Achieving Ti6Al4V alloys with both high strength and ductility via selective laser melting

Abstract

Improving the ductility of manufactured Ti-based alloys by selective laser melting (SLM) while still maintaining the high mechanical strength is one of the major challenges in additive manufacturing. In this work, a systematic investigation on the process parameters for achieving such a material is performed. By employing the optimal parameters during SLM, the fabrication of strong and ductile Ti6Al4V alloys was achieved. The ultimate tensile strength of SLM-built Ti6Al4V alloy was measured as 1170 MPa, while the elongation to failure remained over 10%. Through analysis of the microstructure and mechanical properties of the SLM-built Ti6Al4V alloy, it was found that the process parameters play an essential role in the tensile behavior, in particular the ductility of SLM-built Ti alloy. The considerable enhancement of the mechanical properties in our work is mainly attributed to the limitation of martensite formation and the minimization of pores.