铁白铜合金热压缩应力-应变关系的变参数Arrhenius模型研究

Study on variable parameter Arrhenius model of thermal compression stress-strain relationship of Cu-Ni-Fe alloy

利用Gleeble-3500热模拟机对铁白铜合金进行热压缩实验,实验温度为800~1000℃,应变速率为0.01~15s-1,研究了该合金在高温塑形变形过程中的流变应力行为。引入修正的变参数型Arrhenius本构方程,在不同真应变下进行了多元线性回归拟合,获得了方程中各参量(变形激活能Q、结构因子A及材料常数n、α和β)随应变的变化规律。构建出了铁白铜合金高温流变应力本构方程。对模型预测值与实验值进行了评估,结果表明模型具有较高的预测精度,预测值与实验值拟合相关系数达到0。9951,平均绝对误差为1.81%,平方均方根误差为1.78MPa。

The flow stress behaviors of Cu-Ni-Fe alloy during plastic deformation at elevated temperature have been studied by the isothermal compression test at Gleeble-3500 simulator. The compression test has been performed in the temperature range from 800℃ to 1000! and in the strain rate range from 0.01s-1 to 15s-1. By leading in modified variable parameter Arrhenius constitutive equation, multivariant linear regression fitting has been carried out under different true strain. The changing laws of the parameters (deformed activation energy Q, structural factor A and materials constant n、α、β)with the strain have been obtained. The constitutive equation of the high temperature flow stress of Cu-Ni-Fe alloy has been constructed. The predicted values and experimental values of the model has been evaluated. The results show that the Arrhenius model has high prediction accuracy since correlation coefficient between predicted and experiment value is 0.9951, the average absolute relative error is 1.81% and average root mean square error is 1.78Mpa.