Fabrication and characterization of a novel beta metastable Ti-Mo-Zr alloy with large ductility and improved yield strength

In this paper, a novel ternary beta-metastable titanium alloy, Ti-12Mo-5Zr (wt%), was designed based on the d electron alloy design theory. The Ti-12Mo-5Zr alloy displays excellent combination of improved yielding stress (> 650 MPa), high ductility (uniform elongation approximate to 30%) and work-hardening behaviour. The detailed micro structural analysis indicates that the superior performances arise from the synergic effects between phase transformation induced plasticity (TRIP) and twinning induced plasticity (TWIP). Conforming to the design strategy, the improvement of mechanical performance results from the addition of Zr alloying element in substituting Ti, attributing to solution hardening effect and the increasing of critical resolved shear stress (CRSS) of stress induced martensitic transformation (SIM alpha'').