弥散铜-WC复合材料的热变形行为及动态再结晶临界条件  

Hot deformation behavior and critical conditions of dynamic recrystallization of A_2O_3/Cu-WC composites

作　　者：冯江[1] 田保红[1,2] 孙永伟[1] 刘勇[1,2] 张毅[1,2] 贾淑果[1,2] 

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南省有色金属材料科学与加工技术重点实验室,河南洛阳471003

出　　处：《材料热处理学报》2012年第7期19-23,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助项目(51101052);河南省高校创新人才培养工程(豫教高2005-126)

摘　　要：利用Gleeble-1500D热力模拟试验机,在变形温度为350～750℃、应变速率为0.01～5 s-1、总应变量约为0.5的条件下,对复合材料的高温热变形行为及动态再结晶临界条件进行研究。结果表明:弥散铜-WC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Al2O3/Cu-WC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,其热激活能为208.35 kJ/mol;同时,利用其θ-σ曲线出现拐点及-dθ/dσ曲线上出现最小值研究了动态再结晶的临界条件。Hot deformation behavior and dynamic recrystallization critical conditions of Al2O3/Cu-WC composites were investigated by compression tests at 350-750 ℃ with the strain rate of 0.01 -5 s^-1 and total strain of 0.5 on a Gleeble-1500D simulator. The result shows that the Al2O3/Cu-WC composites exhibits the typical feature of the softening mechanism of dynamic recovery and dynamic recrystallization. The peak stress increases with the decreasing of deformation temperature or the increasing of strain rate. Based on the true stress-strain curves, the established constitutive equation characterizes the high-temperature flow behavior of Al2O3/Cu-WC composites quite well, and activation energy of the composites is about 208.35 kJ/mol. The critical conditions of dynamic recrystallization for the deformed Al2O3/Cu-WC composites are obtained based on the O-tr and dθ/dδ curves.

关 键 词：弥散铜-WC复合材料 本构模型 临界应变 动态再结晶 

分 类 号：TG146.4[一般工业技术—材料科学与工程]