工业纯钛ECAP温变形的力学性能及热稳定性

Mechanical Properties and Thermal Stability of CP-Ti Processed by ECAP at Intermediate Temperature

采用两通道夹角Φ=90°,外圆角Ψ=20°的模具,成功实现了工业纯钛BC方式6道次ECAP温变形,累积等效真应变达到约6.3,制得ECAP温变形试样后,对各道次ECAP温变形后的工业纯钛进行压下量为55%的冷轧变形。同时,观察分析了变形试样的显微组织及性能,并对各道次ECAP温变形试样的热稳定性进行研究。结果表明,经过6道次ECAP变形后,工业纯钛的抗拉强度达到760 MPa,伸长率为40%。当退火温度低于400℃时,ECAP变形试样的组织变化不大,显微硬度下降缓慢;当退火温度高于400℃时,由于发生了再结晶,显微硬度显著下降。

ECAP at intermediate temperature with rout BC was successfully processed to six passes in commercial pure titanium（CP-Ti） using a die with the internal angle Φ of 90° and outer curvature angle Ψ of 20°.The equivalent strain is about 6.3.At the end of the trial after intermediate temperature ECAP,the cold-rolling deformation of the samples was carried out at the reduction of 55%.Meanwhile,the deformation specimens＇ microstructure performance and the effect of passes and annealing temperature on the microstructure and mechanical properties were investigated.Moreover,the ultimate tensile strength（UTS） of CP-Ti is over 760.5 MPa and its elongation is up to 40%.When the annealing temperature is below 400 ℃,the microhardness slightly decreases,but its microstructure changes little.When the annealing temperature is over 400 ℃,because the dislocation density decreases through recovery and causes re-crystallization,and the microhardness decreases markedly.