fe2O3 inside the pores of the Fe3O4 layer in a more oxidizing environment. For 3 m/s, the corrosion intensity increased for both materials when oxygen increased, showing the shear stress effect. These behaviors were more significant at pH 8.5. About pitting corrosion, the analyzes show localized attack in the majority of coupons, however with very low number of pits.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200205&lng=en&tlng=en

20

scielo_articles/scl/1516-1439/S1516-14392022000200205.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Moreira, Rogaciano M.", "Almeida, Tatiana C.", "Bandeira, Merlin C. E.", "Assunção, Felipe R. S.", "Carvalho, Juliana F. A.", "Silva, Elaine F.", "Verbicario, João V. T.", "Mattos, Oscar R.", "Oliveira, Jefferson R.", "Bonfim, André L. C.", "Novgorodecev, André R." ]

null

[ "FAC", "Rotating Cage", "Carbon Steel", "Magnetite Layer" ]

null

[ "Universidade Federal do Rio de Janeiro", "Universidade Federal Fluminense", "Petrobras, Centro de Pesquisas, Desenvolvimento e Inovação" ]

scl/1516-1439/S1516-14392022000100354.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100354

10.1590/1980-5373-mr-2022-0189

ENGINEERING, CHEMICAL

Universidade Federal do Rio Grande do Norte

null

Production of Niobium Nitride Via Nitrogen-Based Solid-Gas Reaction

Silva, Rayane Ricardo da

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Nanostructured niobium nitride was synthesized through a solid-gas reaction in an atmosphere of nitrogen and hydrogen using an oxalic niobium precursor. Crystal phases evolution throughout the reactive processes were evaluated using X-Ray Diffraction, reaction parameters modifications were performed in isotherm time, gas flow, and precursors’ mass. It was verified the synthesis of a stable NbN material with a hexagonal structure under the following conditions: 1g of precursor, 300 min of isotherm at 1100 °C and, the gas flow of N2 = 40% (v/v), and H2 = 60% (v/v). The increase in gas phase flow and the decrease of solid load favored the process, and a pure and single-phase powder was obtained. This set indicates the importance of physical resistance in the fluid-particle interaction process. Under these conditions, the solid obtained had a crystallite size of 30 - 50 nm.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100354&lng=en&tlng=en

31

scielo_articles/scl/1516-1439/S1516-14392022000100354.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Silva, Rayane Ricardo da", "Moriyama, André Luís Lopes", "Araújo, Camila Pacelly Brandão de", "Gomes, Yara Feliciano", "Souza, Carlson Pereira de" ]

null

[ "Solid-gas reaction", "X-ray diffraction", "hexagonal phase", "niobium nitride" ]

null

[ "Universidade Federal do Rio Grande do Norte", "Universidade Federal do Rio Grande do Norte", "Universidade Federal do Rio Grande do Norte" ]

scl/1516-1439/S1516-14392022000100384.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100384

10.1590/1980-5373-mr-2022-0355

ENGINEERING, CHEMICAL

Lanzhou City University

null

Evolution of Grain Orientation in front of the Pin during FSW of the 6082-T6 Aluminium Alloy

Liangliang, Zhang

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Friction stir welding (FSW), a new solid-phase connection method, is considered an excellent welding method for aluminium alloys. Grain orientation, grain boundary structure, and texture types in different regions were characterized by a high-resolution electron backscattered diffraction technology. The results revealed that during the welding process, the coarse grains of the base metal are refined, grains in region 1 (600 μm away from the edge of the keyhole) are arranged in a long strip, and the long axis is approximately parallel to the shear direction. The thermal cycle of the welding process causes some grains to recrystallize, further forming a recrystallization (100) [011] rotating-cube texture. The metal in region 2 (100 μm away from the edge of the keyhole) was severely squeezed by the pin, resulting in an increase in the degree of grain breakage in this region, which were mainly equiaxed grains. Due to the eccentric movement of the pin, the (100) [001]-oriented and (110) [001]-oriented grains alternate on the middle layer, forming a banded structure. Plastic deformation and recrystallization occurred in the base metal, within 383 μm in front of the pin, forming a (110) [001] Goss texture and (100) [001] recrystallized cubic texture.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100384&lng=en&tlng=en

33

scielo_articles/scl/1516-1439/S1516-14392022000100384.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Liangliang, Zhang", "Zhiyuan, Liu", "Xiang, Chen" ]

null

[ "6082-T6 aluminium alloy", "friction stir welding", "crystal orientation evolution", "dynamic recrystallization" ]

null

[ "Lanzhou City University" ]

scl/1516-1439/S1516-14392022000100383.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100383

10.1590/1980-5373-mr-2022-0277

ENGINEERING, CHEMICAL

Universitat Politècnica de Catalunya

null

Production and Characterization of Oxides Formed on Grade 300 and 350 Maraging Steels Using two Oxygen/Steam Rich Atmospheres

Florez, Mauro Andrés Cerra

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

The growing process of a spinel-like oxide film can be obtained through different atmospheres; in this sense Air, O2, steam, and nitrogen atmospheres were used in different steps during the aging heat treatment at 490ºC of maraging 300 and 350 alloys. The oxidation layer produced under different atmospheres was chemically, microstructurally and mechanically characterized by means of advanced techniques. The results showed (in both alloys) a non-homogeneous mix oxide formed by magnetite, nickel and cobalt ferrites and MoO3 heterogeneously distributed along the oxide thickness. It was also founded TiO2 in the innermost areas and a particularly important quantify of hematite on the external surface. A nickel-rich austenite phase was produced at the interphase due to the combination of nickel stability and the preference of cobalt, molybdenum, and iron diffuses through the film as ions. The highest thickness values were found in the oxides produced in maraging 300 steels which could indicate greater susceptibility to oxidation comparing with grade 350 maraging steel. The oxide films produced in both maraging alloys using air atmosphere presents excellent adherence, and the results show the capability for being used for tribological applications under sliding contact tests.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100383&lng=en&tlng=en

61

scielo_articles/scl/1516-1439/S1516-14392022000100383.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Florez, Mauro Andrés Cerra", "Ribas, Gemma Fargas", "Rovira, Joan Josep Roa", "García, Antonio Manuel Mateo", "Lima, Marcos Natan da Silva", "Perdrix, Guiomar Riu", "Cardoso, Jorge Luiz", "Silva, Marcelo José Gomes da" ]

null

[ "maraging alloys", "oxidation treatment", "oxide film", "XRD analysis", "raman analysis", "nanoscratch study" ]

null

[ "Universitat Politècnica de Catalunya", "Universitat Politècnica de Catalunya", "Universidade Federal do Ceará" ]

scl/1516-1439/S1516-14392022000200201.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200201

10.1590/1980-5373-mr-2021-0460

ENGINEERING, CHEMICAL

Instituto Nacional de Tecnologia

null

Evaluation of Structure, Heterogeneities, Thickness and Corrosion Protection of Electrodeposited Sol-Gel Superhydrophobic Coatings

Leoni, Gabriel B.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The present work evaluated the structure and heterogeneities, surface chemistry, hydrophobicity level, and corrosion protection in a saline environment of electrodeposited sol-gel superhydrophobic coatings on carbon steel, using microscopy techniques, energy dispersive X-ray spectroscopy (EDX), water contact angle measurements, and electrochemical impedance spectroscopy (EIS). Furthermore, the effect of silane precursor concentration on the aforementioned response variables was tested. Regarding the structure, results point out rough deposits composed of two layers with different properties and thicknesses, and preferential deposition on the top area of the carbon steel coupon. Elemental mapping proved the chemical stability of the film in NaCl 3.5%wt., while increasing the amounts of silane precursor up to 40 mmol showed also increased results for water contact angle (157o), impedance modulus at 0.01 Hz (107 Ohm.cm2), and film thickness (70 µm). However, the addition of greater amounts resulted in miscibility issues in the hydrolysis solution.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200201&lng=en&tlng=en

25

scielo_articles/scl/1516-1439/S1516-14392022000200201.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Leoni, Gabriel B.", "Freitas, Denise S. de", "Gomes, José A. P. da C.", "Brasil, Simone L. D. C." ]

null

[ "Sol-Gel", "electrodeposition", "superhydrophobicity", "heterogeneities", "corrosion" ]

null

[ "Instituto Nacional de Tecnologia", "Universidade Federal do Rio de Janeiro", "Universidade Federal do Rio de Janeiro" ]

scl/1516-1439/S1516-14392022000200202.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200202

10.1590/1980-5373-mr-2021-0488

ENGINEERING, CHEMICAL

Universidade de São Paulo

null

Influence of Welding Energy on Intergranular and Pitting Corrosion Susceptibility of UNS S32205 Duplex Stainless-steel Joints

Pereira, Henrique Boschetti

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract This study analysed the integrity of welded joints of a UNS S32205 duplex stainless steel, using different welding energies: 0.5 kJ.mm-1, 1.0 kJ.mm-1, and 3.5 kJ.mm-1. Microstructural characterisation, tensile testing, intergranular attack susceptibility testing (ASTM A262 practice A) and pitting/crevice corrosion resistance tests (critical pitting temperature test, ASTM G48 practice C) were performed in these welded joints. The results showed that the tensile properties of the welded joints did not vary significantly with the welding energy. The microstructure's ferrite content in the molten zone (MZ) was proportional to the welding energy: the ferrite concentration in the 0.5 kJ.mm-1 weldings was approximately 75%. When the welding energy increased to 3.5 kJ.mm-1, the amount of ferrite dropped to 54%. The 3.5 kJ.mm-1 welded joint featured a comparatively higher proportion of coarser austenite grains. The HAZ of the 3.5 kJ.mm-1 welded joint was comparatively more susceptible to the intergranular attack along the α/γ interfaces, while in the base metal and the other two welded joints, the intergranular attack along the α/γ interfaces was not prominent. Additionally, the pitting corrosion took place preferentially in the ferrite phase of the HAZ for all welding conditions.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200202&lng=en&tlng=en

