Effect of TaC on microstructure and mechanical properties of 316L stainless steel by selective laser melting

Abstract

Selective laser melting (SLM) is a rapid processing technology used to directly manufacture metal terminal components. TaC is often utilized to enhance mechanical properties of metal due to its excellent performance. In this study, SLM was employed to manufacture TaC/316 L composites with varying TaC volume content. The effect of TaC content on the microscopic appearance and mechanical properties of SLM-316 L stainless steel was then explored. The TaC admixture was efficiently and effectively distributed on 316 L powder particle surfaces using short-duration high energy ball milling. Under the optimal parameters for SLM, the relative densities of the specimens reached over 99.0% because of the high wettability of 316 L with TaC. Moreover, grain refinement was observed after microstructural analysis due to interactions between the TaC and 316 L. Tensile, Charpy impact, and microhardness tests demonstrated that the adjunction of 0.5 vol% and 1.5 vol% TaC provided a significantly enhanced yield strength (increased by 7.4% and 30.9%), ultimate tensile strength (increased by 5.6% and 27.1%), and microhardness (increased by 9.9% and 22.7%). The impact toughness (reduced by 20.3% and 51.4%) and ductility (reduced by 23.1% and 39.5%) were maintained.