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

• DOI: 10.1016/j.scriptamat.2018.10.043
• Publication Date: 2018-11-07T16:59:14Z
• Authors: Junheng Gao; Alexander J. Knowles; Dikai Guan; W. Mark Rainforth
• Keywords: Metastability; Ductility (Earth science); Void (composites); Titanium alloy

This paper provides a novel approach for exploiting ω phase strengthening in a metastable β titanium alloy while retaining high ductility. The addition of 1 wt% Fe into our previously designed Ti-7Mo-3Cr alloy can efficiently control the growth of ω phase following air-cooling, resulting in a ultrahigh yield strength (Rp0.2of 1210 MPa) with large ductility (εf of 0.15). Microstructural analysis of deformed alloys showed that the growth of ω 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 ω-void channels.