MAURICIO DAVID MARTINS DAS NEVES

MAURICIO DAVID MARTINS DAS NEVES

(Fonte: Lattes)

Resumo

Graduate at Engenharia Metalúrgica from Centro Universitário da FEI (1982), graduate at Engenharia Civil from Universidade Guarulhos (1998), master's at Mechanical Engineering from Universidade Estadual de Campinas (1986) and PhD at Tecnologia Nuclear Materiais from Universidade de São Paulo (2005). Has experience in Material and Metallurgical Engineering, focusing on Welding, Powder Metallurgy and Additive Manufacturing , acting on the following subjects: welding, microstructure, and powder metallurgy. Is currently a professor of the graduate program at the University of São Paulo. Currently been active in the mechanical and microstructural behavior of metallic biomaterials processed by casting, machining or by powder metallurgy.and additive manufacturing. Published 4 book chapters, 42 articles in specialized journals and 126 works in the annals of events. It has 10 technological products, processes or techniques, 1 with registration. In terms of guidelines completed or in progress, there are 15 master's dissertations and 5 doctoral theses, in addition to supervising 13 scientific initiation works and 22 course completion works in the areas of Mechanical Engineering and Materials / Metallurgical and Civil Engineering. In the last 20 years he participated in 3 research projects and 14 technological development projects. Provides technical consultancy and teaches courses on industrial processes in companies. Participated in several processes of technology transfer to the industry and in several technological developments in partnerships with numerous companies. (Text obtained from the Currículo Lattes on November 17th 2021)

Possui graduação em Engenharia Metalúrgica pelo Centro Universitário da FEI (1982), graduação em Engenharia Civil pela Universidade Guarulhos (1998), mestrado em Engenharia Mecânica pela Universidade Estadual de Campinas (1986) e doutorado em Tecnologia Nuclear- Materiais pelo Instituto de Pesquisas Energéticas e Nucleares (IPEN) da Universidade de São Paulo (2005). Foi pesquisador do IPEN de 1984 até 2018. Iniciou funções de Professor na Faculdade de Engenharia Industrial (FEI) em fevereiro de 1992, encerrando-as em junho de 2020 na disciplina de Soldagem e Estruturas de construção Metálica. Atualmente é professor e orientador credenciado do programa de pós-graduação do Instituto de Pesquisas Energéticas e Nucleares / Universidade de São Paulo e pesquisador voluntário da Comissão Nacional de Energia Nuclear. Tem experiência na área de Engenharia de Materiais/ Metalúrgica, com ênfase em materiais metálicos nos processamentos envolvendo: Soldagem, Metalurgia do Pó e Manufatura Aditiva, além de em caracterização microestrutural e mecânica de componentes fabricados por estas técnicas. Tem atuado na área de processamento, comportamento mecânico e caracterização microestrutural de biomateriais metálicos. Atua na área de ensino e projeto de estruturas metálicas na construção civil. Publicou 4 capítulos de livros, 42 artigos em periódicos especializados e126 trabalhos em anais de eventos. Possui 10 produtos tecnológicos, processos ou técnicas, sendo 1 com registro. Em termos de orientações concluídas ou em andamento são 15 dissertações de mestrado e 5 teses de doutorado, além de ter orientado 13 trabalhos de iniciação científica e 22 trabalhos de conclusão de curso nas áreas Engenharia Mecânica e Engenharia de Materiais/Metalúrgica e Civil. Nos últimos 20 anos participou de 3 projetos de pesquisa e 14 projetos de desenvolvimento tecnológico. Presta consultoria técnica e ministra cursos sobre processos industriais em empresas. Participou de diversos processos de transferência tecnológica à indústria e de diversos desenvolvimentos tecnológicos em parcerias com inúmeras empresas. (Texto extraído do Currículo Lattes em 17 nov. 2021)

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Tribo-corrosion evaluation of Electron Beam Melting Ti6Al4V-ELI for biomedical applications
2023 - NEVES, M.D.M. das; SILVA, L.C.E.; ANTUNES, R.A.; AGUA, F.P. da; PAZ, J.O. da; PIERETTI, E.F.
