W-50%Cu复合材料的高温变形行为及加工图

Hot deformation behavior and processing maps of W-50%Cu composite

利用Gleeble-1500热力模拟试验机,在温度为650～950℃、应变速率为0.01～5 s-1、总应变量0.7的条件下,对W-50%Cu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了研究和分析。试验结果表明:W-50%Cu复合材料高温流动应力-应变曲线主要以动态回复和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W-50%Cu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W-50%Cu复合材料DMM加工图分析了其变形机制和失稳机制,可确定其热加工工艺优先选择变形温度650～700℃、应变速率1～5 s-1或变形温度850～950℃、应变速率0.01～0.1 s-1。

Using a Gleeble-1500 simulator,the dynamic recrystallization behavior during high-temperature plastic deformation and processing maps of W-50%Cu composite were investigated at 650-950 ℃ with the strain rate of 0.01-5 s-1 and total strain of 0.7.The results show that the high-temperature flow stress-strain curves of W-50%Cu composite are characterized by softening mechanism of dynamic recovery and dynamic recrystallization,and the peak stress increases with decreasing deformation temperature or increasing strain rate.Based on the true stress-strain curves,the established constitutive equation represents the high-temperature flow behavior of W-50%Cu composite,and the calculated results of the flow stress are in good agreement with the high-temperature deformation experimental results.Meanwhile,the obtained processing map of dynamic materials modeling（DMM） is used to analyze the deformation mechanism and the destabilization mechanism of W-50%Cu composite,the optimal deformation processing parameters of the deformation temperatures rang and the strain rates rang are 650-700 ℃ and 1-5 s-1 or 850-950 ℃ and 0.01-0.1 s-1.