The effects of temperature and strain rate on the mechanical properties of TC4 titanium alloy

Abstract To analyse the effect of temperature and strain rate on the uniaxial tensile mechanical properties of TC4 titanium alloy, quasi-static tensile tests were conducted on TC4 titanium alloy at different temperatures and strain rates. The results indicate that at 77 K, the strength and plasticity of TC4 exhibit synergistic enhancement, with increased anisotropy. At 77 K, the yield strength and tensile strength in the RD and TD directions increased by 41.33% and 42.41%, and 35.88% and 35.31%, respectively, compared to room temperature. The ratio of yield strength to tensile strength in the RD and TD directions decreased by 4.28% and 5.34%, respectively, compared to room temperature. As the strain rate decreases, both strength and ductility decrease. When the strain rate decreases from 5×10 −2 s −1 to 5×10 −4 s −1 , the yield strength and tensile strength decrease by 7.46% and 7.16%, respectively, and the elongation decreases by 1.3%. In the variable strain rate experiment, the tensile strength at 77 K was 521.08 MPa higher than at room temperature, while plasticity decreased by 6.38%. The stress differences between room temperature and 77 K before and after the variable strain rate were 29.99 MPa and 28.21 MPa, respectively. Additionally, the activated volume decreased significantly with decreasing temperature, with activated volumes of 29.99 m 3 /b 3 and 7.79 m 3 /b 3 at 293 K and 77 K, respectively. The activated volume at 293 K was 3.85 times that at 77 K.