Dynamic mechanical response and deformation-induced co-axial nanocrystalline grains facilitating crack formation in magnesium-yttrium alloy  

作　　者：Shuang Yang Fei Liu Fei Chen Yuan-Biao Tan Hao Fu Si-Yuan Wei Song Xiang 

机构地区：[1]Key Laboratory for Mechanical Behavior and Microstructure of Materials of Guizhou Province,National and Local Joint Engineering Laboratory for High Performance Metal Structure Materials and Advanced Manufacturing Technology,College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China [2]School of Mechanical and Aerospace Engineering,Nanyang Technological University,Singapore,Republic of Singapore [3]Institute of Materials Research and Engineering(IMRE),Agency for Science,Technology and Research(A^(∗)STAR),2 Fusionopolis Way,Innovis#08-03,Singapore 138634,Republic of Singapor

出　　处：《Journal of Magnesium and Alloys》2025年第1期429-441,共13页镁合金学报(英文)

基　　金：support from the National Natural Science Foundation of China(Grant Nos.52301137,51974097,52364050);the Natural Science Special Foundation of Guizhou University(No.(2023)20);Guizhou Province Science and Technology Project(Grant Nos.[2023]001,[2019]2163);Guiyang city Science and Technology Project(Grant No.[2023]48-16).

摘　　要：The dynamic mechanical response and deformation mechanism of magnesium-yttrium alloy at high strain rate were investigated using split-Hopkinson pressure bar(SHPB)impact,and the microstructure evolution and crack formation mechanism were revealed.The yield strength and work hardening rate increase significantly with increasing impact strain rate.Deformation twinning and non-basal dislocation slip are the primary deformation mechanisms during testing.Contrary to crack initiation mechanism facilitated by adiabatic shear bands,we find that high-density co-axial nanocrystalline grains form near cracks,which leads to local softening and promotes crack initiation and rapid propagation.Most grains have similar<1^(-)21^(-)0>orientations,with unique misorientation of 24°,32°,62°,78°and 90°between adjacent grains,suggesting that these grains are primarily formed by interface transformation,which exhibits distinct differences from recrystallized grains.Our results shed light upon the dynamic mechanical response and crack formation mechanism in magnesium alloys under impact deformation.

关 键 词：Magnesium-yttrium alloy SHPB impact Crack initiation Co-axial nanocrystalline grains Interface transformation 

分 类 号：TG146.22[一般工业技术—材料科学与工程]