MARCELLO VERTAMATTI MERGULHAO

MARCELLO VERTAMATTI MERGULHAO

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Análise de amostras da liga de titânio Ti6Al4V impressas por FSL para ensaios de microfresamento
2019 - GONÇALVES, MARIA C.C.; MERGULHAO, MARCELLO V.; STOETERAU, RODRIGO L.; BATALHA, GILMAR F.; NEVES, MAURICIO D.M.
A fabricação de peças metálicas via impressão 3D tem ganhado destaque pela sua eficácia na manufatura de geometrias complexas e com pouco consumo de material. Uma das estratégias de sinterização utilizadas para impressão 3D é a Fusão Seletiva a Laser (FSL), que consiste na completa fusão dos pós metálicos por meio de um feixe laser. As peças obtidas por esse processo apresentam uma superfície com ondulações periódicas e anisotropias relacionadas à direção da sinterização. No entanto, o efeito dessa ondulação e da anisotropia das peças nas suas propriedades mecânicas e na sua usinabilidade é pouco conhecido. Visto isso, este trabalho visa examinar amostras da liga de titânio Ti6Al4V impressas por FSL, mediante análises de dureza, rugosidade e por microscópio óptico para ensaios de microfresamento.
Perspective of additive manufacturing selective laser melting in Co-Cr-Mo alloy in the consolidation of dental prosthesis
2018 - MERGULHAO, MARCELLO V.; PODESTA, CARLOS E.; NEVES, MAURICIO D.M. das
This chapter seeks to compare the properties of samples manufactured by additive manufacturing (AM) by the selective laser melting (SLM) technology and compare with the precision casting (PC) processes using the Co-Cr-Mo (ASTM F75) alloy to manufacture of dental prosthesis. This AM process can be manufactured three-dimensional models by means of a laser beam that completely melts particles of powder deposited layer by layer. However, it is still relevant to know the properties of: performance, dimensional, mechanical and microstructural of this laser melting process and compare with a convencional process. The results of mechanical evaluation showed that the SLM technique provides superior mechanical properties compared to those obtained by the PC technique. It is possible to verify that the consolidation by SLM technique results in lower presence of porosity than PC technique. In addition, PC samples presented a gross dendritic microstructure of casting process. Microstructural analysis of SLM samples results in a characteristic morphology of layer manufacturing with ultrafine grains and a high chemical homogeneity. In this way, the development of the present study evidenced to improve the manufacture of customized components (copings) using the SLM technology.
Investigation of mechanical, microstructural and thermal behavior of CoCrMo alloy manufactured by selective laser melting and casting techniques
2017 - MERGULHAO, MARCELLO V.; PODESTA, CARLOS E.; NEVES, MAURICIO D.M. das
A route of increasing development in additive manufacturing (3D printing) process using metal alloys is the selective laser melting (SLM). 3D building components is possible by laser power that completely melts the metal powder particles. SLM was applied in a biomaterial of CoCrMo alloy, to study the mechanical properties and microstructural characterization in comparison of the conventional technique – lost wax casting. The gas atomized powder was investigated by their physical (as apparent density, bulk density and flow rate) and chemical properties (X-ray fluorescence). Standard samples evaluated the mechanical properties as yield strength, elongation, elastic modulus, transverse rupture strength and the Vickers hardness. Microstructural characterization was performed using optical microscope (OM) and scanning electron microscope (SEM-EDS). Thermal analysis of CoCrMo alloy were investigated using thermomechanical analysis (TMA) and differential scanning calorimetry (DSC) techniques. The results of mechanical properties showed higher values in the SLM specimens compared with the obtained in the cast specimens. The micrographs revealed a typical morphology of consolidation process, characterized by selected layer used in the SLM technique and the dendrites arms in the casting technique. The thermal results confirm the phase’s transitions of CoCrMo alloy.
Characteristics of biometallic alloy to additive manufacturing using selective laser melting technology
2018 - MERGULHAO, MARCELLO V.; NEVES, MAURICIO D.M. das
Biomaterial powders are in high development due to expansion of additive manufacturing (AM) processes. Selective laser melting (SLM) is a particular AM technology, which completely melts a powder bed layer by laser beam. Investigations of appropriated physical properties of feedstock (powder alloy) were the aim of this study. Cobalt-chromium-molybdenum (Co-Cr-Mo) alloy was used to overview of gas-atomized powder properties in different granulometric ranges (D1 12 - 19 μm, D2 20 - 46 μm and D3 76 - 106 μm), as their: physical, chemical properties and thermal analysis. SLM manufactured standard tensile specimens of usually granulometric range powder size provided mechanical, chemical and thermal properties of biocompatible Co-Cr-Mo alloy. The physical properties showed that powders in the range of 20 to 50 μm provide a better flow ability and packed density, which are relevant characteristics to SLM processing. Manufacturing by SLM process provided suitable mechanical properties in the health area, as well as, maintained the biocompatible properties of the Co-Cr-Mo alloy.
