多向鍛造AZ80A 鎂合金的靜態再結晶行為Static recrystallization behavior of multi-directional forged AZ80A magnesium alloy

采用實驗觀察和理論計算相結合研究經多向鍛造后AZ80A 鎂合金等溫退火過程中的顯微組織演變與再結晶動力學。結果表明：經多向鍛造后的AZ80A 鎂合金在150 ℃退火處理時，隨著退火時間的延長，再結晶晶粒逐漸增多，退火時間為3600 s 時，發生再結晶的體積分數約為88%；175 ℃退火時，合金在1800 s 時已經發生了完全再結晶，且有部分晶粒發生長大；200 ℃退火時，合金在360 s 時的再結晶體積分數約為70%，900 s 時再結晶晶粒發生長大；250 ℃退火時，退火360 s 后，再結晶晶粒已經發生了部分長大。利用Avrami 再結晶動力學方程計算可得到多向鍛造態AZ80A 鎂合金的再結晶激活能為71.48 kJ/mol，合金在150、175、200 和250 ℃退火時再結晶完成的時間分別為4160、1387、485 和85.6 s；計算結果與實驗結果一致。

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.

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