Microstructure,texture evolution and yield strength symmetry improvement of as-extruded ZK60 Mg alloy via multi-directional impact forging  

作　　者：Chao Cui Wencong Zhang Wenzhen Chen Jian He Xuemin Chen Jiabin Hou 

机构地区：[1]School of Materials Science and Engineering,Harbin Institute of Technology,Weihai 264209,China [2]Weihai Lightweight Materials and Forming Engineering Research Center,Weihai 264209,China [3]Harbin Institute of Technology-Weihai Innovation Park,Weihai 264209,China

出　　处：《Journal of Magnesium and Alloys》2022年第10期2745-2760,共16页镁合金学报（英文）

基　　金：supported by National Natural Science Foundation of China(Grant No.51975146);Key Research and Development Plan in Shandong Province(Grant No.2018JMRH0412,2019JZZY010364);National Defense Basic Scientific Research of China(Grant no.JCK2018603C017)。

摘　　要：Multi-direction impact forging(MDIF)was applied to the as-extruded ZK60 Mg alloy,and the microstructure,texture evolution and yield strength symmetry were investigated in the current study.The results showed that the average grain size of forged piece was greatly refined to 5.3μm after 120 forging passes,which was ascribed to the segmenting effect of{10–12}twins and the subsequent multiple rounds of dynamic recrystallization(DRX).A great deal of{10–12}twins were activated at the beginning of MDIF process,which played an important role in grain refinement.With forging proceeding,continuous and discontinuous DRX were successively activated,resulting in the fully DRXed microstructure.Meanwhile,the forged piece exhibited a unique four-peak texture,and the initial<10-10>//ED fiber texture component gradually evolved into multiple texture components composed of<0001>//FFD(first forging direction)and<11–20>//FFD texture.The special strain path was the key to the formation of the unique four-peak texture.The{10–12}twinning and basal slip were two dominant factors to the evolution of texture during MDIF process.Grain strengthening and dislocation strengthening were two main strengthening mechanisms of the forged piece.Besides,the symmetry of yield strength was greatly improved by MDIF process.

关 键 词：Multi-directional impact forging Twinning Dynamic recrystallization Texture Yield strength symmetry 

分 类 号：TG319[金属学及工艺—金属压力加工]