Enhancing the strain hardening and ductility of Mg-Y alloy by introducing stacking faults

作     者：Kang Wei Lirong Xiao Bo Gao Lei Li Yi Liu Zhigang Ding Wei Liu Hao Zhou Yonghao Zhao Kang Wei;Lirong Xiao;Bo Gao;Lei Li;Yi Liu;Zhigang Ding;Wei Liu;Hao Zhou;Yonghao Zhao

作者机构：Nano and Heterogeneous Materials CenterSchool of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China 

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

年 卷 期：2020年第8卷第4期

页      面：1221-1227页

核心收录：

学科分类：08[工学] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：the National Key R&D Program of China(2017YFA0204403) National Natural Science Foundation of China(51601003,51901103) the Fundamental Research Funds for the Central Universities(30918011342). 

主　　题：Magnesium alloys Ductility Stacking faults Non-basal slip Transmission electron microscopy 

摘      要：Due to the insufficient slip systems,Mg and its alloys exhibit poor ductility during plastic deformation at room temperature.To solve this problem,alloying is considered as a most effective method to improve the ductility of Mg alloys,which attracts wide attentions of industries.However,it is still a challenge to understand the ductilization mechanism,because of the complicated alloying elements and their interactions with Mg matrix.In this work,pure Mg and Mg-Y alloys were comparatively studied to investigate the effect of Y addition on microstructure evolution and mechanical properties.A huge increase of uniform elongation,from 5.3%to 20.7%,was achieved via only 3 wt%addition of yttrium.TEM results revealed that the only activated slip system in pure Mg was basalslip,led to its poor ductility at room temperature.In contrast,a large number of stacking faults and non-basal dislocations withcomponent were observed in the deformed Mg-Y alloy,which was proposed as the main reason for significant improvement of strain hardening and ductility.High resolution TEM indicated that most of the stacking faults were II and 12 intrinsic faults,which played a critical role in improving the ductility of Mg-Y alloy.Addition of Y into Mg alloy decreased the stacking fault energy,which induced high density stacking faults in the grain interior.