A new type metastable β titanium alloy Ti-B20 with high strength

According to the principle of 'critical moly equivalence and multicomponent strengthening', a new type metastable beta titanium alloy with high strength was designed, and the tensile properties at room temperature and microstructure on hot rolled bar (φ 12 mm - 20 mm) of this alloy under different heat treatment conditions were studied. Compared with traditional metastable β titanium alloys, it's ageing response is fast, the distribution of dispersion phase is uniform, the hardening effect is high and no precipitate-free regions have been found during high temperature ageing treatment. Solution treatment below beta transus followed by ageing is suitable for keeping high plasticity. In this case, excellent strength/plasticity properties can be achieved (UTS: 1200 MPa - 1500 MPa; EL: 8% - 18%) by 500°C -600°C aging treatment. However, much higher strengthening effect can be obtained by direct ageing on hot rolled bar.