(1.中南工业大学测试中心，
2.中南工业大学材料科学与工程系，长沙410083)
摘 要: 利用透射电镜对2091铝锂合金在不同热处理状态下的变形断裂过程进行了原位观察，结果表明，在不同的时效状态，合金的应变局部化不同，在近峰值时效合金变形时，位错切割δ相而产生强的共面滑移，引起应变不均匀；而在过时效态合金中，应变集中于晶界PFZ内，晶内的共面滑移带明显减弱。
关键字: 铝锂合金 变形断裂机制 原位观察
FRACTURE IN2091Al-Li ALLOY
（1Test and Analysis Center,
2Department of Materials Science and Engineering,
Central South University of Technology, Changsha 410083）
Abstract:The processes of deformation and fracture in a 2091 Al-Li alloy under various heat treatment conditions were investigated in situ by transmission electron microscopy. In near-peak aged alloy, the shearable nature of theδ′precipitates tends to localize the strain in intense deformation bands. On the other hand, in over-aged alloy, the presence of wide PFZs with copious grain boundary precipitates stimulates localized deformation in the PFZs, and the planar slip bands
are obviously weakened.
Key words: Al-Li alloy deformation fracture in situ observation
