(1. 中国科学技术大学 力学和机械工程系，合肥 230027；
2. 中国科学院 中国科学技术大学 材料力学行为和设计重点实验室，合肥 230027；
3. 深圳大学 土木工程学院，深圳 518060)
摘 要:
关键字: 纯钛；孪晶变形；动态拉伸；高温
（1. Department of Mechanics and Mechanical Engineering, University of Science and Technology of China, Hefei 230027, China;
Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230027, China;
3. College of Civil Engineering, Shenzhen University, Shenzhen 518060, China）
Abstract:The influences of temperature and strain rate on the deformation twinning of polycrystalline titanium were studied by tensile experiments in a temperature range of 298−973 K and a strain rate range of 0.001−1 400 /s. The tests at elevated temperatures and high strain rates were carried out using a modified split Hopkinson tension bar apparatus. The experimental results show that deformation twinning is dependent on both temperature and strain rate. The density of deformation twinning increases with increasing test strain rate. However, it decreases with increasing test temperature. A constitutive model based on the dislocation kinetics and twinning effect was used to describe the stress-strain relationship of commercially pure titanium (CP-Ti) at the investigated temperatures and strain rates. The simulated results show that the model can well describe the stress-strain relationship of CP-Ti in tensile deformation.
Key words: polycrystalline titanium; deformation twinning; dynamic tension; elevated temperature
