(1 北京科技大學(xué)新金屬材料國(guó)家重點(diǎn)實(shí)驗(yàn)室，北京 100083; 2 北京理工大學(xué)，北京 100022)
摘 要: 單相Al-2Mg合金在300~530℃ 以0.069~1.587s-1形變速率扭轉(zhuǎn)到真應(yīng)變5.5， 隨后立即水冷。 采用真應(yīng)力-真應(yīng)變曲線，偏振光金相和透射電子顯微鏡研究該合金熱扭轉(zhuǎn)過(guò)程的動(dòng)態(tài)復(fù)原機(jī)制。試驗(yàn)證實(shí)，該合金熱扭轉(zhuǎn)過(guò)程中發(fā)生了動(dòng)態(tài)再結(jié)晶，但在一定的Z 參數(shù)范 圍內(nèi)發(fā)生，Z 參數(shù)過(guò)大或過(guò)小，只發(fā)生動(dòng)態(tài)回復(fù)。顯微組織分析并沒(méi)有發(fā)現(xiàn)層錯(cuò)的存在。發(fā)生動(dòng)態(tài)再結(jié)晶的原因是動(dòng)態(tài)回復(fù)被抑制，即在較高形變溫下，加大形變速率，而在較低形變溫度下，降低形變速率。
關(guān)鍵字: Al-2Mg合金；動(dòng)態(tài)再結(jié)晶；熱扭轉(zhuǎn)
（State Key Laboratory for Advanced Metals and Materials,
University of Science and Technology Beijing, Beijing 100083, P.R.China
Beijing Institute of Technology，Beijing 100022，P.R.China）
Abstract:Specimens of single phase Al-2Mg alloy have been deformed by hot torsion at 300~530℃ and strain rates of 0.069~1.587 s-1 to true strain of 5.5 followed by water quenched immediately. The dynamic restoration mechanisms during hot torsion were examined by the true stress-true strain curves，optical and electron microscopy. It has been shown that dynamic recrystallization occurs in certain range of parameter Z. If Al-2Mg alloy is deformed by torsion out of the range， only dynamic recovery occurs. The microstructural observations indicate that there are not the regions of stacking faults in the matrix. The occurrence of dynamic recrystallization results from the depression of dynamic recovery，i. e. increasing strain rate at higher temperature and reducing strain rate at lower temperature.
Key words: alaminium-magnesium alloys；dynamic recrystallization；hot torsion tests
