Low-cycle fatigue behaviour of Mg-9Gd-4Y-2Zn-0.5Zr alloys with different structures  

作　　者：Jinsheng Ji Jie Zheng Leichen Jia Yong Zhang Yunfei Jia Yusha Shi Heng Zhang Yong Xue 

机构地区：[1]School of Materials Science and Engineering,North University of China,Taiyuan 030051,China [2]Key Laboratory of Pressure Systemsand Safety,Ministry of Education,School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China

出　　处：《Journal of Magnesium and Alloys》2023年第9期3382-3393,共12页镁合金学报（英文）

基　　金：the supports provided by the National Natural Science Foundation of China (Grant No.52075501);“XX supporting scientific research project”(xxxx2019-021);JCKY2018408B003,Magnesium alloy highperformance XXX multi-directional extrusion technology。

摘　　要：The strain-controlled cyclic deformation behaviour of Mg-9Gd-4Y-2Zn-0.5Zr with different structures was investigated. Alloys were prepared by solution, extrusion and pre-ageing extrusion, and the microstructures before and after the fatigue tests were characterized.Experimental results indicated that the bimodal structure owned the better performance in fatigue test, which was attributed to the higher yield strength. For the equiaxed structure, cyclic hardening induced stress concentration until the failure. Stable cyclic deformation and persistent cyclic softening played an important role at the low and high strain amplitudes, respectively. This was attributed to the formation of fine grains relieving the stress concentration during cyclic loading. In addition, residual twins were observed in equiaxed structure to induce crack, and the bimodal structure effectively restrain it.

关 键 词：Strain-controlled fatigue Bimodal structure FRACTOGRAPHY Mg-Gd-Y-Zn-Zr alloy 

分 类 号：TG146.22[一般工业技术—材料科学与工程]