Evolution of Quasicrystals and Long-Period Stacking Ordered Structures During Severe Plastic Deformation and Mixing of Dissimilar Mg Alloys Upon Friction Stir Welding

作     者：Meichen Liang Hao Zhang Lifeng Zhang Peng Xue Dingrui Ni Weizhen Wang Zongyi Ma Hengqiang Ye Zhiqing Yang Meichen Liang;Hao Zhang;Lifeng Zhang;Peng Xue;Dingrui Ni;Weizhen Wang;Zongyi Ma;Hengqiang Ye;Zhiqing Yang

作者机构：Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of SciencesSchool of Materials Science and EngineeringUniversity of Science and Technology of ChinaShenyang 110016China Jihua LaboratoryFoshan 528251China 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2021年第34卷第1期

页      面：12-24页

核心收录：

学科分类：08[工学] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 0703[理学-化学] 0811[工学-控制科学与工程] 080201[工学-机械制造及其自动化] 

基　　金：financially supported by the National Nature Science Foundation of China(Nos.51771202,51971225,U1760201) the Key Research Program of Frontier Science,Chinese Academy of Sciences(No.QYZDY-SSW-JSC207)。 

主　　题：Mg alloy Microstructure Phase transformation Severe plastic deformation Mechanical property 

摘      要：Microstructural evolution during severe plastic deformation and mixing of Mg95.8Zn3.6Gd0.6 and Mg97Cu1Y2(at%)alloys upon friction stir welding was studied.A laminated onion-ring structure composed of alternative distribution of layers with signifi cantly refi ned microstructures from diff erent alloys was formed in the stirred zone.Coarse quasicrystals were broken up and dispersed with most of them being transformed into cubic W-phase particles,and thick 18R long-period stacking ordered plates were fractured and transformed into fi ne 14H-LPSO lamellae in the stirred zone(SZ)experiencing complex material flow under high strain rate.Fine W-phase particles and 14H-LPSO lamellae formed during dissimilar friction stir welding(FSW)usually have no specifi c orientation relationship with surrounding Mg matrix.Chemical measurements demonstrated occurrence of interdiff usion between dissimilar layers in the SZ.Phase transformation was observed for some particles of quasicrystals and long-period stacking ordered(LPSO)in regions slightly outside the SZ.An ultimate tensile strength of~415 MPa and an elongation to failure of~27.8%,both exceeding those of base materials,were obtained in the SZ,due to microstructural refi nement and formation of a laminated structure.