抗蠕变Zn-Cu-Cr合金的热压缩流变应力行为

Flow stress behavior of Zn-Cu-Cr alloy during hot compression deformation

通过Gleeble1500D热模拟机的热压缩实验,研究了Zn-8Cu-0.2Cr合金在应变速率为0.01/s^10/s、温度为230℃~380℃条件下的流变应力行为;采用双曲正弦模型求解材料常数,并采用非线性回归,建立了真应变ε与Q、lnA、n和α之间的关系。结果表明,变形条件对流变应力具有显著的影响,流变应力随应变速率的增大和温度的升高而减小;Q、lnA、n和α可表示为真应变ε的5次指数函数,利用该函数,可以计算任意变形条件下的流变应力,其平均误差为5.9%,该模型能准确反映Zn-8Cu-0.2Cr合金的高温变形力学行为。

The hot deformation behavior of Zn 8Cu-0.2Cr alloy at strain rate ranging from 0.01s^-1 to 10.0s^-1 and deformation temperatures ranging from 230℃ to 380℃ was studied by isothermal compression performed on a Gleeble-1500D thermal mechanical simulator. The flow stress of the alloy during high temperature deformation can be represented by a Zenter-Hollomon parameter in the hyperbolic Arrhenius-type equation. Material constant Q, lnA, n and a can be expressed by higher index function of ε. The experimental results show that the deformation condition has a significant effect on the flow stress. The flow stress increases with the increase of strain rate and decrease of temperature. The relationship of Q, lnA, n, αand ε can be expressed by 5 exponential function, which can calculate the flow stress under any deformation condition with the average error as 5.9%, and can accurately reflect the thermal deformation of Zn-8Cu-0.2Cr alloy.