Improvement of mechanical properties through inhibition of oxidation by adding TiC particles in laser aided additive manufacturing of stainless steel 316L

Abstract

Additive manufacturing has gained significant attention in recent years. However, oxidation is hard to be avoided especially for the directed energy deposition (DED) processes, which are normally operated in an open environment with inert gas shielding. Excessive oxidation will negatively affect the mechanical properties of the deposited materials. In this work, inhibition of oxidation was studied through adding TiC particles for laser aided additive manufacturing (LAAM) of stainless steel 316L. Notably, oxygen content can be reduced significantly, as TiC particles functioned as deoxidizers through chemical reaction with oxygen. Meanwhile, the large Si–Cr–Mn oxides can be changed into uniformly distributed fine TiO2 in the deposited stainless steel 316L. Consequently, ductility of the deposited stainless steel 316L was significantly improved by 54.1% with 5.6% increase in yield strength and 11.4% increase in ultimate tensile strength. This study shows a new way to overcome the negative effects of oxidation on the properties of the additively manufactured materials.