Microstructural evolution and fracture mechanism of a new AlZn-Mg-Cu-Zr alloy processed by equal-channel angular pressing  

作　　者：Hong-Li Liu Ping Li Ke-Min Xue Chen-Hao Qian Rui Hua 

机构地区：[1]School of Materials Science and Engineering,Hefei University of Technology,Hefei,230009,China

出　　处：《Rare Metals》2022年第10期3546-3551,共6页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos.51175138, 50875072 and 51575153);the Program for New Century Excellent Talents in University (No.NCET-13-0765)。

摘　　要：Equal-channel angular pressing(ECAP) is considered to be one of the most effective processing procedures to produce ultrafine-grained(UFG) materials.A new AI-ZnMg-Cu-Zr alloy was subjected to ECAP experiment in Route B_(C)(i.e.,rotated 90° in the same sense between each pass).The effect of ECAP on the microstructural evolution and fracture mechanism of the alloy was analyzed by optical microscope(OM),X-ray diffraction(XRD),tensile test(at room temperature),and scanning electron microscope(SEM).The results show that the main strengthening phase of the alloy is MgZn_(2),whose content increases apparently after ECAP,the dislocation density increases by one order of magnitude,the hardness value of the 1 pass ECAPed sample increases by 53 %,the ultimate tensile strength(UTS)increases by 29 %,and the true strain increases by 15.4 %.But the further increase in the strength with the passes increasing would cost a slight drop in the true strain.The morphology of the tensile dimples is converted from elongated one to equiaxed one with a uniform distribution of size and depth after pressing.

关 键 词：Al-Zn-Mg-Cu-Zr alloy Equal-channel angular pressing Microstructural evolution Crystallite size Mechanical properties Fracture mechanism 

分 类 号：TG146.21[一般工业技术—材料科学与工程]