Biomaterials surfaces need to be adequate to the function they perform; for this reason, the importance of studying surface finish increases as design requirements grow, regarding geometry and precision requirements in bioengineered materials. These biomaterials are subject to several types of premature failure, such as wear, fatigue, micro movements, particle detachment and degradation, which may generate the need for new interventions [1]. Titanium alloys have been widely used in the production of biomaterials due to their high physicochemical stability, mechanical resistance and biocompatibility. Currently, a route widely used on the implants production is the additive manufacturing using Selective Laser Melting (FSL) technology and Electron Beam Melting (EBM). The surfaces built by these technologies are covered with a certain amount of adhered material, which is partially melted on its surface, being a disadvantage in melting techniques using a bed of particulate materials, where a very smooth and low roughness surface cannot be achieved [2]. Additionally, surface characteristics are still influenced by the process parameters used in consolidation, in particular: power, speed, movement directions of the laser beam and other parameters. The objective of this work was to evaluate the tribological and corrosion behavior of electron beam melting Ti6Al4V samples. Titanium alloy samples was produced with Ti6Al4V-ELI (extra low interstitials) powder by electron beam melting technique, at 5 differrent speed parameters. Confocal microscopy was also used to evaluate samples roughness and topography. The tribo-corrosion tests were carried out during 10 min, solid spheres of 52- 100 chrome steel, with 10 mm in diameter, were used as counter-bodies. The electrolyte used to simulate body fluids was Ringer´s solution at 37ºC. Current density and open circuit potential versus time were monitored throughout the test. There is a tendency towards an increase in friction force values according to the surface topography. The results indicated that the tribo-corrosion behavior is influenced by the Ti6Al4V-ELI surfaces finishing, and the wear rate is dependent of the normal force and the roughness of each sample; which is closely linked to the change in the speed parameters used in the preparation of the samples. Therefore, it is necessary to constantly advance research on the use of electron beam melting for biomaterials surfaces produced with titanium powder alloys.
Study of corrosion resistance of Lean Duplex Stainless Steel 2101 welded by the Gas Tungsten Arc Welding Double Fusion (GTAW-DF) process for use in the citrus juice industry
2024 - BUGARIN, A.F.S.; VIVEIROS, B.V.G.; TERADA, M.; RIBEIRO, G.L.X.; GUILHERME, L.H.; NEVES, M.D.M.; COSTA, I.
This work aims to investigate the influence of optimized welding parameters on the corrosion performance of the lean duplex stainless steel (LDSS) UNS S32101. The correlation between microstructure and electrochemical behavior of the fusion line (FL) and fusion zone (FZ) has been investigated. In the study, six welded samples were manufactured with different welding parameters, specifically the welding current, travel speed and heat input. A mini-cell and Syringe Cell were used to characterize the electrochemical behavior of the different welded zones by means of the double loop electrochemical potentiokinetic reactivation test (DL-EPR) and potentiodynamic polarization tests. The results showed that the welding parameters tested in this study significantly affected the corrosion resistance of the LDSS UNS S32101. The heat-affected zone (HAZ) was the most susceptible zone to localized corrosion and the specific region most affected by corrosion process was that of the LDSS UNS S32101 adjacent to the FL.
Corrosion analyses of anodized aluminum for biomedical purposes
2023 - PIERETTI, EURICO F.; NEVES, MAURICIO D.M.; CORREA, OLANDIR V.; ANTUNES, RENATO A.; OLIVEIRA, MARA C.L.; PILLIS, MARA C.L.
Introduction and objective: Anodic aluminum oxide has attracted a lot of interest due to the regular arrangement of nanopores, ease of control of the nanopores diameter, large specific surface area, low cost, good thermal stability, absence of toxicity and biocompatibility. The geometric arrangement of nanopores makes it possible to use alumina as a mold for the synthesis of various nanostructures, such as nanopores, nanotubes, nanorods and nanowires that have many advantages in advanced application areas due to their unique chemical, physical, mechanical, and optical properties [1,2]. The objective of this work was to study the corrosion susceptibility of anodized aluminum samples for biomedical applications. Methodology: In the present work, the localized corrosion resistance of AA6061aluminum alloy anodized in oxalic acid solution (C2H2O4) and sulfuric acid (H2SO4) was evaluated by electrochemical techniques. Prior to the anodization stage, the samples were electrolytically polished in a solution of perchloric acid and ethanol. Results and discussion: All samples showed a protective behavior on their surfaces, higher corrosion potentials in relation to the standard reference sample and a shift towards lower values of corrosion current densities in relation to the sample without passivation treatment. These results indicate that the anodizing treatments of AA6061 aluminum surfaces in oxalic or sulfuric acid are effective in producing surfaces resistant to localized corrosion and can therefore be used to coat this type of surface, ensuring an increase in the useful life of the devices. Conclusions: The results indicated superior corrosion resistance in the anodized samples in both conditions. Therefore, it is necessary to constantly advance research on the use of nanoporous anodic alumina coatings on biomaterials surfaces.
