Effect of Heat Treatment on Mechanical Properties of TC11 Titanium Alloy at Room Temperature

The microstructures and mechanical properties of TC11 titanium alloy by different heat treatments were studied through optical microscope, tensile property tests and impact tests. The results showed that the fluctuation of properties at room temperature of the edge of 280 mm bar was related to the friction and temperature dropping during hot working. When the solution temperature was increased from 940℃ to 970℃, the room temperature strength and plasticity obviously decreased. The strength decreased by about 50 MPa, and the relative value of the elongation about 8%. When solution temperature continued to rise to 980℃, the strength increased by about 30 MPa, and the elongation and the reduction of area improved compared with those of 970℃. The effect of ageing time on the mechanical properties of TC11 titanium alloy was not significant, but it had a significant effect on the impact at room temperature. When the ageing time increased from 4 h to 8 h, the spheroidization of microstructure was obvious, the number of the elongated primary α phase was significantly reduced, and the primary α phase and secondary α phase grew up, resulting in significant improvement in impact, increasing by 30. 4~33. 6 J, but the changes of tensile strength and plasticity at room temperature were not obvious.