AZ31镁合金热压缩过程动态再结晶行为研究  

Dynamic Recrystallization Behavior of AZ31 Magnesium Alloy During Thermal Compression

作　　者：苏辉 楚志兵[1,2] 薛春 李玉贵 马立峰[1] Su Hui;Chu Zhibing;Xue Chun;Li Yugui;Ma Lifeng(Engineering Research Center Heavy Machinery Ministry of Education,Taiyuan University of Science and Technology,Taiyuan 030024,China;School of Mechanics and Architectural Engineering,Jinan University,Guangzhou 510632,China)

机构地区：[1]太原科技大学重型机械教育部工程研究中心,山西太原030024 [2]暨南大学力学与建筑工程学院,广东广州510632

出　　处：《稀有金属材料与工程》2021年第6期2033-2039,共7页Rare Metal Materials and Engineering

基　　金：国家重点研发计划项目(2018YFB1307902);国家自然科学基金(U1710113);山西省研究生联合培养基地人才培养项目(2018JD33);山西省青年拔尖人才;山西省优秀青年基金(201901D211312);山西省高等学校创新人才优秀青年学术带头人;山西省高等学校科技成果转化培育项目(2019KJ028);山西省新兴产业领军人才;山西省研究生教育创新计划(2019SY482)。

摘　　要：通过AZ31镁合金热压缩试验,采用电子背散射衍射(EBSD)技术,对不同变形条件(不同温度、应变速率和变形程度)下镁合金热变形过程中的动态再结晶行为、晶粒取向和织构的产生等现象进行研究。结果表明,变形温度越高,再结晶程度表现得越充分,晶粒组织也越均匀,而变形程度越大或应变速率越小,再结晶程度则越大。在镁合金热变形过程中,变形温度是决定其动态再结晶机制的最大影响因素。300℃时,AZ31镁合金再结晶晶粒在原始晶界和亚晶界处形核,再结晶行为主要由亚晶界的转动形成,表现出典型的连续动态再结晶(CDRX)特征。400℃时,局部剪切变形时再结晶晶粒取向发生偏转,表现出典型的旋转动态再结晶(RDRX)特征。热压缩过程中产生(1012)拉伸孪生,晶粒重新旋转基面取向形成基面垂直于压缩方向的纤维织构。The dynamic recrystallization behavior, grain orientation and texture formation of magnesium alloy under different deformation conditions(temperature, strain rate and deformation degree) were studied by electron backscattering diffraction(EBSD) in the thermal compression experiment of AZ31 magnesium alloy. The results show that the greater the deformation temperature, the more adequate the degree of recrystallization and the more uniform the grain structure. The greater the degree of deformation or the smaller the strain rate, the greater the degree of recrystallization. During the hot deformation of magnesium alloys, the deformation temperature is the biggest factor influencing the dynamic recrystallization mechanism. At 300 ℃, the recrystallized grains of AZ31 magnesium alloy nucleate at the original grain boundary and sub-grain boundary. The recrystallization behavior is mainly formed by the rotation of sub-grain boundary, which shows the typical continuous dynamic recrystallization(CDRX) characteristics. At 400 ℃, the orientation of the recrystallized grains is deflected during local shear deformation,showing the typical characteristics of rotational dynamic recrystallization(RDRX). During the thermal compression process,(1012) tensile twins are generated, and the grains re-rotate the basal plane orientation to form a fiber texture with the basal plane perpendicular to the compression direction.

关 键 词：热压缩 动态再结晶 变形织构 变形温度 

分 类 号：TG146.21[一般工业技术—材料科学与工程]