多晶纯钛在高应变率不同温度下的拉伸力学行为实验研究

利用MTS809和自行研制的旋转盘冲击拉伸试验机,对多晶纯钛进行了应变率为0.001s-1和300s-1、温度为298K至973K的拉伸试验和应变率为300 s-1不同温度下的冲击拉伸复元试验,得到了多晶纯钛的拉伸应力应变曲线和高应变率等温应力应变曲线。试验结果表明,多晶纯钛的拉伸力学行为具有应变率和温度相关性。采用修正的Johnson-Cook模型进行数值拟合,结果表明,该本构模型能较好地表征多晶纯钛在试验应变率和温度范围内的拉伸力学行为。

Experimental Study on Tensile Properties of CP-Ti at High Strain Rate and Different Temperatures

Quasi-static and dynamic monotonic tensile experiments and loading-unloading tests were performed on MTS809 testing machine and self-designed rotating disk impact apparatus, respectively. Tensile stress-strain curves at strain rates of 0.001 s^-1 and 300 s^-1, and isothermal stress-strain curves at a strain rate of 300 s^-1 were obtained within a wide temperature range from 298K to 973K. Experimental results indicate that the tensile properties of CP-Ti are dependent on strain rate and temperature. A modified constitutive model based on Johnson-Cook model was used to describe the tensile behavior of CP-Ti. The simulation results are in good agreement with the experimental ones.