Dissolution and reprecipitation of 14H-LPSO structure accompanied by dynamic recrystallization in hot-extruded Mg_(89)Y_(4)Zn_(2)Li_(5) alloy

作     者：Wei Liu Yu Su Yuntao Zhang Liwen Chen Hua Hou Yuhong Zhao 

作者机构：College of Materials Science and EngineeringNorth University of ChinaTaiyuan 030051China 

出 版 物：《Journal of Magnesium and Alloys》 (镁合金学报（英文）)

年 卷 期：2023年第11卷第4期

页      面：1408-1421页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：the assistance from the Provincial and Ministry Collaborative Innovation Center of Development and Application of High-Performance Aluminum/Magnesium Alloy Materials the financial supports from the Research Project Supported by Shanxi Scholarship Council of China(No.2021-125) Natural Science Foundation of Shanxi Province(No.20210302124631) 

主　　题：Magnesium Extrusion LPSO Recrystallization Precipitation 

摘      要：We investigate the variation induced in long-period stacking ordered(LPSO)structures,dynamic recrystallization(DRX),and mechanical performance of hot-extruded Mg89Y4Zn2Li5 alloys fabricated at different extrusion speeds(Ve=0.4,0.8,1.0,1.2 mm/s)and die angles(α=30°,60°,90°)under 400℃,the dissolution and reprecipitation of 14H LPSO structure accompanied by DRX process are then clarified in *** all extrusion conditions,the block 18R LPSO structures elongate in the extrusion direction,while the lamellar 14H LPSO structures dissolve under the deformation *** addition,due to discontinuous and continuous DRX mechanisms,all hot-extruded alloys have a full DRX microstructure consisting of equiaxed recrystallized grains,but the DRX grain size reduces when both extrusion speed and die angle *** that,in the interior of DRX grains,thin LPSO lamellae mixing 14H,18R and 24R structures nucleate and dynamically precipitate due to the dissolution of the original lamellar 14H LPSO ***,the hot-extruded Mg_(89)Y_(4)Zn_(2)Li_(5)alloy becomes stronger as decreasing of the extrusion speed and die angle,whereas the ductility remains nearly ***,the hotextruded Mg_(89)Y_(4)Zn_(2)Li_(5)alloy achieves an excellent strength-ductility balance at a relatively low extrusion speed(0.4 mm/s)and small die angle(30°)mainly due to the elongated 18R LPSO structure,fine and full DRX microstructure,thin mixed LPSO precipitates in the DRX grains,twins and dislocations.