44

scielo_articles/scl/1516-1439/S1516-14392022000200202.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Pereira, Henrique Boschetti", "Pimentel, Tarcisio Henrique Carvalhaes", "Silva, Carlos Alberto da", "Panossian, Zehbour", "Azevedo, Cesar Roberto Farias de" ]

null

[ "duplex stainless-steel", "UNS S32205", "welding energy", "intergranular corrosion", "pitting corrosion" ]

null

[ "Universidade de São Paulo", "Instituto de Pesquisas Tecnológicas do Estado de São Paulo" ]

scl/1516-1439/S1516-14392022000200203.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200203

10.1590/1980-5373-mr-2021-0623

ENGINEERING, CHEMICAL

Soudap Soldas Sanitárias

null

Passivation Level of AISI 316L Aseptic Tank Surface Quantified by On-Site Electrochemical Techniques

Guilherme, Luis Henrique

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Frequently stainless steel AISI 316L aseptic tanks have their passivity and corrosion resistance properties degraded by biofilm formation and localized corrosion processes. Thereby, maintenance projects are performed to repair the surface in food-grade product contact to obtain an aseptic property as defined by ASME BPE. However, the on-site non-destructive testing are limited to the liquid penetrant examination and the average roughness measurement. The on-site open circuit potential and on-site cyclic polarization measurements were conducted using a portable electrochemical minicell. The level of passivation was quantified on the tank surface, and it was performed before and after the repairing maintenance protocol be made. The results of the on-site electrochemical measurements showed a clear difference between as-degraded and repaired surfaces, indicating a sensible response to aseptic surface inspection. The on-site open circuit potential together with the on-site cyclic polarization were considered an advanced tool to support the maintenance projects of the AISI 316L aseptic surfaces.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200203&lng=en&tlng=en

33

scielo_articles/scl/1516-1439/S1516-14392022000200203.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Guilherme, Luis Henrique", "Benedetti, Assis Vicente", "Fugivara, Cecílio Sadao", "Engelberg, Dirk" ]

null

[ "On-site cyclic polarization", "316L stainless steel", "ASME BPE", "Aseptic tank", "Localized corrosion", "Corrosion monitoring" ]

null

[ "Soudap Soldas Sanitárias", "Universidade Estadual Paulista", "The University of Manchester" ]

scl/1516-1439/S1516-14392022000300201.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300201

10.1590/1980-5373-mr-2022-0038

ENGINEERING, CHEMICAL

Universidade de São Paulo

null

Synthesis and Application of the Ternary Zn0.5Cd0.5S/ZnO/carbon Xerogel Composite in the Photocatalytic Degradation of 4-chlorophenol

Dantas, Gustavo Viégas Jucá

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The Zn0.5Cd0.5S/ZnO/carbon xerogel photocatalyst was synthesized through the thermal treatment of ZnO, CdS, and a low-cost carbon xerogel matrix at high temperature (600 ºC). ZnO is one of the most widely used photocatalysts, but it has low visible-light absorption, while Zn0.5Cd0.5S is a visible-light active photocatalyst, which can be used as a co-catalyst to enhance photoactivity under natural radiation and promote charge separation through the creation of Z-scheme heterojunctions. The further addition of the carbon xerogel can be justified by its highly developed porous structure and ability to capture photogenerated electrons, which will also promote charge separation. The creation of the hexagonal Zn0.5Cd0.5S and ZnO phases was confirmed through the X-ray diffractometry technique. The addition of the carbon xerogel led to an increase in the specific surface area of the XC/ZnO (630%) and XC/ZnO-Zn0.5Cd0.5S (320%) and a decrease in particle size when compared to the pure ZnO. Regarding the photocatalytic performance of the materials, the Zn0.5Cd0.5S/ZnO/carbon xerogel displayed an enhanced photocatalytic activity for 4-chlorophenol degradation, with 84% degradation after 300 minutes of artificial solar irradiation. The enhanced photoactivity of the Zn0.5Cd0.5S/ZnO/carbon xerogel composite was further confirmed by chronoamperometry, as the composite presented higher photocurrent generation under light irradiation.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300201&lng=en&tlng=en

35

scielo_articles/scl/1516-1439/S1516-14392022000300201.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Dantas, Gustavo Viégas Jucá", "Moraes, Nicolas Perciani de", "Rocha, Robson da Silva", "Siervo, Abner de", "Lanza, Marcos Roberto de Vasconcelos", "Rodrigues, Liana Alvares" ]

null

[ "Photocatalysis", "carbon xerogel", "zinc oxide", "cadmium sulfide", "Zn0.5Cd0.5S", "4-chlorophenol" ]

null

[ "Universidade de São Paulo", "Universidade Estadual de Campinas", "Universidade de São Paulo" ]

scl/1516-1439/S1516-14392022000300207.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300207

10.1590/1980-5373-mr-2022-0157

ENGINEERING, CHEMICAL

Universidade Estadual de Santa Cruz

null

Sustainable Carbon Xerogel in the Production of Electromagnetic Radar Absorbing Composites in the Ku-Band

Medeiros, Nila Cecília de Faria Lopes

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Carbonaceous porous materials are strong candidates for producing low-cost, lightweight, and sustainable electromagnetic (EM) absorbing materials. This work investigates the production of radar-absorbing materials (RAM) by a simple method. Sustainable carbon xerogel (CX) was synthesized from tannin, a biosourced molecule. CX and commercial carbon nanotube (CNT) were embedded in a silicone matrix at proportions of 10 and 15 wt.% of CX and 0.1 wt.% of CNT to produce flexible composites. The morphology and structure of the carbonaceous materials were evaluated by field-emission scanning electron microscopy (FEG-SEM), Raman spectroscopy, X-ray diffraction (XRD), textural properties by N2 adsorption-desorption isotherms, and mercury porosimetry. The electromagnetic characterization of the composites was analyzed by a vector network analyzer (VNA) in the Ku-band. The results demonstrated that an increased concentration of CX in the composite improved reflection loss reaching -43.19 dB at 13.79 GHz.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300207&lng=en&tlng=en

75

scielo_articles/scl/1516-1439/S1516-14392022000300207.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Medeiros, Nila Cecília de Faria Lopes", "Medeiros, Leonardo Iusuti de", "Silva, Guilherme Frederico Bernardo Lenz e", "Boss, Alan Fernando Ney", "Gomes, Newton Adriano dos Santos", "Sardinha, André Ferreira", "Baldan, Maurício Ribeiro", "Amaral-Labat, Gisele" ]

null

[ "Carbon Xerogel", "Carbon Nanotube", "Sustainability", "Reflectivity", "RAM" ]

null

[ "Universidade Estadual de Santa Cruz", "Universidade de São Paulo", "Instituto Nacional de Pesquisas Espaciais" ]

scl/1516-1439/S1516-14392022000300206.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300206

10.1590/1980-5373-mr-2022-0052

ENGINEERING, CHEMICAL

Instituto Nacional de Pesquisas Espaciais

null

Growth and Characterization of Polycrystalline CVD Diamond Films Obtained by MWPACVD at High Power 2,45GHz Microwave Discharge

Silva Neto, J. V.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Among all the allotropic forms of carbon, diamond has attracted a broad scientific and technological interest for its extreme and unique properties rarely matched by other materials in nature. In a rapid rise from a technological point of view, much has been achieved in the study of obtaining this material through CVD technique. Studies of CVD diamond growth parameters of monocrystalline structure, underway in the team, are very expensive and time-consuming requiring in-depth studies of CVD diamond growth parameters of polycrystalline structure. So, this work presents an analysis focused on obtaining CVD diamond films with polycrystalline structure through the 2.45 GHz microwave plasma activation method (MWPACVD) in high power regime using a modified substrate holder to find a set of parameters appropriated for getting uniform quality and growth rate of thick films. The films were characterized using Raman scattering spectroscopy and scanning electron microscopy. The results point to optimized conditions for depositing films with growth rates of up to 20 µm/h with low levels of intrinsic stress, good structural quality and uniform microcrystalline morphology along the deposition surface.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300206&lng=en&tlng=en

59

scielo_articles/scl/1516-1439/S1516-14392022000300206.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Silva Neto, J. V.", "Gómez, J. S.", "Corat, E. J.", "Trava-Airoldi, V. J." ]

null

[ "Polycrystalline", "CVD diamond", "Raman spectroscopy", "MWPACVD", "Plasma", "Characterization" ]

null

[ "Instituto Nacional de Pesquisas Espaciais" ]

scl/1516-1439/S1516-14392022000300205.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300205

10.1590/1980-5373-mr-2022-0143

ENGINEERING, CHEMICAL

Instituto Nacional de Pesquisas Espaciais

null

Bio-based Carbon Electrochemically Decorated with Cu Nanoparticles: Green Synthesis and Electrochemical Performance

Fonseca, Beatriz Carvalho da Silva

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

This study aimed to synthesize a composite material composed of bio-based, porous carbon matrix and Cu nanoparticles through a simple, low-cost, and environmentally friendly method. Concentrated Kraft black liquor was used as a carbon precursor, and Cu nanoparticles were homogeneously deposited on the carbon matrix using electrochemical deposition. The textural properties determined using N2 isotherms indicated increased surface area of a carbon matrix with a micro-mesoporous structure. Voltammetric tests demonstrated that the composite exhibited catalytic properties for electrochemical CO2 reduction. Compared to the bio-based, porous carbon sample (C matrix), the bio-based carbon electrode electrochemically decorated with Cu nanoparticles (C–Cu composite) exhibited increased current values of approximately 2.4 times, a potential shift of approximately 90 mV, and an onset potential of −1.02 V, under CO2 saturation.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300205&lng=en&tlng=en

