ω phase strengthened 1.2GPa metastable β titanium alloy with high ductility

This paper provides a novel approach for exploiting omega phase strengthening in a metastable beta titanium alloy while retaining high ductility. The addition of I wt% Fe into our previously designed Ti-7Mo-3Cr alloy can efficiently control the growth of omega phase following air-cooling, resulting in a ultrahigh yield strength (R-p0.2 of 1210 MPa) with large ductility (epsilon(f) of 0.15). Microstructural analysis of deformed alloys showed that the growth of omega phase in the air-cooled Ti-7Mo-3Cr-1Fe alloy modified the deformation mechanism from {332} twinning and dislocation slip, in the water-quenched alloy, to localized dislocation plasticity in omega-void channels. (C) 2018 Published by Elsevier Ltd on behalf of Acta Materialia Inc.