Achieving strong and ductile Ti-9Cr alloy with deformable TiCr2 nano-particles by direct energy deposition

Abstract

Due to the strong segregation of Cr, the content of Cr was restricted in the commercial titanium alloy to avoid β-flecks and deterioration of mechanical performance. Here, we prepared a homogeneous Ti-9Cr alloy with uniform distribution of Cr element by additive manufacturing technology. Fine α laths and dispersed TiCr2 nano-particles were acquired in the alloy, generating a high ultimate tensile strength of 1000 MPa with elongation of 16 %. It was demonstrated that the TiCr2 nano-particles showed a face-centered cubic structure. Stacking faults occurred on the {111} plane of the TiCr2 during deformation, which relieved local stress.