AZ31镁合金轧制弱基面织构板材热变形行为研究  

Hot Deformation Behavior of AZ31 Magnesium Alloy Sheet with Weakbasal Texture During Rolling

作　　者：李少琪 王强[1] 杨勇彪[1] LI Shaoqi;WANG Qiang;YANG Yongbiao(School of Materials Science and Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学材料科学与工程学院,山西太原030051

出　　处：《中北大学学报（自然科学版）》2023年第5期575-582,共8页Journal of North University of China(Natural Science Edition)

摘　　要：本文采用AZ31镁合金轧制弱织构板材进行热拉伸行为研究。使用Gleeble-3500型热模拟试验机,在变形温度为300℃~420℃、应变速率为0.001s^(-1)~1.0s^(-1)的条件下,进行高温拉伸试验,研究了变形参数对真实应力-应变曲线和样品微观组织的影响。同时,利用Arrhenius本构模型建立了本构方程,并依据试验结果绘制了热加工图。结果表明:合金的峰值应力和对应应变值随着温度的升高和应变速率的降低而不断减小。随着温度的升高,动态再结晶晶粒的体积分数明显减小,合金平均晶粒尺寸变大。当应变速率为0.1s^(-1),同时在低温(300℃,340℃)时,合金发生完全动态再结晶,晶粒细小且分布均匀。另外,镁合金轧制弱织构板材的激活能Q为170.98kJ/mol,且最佳热变形区域为变形温度300℃~350℃及应变速率0.01 s^(-1)~0.1 s^(-1)。The hot tensile behavior of AZ31 magnesium alloy sheet with weak basal texture was studied.High temperature tensile tests were carried out on a Gleeble-3500 thermal simulator at deformation temperatures from 300℃ to 420℃and strain rates from 0.001 s^(-1) to 1.0 s^(-1).The effects of deformation parameters on the true stress-strain curves and microstructure of the samples were studied.Then the constitutive equation was established by Arrhenius constitutive model,and the hot processing map was established according to the experimental results.The results show that the peak stress and the strain corresponding to the peak stress of the alloy decrease with the increasing temperature and decreasing of strain rate.With the increase of temperature,the volume fraction of dynamic recrystallized small grains decreases obviously,while the average grain size of the alloy shows the opposite trend.When the strain rate is 0.1 s^(-1),the alloy undergoes complete dynamic recrystallization at low temperatures(300℃,340℃),and the grains are refined and evenly distributed.In addition,the activation energy Q of magnesium alloy sheet with weak basal texture during rolling is 170.98 kJ/mol,and the optimized hot deformation area is in the temperature from 300℃to 350 C,and strain rate from 0.01 s^(-1) to 0.1 s^(-1).

关 键 词：AZ31镁合金 热拉伸 应力-应变 本构方程 热加工图 

分 类 号：TG331[金属学及工艺—金属压力加工]