Al₂O₃/Cu-WC复合材料热变形行为及热加工图

冯 江^{1, 2}，田保红^{1, 2}，孙永伟^{1, 2}，刘 勇^{1, 2}，张 毅^{1, 2}，任凤章^{1, 2}

(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：在Gleeble-1500D热模拟机上对Al₂O₃/Cu-WC复合材料进行热压缩实验，研究变形温度为350~750 ℃、应变速率为0.01~5 s^-1条件下的热变形行为。结果表明：Al₂O₃/Cu-WC复合材料高温流变应力-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；热变形过程中的稳态流变应力可用双曲正弦本构关系式来描述，其激活能为229.17 kJ/mol。根据材料动态模型，计算并建立Al₂O₃/Cu-WC复合材料的热加工图，据此确定热变形流变失稳区及热变形过程的最佳工艺参数，其热加工温度为650~750 ℃，应变速率为0.1~1 s^-1。

关键词：Al₂O₃/Cu-WC复合材料；热变形；流变应力方程；热加工图

Hot deformation behavior and processing maps of Al₂O₃/Cu-WC composites

FENG Jiang^{1, 2}, TIAN Bao-hong^{1, 2}, SUN Yong-wei^{1, 2}, LIU Yong^{1, 2}, ZHANG Yi^{1, 2}, REN Feng-zhang^{1, 2}

(1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China;
2. Henan Key Laboratory of Advanced Non-ferrous Metals, Henan University of S)

Abstract:The hot deformation behavior of A₂O₃/Cu-WC composites was investigated by compression tests on Gleeble-1500D thermal simulator. The tests were performed in the temperature range of 350-750 ℃ and strain rates of 0.01-5 s^-1. The results show that A₂O₃/Cu-WC composite has the typical feature of the softening mechanism of dynamic recovery and dynamic recrystallization. The peak stress increases with decreasing the deformation temperature or increasing the strain rate. The flow behavior is described by the hyperbolic sine constitutive equation, and the activation energy of the composite is about 229.17 kJ/mol. The processing map was calculated and analyzed according to the dynamic materials model. The process of hot deformation in the temperature range and different strain rate can be attained by the map, of which the optimum hot deformation temperature ranges in 650-750 ℃ and strain rate ranges in 0.1-1 s^-1, and the instability zones of flow behavior can also be recognized by the processing map.

Key words:A₂O₃/Cu-WC composite; hot deformation; flow stress equation; processing map