Surface investigation of a laser etched metallic biomaterial
2023 - PIERETTI, EURICO F.; NEVES, MAURICIO D.M.; CORREA, OLANDIR V.; ANTUNES, RENATO A.; OLIVEIRA, MARA C.L.; PILLIS, MARINA F.
Introduction and objective: Surface treatments are used to improve characteristics, such as: markings, texturing and polishing. The texturizations are produced to provide roughness and, consequently, adherence in specific locations of implantable medical devices of permanent character, that is, implants of prolonged use. Sometimes this process can generate stress concentrators and regions with probability for the occurrence of failures that can lead to fracture; in addition to damaging the passive layer, favouring the initiation of various forms of corrosion [1]. This work aims to evaluate the effect of the laser beam texturing technique in metallic implants on the corrosion resistance of ASTM 316L stainless steel. Methodology: Samples were prepared from the stainless steel textured by fiber optic laser doped with ytterbium (Yb) by changing the values of the frequency of the laser pulse cadence and keeping the other parameters constant. As a comparison, samples of the biomaterial without any type of laser treatment were also evaluated. The electrochemical tests performed consisted of open circuit corrosion potential (OCP) monitoring and cyclic potentiodynamic polarization measurements, determined after hours of immersion at 37°C body temperature. The scanning vibrating electrode electrochemical technique (SVET) was used as a tool to determine the corrosion current density in 0.1M NaCl solution. Results and discussion: The results obtained revealed the highest anodic current densities in the regions engraved by the laser beam and cathodic current densities in the regions farthest from the engravings, which indicates that laser engraving, in addition to increasing the roughness of the surfaces, makes them essentially anodic, changes the passive layer, affects the distribution of corrosion current densities and decreases the resistance to localized corrosion of this biomaterial. Conclusions: The change in the laser pulse frequency values is directly related to the behaviour observed on the analysed surfaces, indicating that the laser texturing treatment affects the passive layer of the material decreasing the resistance to localized corrosion.
Magnetic properties evaluation of 316L stainless steel produced by additive manufacturing for biomedical use
2023 - PIERETTI, EURICO F.; BONANI, EDUARDO G.; NEVES, MAURICIO D.M.; ANTUNES, RENATO A.; MARTIN, RAMON V.
Introduction and objective: The modern additive manufacturing (AM) techniques represent the current state of the art of industry 4.0. Advanced selective laser melting techniques allow the production of parts with the most varied sizes, shapes and complex geometries, which would be difficult to obtain previously with casting, joining, machining, among others. In addition to saving material, they are automated, do not generate wear to the tooling and little waste. The durability of surgical instruments, implants, and prostheses with this type of manufacturing can be considered greater than that using conventional methods with cutting tools [1]. Austenitic stainless steels have been widely used for the manufacture of implants due to their good mechanical and electrochemical properties and their relative low cost. The present work evaluated the variation of some laser beam conditions, regarding the magnetic susceptibility in AISI 316L stainless steel samples produced by additive manufacturing (AM). Methodology: The magnetic susceptibility of AISI 316L stainless steel was measured on samples produced by selective laser melting (SLM), in the dimensions: (12 x 35 x 3) [mm], layer thickness: 30 [μm], power: 53, 73, 93, 132 [W] and scanning speed: 800, 900, 1000, 1100 [mm/s]; seeking to meet requirements of: adequate surface finish, i.e. low roughness, high density (with low porosity index), according to the standard for metallic materials obtained by additive manufacturing (ASTM F3122-14). Results and discussion: This occur because there is a microstructural transformation of the austenitic steel surface from the temperature increase generated by the laser beam energy. As the austenitic phase is paramagnetic, but the altered phase is ferromagnetic, a magnetic method was used to identify this transformation. The amount of altered material is tiny, and so the magnetic method must be extremely sensitive. To this end, a device like a susceptibility balance was set up. The use of an analytical balance allowed the measurement of this transformation with acceptable uncertainties. Conclusions: The powder metallurgy production process using selective laser melting induced the formation of magnetic phases on the surfaces of the evaluated samples, resulting in small but significant changes in the magnetic susceptibility values.
