(1. 河南科技大学 材料科学与工程学院，洛阳 471003;
2. 河南科技大学 河南省有色金属材料科学与加工技术重点实验室，洛阳 471003)
摘 要: 采用Gleeble−1500D热模拟试验机，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1~5 s−1，或者变形温度为850~950 ℃、应变速率为0.01~0.1 s−1。
关键字: W-Cu复合材料；应变速率；峰值应力；动态再结晶；加工图
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China;
2. Henan Key Laboratory of Advanced Non-Ferrous Materials, Henan University of Science and Technology,
Luoyang 471003, China）
Abstract:Using 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.
Key words: W-Cu composite; strain rate; peak stress; dynamic recrystallization; processing map
