沈阳工业大学学报2025，Vol.47Issue(1)：45-52,8.DOI:10.7688/j.issn.1000-1646.2025.01.06
基于准原位AZ31镁合金双轴动态压缩变形行为
Quasi-in-situ deformation behavior of AZ31 magnesium alloy subjected to biaxial dynamic compression
摘要
Abstract
[Objective]Magnesium alloy is widely used due to its advantages of light weight,high specific strength,high specific stiffness,and easy recovery.The parts of magnesium alloy in the front of automobiles and aircraft as well as the side and tail of automobiles are exposed to impact loads at a high strain rate.This causes structural parts to fail in a very short of time,posing a risk to safety performance of automobiles and aircrafts and resulting in unpredictable situation.Therefore,studying the quasi-in-situ deformation processes and mechanisms of magnesium alloys under dynamic compression at a high strain rate is of important significance.[Methods]To study the dynamic mechanical performance of AZ31 magnesium alloy under dynamic impact loads,this study systematically investigated an extruded-sheared AZ31 magnesium alloy under biaxial dynamic compression.Based on the quasi-in-situ method,dynamic compression experiments were conducted on AZ31 magnesium alloy with the split Hopkinson pressure bar(SHPB).The microstructure evolution of the specimens was characterized by electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM).[Results]The results of biaxial dynamic compression experiments show that the AZ31 magnesium alloy exhibits plastic deformation.A large number of extension twins were activated under radial compression in the extrusion direction.Detwinning accompanied with activation of a small number of extension twins was observed during the reverse loading.The in-depth analysis of the detwinning behavior indicates that the higher Schmid factor(SF)is mainly accounted for detwinning.The slip trace method was used to determine the slip system activated and combined with the detwinning behavior for investigating the contribution of slip to detwinning.When compression was perpendicular to the crystal c-axis,extension twins were easily activated during this process,and the twin had an angle of 86.3 ° relative to the parent grain.The c-axis of the twin was nearly parallel to the direction of compression.When the compression direction was changed to perpendicular to the c-axis of the twin,detwinning occurred.With the accumulation of cumulative strain,the peak value of low-angle grain boundaries(LAGBs)continued to increase.The whole deformation process was accompanied by slip.These results indicate that the generation of LAGBs is caused by slip,and slip plays a crucial role in plastic deformation.During the plastic deformation of the AZ31 magnesium alloy,the twins activated first exhibit detwinning with the change of compression direction.Slips are activated throughout the dynamic compression process,despite the fact that the direction of dynamic compression is adjustable.Both twinning and detwinning processes are accompanied by slip.The synergy between slip and twinning is primarily responsible for the dynamic compression deformation of AZ31 magnesium alloy in various directions.[Conclusion]In this paper,the microstructure deformation behavior of AZ31 magnesium alloy was studied to provide a theoretical basis for its wide application.关键词
AZ31镁合金/分离式霍普金森压杆/滑移/孪生/退孪生/施密特因子(SF)/晶界取向差/孪晶变体Key words
AZ31 magnesium alloy/split Hopkinson pressure bar/slip/twinning/detwinning/Schmid factor(SF)/grain boundary orientation difference/twin variant分类
矿业与冶金引用本文复制引用
周乐,何振宇,闫瑞华,王志,毛萍莉..基于准原位AZ31镁合金双轴动态压缩变形行为[J].沈阳工业大学学报,2025,47(1):45-52,8.基金项目
辽宁省教育厅基本科研面上项目(LJKMZ20220462). （LJKMZ20220462）
