CARLOS EDUARDO PODESTE

CARLOS EDUARDO PODESTE

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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.
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.
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.