利用Gleeble-1500热力模拟试验机,在温度为450~750℃、应变速率为0.01~5s-1、总应变量0.7的条件下,对30%Mo/Cu-Al2O3复合材料高温塑性变形过程中的动态再结晶行为及其热加工图进行研究和分析。实验结果表明30%Mo/Cu-Al2O3复合材料高温流动应力-应变曲线主要以动态再结晶软化机制为特征,峰值应力随变形温度的降低或应变速率的升高而增加;在真应力-应变曲线基础上,建立的30%Mo/Cu-Al2O3复合材料高温变形本构模型较好地表征了其高温流变特性;同时,利用30%Mo/Cu-Al2O3复合材料DMM加工图分析了其变形机制和失稳机制,确定了热加工工艺参数为变形温度650~750℃,应变速率0.01~0.1s-1。
Using the Gleeble-1500D thermal simulator,the high-temperature plastic deformation behavior and processing map of 30%Mo/Cu-Al2O3 composite were investigated at 450-750℃ with the strain rate of 0.01-5s-1 and total strain of 0.7.The results show that the softening mechanism of dynamic recrystallization is a feature of high-temperature flow stress-strain curves of 30%Mo/Cu-Al2O3 composite,and the peak stress increases with the decreased deformation temperature or the increased strain rate.Based on the true stress-strain curves,the established constitutive equation represents the high-temperature flow behavior of 30%Mo/Cu-Al2O3 composite,and the calculated results of the flow stress are in good agreement with the experimental results of the high-temperature deformation.Meanwhile,the obtained processing map of dynamic material modeling is used to analyze the deformation mechanism and the destabilization mechanism of 30%Mo/Cu-Al2O3 composite,the optimal deformation processing parameters of the deformation temperatures rang and the strain rates rang are 650-750℃,and 0.01-0.1s-1,respectively.