Selective laser melting of stainless steel for biomedical applications

Abstract

Metal Additive Manufacturing (metal-AM) process has been used to produce biocompatible parts or prototypes for biomedical applications. Selective laser melting (SLM), which considerate a powder melt, layer by layer, and consolidated by a rapid solidification process, can be employed for the manufacture of the designed parts by a computer. In the biomedical industry, advances in the selection and application of metallic materials within the transformation industry have included titanium alloys, cobalt-based alloys, stainless steels, and nickel-titanium. ASTM F 138 austenitic stainless steel (special grade of 316L stainless steel) is the most common within of stainless steels, but its employed is limited to temporary implants, due to their localized corrosion with the permanent contact in body fluids, besides its low mechanical strength. So, a new class of austenitic stainless steels, with high nitrogen content, has been considered for this purpose, once it presents high mechanical strength and corrosion resistance, if compared to the previous material. The objective of this work is to employ the SLM in an austenitic stainless steel, considering a nitrogen atmosphere during its processing, to evaluate the element dissolution in the alloy and its influence on the microstructural and mechanical properties of the material. The work is based on research for optimized process parameters for fabrication of metal parts by SLM with suitable characteristics for future biomedical applications. (AU)