Transformation-induced plasticity and high strength in beta titanium alloy manufactured by selective laser melting

This work reports simultaneous achievement of high strength and large tensile ductility in a beta titanium alloy manufactured by selective laser melting (SLM). The SLM-produced samples present a unique microstructure and great mechanical behavior due to fast cooling in SLM process. Simultaneous improvement in yield strength (similar to 592 +/- 21 MPa), ultimate tensile strength (716 +/- 14 MPa) and ductility (37 +/- 5%) of SLM-produced sample results from the combination of fine columnar grains and sub-grains, strong texture and the transformation-induced plasticity (TRIP) and hard-wraps-soft effects. The large amount of sub-grain boundaries and strong texture delay the initiation of martensitic transformation in the SLM-produced sample, thereby increasing its yield strength.