High strength and high ductility Mg-Gd-Y-Zn-Zr alloys obtained by controlling texture and dynamic precipitation through LPSO phase structure of different initial morphologies  

作　　者：Yayun He Rui Guo Xi Zhao Zhimin Zhang 

机构地区：[1]College of Mechanical and Electrical Engineering,North University of China,Taiyuan,030051,China [2]School of Aeronautics and Astronautics,North University of China,Taiyuan,030051,China [3]College of Materials Science and Engineering,North University of China,Taiyuan,030051,China

出　　处：《Journal of Rare Earths》2024年第12期2217-2230,I0002,共15页稀土学报（英文版）

基　　金：Project supported by the Innovative Talents Support Program of Higher Education Institutions in Shanxi Province;financial support from the North University of China Project of Science and Technology in 2022(20221878).

摘　　要：This paper investigated the effects of three different initial phase structures on the microstructure evolution and tensile properties of extruded Mg-Gd-Y-Zn-Zr alloy,using an extrusion ratio of 3.6.These three initial phase structures were obtained by heat treatment,which is narrow spacing long-period stacking ordered phase(LPSO)phase structure alloy(EN alloy),wide spacing LPSO phase structure alloy(EW alloy),and narrow spacing LPSO phase andβphase overlapping phase structure alloy(EO alloy).The dynamic recrystallization(DRX)and dynamic precipitation behavior of extruded alloys with different initial structures,as well as their strengthening and ductility mechanisms were studied in detail.After hot extrusion with a low extrusion ratio,the alloy exhibits a bimodal structure composed of undynamic recrystallization(UN-DRX)grains and dynamic recrystallization(DRX)grains with strong textures.The narrow-spacing LPSO phase structure inhibits DRX and dynamic precipitation,while both the wide-spacing LPSO phase structure and the overlapping phase structure alloys promote DRX and dynamic precipitation.The strength improvement is mainly due to the strong texture and internal dislocation pinning of the undynamic recrystallization zone(UN-DRX)and the high strengthening effect of the narrow spacing LPSO phase.Although the promotion of DRX improves grain boundary strengthening effect,it cannot make up for reducing the UN-DRXed grain strengthening effect.A lower volume fraction ofβdynamic precipitation phase is beneficial for improving the ductility of the alloy.

关 键 词：Mg-Gd-Y-Zn-Zr alloy Recrystallization behavior Mechanical property Rare earths 

分 类 号：TG146.22[一般工业技术—材料科学与工程]