(1. 石油大學（華東） 機電工程系， 東營 257061；
2．中南大學 材料科學與工程系， 長沙 410083)
摘 要: 研究了2091鋁鋰合金動態(tài)再結(jié)晶誘發(fā)超塑變形中的空洞行為。金相觀察和圖象分析表明，在最佳變形條件下，空洞率及空洞平均直徑先隨著變形增大而增大，變形至ε=1.03時，空洞率及空洞平均直徑均減小，出現(xiàn)了超塑變形初期的空洞彌合現(xiàn)象。超塑變形初期的空洞形核取決于應(yīng)變速率，最佳應(yīng)變速率下斷裂試樣出現(xiàn)大量的圓角空洞，并且此時空洞率出現(xiàn)最大值。
關(guān)鍵字: 鋁鋰合金； 動態(tài)再結(jié)晶； 超塑性； 空洞
during superplastic deformation induced by
dynamic recrystallization
（1. Electromechanical Department, University of Petroleum (East China),
Dongying 257061, P.R.China；
2. Department of Materials Science and Engineering,
Central South University,Changsha 410083, P.R.China）
Abstract:Cavity behaviors of 2029 Al-Li alloy during superplastic deformation induced by dynamic recrystallization were investigated. Metallographic observation and image analyses show that on the optimum deformation condition (ε·=5×10-3 s-1), the deformation cavity ratio and cavity average diameter first increase with deformation, then decrease from ε=0.37 to ε=1.03 obviously. A phenomenon of cavity annihilation occurs at the initial stage of deformation. The observation also shows that cavity nucleation at initial stage of deformation depends on strain rate. More cavities with smooth corner exhibits in fractured specimens only at optimum strain rate, and cavity ratio reachs the top value.
Key words: Al-Li alloys; dynamic recrystallization; superplasticity; cavity
