Zr-4合金热变形行为及物理本构模型

Hot Deformation Behavior and Strain Compensation Physical Constitutive Model of Zr-4 Alloy

利用Gleeble-3500型热模拟试验机对Zr-4合金试样进行等温恒应变速率压缩实验,对其热变形行为进行分析,综合考虑变形温度对Young’s模量和自扩散系数的影响,建立了Zr-4合金基于应变耦合的物理本构模型。研究结果表明:合金的峰值应力对变形温度和应变速率敏感,峰值应力会随应变速率的增加或变形温度的降低而增大;基于应变耦合构建的物理本构模型能够较好地预测合金在热变形过程中的流变应力,其相关系数R为0.986,预测值偏差在10%以内的数据点占93.2%,平均相对误差为6.3%。

The isothermal constant strain rate compression experiment was carried out on Zr-4 alloy samples by Gleeble-3500 thermal simulator. The thermal deformation behavior was analyzed, and the physical constitutive model of Zr-4 alloy based on strain compensation was established by combining the influence of deformation temperature on Young’s modulus and self-diffusion coefficient. The results show that the peak stress of the alloy is sensitive to the deformation temperature and strain rate, and the peak stress increases with the increase of the strain rate or the decrease of the deformation temperature. The constructed physical constitutive model based on strain compensation can better predict the flow stress of the alloy in the thermal deformation process, and its correlation coefficient R is 0.986. The data points with the predicted value deviation less than 10% account for 93.2%, and the average relative error is 6.3%.