Cu-Cr-Zr合金的热变形行为  

Hot-Compression Deformation Behavior of Cu-Cr-Zr Alloy

作　　者：王庆娟[1] 刘锋[1] 杜忠泽[1] 王静怡[1] 

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055

出　　处：《稀有金属》2013年第5期687-694,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51104113)资助

摘　　要：采用Gleeble-3500热模拟实验机对Cu-Cr-Zr合金进行了压缩变形实验，分析了在变形温度为25～700℃、应变速率为0．0001～0．1000s11的条件下流变应力的变化规律，利用扫描电镜及透射电镜分析合金在热压缩过程中的组织演变及动态再结晶机制。结果表明：Cu—Cr-Zr合金在热变形过程中发生了动态再结晶，且变形温度和应变速率均对流变应力有显著的影响，流变应力随着变形温度的升高而降低，随着应变速率的增加而升高，说明该合金属于正应变速率敏感材料；当变形温度为400—500℃时，低应变速率（0．01301～0．0010s11）的真应力．真应变曲线呈现动态再结晶曲线特征，高应变速率（O．01～0．10s。）的真应力一真应变曲线呈现动态回复特征；在真应力．真应变曲线的基础上，采用双曲正弦模型能较好地描述Cu-Cr-Zr合金高温变形时的流变行为，建立了完整描述合金热变形过程中流变应力与应变速率和变形温度关系的本构方程，确定了合金的变形激活能为311．43kJ·mol^-1。Hot compression deformation of Cu-Cr-Zr alloy was performed on Gleeble-3500 under conditions of strain rates of 0.0001 - 0. 1000 s^-1 and deformation temperatures of 25 - 700℃, and the flow stresses in different deformation conditions were investigated. The microstructure evolution and dynamic recrystallization nucleation mechanisms of Cu-Cr-Zr alloy were analyzed by using SEM and TEM. The results showed that the dynamic recrystallization occurred during hot compression deformation, and the flow stress was sig- nificantly affected by both deformation temperature and strain rate, the flow stress increased with the increase of strain rate and de- creased with the increase of deformation temperature, which indicated that Cu-Cr-Zr alloy was a kind of positive strain rate sensitive material; when the temperature was 400 - 500 ℃, dynamic recrystallization occurred in the strain rate range of 0.0001 - 0.0010 s^-1, and dynamic recovery occurred in the strain rate range of 0.01 - 0.10 s^-1 ; based on the true stress-strain cures, the flow stress of Cu- Cr-Zr alloy during high temperature deformation could be expressed by the hyperbolic - sine mathematics model, and hot compression deformation constitutive equation which described the relation among flow stress and strain rate and deformation temperature was com- pletely established. The deformation activation energy was 311.43 kJ.mol^-1.

关 键 词：Cu—Cr—Zr合金 热变形 流变应力 激活能 

分 类 号：TG146.11[一般工业技术—材料科学与工程]