(中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 針對(duì)半連續(xù)鑄造的AZ31B鎂合金，采用Gleeble−1500熱/力模擬機(jī)在變形溫度為473~723 K、應(yīng)變速率為0.01~10 s−1、最大變形量為80%條件下進(jìn)行熱/力模擬研究；結(jié)合熱變形后的顯微組織，分析合金力學(xué)性能與顯微組織之間的關(guān)系。結(jié)果表明：當(dāng)變形溫度一定時(shí)，流變應(yīng)力和應(yīng)變速率之間存在對(duì)數(shù)關(guān)系，并可用包含Arrheniues項(xiàng)的Z參數(shù)描述半連續(xù)鑄造的AZ31B鎂合金熱壓縮變形的流變應(yīng)力行為；實(shí)驗(yàn)合金在523 K時(shí)開始發(fā)生動(dòng)態(tài)回復(fù)；隨著變形溫度的升高和應(yīng)變速率的降低，動(dòng)態(tài)再結(jié)晶開始對(duì)AZ31B合金的變形行為產(chǎn)生明顯影響，在變形溫度623 K以上的各種應(yīng)變速率下，AZ31B鎂合金易變形。
關(guān)鍵字: AZ31B鎂合金；熱壓縮變形；流變應(yīng)力；組織演變
semi-continuous cast AZ31B magnesium alloy
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The deformation behaviors of AZ31B magnesium alloy at different strain rates of 0.01−10 s−1 and different deformation temperatures of 473−723 K were investigated by using Gleeble-1500 simulator with a maximum strain of 80%. The microstructure of the experimental alloy was studied after the hot-compression procedure. The result shows that the relationship among the peak flow stress, strain rate and temperature can be described by Z parameter containing Arrheniues item. The strain rate and the deformation temperature are the key parameters affecting the alloy deformation activation energy. Dynamic recovery starts at the temperature of 523 K. With increasing the temperature or decreasing the strain rate, the dynamic recrystallization procedure has great influence on the deformation behavior. The alloy is easy to deform at the temperature above 623 K.
Key words: AZ31B magnesium alloy; hot-compressive deformation; flow stress; microstructure evolution
