(1. 石油大学（华东） 机电工程系， 东营 257061；
2．中南大学 材料科学与工程系， 长沙 410083)
摘 要: 研究了2091铝锂合金动态再结晶诱发超塑变形中的空洞行为。金相观察和图象分析表明，在最佳变形条件下，空洞率及空洞平均直径先随着变形增大而增大，变形至ε=1.03时，空洞率及空洞平均直径均减小，出现了超塑变形初期的空洞弥合现象。超塑变形初期的空洞形核取决于应变速率，最佳应变速率下断裂试样出现大量的圆角空洞，并且此时空洞率出现最大值。
关键字: 铝锂合金； 动态再结晶； 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
