基于位错密度模型的AZ31镁合金热压缩微观组织预测  

Microstructure prediction of AZ31 magnesium alloy during thermal compression based on dislocation density model

作　　者：汪建强 郭丽丽[1] 王长峰 WANG Jian-qiang;GUO Li-li;WANG Chang-feng(Engineering Research Center of Continuous Extrusion,School of Materials Science and Engineering,Dalian Jiaolong University,Dalian 116028,China)

机构地区：[1]大连交通大学材料科学与工程学院连续挤压工程研究中心,辽宁大连116028

出　　处：《塑性工程学报》2020年第10期92-99,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51401043);辽宁省自然科学基金资助项目(2019-MS-035)。

摘　　要：运用ABAQUS软件的VUSDFLD子程序,结合建立的位错密度模型对AZ31镁合金进行热压缩过程的微观组织预测,研究了变形温度和应变速率对低角晶界(Low Angle Grain Boundaries,LAGBs)位错密度、高角晶界(High Angle Grain Boundaries,HAGBs)位错密度和动态再结晶(Dynamic Recrystallization,DRX)体积分数XDRX的影响。结果表明:变形温度为400℃时,LAGBs和HAGBs位错密度与宏观应力具有一致的变化趋势,表明LAGBs和HAGBs位错密度能够体现宏观应力的变化;较大的变形量和较高的变形温度能促进DRX的进行,但在相同的变形量下,XDRX随着应变速率增加而降低;变形温度为300℃时,易变形区和自由变形区的LAGBs和HAGBs位错密度都呈现出先增后减的变化趋势;但变形温度在400和500℃时,易变形区的LAGBs和HAGBs位错密度会出现缓慢上升的趋势,而自由变形区则出现了下降趋势。The microstructure prediction of AZ31 magnesium alloy during the thermal compression processes was performed by using the VUSDFLD subroutine of ABAQUS software combined with the established dislocation density model.The effects of deformation temperature and strain rate on low angle grain boundaries(LAGBs)dislocation density,high angle grain boundaries(HAGBs)dislocation density and dynamic recrystallization(DRX)volume fraction XDRXwere studied.The results show that the change of LAGBs and HAGBs dislocation density has a consistent trend with macroscopic stress when the deformation temperature is 400℃,which indicates that the LAGBs and HAGBs dislocation density can show the changes of macroscopic stress.The larger deformation strain and higher deformation temperature can enhance DRX.Nevertheless,at the same deformation amount,XDRXdecreases with the increase of strain rate.When the deformation temperature is 300℃,LAGBs and HAGBs dislocation density in the easy-deformation zone and free-deformation zone shows a change trend of increasing firstly and then decreasing.However,when the deformation temperature is 400 and 500℃,the LAGBs and HAGBs dislocation density in the easy-deformation zone slowly increase,while in the free-deformation zone,the decreasing trend appears.

关 键 词：AZ31镁合金 位错密度模型 微观组织预测 有限元模拟 

分 类 号：TG146.22[一般工业技术—材料科学与工程]