(1. 中南大学 材料科学与工程学院,长沙 410083;
2. 中南大学 教育部有色金属材料科学与工程重点实验室,长沙 410083)
摘 要: 通过光学显微镜及SEM/EBSD观察研究强变形AZ31镁合金在300~673 K的退火行为,分析显微组织、晶粒尺寸分布、平均晶粒尺寸、硬度及变形织构随退火温度的变化。结果表明:细晶组分随着温度的升高不断降低,退火过程按退火温度可分为孕育、再结晶急速长大及晶粒正常长大3个阶段。强变形过程中,发生连续动态再结晶的镁合金在随后的退火过程中主要受晶粒长大控制,没有发生织构变化,即为连续静态再结晶。
关键字: 强变形镁合金;退火;连续再结晶;微观织构
severe deformation
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China)
Abstract:Static recrystallization of severely deformed magnesium alloy was studied by optical and SEM/EBSD observation at temperatures from 300 K to 673 K. The changes of microstructure, grain size distribution, average grain size, hardness and deformation texture with annealing temperature were analysed. The results show that the proportion of fine grain reduces as the annealing temperature increases. The annealing temperature dependence of the average grain size is categorized into three temperature regions, i.e. the first period for grain incubation, the second period for rapid grain coarsening, and the third period for grain normal growth. The annealing processes operating in severely deformed magnesium alloy with continuous dynamic recrystallized grain structures can be mainly controlled by grain coarsening accompanied with no texture change, which is continuous static recrystallization.
Key words: severely deformed magnesium alloy; annealing; continuous recrystallization; microtexture