粉末冶金TA15钛合金的高温塑性变形行为

High temperature plastic deformation behavior of powder metallurgic TA15 titanium alloy

利用Gleeble-1500热模拟机对粉末冶金TA15钛合金的高温变形行为进行研究，求得该材料的变形激活能，并建立本构方程。实验条件为温度850~1050℃、应变速率0.001~10 s？1、最大变形量60%。结果表明：粉末冶金 TA15钛合金的流变应力随变形温度升高和应变速率降低而减小。材料在β相区的变形激活能为245.57 kJ/mol，发生动态回复；在（α＋β）相区激活能为945.69 kJ/mol，远高于纯钛的扩散激活能，也高于相同成分的常规熔炼的TA15钛合金的变形激活能。热变形机制受动态再结晶行为影响。

The hot deformation behaviors of P/M TA15 alloy in the temperature scope of 850~1 050℃, with strain rates of 0.001~10 s？1 and maximum deformation of 60% were investigated using Gleeble-1500 thermal simulation test machine. The deformation activation energy of this alloy was calculated and the constitutive equation was obtained. The results show that the true stress of hot deformation of P/M TA15 alloy increases with decreasing deformation temperature and increasing strain rate. The deformation activation energy is 245.57 KJ·mol？1 inβphase region, which reveals that the main softening mechanism is dynamic recovery in β phase region. the deformation activation energy of （α＋β） phase region is 945.69 KJ·mol？1, far higher than the diffusion activation energy of pure titanium, also higher than the deformation activation energy of conventional melting TA15 alloy, which shows that the hot deformation is associated with dynamic recrystallization.