(1. 中南大学 材料科学与工程学院，长沙 410083；
2. 中南大学 粉末冶金国家重点实验室，长沙 410083；
3. 中南大学 有色金属材料科学与工程教育部重点实验室，长沙 410083)
摘 要: 采用实验观察和理论计算相结合研究经多向锻造后AZ80A 镁合金等温退火过程中的显微组织演变与再结晶动力学。结果表明：经多向锻造后的AZ80A 镁合金在150 ℃退火处理时，随着退火时间的延长，再结晶晶粒逐渐增多，退火时间为3600 s 时，发生再结晶的体积分数约为88%；175 ℃退火时，合金在1800 s 时已经发生了完全再结晶，且有部分晶粒发生长大；200 ℃退火时，合金在360 s 时的再结晶体积分数约为70%，900 s 时再结晶晶粒发生长大；250 ℃退火时，退火360 s 后，再结晶晶粒已经发生了部分长大。利用Avrami 再结晶动力学方程计算可得到多向锻造态AZ80A 镁合金的再结晶激活能为71.48 kJ/mol，合金在150、175、200 和250 ℃退火时再结晶完成的时间分别为4160、1387、485 和85.6 s；计算结果与实验结果一致。
关键字: AZ80A 镁合金；等温退火；静态再结晶；再结晶动力学；
（1. School of Materials Science and Engineering,Central South University,Changsha 410083,China;
2. State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;
3. Key Laboratory of Nonferrous Metal Materials Science and Engineering,
Ministry of Education,Central South University,Changsha 410083,China）
Abstract:The microstructure evolution and the kinetics analysis of static recrystallization during annealing of multiple forged AZ80A magnesium alloy were studied by experimental observation and theoretical calculation. The results show that,with the extension of annealing time,the recrystallized grains increase gradually at the annealing time of 3600 s,the volume function of recrystallization is about 88% after annealing heat treatment at 150 ℃; when the annealing temperature is 175 ℃ and the annealing time is 1800 s,the fully static recrystallization occurs and some grains grow up; at the annealing temperature of 200 ℃,the volume fraction of recrystallized grains is about 70% at the annealing time of 360 s,and some of the recrystallied grains grow up at annealing time of 900 s. At the temperature of 250 ℃,the recrytallized grains grow up after 360 s. Based on the Avrami kinetics analysis of static recrystallization process,the full recrystallization times at 150,175,200 and 250 ℃ are 4160,1387,485 and 85.6 s,respectively. The recrystallization energy for multiple forged AZ80A magnesium alloy is 71.48 kJ/mol,and calculated results are consistent with the experimental ones.
Key words: AZ80A magnesium alloy; isothermal annealing; static recrystallization; recrystallization kinetics
