Heterogeneous twin formation and its effect on tensile properties in Ti-Mo based β titanium alloys

The deformation modes and the tensile properties were investigated in a Ti-15Mo-5Zr alloy with different heat treatments. Both the {3 3 2}〈1 1 3〉 twinning and the dislocation slip occurred in the samples with the heterogeneous distribution of Mo and Zr atoms. On the other hand, the twinning disappeared when the elemental distribution became homogeneous. The high yield strength and significant uniform elongation resulted from the combination of the twinning and the slip, and the more significant work hardening rate was obtained by the enhancement of the twinning. The heterogeneous twin formation was mainly discussed based on the effects of the interval of heterogeneous elemental distribution and the grain orientation.