Selective laser melting of CP-Ti to overcome the low cost and high performance trade-off

Abstract In this study, commercially pure titanium (CP-Ti) parts were successfully fabricated by selective laser melting (SLM) using cost-effective hydride-dehydride (HDH) Ti powders for the first time modified by jet milling. Jet milling effectively improves the particle-shape sphericity, suppresses the impurity pick-up, and produces localized plastic deformation. The flowability of the jet-milled powders is tremendously improved to 29.7 s/50 g that satisfies the SLM processing well, while the oxygen content only increases by 0.02 wt.% (the raw oxygen level: 0.15 wt.%). The oxide layer in the powder surface is determined with the thickness of ∼8 nm and TiO being the predominant phase before and after jet milling. The SLM-made (SLMed) CP-Ti achieves dominant martensitic α’ phase with the fracture tensile strength up to 731.5 ± 5.7 MPa and elongation of 20.5 ± 1.1 %, comparable with those using expensive atomized powders. Contrary to the conventional metallurgical mechanism for Ti which suffers the cost-performance dilemma, this work presents SLMed CP-Ti with excellent synergy of strength and ductility while using the cost-affordable HDH Ti powders.