Improved mechanical properties of β metastable Ti alloys processed by laser powder bed fusion

Abstract

This study proposes a thorough investigation of the mechanical properties of two β metastable titanium alloys (Ti–12Mo and Ti-8.5Cr-1.5Sn (wt %)) processed by laser powder bed fusion. Particular emphasis is put on the influence of chemical homogenization and defects formation as a function of the processing parameters. It is demonstrated that the Transformation/Twinning – induced plasticity (TRIP/TWIP) mechanisms already revealed as beneficial in the case of wrought alloys, still bring a larger work hardening level and a larger ductility in the case of laser powder bed fusion (L-PBF) processing. Improved mechanical properties in terms of yield and ultimate tensile strengths with similar uniform deformation compared to the wrought counterparts are thus achieved after L-PBF and a very short annealing.