Mechanical properties and microstructural characterization of Cobalt-Chromium (CoCr) obtained by casting and Selective Laser Melting (SLM)
2017 - MERGULHAO, MARCELLO V.; PODESTA, CARLOS E.; NEVES, MAURICIO D.M. das
The aim of this study is the consolidation of Cobalt-Chromium (CoCr) alloy powder using the additive manufacturing - selective laser melting (SLM) and the investment casting techniques. The research of this study has been applied to their biomaterial applied to development of prosthesis and dental implants. The gas atomized powder are spherical (mean diameter equal to 42,74 μm) and was analyzed by their physical and chemical properties. The microstructure of the powder and specimens was evaluated using optical microscope (OM) and scanning electron microscope with energy-dispersed X-ray spectroscopy (SEM-EDS). The mechanical properties were evaluated of standard samples using a tensile (yield strength, maximum tensile, rupture tensile and elongation), three point bending (transverse rupture strength) and micro hardness tests. The mechanical results indicate higher values for the SLM than casting specimens. The micrographs revealed a characteristic morphology of laser been used in the SLM technique and the dendrites in the casting technique. The microstructure of samples made by SLM is thinner than the samples obtained in the cast.
Valuation of mechanical properties and microstructural characterization of ASTM F75 Co-Cr alloy obtained by Selective Laser Melting (SLM) and casting techniques
2017 - MERGULHAO, MARCELLO V.; PODESTA, CARLOS E.; NEVES, MAURICIO D.M. das
Advances in processes using the powder metallurgy techniques are making this technology competitive compared to the other traditional manufacturing processes, especially in medicine area. The additive rapid prototyping technique – selective laser melting (SLM) was applied in a biomaterial of CoCrMoFe alloy (ASTM F75), to study the mechanical properties and microstructural characterization in comparison between the conventional technique – casting. The gas atomized powder was investigated by their physical (as apparent density, bulk density and flow rate) and the chemical properties. The powder was analyzed using scanning electron microscope with energy-dispersed X-ray spectroscopy (SEM-EDS) and X-ray fluorescence. Specimens of standard samples were manufactured using these techniques to evaluate the mechanical properties as uniaxial tensile (yield strength, rupture tensile and elongation), transverse rupture strength and the micro hardness. The mechanical properties showed higher values in the SLM specimens than the casting specimens. Before the mechanical tests the specimens were examined using optical microscope (OM) and SEM-EDS. The micrographs revealed a microstructure with finer morphology in the SLM technique and the dendrites in the casting technique.
Mechanical and microstructural evaluation of CoCr alloys manufactured via selective laser melting (SLM)
2016 - MERGULHAO, M.V.; PODESTA, C.E.; NEVES, M.D.M. das
Dental prosthesis components are widely produced with CoCr alloys. New near net shape techniques has been used nowadays as an alternative route. The aim of this study was evaluated the mechanical properties and the microstructural characterization of CoCr dental alloys manufactured by SLM and to investigated the correlation of chemical composition between mechanical properties of standard specimens. The tensile specimens was manufactured by SLM technique in standard dimensions by two different composition of CoCr dental alloy and were chemical analyzed using scanning electron microscope with energy-dispersed X-ray spectroscopy (SEM-EDS) and X-ray fluorescence. The mechanical properties as uniaxial tensile (yield strength, maximum tensile, rupture tensile, elongation and elastic modulus) and Vickers hardness were evaluated. The microstructure of the samples were characterized using optical microscope (OM) and SEM-EDS. The mechanical results indicate higher values for both composition of CoCr alloys fabricated via SLM technique. The micrographs revealed a characteristic morphology of layer used in the SLM technique. Keywords: CoCr alloys, selective laser melting, biomaterial, dental prothesis.
Mechanical properties and microstructural characterization of Cobalt-Chromium (CoCr) sintered obtained by casting and Selective Laser Sintering (SLS)
2015 - MERGULHAO, MARCELLO V.; PODESTA, CARLOS E.; NEVES, MAURICIO D.M. das
The aim of this study is the consolidation of Cobalt-Chromium (CoCr) alloy powder, using the additive rapid prototyping technique by selective laser sintering (SLS) and the conventional technique casting. The research of this study have been applied for this biomaterial to the development of prosthesis and dental implants. The gas atomized powder was analyzed by their physical and chemical properties. The mechanical properties as uniaxial tensile, three point bending and micro hardness were evaluated of standard samples manufactured by SLS and casting technique. The microstructural characterization were examined using optical microscope (OM) and SEM-EDS. The micrographs revealed a characteristic morphology of layer used in the SLS technique and the dendrites in the casting technique.
Comparison of mechanical properties and microstructural characterization of CoCrMo alloy obtained via selective laser melting (SLM) and casting technique
2016 - MERGULHAO, M.V.; PODESTA, C.E.; NEVES, M.D.M.
Advances in processes using the powder metallurgy techniques are making this technology competitive compared to the other traditional manufacturing processes, especially in medicine area. The additive manufacturing technique – selective laser melting (SLM) was applied in a biomaterial of CoCrMo alloy (ASTMF75), to study the mechanical properties and microstructural characterization in comparison between the conventional technique – lost wax casting. Yet there is an important knowledge of performance properties, dimensional, mechanical and microstructural of this sintered alloy compared to casting, as reported recently (MERGULHÃO et al., 2015a, 2015b; PODESTÁ et al., 2015). The aim of this study is to demonstrate the mechanical properties and microstructures of specimens manufactured by powder metallurgy techniques using the SLM, using the Co-Cr-Mo alloy in the form of particulate matter.
Evaluation of mechanical properties and microstructural characterization ASTM F75 Co-Cr alloy obtained by Selective Laser Sintering (SLS) and casting techniques
2015 - MERGULHAO, MARCELLO V.; PODESTA, CARLOS E.; NEVES, MAURICIO D.M. das