58

scielo_articles/scl/1516-1439/S1516-14392022000300205.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Fonseca, Beatriz Carvalho da Silva", "Araújo, Luana Santos", "Pinheiro, Bárbara da Silva", "Santos, Alan Silva dos", "Amaral-Labat, Gisele", "Matsushima, Jorge Tadao", "Baldan, Maurício Ribeiro" ]

null

[ "Carbon material", "black liquor", "copper nanoparticles", "CO2 reduction", "electrochemical deposition" ]

null

[ "Instituto Nacional de Pesquisas Espaciais", "Faculdade de Tecnologia Prof. Jessen Vidal", "Instituto Tecnológico de Aeronáutica", "Universidade Federal de Minas Gerais" ]

scl/1516-1439/S1516-14392022000300204.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300204

10.1590/1980-5373-mr-2022-0051

ENGINEERING, CHEMICAL

Universidade Estadual de Campinas

null

The Utilization of Pearson’s Method to Analyze Piezoresistive Effect in Self-Sensing Cement Composite with Graphite

Silva, João Batista Lamari Palma e

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Structural health monitoring (SHM) techniques aim to detect and prevent failures in constructions, although their use may require many sensors, which makes this technique expensive and laborious. In this sense, the use of self-sensing cementitious composites based on the piezoresistivity effect could be a solution to some monitoring problems. Thus, the evaluation of the piezoresistive effect is commonly performed by analyzing the linearity between mechanical forces and the variation of electrical resistivity, through the coefficient of determination (R2). However, this work has been used to perform the analysis through Pearson's correlation in samples of self-sensing cementitious composites with graphite addition. The results obtained have shown that Pearson's correlation has the potential to be used for the evaluation of the correlation between electrical resistivity and mechanical forces to verify the piezoresistive effect in the cases studied.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300204&lng=en&tlng=en

58

scielo_articles/scl/1516-1439/S1516-14392022000300204.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Silva, João Batista Lamari Palma e", "Lintz, Rosa Cristina Cecche", "Gachet, Luísa Andréia" ]

null

[ "Self-sensing composite", "piezoresistivity", "cement", "graphite", "Pearson's correlation" ]

null

[ "Universidade Estadual de Campinas" ]

scl/1516-1439/S1516-14392022000300203.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300203

10.1590/1980-5373-mr-2022-0169

ENGINEERING, CHEMICAL

Instituto Nacional de Pesquisas Espaciais

null

Improved Microwave Absorption Performance with Sustainable Porous Carbon/Carbon Nanotube Composites

Medeiros, Leonardo Iusuti de

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

The great technological advancement in wireless communication systems and devices generated the problem of electromagnetic pollution. Developing lightweight, sustainable, and low-cost materials is necessary to minimize electromagnetic pollution. A sustainable porous carbon (PC) absorber material was obtained from the crude black liquor by a simple and low-cost synthesis, and combined with carbon nanotube (CNT), presenting excellent microwave attenuation results. The PC absorber at 20 wt.% filling ratio exhibited an intense reflection loss of ‑35.7 dB at 15.5 GHz, and bandwidth of 1.15 GHz for a thickness of 5.90 mm. By adding 0.2 wt.% of CNT, the reflection loss was -34.6 dB at 17.9 GHz, and a bandwidth of 1.54 GHz for 4.90 mm. The study reveals that the combination of PC and CNT improves the attenuation capacity, allows adjustment in the frequency range of the attenuation peak, and promotes thickness reduction. The results obtained allow us to advance studies in developing high-performance, sustainable, and low-cost microwave-absorbing materials.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300203&lng=en&tlng=en

76

scielo_articles/scl/1516-1439/S1516-14392022000300203.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Medeiros, Leonardo Iusuti de", "Medeiros, Nila Cecília de Faria Lopes", "Lenz e Silva, Guilherme Frederico Bernardo", "Lima, Rodrigo Gabas Amaro de", "Amaral-Labat, Gisele", "Boss, Alan Fernando Ney", "Baldan, Maurício Ribeiro" ]

null

[ "Electromagnetic Interference", "Porous Carbon", "Carbon Nanotubes", "Absorber", "Permittivity" ]

null

[ "Instituto Nacional de Pesquisas Espaciais", "Universidade Estadual de Santa Cruz", "Universidade de São Paulo" ]

scl/1516-1439/S1516-14392022000300202.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300202

10.1590/1980-5373-mr-2022-0140

ENGINEERING, CHEMICAL

Instituto Militar de Engenharia

null

Comparison Between Graphene Oxides Reduced by Microwave System with Different Power Sets

Martins, A.L.B. S.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

The present work compares graphene oxides produced by the Marcano's method and the subsequent reduction process using a microwave system with different power and time sets. The thermal profiles of the reduction processes were analyzed, emphasizing the heat capacity from the 600 W test of 3.44 kJ/K. The X-ray diffraction showed a reduction in the interlayer space and the number of layers in all powers. The infrared and UV-Vis spectroscopy results showed a clear decrease in the bands corresponding to the oxygenated group and partial restoration of aromatic bonds. The Raman spectroscopy showed that the 1000 W power set originated a higher defective structure. The observed results allow the conclusion that the 600 W power promotes a little better result between the analyzed power sets.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300202&lng=en&tlng=en

20

scielo_articles/scl/1516-1439/S1516-14392022000300202.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Martins, A.L.B. S.", "da Silva, E.F.", "Marques, M.F.V.", "Pinheiro, W.A." ]

null

[ "graphene oxide", "microwave reduction", "X-ray diffraction", "FTIR" ]

null

[ "Instituto Militar de Engenharia", "Universidade Federal do Rio de Janeiro", "Universidade Federal do Rio de Janeiro" ]

scl/1516-1439/S1516-14392022000300101.xml

en

editorial

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300101

10.1590/1980-5373-mr-2023-e001

ENGINEERING, CHEMICAL

Instituto Nacional de Pesquisas Espaciais

null

9th Brazilian Carbon Congress: A Virtual Meeting

Lenz e Silva, Guilherme Frederico B.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300101&lng=en&tlng=en

null

scielo_articles/scl/1516-1439/S1516-14392022000300101.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Lenz e Silva, Guilherme Frederico B.", "Baldan, Mauricio R." ]

null

[ "Instituto Nacional de Pesquisas Espaciais", "Universidade de São Paulo" ]

scl/1516-1439/S1516-14392022000200204.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200204

10.1590/1980-5373-mr-2021-0497

ENGINEERING, CHEMICAL

Universidad Veracruzana

null

Morphological and Structural Study of Anodized Titanium Grade 2, Using HCl in Aqueous Solution

Maytorena-Sánchez, A.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract In this work, the electrochemical anodization process was carried out on titanium grade 2, using an electrolytic solution of 3 M and 0.15 M HCl with voltages of 11 V, 12 V and 15 V, as well as time variations in the experimental process and later an annealing process at 750 °C. According to the results obtained, the TiO2 coatings presented different morphologies on their surface, which consisted of nanopores, nanowires and clusters of oxide grains, as well as a combination of anatase and rutile crystalline phases. Band Gap variations were found to be non-significant despite changes in the morphology of the coatings at different anodization conditions, with an average value of 2.91 eV. It was observed that the anodized samples treated by the annealing process at 750 °C, thickness values up to 16 μm were obtained.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200204&lng=en&tlng=en

30

scielo_articles/scl/1516-1439/S1516-14392022000200204.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Maytorena-Sánchez, A.", "Hernández-Torres, J.", "Orozco-Cruz, R.", "Zamora-Peredo, L.", "López-Huerta, F.", "Pacio-Castillo, M.", "Serrano-de la Rosa, L. E.", "García-González, L." ]

null

[ "Electrochemical anodization", "HCl", "nanostructures", "Titanium Grade 2", "TiO2" ]

null

[ "Universidad Veracruzana", "Universidad Veracruzana", "Universidad Veracruzana", "Benemérita Universidad Autónoma de Puebla", "Benemérita Universidad Autónoma de Puebla" ]

scl/1516-1439/S1516-14392022000200215.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200215

10.1590/1980-5373-mr-2021-0487

ENGINEERING, CHEMICAL

Universidade Federal de São João del-Rei

null

The Influence of Rotating Cage Geometry and Baffles on the Wall Shear Stress Equation in Sweet/Sour Corrosion

Souza, Rhuan C.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Flow-accelerated corrosion has been studied by means of computational fluid dynamics (CFD) techniques and rotating cage (RC) autoclave tests according to ASTM G170. This study evaluated through CFD and laboratory tests the influence of RC geometry and baffles on the wall shear stress (τw) proposed by the aforementioned standard. The experimental were performed at 120 °C and 2 angular velocities (500 and 800 rpm) during 25 h in a solution with 600 mg/L of Cl- ions and 10-3 mol/L of sodium thiosulfate. Corrosion rates were obtained by ASTM G31 and the surfaces were evaluated by OM and XRD. Corrosion rate values and XRD analyses showed divergence between samples in different positions in the RC and between distinct regions in the same sample. The numerical simulations and the experimental tests showed a great influence of the baffles on τw. The conservatism in the values obtained with this technique is caused by excessive corrosion close to the samples edges and the non-uniformity of τw on the internal samples surfaces. Thus, the main conclusion of the study is related to the importance of better knowledge on experimental methodology and mathematical approximations for updating the criterion for the correct τw calculation on sample surfaces.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200215&lng=en&tlng=en

