Ti_3Al基合金的热变形行为及本构方程  

Hot deformation behavior and constitutive equation of Ti_3Al-based alloy

作　　者：梁培新[1] 翟月雯[1] 刘桂华[1] 钟志平[1] 

机构地区：[1]北京机电研究所,北京100083

出　　处：《塑性工程学报》2017年第2期174-178,共5页Journal of Plasticity Engineering

基　　金：国家国际科技合作专项资助项目(2015DFA51740)

摘　　要：采用DDL50高温电子万能试验机对Ti_3Al基合金进行等温恒应变速率拉伸试验,研究了该合金在热变形温度900~1020℃,应变速率2×10^(-4)~2×10^(-2)s^(-1)范围内的高温热变形行为。结果表明:Ti_3Al基合金的流变应力在应变速率一定时,随温度的升高而减小,在温度一定时,随应变速率的升高而增大,流变应力在达到峰值后开始逐渐降低,呈软化现象;应变速率越高,Ti_3Al基合金的软化越明显。依据高温拉伸试验得到的真应力-真应变曲线关系,计算得出了Ti_3Al基合金热变形激活能为472.7992 k J·mol^(-1)。建立了Ti_3Al基合金热变形的双曲正弦形式的本构方程和Zener-Hollomon参数方程。The flow stress of Ti3Al-based alloy was investigated at the temperature of 900-1020 ℃ and strain rate of 2 × 10^-4-2 × 10^-2s^-1by isothermal constant strain rate tensile test on DDL50 high temperature electronic universal testing machine. The result shows that the flow stress decreases with the increasing temperature when the strain stress is constant. And the flow stress rises with the increasing strain rate when the deformation temperature is constant. The flow stress begins to decrease gradually after reaching the peak,showing a softening phenomenon. The higher the strain rate is,the more obvious the softening of Ti3Al-based alloy is. According to the true stresstrue strain curve obtained by the tensile experiment and high temperature,the deformation activation energy Q was calculated to be472. 7992 k J·mol^-1. The hyperbolic sine constitutive equation and Zener-Hollomon parameter equation of Ti3Al-based alloy were established.

关 键 词：TI3AL基合金 热变形 本构方程 ZENER-HOLLOMON参数 

分 类 号：TG146.2[一般工业技术—材料科学与工程]