Corrosion behavior of selective laser melted biomaterials in a physiological environment

Abstract

Medical applications are today the most important areas that use additively manufactured parts. The choose of the convenient biomaterial during implant design depends on several criteria such as biocompatibility, osteointegration and processing cost. The purpose of this work is to compare the corrosion behavior of AISI 316L austenitic stainless steel and Titanium TiAl6V4 orthopedic implants manufactured by selective laser melting. For each material the process parameters were varied to obtain comparable surface states mainly evaluated by microgeometric quality and porosities distribution. The electrochemical interaction between biomaterial and the physiological environment was simulated by corrosion tests performed in a Ringer type solution. From the obtained results it can be seen that selective laser melted Titanium TiAl6V4, despite its higher roughness, exhibits the highest corrosion resistance compared to AISI.316L stainless steel samples. In fact, for comparable porosities distribution density, enhanced corrosion properties, such as corrosion rate, pitting potential (Epp) and corrosion potential (Ecorr) were achieved for Titanium alloy.