63

scielo_articles/scl/1516-1439/S1516-14392022000200215.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Souza, Rhuan C.", "Coelho, Bernardo", "Oliveira, Jefferson R.", "Vaz, Gustavo L.", "Bonfim, André L.C.", "Gomes, José Antônio C.P.", "Vilalta-Alonso, Guillermo", "Bueno, Alysson H.S." ]

null

[ "Flow accelerated corrosion", "rotating cage autoclave", "CFD", "API X65 steel", "CO2/H2S" ]

null

[ "Universidade Federal de São João del-Rei", "Centro de Pesquisa da Petrobras", "Universidade Federal do Rio de Janeiro" ]

scl/1516-1439/S1516-14392022000200209.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200209

10.1590/1980-5373-mr-2022-0268

ENGINEERING, CHEMICAL

Universidade Federal do Rio Grande do Sul

null

Superhydrophobic Stearic Acid Deposited by Dip-Coating on AISI 304 Stainless Steel: Electrochemical Behavior in a Saline Solutions

Sacilotto, D. Guerra

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract A superhydrophobic surface with excellent corrosion resistance was prepared on sandblasted AISI 304 stainless steel by applying stearic acid through dip-coating. Superhydrophobic surfaces have several advantages, such as self-cleaning, anti-icing, anti-adherent, and anti-corrosion. In this work, roughness and superhydrophobic properties were studied by contact angle, optical profilometry, electrochemical impedance spectroscopy, and potentiostatic polarization techniques. The lowest surface wettability was obtained in sandblasted samples (146.2°, due to the roughness change). The stearic acid coating response on sandblasted substrates was acquired by EIS analysis. The sample set with higher corrosion resistance at saline solution during the polarized potentiostat tests was the smoothly coated sandblasted samples. For comparison, corrosion current density of sample without coating was 3.13x10-7, whilst the coated sample was 1.34x10-8. Further, the passive current density was 6.02x10-7 for as-received samples and 2.16x10-8 for coated samples. The modified surface proved to be effective against corrosion when compared to smooth surfaces.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200209&lng=en&tlng=en

61

scielo_articles/scl/1516-1439/S1516-14392022000200209.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Sacilotto, D. Guerra", "Costa, J. Soares", "Ferreira, J. Zoppas" ]

null

[ "superhydrophobic coating", "stainless steel", "corrosion", "contact angle", "stearic acid" ]

null

[ "Universidade Federal do Rio Grande do Sul" ]

scl/1516-1439/S1516-14392022000200208.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200208

10.1590/1980-5373-mr-2022-0079

ENGINEERING, CHEMICAL

Universidade Federal Fluminense

null

Thermal Aging Effects on Mechanical and Intergranular Corrosion Resistance of Super-Austenitic Stainless Steel exposed at 600˚C

Cardoso, A.S.M

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Super-austenitic stainless steels (SASS) are alloys with better performance in industrial applications in comparison with standard degrees of austenitic stainless steels (ASS), mainly because of elevated Ni and Mo contents and residual control of certain elements because the improvement of refine techniques. These facts, promotes an improvement of mechanical properties and minimize detrimental effects of intergranular corrosion. Besides, some industrial applications involve high temperatures services, because these alloys families have an excellent creep and oxidation resistances performances. In this work, the objective is evaluate the microstructural and mechanical properties in high Mo SASS exposed at 600˚C in specimens aged until 2000 hours. Thus, hardness and toughness values and Double Loop Electrochemical Potentiodynamic Reactivation (DL-EPR) measurements were analyzed in several thermal aging in comparison to solution treatment condition. Complementary, analysis by Light Optical (LOM), of specimens tested by DL-EPR, and Scanning Electron Microscopies (SEM) in fractured surface from Charpy specimens were also analysed by SEM by backscattered electron mode (BSE). The results show that the aging provokes intergranular embrittlement by inhomogeneous distribution in grain boundaries of Mo rich phase precipitation.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200208&lng=en&tlng=en

20

scielo_articles/scl/1516-1439/S1516-14392022000200208.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Cardoso, A.S.M", "Pardal, J.M.", "Souza, A.P.", "Tavares, S.S.M.", "Nogueira, C.S.C.", "Xing, Y.", "Cardoso, J.L.", "Silva, M.J.G.", "Velasco, J.A.C." ]

null

[ "Super Austenitic Stainless Steels", "Thermal Aging", "Mechanical Properties", "Corrosion Resistance", "Double Loop Electrochemical Potentiodynamic Reactivation" ]

null

[ "Universidade Federal Fluminense", "Universidade Federal do Ceará", "Instituto Nacional de Tecnologia" ]

scl/1516-1439/S1516-14392022000200207.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200207

10.1590/1980-5373-mr-2021-0616

ENGINEERING, CHEMICAL

Instituto de Pesquisas Energéticas e Nucleares

null

A Cerium-Based Nanocoating for Corrosion Protection of the AA1230 as Clad Material for the AA2024-T3 Alloy

Klumpp, Rafael Emil

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Aluminum alloys are the state-of-art materials for structural components of aircrafts. As they are susceptible to localized corrosion, this kind of damage can become a major threat for its safe use in aircraft components. Therefore, surface protection of aluminum alloys against corrosion is a core issue in these applications. In this work, an alternative eco-friendly cerium-based surface pretreatment was developed and applied on the AA1230 clad of the AA2024-T3 alloy for corrosion protection. The corrosion resistance evaluation of this modified surface was evaluated by several techniques. The results were compared to chromium based conventional treatments and revealed that the coating layer, composed of spherical nodular nanostructures of cerium, obtained with the proposed eco-friendly treatment, improved the corrosion resistance of the alloy. Moreover, it was comparable to the corrosion behavior of chromate-treated alloy, showing that this treatment is a promising alternative to replace chromate based surface treatments.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200207&lng=en&tlng=en

39

scielo_articles/scl/1516-1439/S1516-14392022000200207.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Klumpp, Rafael Emil", "Araujo, João V. de S.", "Antunes, Renato Altobelli", "Viveiros, Bárbara Victoria Gonçalves de", "Magnani, Marina", "Costa, Isolda" ]

null

[ "AA1230", "Surface treatment", "Corrosion", "Clad 2024" ]

null

[ "Instituto de Pesquisas Energéticas e Nucleares", "Universidade Federal do ABC", "Universidade Estadual Paulista Júlio de Mesquita Filho" ]

scl/1516-1439/S1516-14392022000200206.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000200206

10.1590/1980-5373-mr-2022-0231

ENGINEERING, CHEMICAL

Universidade Federal do Rio Grande do Sul

null

Optimization of Cutting Parameters for Finish end Milling CFRP Under Vortex-Cooled Compressed Air

Klein, Rodrigo F.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Carbon fiber reinforced plastics (CFRP) offer several advantages in the aeronautical and automotive industry due to their combination of lightweight, high strength, and corrosion resistance. CFRP parts are usually produced in near-net-shape; however, additional machining processes are often required for achieving desired dimensional accuracy and surface finish. Thus, this work evaluates the influence of the cutting parameters in CFRP end milling to generate a better surface finish. The experiment was designed using a three-factor, three-level Box-Behnken considering feed rate (f), axial depth of cut (ap), and cooling conditions (cc) as controllable factors, and roughness parameters (Ra, Rq, Rz, Rt) as response variables (the occurrence of defects was evaluated qualitatively). Results indicated a strong influence of the quadratic effect of axial depth of cut and its interactions with feed rate and cooling condition on the roughness values and a milder but significant influence of the feed rate and cooling conditions. Multivariate analysis returned the optimum level of input parameters (f= 0.21 mm/rev and ap= 0.8 mm with cooled compressed air), resulting in Ra= 1.58 µm, Rq= 1.98 µm, Rz= 9.39 µm, Rt= 13.63 µm. Also, no defects were observed after machining under the optimum conditions.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000200206&lng=en&tlng=en

58

scielo_articles/scl/1516-1439/S1516-14392022000200206.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Klein, Rodrigo F.", "Hoffmann, Nícholas", "Souza, André J.", "Rebelo, Franciele J.", "Amorim, Heraldo J." ]

null

[ "Carbon fiber reinforced plastic", "end milling", "surface roughness", "vortex-cooled compressed air" ]

null

[ "Universidade Federal do Rio Grande do Sul" ]

scl/1516-1439/S1516-14392022000300209.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300209

10.1590/1980-5373-mr-2022-0141

ENGINEERING, CHEMICAL

Universidade Federal de São Carlos

null

Study of the Effect of Nitrogen on Corrosion, Wear resistance and Adhesion Properties of DLC Films Deposited on AISI 321H

Almeida, L. S.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The deposition of DLC films on 321H stainless steel aims at attributing properties such as high wear resistance and low friction coefficient to the substrate material. Nitrogen added to DLC can improve the film adhesion to metal substrates, but the investigation of its effect on corrosion resistance, an important property for stainless steels, is lacking. The DLC film was deposited by plasma-enhanced chemical vapor deposition (PECVD) using a pulsed-DC power supply with a gas mixture of Ar and CH4, and to the DLC(N) film deposition was used CH4 and N2 varying the percentage of nitrogen from 10 to 50% in the treatment. DLC films improved both the wear and corrosion resistance of 321H stainless steel. The results show that the 10, 20 and 30% of N2 supply during the deposition increased the adhesion of the film on the substrate, enhancing the wear resistance of the treated material. The addition of 40 and 50% of N2 during the deposition, however, impaired the corrosion resistance compared with the substrate. An improvement of adhesion, wear and corrosion resistance were observed for 30% N2 condition. Thus, the incorporation of suitable concentration of nitrogen modifies the features of the DLC film, obtaining a good combination of high wear resistance and corrosion protection due to a combination of structure, high thickness, and high adhesion of the film to 321H stainless steel.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300209&lng=en&tlng=en

