(1. 湖南大學(xué) 汽車車身先進設(shè)計制造國家重點實驗室，長沙 410082；
2. 湖南大學(xué) 機械與運載工程學(xué)院，長沙 410082)
摘 要: 通過Gleeble-3500熱壓縮試驗機對AZ31鎂合金進行熱壓縮實驗，得到溫度為300、350、400、450和500 ℃，應(yīng)變速率為0.03、0.3、和3 s-1的流變應(yīng)力曲線。對流變應(yīng)力曲線進行圖形變換求解出不同應(yīng)變速率下的回復(fù)參數(shù)r，求得的回復(fù)參數(shù)的自然對數(shù)lnr與溫度的倒數(shù)1/T成線性相關(guān)。結(jié)果表明：可以采用修正的Laasraoui-Jonas(L-J)位錯密度模型計算AZ31鎂合金動態(tài)再結(jié)晶過程中的位錯密度演變；修正的L-J位錯密度模型結(jié)合元胞自動機(CA)能精確地模擬位錯密度動態(tài)再結(jié)晶過程。
關(guān)鍵字: AZ31鎂合金；L-J位錯密度模型；動態(tài)再結(jié)晶
（1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University,
Changsha 410082, China;
2. College of Mechanical and Vehicle Engineering, Hunan University, ）
Abstract:The hot compression tests of AZ31 magnesium alloy were performed on the Gleeble-3500 machine to obtain the flow stress curves under temperatures of 300, 350, 400, 450 and 500 ℃ and strain rates of 0.03, 0.3 and 3 s-1. The recovery parameter (r) under different strain rates were calculated by transformation of flow stress curves. A linear correlation between lnr and 1/T was observed. The results show that the modified Laasraoui-Jonas (L-J) dislocation density equation can be employed to calculate the dislocation evolution during dynamic recrystallization of AZ31 magnesium alloy. The results simulated from modified L-J dislocation density model coupled with Cellular Automata (CA) method are well matched with the experimental results.
Key words: AZ31 magnesium alloy; L-J dislocation density model; dynamic recrystallization
