Enhancing strength and ductility in back extruded WE71 magnesium alloy cylindrical parts by introduction of multi-direction forging process  

作　　者：Dehao Bu Ting Li Xiaolei Han Zhiwei Du Jiawei Yuan Kui Zhang Yongjun Li Yonggang Peng Zheng Pang Chunlei Zhao 

机构地区：[1]National Center of Analysis and Testing for Nonferrous Metals and Electronic Materials,GRINM Group Co.,Ltd.,Beijing 100088,China [2]Guobiao(Beijing)Testing&Certification Co.,Ltd.,China United Test&Certification Co.,Ltd.,Beijing 100088,China [3]General Research Institute for Nonferrous Metals,Beijing 100088,China [4]State Key Laboratory for Fabrication and Processing of Non-Ferrous Metals,GRIMAT Engineering Institute Co.,Ltd.,Beijing 101407,China [5]Gaona Aero Material Co.,Ltd.,Beijing 100081,China

出　　处：《Journal of Rare Earths》2023年第3期462-470,I0006,共10页稀土学报（英文版）

基　　金：Project supported by the General Program of National Natural Science Foundation of China(51871195,51501015)。

摘　　要：Magnesium cylindrical parts have relatively poor mechanical properties and distinct anisotropy of microstructure,which hinder their application as structural components.To improve the performance of WE71 cylindrical parts,multi-direction forging(MDF)was introduced before back extrusion,and the microstructure and mechanical properties were investigated.Results of microstructure show that the grain size in the outer of the cylindrical bottom is refined from 30.1 to 27.7μm,the micro structure is more uniform and the dislocation density is higher.The bimodal grain structure is formed in the outer of the cylindrical wall,which is ascribed to the formation of MgsRE phases along grain boundaries.These phases result in the Zener pinning effect on grain boundaries and the reduction of DRX volume fraction.The texture type of the cylindrical bottom is<0001>‖ED and the cylindrical wall is<1010>‖ED,and the maximum pole intensity is 1.986 and 1.664,respectively.Results of the tensile test at room temperature show that combined improved strength and ductility of the cylindrical part is attained after introducing the MDF process.The ultimate tensile strength(UTS),yield strength(YS)and elongation are279 MPa,185 MPa and 12%at the bottom and 299 MPa,212 MPa and 20%at the wall.

关 键 词：WE71 magnesium alloy Multi-direction forging Backward extrusion Bimodal grain structure Rare earths 

分 类 号：TG316[金属学及工艺—金属压力加工] TG146.22[一般工业技术—材料科学与工程]