41

scielo_articles/scl/1516-1439/S1516-14392022000300209.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Almeida, L. S.", "Pereira, M. S.", "Antônio Junior, C. A.", "Silva, F. C.", "Ramirez, O.M. Prada", "Schön, C. G.", "de Melo, H.G.", "Manfrinato, M. D.", "Rossino, L. S." ]

null

[ "micro-abrasive wear", "DLC", "corrosion potential", "nitrogen" ]

null

[ "Universidade Federal de São Carlos", "Faculdade de Tecnologia de Sorocaba", "Faculdade de Tecnologia do Estado de São Paulo", "Universidade de São Paulo", "Faculdade de Tecnologia do Estado de São Paulo" ]

scl/1516-1439/S1516-14392022000100382.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100382

10.1590/1980-5373-mr-2022-0225

ENGINEERING, CHEMICAL

Universidade Federal de Alfenas

null

Elastic Modulus and Hardness of Potassium Tantalum Germanate Glasses and Glass-Ceramics

Lima, Clarissa L. Justino de

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Whilst the optical and structural properties of the glasses containing tantalum oxide have been considerably investigated, research into their mechanical properties is not substantially established. This work reports on the mechanical characterization of transparent germanate glass samples, obtained via the melt-quenching technique, with a molar content of Ta2O5 ranging from 0% to 20%. The introduction of Ta2O5 in the samples is related to significant improvements in the mechanical properties. The transition from glass to transparent glass-ceramic via the controlled crystallization of Ta2O5 proved to be a tool to increase both the elastic modulus and the hardness while keeping the transparency of the material. The average elastic modulus of the studied compositions ranged from 69.2 GPa to 99.1 GPa, while the average hardness of the same samples varied from 5.10 GPa to 7.34 GPa.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100382&lng=en&tlng=en

26

scielo_articles/scl/1516-1439/S1516-14392022000100382.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Lima, Clarissa L. Justino de", "Veer, Fred A.", "Šavija, Branko", "Cassanjes, Fabia Castro", "Poirier, Gael Y." ]

null

[ "Tantalum oxide", "glass", "germanium oxide", "nanoindentation" ]

null

[ "Universidade Federal de Alfenas", "Delft University of Technology", "Delft University of Technology", "American Glass Research" ]

scl/1516-1439/S1516-14392022000100381.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100381

10.1590/1980-5373-mr-2022-0179

ENGINEERING, CHEMICAL

Universidade de Vigo

null

Pitting and Crevice Corrosion Behavior of the Duplex Stainless Steel UNS S32205 Welded by Using the GTAW Process

Rosa, Yamid E. Nuñez de la

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract This study investigated the pitting and crevice corrosion behavior of the gas tungsten arc welding (GTAW) process in the UNS S32205 according to industrial parameters. Results revealed that the welding process presented a weld metal chemical composition similar to the base metal and an adequate balance of the austenite and ferrite phases. No relevant variation in the hardness was observed and XRD spectra did not identify the presence of deleterious phases in the weld bead. Cyclic polarization tests revealed similarities between welded and base metal samples (20±2°C, NaCl 3.5% wt.). When comparing the behavior obtained in the crevice, and pitting tests, a decrease in the corrosion resistance was observed in the presence of a crevice former. The SEM-EDS proved that the attack occurred mainly in secondary austenites. Profilometry measurements revealed that the crevice corrosion in the weld region was deeper than in the base metal. However, considering the welded samples as a unit, making no difference between regions: weld metal, HAZ, and base metal, the average crevice corrosion depth was comparable to that of the base metal samples. Finally, it was concluded that the welding process used for the UNS S32205 steel did not harm its corrosion resistance.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100381&lng=en&tlng=en

54

scielo_articles/scl/1516-1439/S1516-14392022000100381.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Rosa, Yamid E. Nuñez de la", "Calabokis, Oriana Palma", "Uris, Gloria M. Pena", "Borges, Paulo César" ]

null

[ "DSS", "UNS S32205", "weld", "GTAW", "pitting corrosion", "crevice corrosion" ]

null

[ "Universidade de Vigo", "Universidade Tecnológica Federal do Paraná" ]

scl/1516-1439/S1516-14392022000100380.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100380

10.1590/1980-5373-mr-2022-0316

ENGINEERING, CHEMICAL

Universidade Presbiteriana Mackenzie

null

Characterization and Evaluation of Employment in Rigid Packaging of Polypropylene Composites with Bamboo Fiber

Silva, Lindomar Paulo da

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

The packaging industry is the industrial segment that, historically, is one of the largest consumers of polymers, highlighting the great use of polypropylene. Seeking to reduce the consumption of non-renewable raw materials in packaging, this work aimed to study the use of bamboo fiber in polypropylene composites with 15wt% and 25wt% of fiber. Also, the mechanical and thermal properties were evaluated. The density and fluidity of the composites were compared with the virgin polymer. Regarding the density of the composites, it was observed that this was not significantly affected by the addition of fibers. In the melt flow index of the composites, it was observed that the fluidity of the composite with 25wt% bamboo fiber was reduced by more than 50%. The fluidity of the composite with 15wt% fiber has not undergone considerable change compared with the data of the virgin polymer. In tensile analysis, the only property that increased with adding fibers to the polymer was the modulus of elasticity. The impact resistance analysis showed that the composites significantly increased impact resistance and energy absorption. It was concluded that the composites of PP with bamboo fiber showed potential application in the packaging industry.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100380&lng=en&tlng=en

20

scielo_articles/scl/1516-1439/S1516-14392022000100380.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Silva, Lindomar Paulo da", "Munhoz Junior, Antonio Hortencio", "Peres, Renato Meneghetti", "Machado, Miriam Lucia Chiquetto" ]

null

[ "Polypropylene", "Composites with natural fibers", "Bamboo fibers", "Composites. Packaging" ]

null

[ "Universidade Presbiteriana Mackenzie" ]

scl/1516-1439/S1516-14392022000100353.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100353

10.1590/1980-5373-mr-2021-0449

ENGINEERING, CHEMICAL

National Research Centre

null

The role of Preparation Technique on the Structure, Electrical Properties of CoxZn1-xFe2O4 and its Electrocatalytic Effect on Hydrogen Evolution Reaction

Fathi, A.M.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Zinc-ferrite ZnFe2O4 and CoxZn1-xFe2O4 (x= 0.2, 0.5 and 0.8) were prepared by two different techniques. The first was the solid state reaction based on utilizing electric arc furnace dust (waste material), and the second was the microwave treatment (pure materials). The structure and characterization of the prepared samples were studied by using XRD and SEM which ensured the formation of cubic spinel structure with some hematite phases. The physical properties as the density and porosity were measured where the microwave samples showed lower porosity and higher density than the solid state samples. Semiconducting properties has been observed for the prepared samples. The electrocatalytic activity of the hydrogen evolution reaction (HER) has been studied for all the samples in 1.0 M KOH (25 °C) by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance techniques. The results showed that the catalytic activity increased with increase of Co content as the surface area and the total pore volume increases in the ferrite prepared by solid state method while Co0.2Zn0.8Fe2O4 prepared by microwave method showed the highest surface area and optimum improvement in the apparent HER catalytic activity. Lower resistance and faster charge transfer were shown for CoxZn1-xFe2O4 than the pure phase.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100353&lng=en&tlng=en

58

scielo_articles/scl/1516-1439/S1516-14392022000100353.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Fathi, A.M.", "Khattab, R.M.", "Sadek, H.E.H.", "Salama, A.H." ]

null

[ "Spinel", "Feritte", "microwave", "electrocatalyst", "HER" ]

null

[ "National Research Centre", "National Research Centre" ]

scl/1516-1439/S1516-14392022000100359.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100359

10.1590/1980-5373-mr-2021-0562

ENGINEERING, CHEMICAL

Instituto Federal de Educação, Ciência e Tecnologia de Minas Gerais

null

Influence of Niobium Adding on the Microstructure and Abrasive Wear Resistance of a Heat-Treated High-Chromium Near-Eutectic Cast Iron Alloy

Melo, Ismael Nogueira Rabelo de

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract High chromium cast iron (HCCI) with levels around 26% Cr - 2.9% C according to ASTM A 532 IIIA is widely used in systems where high abrasive wear resistance is required. To evaluate the niobium influence, HCCI with 0.5% Nb and 1% Nb additions were melted, besides one without niobium addition of for comparison. For characterization, X-ray diffractometry, scanning electron microscopy (SEM), Vickers microhardness tests, Rockwell C hardness, carbide quantifications, quantification of the retained austenite by Mössbauer spectroscopy, and rubber wheel abrasion test according to procedure A of ASTM G-65 were performed. The results indicated a reduction in the average size, average perimeter, and carbides volumetric fraction (CVF) due to the addition of niobium, also changing the microstructure of the HCCI from eutectic to hypoeutectic. In some regions, NbC0.75 carbides formed a coating around M7C3 carbides. The 0.5% Nb alloy showed the best performance in the rubber wheel abrasive wear test, with a 37% average volume loss reduction as compared to the sample without niobium addition with a 130N load and 34% with a 45N load. The 0.5% Nb alloy also had the highest content of retained austenite among the investigated alloys.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100359&lng=en&tlng=en

