稀土镁合金热变形行为和组织演变研究  

Hot Deformation Behavior and Microstructure Evolution of Rare Earth Magnesium Alloy

作　　者：王艳彬[1] 陈文[1] 黄少东[1] 胡传凯[1] 吴洋 夏祥生[1] WANG Yan-bin;CHEN Wen;HUANG Shao-dong;HU Chuan-kai;WU Yang;XIA Xiang-sheng(No.59 Research Institute of China Ordnance Industry,Chongqing 400039,China)

机构地区：[1]中国兵器工业第五九研究所,重庆400039

出　　处：《精密成形工程》2020年第6期123-129,共7页Journal of Netshape Forming Engineering

摘　　要：目的通过热模拟试验研究Mg-3.94Gd-2.0Y-0.78Zn-0.56Mn(质量分数)合金的高温变形特性,建立合金的本构方程,并分析变形条件对显微组织的影响。方法在Gleeble3500热模拟机上进行单向压缩试验,变形温度为350~500℃,变形速率为0.0005~0.5 s^−1,变形量为60%。结果流变应力受到应变速率与变形温度的共同影响,计算得到了合金的本构方程。当变形速率一定时,随着变形温度的升高,动态再结晶比例逐渐提高,而再结晶晶粒尺寸也逐渐增大,在变形速率为0.0005 s^−1时,当变形温度从350℃增大到500℃时,动态再结晶晶粒尺寸从1.2μm增大到51.3μm;当变形温度一定时,随着变形速率的升高,再结晶比例逐渐降低,而再结晶晶粒尺寸也逐渐减小,在变形温度为500℃时,当变形速率从0.0005 s^−1增大到0.5 s^−1时,动态再结晶晶粒尺寸从51.3μm减少到11.0μm。结论得到了合金的本构方程,再结晶晶粒尺寸随温度的升高而逐渐增大,随变形速率的升高而逐渐减小。The work aims to study the high temperature deformation characteristics of Mg-3.94Gd-2.0Y-0.78Zn-0.56Mn(mass fraction)alloy,establish the constitutive equation of the alloy and analyze the influence of deformation conditions on the microstructure.Unidirectional compression tests were carried out on the Gleeble3500 thermal simulator.The deformation temperature was 350-500℃,the strain rate was 0.0005-0.5 s^−1,and the deformation amount was 60%.The flow stress was affected by both the strain rate and the deformation temperature.The constitutive equation of the alloy was obtained through calculation.When the stain rate was constant,as the deformation temperature increased,the dynamic recrystallization ratio gradually increased,and the recrystallized grain size also gradually increased.When the strain rate was 0.0005 s‒1,and when the deformation temperature increased from 350℃to 500℃,the dynamic recrystallization grain size increased from 1.2μm to 51.3μm.When the deformation temperature was constant,as the strain rate increased,the dynamic recrystallization ratio gradually decreased,and the recrystallized grain size also gradually decreased.When the deformation temperature was 500℃,and when the strain rate increased from 0.0005 s^−1 to 0.5 s^−1,the dynamic recrystallization grain size decreased from 51.3μm to 11.0μm.The constitutive equation of the alloy is obtained,and the recrystallized grain size gradually increases with the increase of temperature,and gradually decreases with the increase of strain rate.

关 键 词：稀土镁合金 热变形行为 本构方程 显微组织 

分 类 号：TG146.22[一般工业技术—材料科学与工程]