利用Gleeble-1500D热模拟试验机,在温度650~950℃、应变速率0.01~5s-1、总应变量0.7的条件下,对W-75%Cu复合材料高温塑性变形行为及其热加工图进行研究和分析。结果表明:W-75%Cu复合材料高温流动应力-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加;在真应力-应变曲线基础上,建立的W-75%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-75%Cu复合材料DMM加工图分析其变形机制和失稳机制,可确定其热加工工艺参数应优先选择变形温度800~950℃、应变速率0.01~0.1s-1。
Using the Gleeble-1500D simulator,the high-temperature plastic deformation behavior and processing map of W-75%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 softening mechanism of dynamic recrystallization is a feature of high-temperature flow stress-strain curves of W-75%Cu composite,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-75%Cu composite,and the calculated results of the flow stress are in good agreement with the experimental results of the high-temperature deformation of W-75%Cu composite.Meanwhile,the obtained processing map of Dynamic Material Modeling is used to analyze the deformation mechanism and the destabilization mechanism of W-75%Cu composite,the optimal deformation processing parameters of the deformation temperatures range and the strain rates range are 800~950 ℃ and 0.01~0.1 s-1,respectively.