钨含量对W-Cu复合材料高温变形行为的影响

Effect of W content on hot deformation behavior of W-Cu composite at elevated temperature

采用Gleeble-1500D热模拟试验机，在温度为650-950℃、应变速率为0．01-5S、总应变量为0．7的条件下，对25％W-Cu和50％W-Cu（质量分数）复合材料的热变形行为及其热加工图进行研究和分析。结果表明：此两种复合材料的高温流动应力-应变曲线主要以动态再结晶为特征，峰值应力随变形温度的降低或应变速率的升高而增大；在真应力-应变曲线基础上建立的W-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50％W-Cu复合材料DMM加工图分析了其变形机制和失稳机制，确定其热加工工艺参数应优先选择变形温度为650-700℃、应变速率为1-5s^-1，或者变形温度为850-950℃、应变速率为0．01-0．1s^-1。

AUsing the Gleeble-1500D simulator, the high-temperature plastic deformation behavior and processing map of 25%W-Cu and 50%W-Cu （mass fraction） composites 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 softening mechanism of the dynamic recrystallization is a feature of high-temperature flow stress--strain curves of the two composites, and the peak stress increases with the decrease of deformation temperature or the increase of strain rate. Based on the true stress-strain curves, the established constitutive equation represents the high-temperature flow behavior of W-Cu composite, and the calculated results of the flow stress are in good agreement with the experimental results of the high-temperature deformation of the two composites. Meanwhile, the obtained processing map of dynamic material modeling is used to analyze the deformation mechanism and the destabilization mechanism of 50%W-Cu composite, the optimal deformation processing parameters of the deformation temperatures range and the strain rates range are 650-700 ℃ and 1-5 s^-1 or 850-950 ℃ and 0.01-0.1 s^-1, respectively.