26

scielo_articles/scl/1516-1439/S1516-14392022000100359.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Melo, Ismael Nogueira Rabelo de", "Silva, Anderson Edson da", "Faria, Fabrício Gonçalves de", "Pinheiro, Ivete Peixoto", "Silva, Leonardo Roberto da", "Paniago, Roberto Magalhães" ]

null

[ "Niobium", "High Chromium Cast Iron", "Abrasive Wear", "Mössbauer Spectroscopy", "Dry Sand Rubber Wheel" ]

null

[ "Instituto Federal de Educação, Ciência e Tecnologia de Minas Gerais", "Centro Federal de Educação Tecnológica de Minas Gerais", "Universidade Federal de Minas Gerais" ]

scl/1516-1439/S1516-14392022000100358.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100358

10.1590/1980-5373-mr-2021-0518

ENGINEERING, CHEMICAL

Université Grenoble Alpes

null

PI Controller for IPMC Actuators Based on Nafion®/PT Using Machine Vision for Feedback Response at Different Relative Humidities

Zuquello, Ariel Gustavo

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Ionomeric Polymer-Metal Composites (IPMCs) are sandwich-like materials based in a polymeric membrane covered on both sides by metallic electrodes. Its operation mechanism consists of hydrated ions migration in response to an external electrical field generated between the electrodes, leading to a spatially nonuniform mass accumulation which causes the device to bend. Its performance as an actuator depends mainly on the environment's relative humidity and electrical stimuli. Consequently, IPMCs present variations in the electromechanical properties exhibiting nonlinearities and time-varying behaviors, limiting the major applications. For this reason, this paper investigated a PI controller performance to overcome these drawbacks and effectively control a Nafion-based IPMC-Li+ exposed to different relative humidities and electrical stimulis. The PI control system uses a camera with a machine vision application as a feedback sensor. Support instrumentation was developed to control the relative humidity, apply an electrical stimulus, and measure the electromechanical response. The pattern recognition algorithm implemented in the controller is efficient, with accuracy above 95%, making the feedback sensor reliable. Therefore, the PI controller was effective, stable, and capable of controlling and characterizing IPMC devices when relative humidity was above 60% at a low-frequency displacement and avoided the undesired back-relaxation phenomenon.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100358&lng=en&tlng=en

81

scielo_articles/scl/1516-1439/S1516-14392022000100358.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Zuquello, Ariel Gustavo", "Saccardo, Matheus Colovati", "Gonçalves, Roger", "Tozzi, Kaique Afonso", "Barbosa, Rafael", "Hirano, Laos Alexandre", "Scuracchio, Carlos Henrique" ]

null

[ "IPMC", "PI controller", "Machine vision", "Relative humidity", "Camera" ]

null

[ "Université Grenoble Alpes", "Universidade Federal de Alfenas", "Universidade Federal de São Carlos", "Universidade Comunitária da Região de Chapecó", "Instituto Federal de Educação, Ciência e Tecnologia de São Paulo" ]

scl/1516-1439/S1516-14392022000100357.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100357

10.1590/1980-5373-mr-2022-0239

ENGINEERING, CHEMICAL

M.Kumarasamy College of Engineering

null

Analyze the Effect of Crater Cutting Tool Wear Modeling in the Machining of Aluminium Composite

Nagarajan, N.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The present investigation is used to analyze the effect of crater wear modeling in the machining of aluminium composite. Response surface methodology (RSM) is one of the best optimization technique used to bring out the optimal values of speed, feed and depth of cut for attain minimum surface roughness, cutting tool temperature and tool wear. AA7075 alloy with 15wt% of silicon carbide has been investigated in the dry machining condition. The double layered TiCN/Al2O3 coated tool was preferred. The worn surface analysis in coated tool was concentrated. The outcomes of the machining conditions were expected to improve surface finish. Novel approach of this investigation is to analyze the surface morphology to visualize the surface peak and valley profile of the coated tool and analyzed with various surface parameters that decide the surface roughness of the profile.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100357&lng=en&tlng=en

44

scielo_articles/scl/1516-1439/S1516-14392022000100357.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Nagarajan, N.", "Kamalakannan, R." ]

null

[ "Aluminum", "tool wear", "cutting tool temperature", "coating", "surface morphology", "surface roughness" ]

null

[ "M.Kumarasamy College of Engineering", "Anna University" ]

scl/1516-1439/S1516-14392022000100356.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100356

10.1590/1980-5373-mr-2022-0235

ENGINEERING, CHEMICAL

Universidade Federal de Alfenas

null

Effect of Rapid Solidification Processing on the Microstructure and Corrosion of 316L Austenitic Stainless Steel

Apolinario, Raíra Chefer

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Austenitic stainless steels processed by rolling are widespread in technological applications, since they have excellent mechanical and corrosion properties. This study investigated the effect of the cooling rate, microstructure and properties of 316L austenitic stainless steel under cold rolled conditions and by rapid solidification. The microstructure of the cold rolling processing steel was composed of austenite and a low percentage of delta ferrite. For the rapid solidification condition, the microstructure evolved from columnar and acicular dendrites to equiaxed dendrites with decreasing cooling rates, without the presence of delta ferrite due to the high cooling rate. Furthermore, thermal analyses in both routes revealed that oxidation kinetics was slower after rapid solidification in synthetic air. The microhardness in the cold rolling condition was lower than in the rapid solidification condition since the microstructure under the solidification condition is more refined. The sample in the rapid solidification condition region RS1 presented the highest corrosion resistance considering the pit potential. The passivation current density in the cold rolled condition was 5.72x10-5A/cm2, while under the rapid solidification condition, regions RS1 and RS2 were 2.24x10-5 A/cm2 and 3.72x10-6 A/cm2, respectively, and region RS3, did not present a passivation region in a broad range of potentials.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100356&lng=en&tlng=en

37

scielo_articles/scl/1516-1439/S1516-14392022000100356.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Apolinario, Raíra Chefer", "Daianezi, Isabela", "Borges, Spyridion Haritos", "Sousa, Lucíola Lucena de", "Pinto, Haroldo Cavalcanti", "Mariano, Neide Aparecida" ]

null

[ "Rapid solidification", "Cold rolled", "Stainless steel", "Microstructure" ]

null

[ "Universidade Federal de Alfenas", "Universidade de São Paulo", "Universidade Federal de São Carlos" ]

scl/1516-1439/S1516-14392022000100355.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100355

10.1590/1980-5373-mr-2022-0129

ENGINEERING, CHEMICAL

Universidade Estadual Paulista

null

Assessment of Charge Transport Through Barrier Membranes Before Application on Materials Surfaces

Nardeli, Jéssica Verger

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract This work aims at investigating the charge transfer resistance (RCT) of the two membranes derived from vegetable oils which are intended to protect materials against corrosion. The membranes were characterized by thickness measurement (328±1 μm and 491± 1 μm), atomic force microscopy (AFM) to estimate of roughness (<0.5 μm), Raman spectroscopy while the RCT values were evaluated by electrochemical impedance spectroscopy (EIS) in 0.1 mol/L KCl solution. EIS was used to measure the impedance at low frequency (Z0.01Hz ≅ 109 Ω cm2), RCT ≅ 109 Ω cm2 and exchange current density (i0 ≅ 10-11 Ω cm2), employing simple instrumentation. The thickness of the membrane must be considered for coherent interpretation of the impedance results. The study of electrolytes permeation in membranes is important to previously estimate the lifetime offered to a substrate over the time of immersion even before being applied to the metallic surface. The impedance measurements demonstrated that the most resistant membrane to permeation presented a RCT around 2 GΩ cm2. This EIS measurements approach enables the optimization of membrane fabrication by conveniently identifying the best formulation.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100355&lng=en&tlng=en

37

scielo_articles/scl/1516-1439/S1516-14392022000100355.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Nardeli, Jéssica Verger", "Fugivara, Cecílio Sadao", "Benedetti, Assis Vicente" ]

null

[ "Membrane", "pristine organic film", "permeation", "corrosion protection" ]

null

[ "Universidade Estadual Paulista" ]

scl/1516-1439/S1516-14392022000100352.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000100352

10.1590/1980-5373-mr-2021-0629

ENGINEERING, CHEMICAL

Universidade Federal de Pernambuco

null

Influence of Welding Parameters on the Mechanical Properties and Microstructure of 7075-T651 Aluminum Alloys Welded Joints Performed by FSW Process

Lima, Jefferson Segundo de

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Aluminum alloys of 7xxx series have excellent characteristics and mechanical properties, being widely used in primary aircraft structures. However, the welding of these alloys by conventional arc welding processes results in an excessive mechanical resistance degradation and increasing in residual stress level. In this context, Friction Stir Welding (FSW) process has received attention in recent years mainly because it does not reach the materials melting point during the process. This work aims to evaluate the influence of the tool rotation and welding speed on microstructure and mechanical properties of AA 7075-T651 aluminum alloy welded joints by FSW process. Therefore, four welded joints obtained with different welding and tool rotation speed were subjected to tensile and microhardness tests. The microstructures of the welded joints were evaluated through analysis by optical microscopy and Scanning Electron Microscopy (SEM). The retreating side of the welded joints showed a higher occurrence of microstructural welding defects. Welded joints with yield strength (YS) 50% higher than those of base metal and with ultimate tensile strength up to 380 MPa were achieved.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000100352&lng=en&tlng=en

34

scielo_articles/scl/1516-1439/S1516-14392022000100352.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Lima, Jefferson Segundo de", "Santos, Oclávio Coutinho dos", "Silva, Antônio Almeida", "Melo, Raphael Henrique Falcão de", "Maciel, Theophilo Moura" ]

null

[ "Welded joint", "Friction Stir Welding", "7075-T651 Aluminum Alloy", "Microstructure", "Mechanical properties" ]

null

[ "Universidade Federal de Pernambuco", "Universidade Federal de Campina Grande", "Instituto Federal de Educação Ciência e Tecnologia da Paraíba" ]

scl/1516-1439/S1516-14392022000300210.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392022000300210

10.1590/1980-5373-mr-2022-0142

ENGINEERING, CHEMICAL

Consultoria em Materiais e Informática Ltda

null

Electrochemical Properties of Iron Oxide Decorated Activated Carbon Cloth as a Binder-Free Flexible Electrode

Munhoz, M. G. C.

