Al-Zn-Mg-Cu-Sc合金中剪切带形成与演化机理研究  

Mechanmism of shear band formation and evolution of Al-Zn-Mg-Cu-Sc alloy

作　　者：贺永东[1] 张新明[1] 陈明安[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《材料科学与工艺》2009年第5期624-631,共8页Materials Science and Technology

基　　金：国家重大基础研究项目(2005CB623706)

摘　　要：Al-Zn-Mg-Cu合金是超高强难变形合金,加工过程中易产生大的剪切带和裂纹等缺陷.制备了一种含钪Al-Zn-Mg-Cu合金,研究了该合金在热轧和热处理过程中宏观剪切带和轧制裂纹的形成与扩展规律.采用光学显微镜、扫描电镜、透视电镜和能谱分析对该合金热轧时产生变形局部化的力学条件和微观结构进行了深入分析.结果表明:在非均匀变形条件下,变形局部化导致局部变形区应变大和应变率高是产生剪切带和轧制裂纹的原因,与合金基体中组织和成分的不均匀性有关.在高温固溶条件下剪切带内发生了再结晶.It is easy to produce slipping and crack during processing for Al-Zn-Mg-Cu alloy, which belongs to the ultra-high strength aluminum alloy. So a sort of Al - Zn - Mg - Cu alloy with 0.15% Sc was prepared. Formation and propagaration of macroscopical shear band and hot-rolling crack during hot rolling and heat treatment were studied. Mechanical conditions and microstructure on deformation localization were studied by means of optical microscopy （ OM）, and scanning electron microscopy （ SEM）, energy dispersive X-ray spectroscopy （EDS） and transmission electron microscopy （TEM）. Results show that deformation localization induces the augmentation of distortion and stress for nonuniform deformation, which results in the occurrence of shear band and crack. It is relative to the nonuniformity of microstructure and chemical components of the alloy. Recrystallization occurs in shear band due to high temperature solution.

关 键 词：Al—Zn—Mg—Cu合金 剪切局部化 位错 再结晶 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG146.21[金属学及工艺—金属材料]