5083铝合金热压缩流变应力曲线修正与本构方程

摘要

在Gleeble-3800热模拟机上采用等温压缩实验研究5083铝合金在变形温度为523～723K、应变速率为0.01～10s-1、真应变为0～0.7条件下的高温流变应力行为.基于热传导对合金变形热效应的影响,对流变应力曲线进行了变形热修正.结果表明:热传导对变形过程中产生的温升影响不可忽略,其影响随着真应变的增加而更加显著;修正后的流变应力对峰值应力影响不大,但稳态流变应力软化趋势得到一定程度的减弱.建立了Zener-Hollomon参数的本构方程,可对5083铝合金在不同变形条件下的流变应力进行预测,温升修正后的流变应力值与本构方程的预测值吻合较好,平均相对误差仅为5.21％.%The flow stress behavior of 5083 aluminum alloy was investigated under hot compression deformation at 523-723K,strain rates of 0.01-10s-1 and true strains of 0-0.7 with Gleeble-3800 thermal simulator.Based on the heat transfer effect on alloy deformation heat effect,the flow stress curves were corrected.The results show that influence of heat conduction can not be neglected and becomes more obvious with the increase of true strain.The corrected flow stress has little influence on the peak stress,but the steady flow stress softening trends to be diminished to some degree.The flow stress can be predicted by the Zener-Hollomon parameters in the constitutive equation.The corrected measured value exhibits a good agreement with the flow stress predicted by the constitutive equation,and the average relative error is only 5.21％.