2,022

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The oxidation and deposition of transition metal oxides on porous carbon precursor materials strongly influence the final performance of supercapacitor electrodes. Thus, the influence of oxidation time combined with simple iron oxide deposition was evaluated on a flexible carbon fiber cloth electrode oxidized at three different times and exposed to spontaneous iron oxide deposition. The 140 minutes oxidation time increased by two times the iron quantity deposited on the activated carbon fiber cloth (ACC) and also increased the crystallinity of the carbon matrix. The iron oxide deposition improved the contribution of anions to store energy, enhancing the pseudocapacitive effect in the samples. The optimal oxidation time of the ACC140_Fe sample with the greater iron oxide deposition achieves 116.8 F g-1. The binder-free flexible electrode presents a successful design through pre-oxidation and spontaneous iron oxide deposition on the carbon matrix without expensive and environmentally unfriendly chemical treatments.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392022000300210&lng=en&tlng=en

57

scielo_articles/scl/1516-1439/S1516-14392022000300210.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Munhoz, M. G. C.", "Rodrigues-Siqueli, A. C.", "Fonseca, B. C. S.", "Marcuzzo, J. S.", "Matsushima, J. T.", "Silva, G. F. B. Lenz e", "Baldan, M. R.", "Amaral-Labat, G." ]

null

[ "Energy storage", "Flexible electrodes", "Supercapacitors", "Spontaneous deposition", "Oxidation" ]

null

[ "Consultoria em Materiais e Informática Ltda", "Universidade de São Paulo", "Instituto Nacional de Pesquisas Espaciais", "Faculdade de Tecnologia de São José dos Campos" ]

scl/1516-1439/S1516-14392023000100237.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100237

10.1590/1980-5373-mr-2022-0401

ENGINEERING, CHEMICAL

PSG College of Technology

null

Thermomechanical Simulation of Heat-Affected Zones in Nickel-Free High Nitrogen Stainless Steel: Microstructural Evolution and Mechanical Property Studies

Ramalingam, Dhanasekar

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Three different Heat Affected Zones (HAZ) in hot rolled Nickel Free High Nitrogen Stainless Steels (NFHNSS) based on three different peak temperatures were physically simulated using Gleeble Simulator to investigate microstructural evolution and structure-property correlation. Optical microscopy revealed that the austenite grains are recrystallized in the simulated heat affected zone in the peak temperature range of 750 oC to 1050 oC. Extent of recrystallization of grains and nucleation of precipitates varied with peak temperatures. TEM characterization showed the presence of Cr2N precipitate having an average particle size in the range of 300 nm to 395 nm in the simulated HAZ were confirmed by Selected Area Electron Diffraction (SAED) analysis. Precipitation kinetics of Cr2N were simulated using Thermo-Calc were found to correlate well with experimental values. Mechanical properties of specimens taken from three different HAZ were evaluated for tensile strength and hardness. Variation in strength of the different specimens has been discussed using various strengthening models. Fractography analysis was also carried out to understand the effect of peak temperature on fracture behaviour. Transition in fracture patterns in NFHNSS from ductile to mixed mode was observed for different specimens.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100237&lng=en&tlng=en

33

scielo_articles/scl/1516-1439/S1516-14392023000100237.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Ramalingam, Dhanasekar", "Veerappagounder, Balusamy", "Rangaswamy, Sivasankari" ]

null

[ "Nickel free High Nitrogen Stainless Steel (NFHNSS)", "Thermomechanical simulation", "TEM", "Chromium Nitride", "HAZ" ]

null

[ "PSG College of Technology", "Kongu Engineering College" ]

scl/1516-1439/S1516-14392023000100248.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100248

10.1590/1980-5373-mr-2022-0362

ENGINEERING, CHEMICAL

Eskisehir Technical University

null

Influence of Build Direction and Post Processes on the Material and Part Attributes of Hard Resins Fabricated by Photopolymerization Based Additive Manufacturing

Poyraz, Ozgur

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

This study aims to contribute to the scientific knowledge by investigating the influence of build direction and post-curing on the material and part attributes of acrylonitrile butadiene styrene (ABS-like) like resins by photopolymerization based additive manufacturing (AM). Specimens were manufactured in different build directions with the parameters that offer the highest density. Two groups of specimens, one as-built and the other post-cured, were subjected to dimensional inspections, surface characterization, fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), hardness measurements, tensile tests, bending tests, Charpy impact tests and the obtained values were reported and benchmarked. It has been observed that the change in the build direction significantly affects the surface roughness and the average surface roughness of the samples produced in the vertical plane is much higher than those produced in the horizontal plane. It was demonstrated that post-curing has a negligible effect on part dimensions and density. It increases hardness, tensile modulus and flexural modulus while reducing elongation and impact resistance. The effects of post-curing on chemical and thermal properties were also compared and it was determined that it improves the thermal stability. In the absence of post-curing, vertical as-built specimens were observed to have higher strength than their horizontal counterparts.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100248&lng=en&tlng=en

34

scielo_articles/scl/1516-1439/S1516-14392023000100248.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Poyraz, Ozgur" ]

null

[ "additive manufacturing", "vat photopolymerization", "post-curing", "mechanical testing", "surface roughness", "thermal characterization" ]

null

[ "Eskisehir Technical University" ]

scl/1516-1439/S1516-14392023000100206.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100206

10.1590/1980-5373-mr-2022-0326

ENGINEERING, CHEMICAL

Center for Thermal spray Research at Stony Brook University

null

Performance of EPDM Composites Under Thermal Plasma Ablative Tests

Miranda, F. S.

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract In this work, a thermal plasma-based ablation test system was used to evaluate the ablative performance of the EPDM composite. The system produces a high enthalpy plasma jet generated by a plasma (DC) torch, operating at atmospheric pressure using compressed air as working gas, enabling the variation of the thermal flux concerned with the studied EPDM composites. The samples were characterized using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Fourier-Transform Infrared spectroscopy (FTIR), and Thermogravimetric Analysis (TGA) to investigate the morphology, mass-loss rate, the reaction layer (char formation), and chemical changes of the samples for each thermal flux. For a complete evaluation, the thermal fluxes were varied in 0.30, 0.45, 0.60, 0.75, and 0.90 MW/m2 and for each thermal flux, disk-shape samples remained exposed to the plasma jet for 10s. During the plasma jet exposure time, the temperatures of the surface and the back of the samples were collected to verify the formed char layer's insulator capacity and the samples' thermal diffusivity for each experimental condition. The mass loss is continuous under the thermal fluxes of 0.30 and 0.45 MW/m2, stabilizing at 60% until 0.75 MW/m2. The formed char layer begins to lose its protective capacity, evidenced by the size decrease (from 800 µm to 700 µm), due to the ablation process of the reaction layer from the thermal flux of 0.90 MW/m2.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100206&lng=en&tlng=en

37

scielo_articles/scl/1516-1439/S1516-14392023000100206.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Miranda, F. S.", "Prado, E. S. P.", "Silva, R. J.", "Ribeiro, A. M.", "Caliari, F. R.", "Calciolari, F. L.", "Sobrinho, A. S. Silva", "Petraconi, G." ]

null

[ "Thermal Plasma", "EPDM composite", "Ablation", "Reaction layer" ]

null

[ "Center for Thermal spray Research at Stony Brook University", "Instituto Tecnológico de Aeronáutica", "AVIBRAS Indústria Aeroespacial S/A", "Instituto Nacional de Pesquisas Espaciais" ]

scl/1516-1439/S1516-14392023000100212.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100212

10.1590/1980-5373-mr-2022-0373

ENGINEERING, CHEMICAL

Jiangxi Provincial Key Laboratory of Robot and Welding Automation

null

Study on Mechanical Properties and Failure Mechanism of Medium Manganese TRIP Steel / DP590 Dissimilar Steel Resistance Spot Welding Joint

Liu, Hongning

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract This paper presents the resistance spot welding process test and numerical simulation analysis of medium manganese steel TRIP steel (7MnSteel) and DP590 steel plate. The results show that the failure mode is PF-TT failure, and IF and PF-TT are investigated. At the same time, based on the numerical simulation under the typical welding parameters, the welding plate has the stress concentration at the electrode edge at the beginning of the welding. Along with the welding, there is the stress concentration in the heat-affected zone of the medium manganese TRIP steel, which may also be the reason for the failure of the joint here. The current density is concentrated at the contact surface between the electrode and the weld plate, and the error in the diameter of the nugget measured by simulation and experiment is within 7%, which verifies the accuracy and reliability of the model.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100212&lng=en&tlng=en

30

scielo_articles/scl/1516-1439/S1516-14392023000100212.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Liu, Hongning", "Zhu, Yunming", "Tian, Yifeng", "Wei, Fufa", "Zhou, Yongqiang", "Zhu, Zhengqiang" ]

null

[ "Resistance spot welding", "medium manganese TRIP steel", "DP590", "numerical simulation", "failure mode" ]

null

[ "Jiangxi Provincial Key Laboratory of Robot and Welding Automation", "Nanchang University" ]

scl/1516-1439/S1516-14392023000100211.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100211