Biotribological characterization of laser textured Ti6Al4V produced by addictive manufacturing
2023 - PIERETTI, E.F.; OLIVEIRA, M.C.L.; ANTUNES, R.A.; RIBEIRO, M.S.; NEVES, M.D.M.
Tribological characterization of nanoporous anodized anodic alumina coatings for biomedical applications
2023 - PIERETTI, E.F.; CORREA, O.V.; NEVES, M.D.M.; OLIVEIRA, M.C.L.; ANTUNES, R.A.; PILLIS, M.F.
Fracture toughness of vacuum sintered AISI M3:2 high speed steels
2023 - SILVA JUNIOR, MOISES E. da; SILVA, WANDERSON S. da; NEVES, MAURICIO D.M. das; GOLDENSTEIN, HELIO; ARAUJO FILHO, OSCAR O. de
The aim of this investigation was to study and evaluate the fracture toughness (KICV) of an AISI M3:2 high speed steel that was prepared by powder metallurgical processing, which consisted of uniaxial cold compaction of irregularly shaped water atomized powders, without and with 0.3% of carbon in the form of graphite, followed by vacuum sintering to obtain compacts with densities close to its theoretical value. The sintered steels were then hardened by austenitizing, quenching and triple tempering. Chevron fracture toughness test samples were prepared from the compacts and the tests conducted to determine KICV. The microstructures of the specimens were examined by scanning electron microscopy (SEM), and the composition of the phases determined by x-ray diffraction analysis (XRD). The sizes of the primary carbides and of the austenite grains were determined using Quantikov digital analysis software. No significant difference in fracture toughness (KICV) between the two high speed steels AISI M3:2, austenitized at the different temperatures, was observed.
Residual stress and fracture toughness study in A516 Gr70 steel joints welded and repaired by arc processes
2023 - BARROS, REGIS de M.C. de; NEVES, MAURICIO D.M. das
Structural components made of steel are used in several areas and require welding for assembly. In some situations, repair of the weld bead, also performed by electric arc welding, can be used to correct, and eliminate any discontinuities. However, electric arc welding causes the presence of residual stresses in the joint, which can impair its performance and not meet specific design requirements. In this paper, welded joints made of ASTM A 516 GR 70 steel plates, with a thickness of 30.5 mm, welded by the MAG—Metal Active Gas process (20% CO2) and using a “K” groove were analysed. The joints were manufactured with seven welding passes on each side of the groove. After welding, one batch underwent repair of the bead by TIG welding (Tungsten Insert Gas) and another batch underwent two repairs by TIG welding. Were presented results of the behaviour of the residual stress profile measured by X-ray diffraction and the Vickers microhardness profile in the joints as well the fracture toughness in the conditions only welded and submitted to repairs. The results indicated that the greater number of repair passes reduced the residual compressive stress values obtained in the material manufacturing process and caused a stabilization on the Vickers hardness values. It was concluded that compressive residual stresses did not play a major role in the R-curve results. The presence of discontinuities in the welded joint caused greater influence on the behaviour of the R curve.
Syringe cell method to study the corrosion resistance of the UNS S32101 lean duplex stainless steel welded by the gas tungsten arc welding double fusion (GTAW-DF)
2023 - BUGARIN, ALINE de F.S.; VIVEIROS, BARBARA V.G. de; TERADA, MAYSA; GUILHERME, LUIS H.; NEVES, MAURICIO D.M. das; COSTA, ISOLDA
This work aims to investigate the corrosion performance of the UNS S32101 lean duplex stainless steel (LDSS) welded by the gas tungsten arc welding double fusion (GTAW-DF). In the study, six welded samples were manufactured with different welding parameters. A Syringe cell was used to characterize the electrochemical behavior of the different welded zones by potentiodynamic polarization tests in NaCl 3,5 % (w.t.) and in a solution of citric acid with addiction of NaCl to simulate the food industry. The results showed that the welding parameters tested significantly affected the corrosion resistance of the LDSS UNS S32101. Besides, a correlation was stablished between microstructure and electrochemical behavior of fusion line (FL), heat affected zone (HAZ) and fusion zone (FZ).