10.1590/1980-5373-mr-2022-0329

ENGINEERING, CHEMICAL

Universidade de São Paulo

null

Hydroxylation Studies on High-Solid Load Magnesia Aqueous Suspensions

Salomão, Rafael

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The magnesia (MgO) hydroxylation behavior in dilute suspensions (below 50% volumetric solid loads) has been extensively studied over the past decades due to its role in refractory castables. However, its equivalent effects on concentrated systems have not been analyzed in such a systemic way, although they are known to be as or more deleterious than those observed in dilute systems. This study focuses on the hydroxylation behavior of different sources of magnesia (sinter and caustic magnesia) in aqueous suspensions prepared at various solids concentrations (17-96 vol%) and shaped by distinct methods. They were analyzed by thermogravimetry, apparent volumetric expansion measurements, X-ray diffraction, scanning electron microscopy, and in situ temperature measurements during curing. The ratio between experimental and theoretical extents of the hydroxylation degree resulted in the reaction yield. A comparison between samples containing the same water amount revealed those with caustic magnesia showed a faster evolution of hydroxylation degree, apparent volumetric expansion, and higher maximum internal temperature during curing. In both systems, the yield levels of compositions of heavier solid loads were higher, despite the small quantity of hydroxylation products formed. Significant differences in the products’ microstructure were observed and related to the ions' mobility toward crystallization nuclei.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100211&lng=en&tlng=en

56

scielo_articles/scl/1516-1439/S1516-14392023000100211.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Salomão, Rafael", "Fernandes, Leandro" ]

null

[ "Magnesia", "hydroxylation", "sinter", "caustic", "expansion", "solid load" ]

null

[ "Universidade de São Paulo" ]

scl/1516-1439/S1516-14392023000100210.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100210

10.1590/1980-5373-mr-2022-0295

ENGINEERING, CHEMICAL

Technical University of Denmark

null

Combined Experimental and First Principles Study on Nanostructured NbFeSb Half-Heusler Alloy Synthesized by Mechanical Alloying

Dias, Cleverton Oliveira

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The Half-Heusler semiconductor alloys can be used efficiently as thermoelectric materials to transform the waste heat into useful electrical energy. The low-cost and large-scale production of suitable half-Heusler alloys are important in the present context. In this work, a nanostructured half-Heusler NbFeSb alloy is obtained by mechanical alloying with 15h of milling. The structural parameters of the sample are investigated by powder X-ray diffraction followed by Rietveld refinement. Differential scanning calorimetry indicates that the NbFeSb phase is stable up to about 420 K. The electrical resistivity is obtained as a function of temperature. A band gap of 0.37(3) eV is obtained from UV-Vis measurements. Density functional theory calculation shows an indirect band gap of 0.52 eV. Analyses of the obtained data indicate that structural defects and nanometric crystallites sizes present in the nanostructured NbFeSb produced by mechanical alloying do not degrade the electrical and optical properties of the compound.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100210&lng=en&tlng=en

43

scielo_articles/scl/1516-1439/S1516-14392023000100210.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Dias, Cleverton Oliveira", "Monteiro, Joziano Rony de Miranda", "Oliveira, Leonardo Soares de", "Chaudhuri, Puspitapallab", "Souza, Sérgio Michielon de", "Trichês, Daniela Menegon" ]

null

[ "Nanostructured alloys", "thermoelectric materials", "half-heusler alloys", "mechanical alloying", "density functional theory" ]

null

[ "Technical University of Denmark", "Universidade Federal do Amazonas" ]

scl/1516-1439/S1516-14392023000100209.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100209

10.1590/1980-5373-mr-2022-0300

ENGINEERING, CHEMICAL

Universidade Federal da Paraíba

null

CuO and Ce-doped CuO Prepared by Microwave Hidrotermal Method in Photodegradation of Remazol Golden Yellow Dye

Quirino, Max Rocha

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Copper oxide (CuO) is a heterogeneous catalyst applied with success in several systems like vegetable oils transesterifications. The Ce-dopoing CuO is a promisor material with a potential improve catalysis performances. In this work, CuO and Ce-doping CuO were synthesized by the microwave hydrothermal method in only 5 min at low temperature (100 oC) without templates or other petroleum dependent organic substances, using only copper and cerium nitrates and sodium hydroxide as a precursors. Both materials were applied as photocatalysts for the degradation of remazol golden yellow dye (RNL). X-ray diffraction analysis showed that CuO and Ce-doped CuO has monoclic copper oxide structure without secondary phases. SEM analysis showed the Ce-doping full modify the CuO powder morphology. The dye RNL degradation rate of Ce-doping CuO was bigger than pure CuO and the expensive CeO2.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100209&lng=en&tlng=en

41

scielo_articles/scl/1516-1439/S1516-14392023000100209.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Quirino, Max Rocha", "Lucena, Guilherme Leocárdio", "Araújo, Renata Júlia Cordeiro de", "Silva, Adriano Ribeiro da", "Melo, Anely Maciel de", "Santos, Ieda Maria Garcia dos", "Gama, Luciana" ]

null

[ "Ceramics", "Catalytic proprieties", "Chemical reaction", "Nanostructures" ]

null

[ "Universidade Federal da Paraíba", "Universidade Federal da Paraíba", "Universidade Federal de Campina Grande" ]

scl/1516-1439/S1516-14392023000100208.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100208

10.1590/1980-5373-mr-2022-0213

ENGINEERING, CHEMICAL

University of Michigan-Dearborn

null

Ti-containing High-Entropy Alloys for Aeroengine Turbine Applications

Canumalla, R.

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract Sustained research in high-entropy alloys (HEAs) has presented opportunities for relatively lighter alloys, specifically the Ti-containing HEAs, having an excellent combination of properties, and a great potential to replace heavier superalloys. We adopted a novel data-driven methodology to sort and select Ti-containing HEAs from the literature for their potential applications in aeroengine turbines by applying multiple-attribute decision-making (MADM). The ranks of the alloys evaluated by diverse MADMs were consistent. The data-driven methodology identified the following top five Ti-containing HEAs: ONS-BCC-Ti17.8 (Al20.4-Mo10.5-Nb22.4-Ta10.1-Ti17.8-Zr18.8), EF-BCC-Cr20-Ti20 (Ti20-Zr20-Hf20-Nb20-Cr20), ONS-BCC-Ti27.9 (Al11.3-Nb22.3-Ta13.1-Ti27.9-V4.5-Zr20.9), ONS-BCC-Ti27.7 (Al5.2-Nb23.4-Ta13.2-Ti27.7-V4.3-Zr26.2), and ONS-BCC-Ti20 (Nb20-Cr20-Mo10-Ta10-Ti20-Zr20); the methodology provides directives for further development of the identified Ti-containing HEAs for potential replacement of legacy superalloys in aeroengine turbines. The top-ranked alloy (Al20.4-Mo10.5-Nb22.4-Ta10.1-Ti17.8-Zr18.8) is lighter than the current industry benchmark, Inconel 718, by ~13%. All the top five Ti-containing HEAs have configurational entropy greater than ~13.3 J/mol K and body-center cubic crystal structure. The potency of the methodology could further be tapped by choosing appropriate weights of the properties for specific aeroengine turbine applications.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100208&lng=en&tlng=en

70

scielo_articles/scl/1516-1439/S1516-14392023000100208.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Canumalla, R.", "Jayaraman, T.V." ]

null

[ "High-entropy alloys", "aeroengine", "turbines", "multiple-attribute decision making" ]

null

[ "University of Michigan-Dearborn", "Weldaloy Specialty Forgings" ]

scl/1516-1439/S1516-14392023000100207.xml

en

research-article

Materials Research

1980-5373

SciELO Brazil

ABM, ABC, ABPol

S1516-14392023000100207

10.1590/1980-5373-mr-2022-0341

ENGINEERING, CHEMICAL

Universidade de Caxias do Sul

null

Evaluation of Biochar Production Temperature in Interaction with Elastomers of Different Polarities

Ribeiro, Willian B.

2,023

null

This work is licensed under a Creative Commons Attribution 4.0 International License.

null

Abstract The present work is to study the production and characterization of biochar produced at two different temperatures (400 and 900 °C) and its influence on the interaction of biochar with elastomers of different polarity, aiming at the replacement of carbon black in elastomer compounds, based on the rheometric, physical, chemical and mechanical properties. The biochar production temperature of 900 ºC affected the optimum vulcanization time (t90), with compounds containing NR and NBR having the shortest vulcanization times because temperatures above 400 ºC produce an alkaline biochar that accelerates vulcanization. The biochar interacted with the two elastomers, being superior to NBR due to the oxygen concentration. Therefore, the blends with biochar showed a demonstrated reinforcement of the tensile strength, even if the biochar had a surface area of 3 m2.g-1 for the observed irregular surface, in addition to the mechanical properties, analogous to the blends with carbon black.

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000100207&lng=en&tlng=en

49

scielo_articles/scl/1516-1439/S1516-14392023000100207.xml

scielo.br

scl

[ "ENGINEERING, CHEMICAL", "MATERIALS SCIENCE, MULTIDISCIPLINARY", "METALLURGY & METALLURGICAL ENGINEERING" ]

[ "Ribeiro, Willian B.", "Bérti, Giovani B.", "Faccio, Maíra", "Godinho, Marcelo", "Brandalise, Rosmary N." ]

null

[ "Interaction", "polarity", "biochar", "carbon black", "pyrolysis" ]

null

[ "Universidade de Caxias do Sul", "Universidade de Caxias do Sul" ]