(1.中南工業(yè)大學(xué)測試中心，
2.中南工業(yè)大學(xué)材料科學(xué)與工程系，長沙410083)
摘 要: 利用透射電鏡對2091鋁鋰合金在不同熱處理狀態(tài)下的變形斷裂過程進(jìn)行了原位觀察，結(jié)果表明，在不同的時(shí)效狀態(tài)，合金的應(yīng)變局部化不同，在近峰值時(shí)效合金變形時(shí)，位錯(cuò)切割δ相而產(chǎn)生強(qiáng)的共面滑移，引起應(yīng)變不均勻；而在過時(shí)效態(tài)合金中，應(yīng)變集中于晶界PFZ內(nèi)，晶內(nèi)的共面滑移帶明顯減弱。
關(guān)鍵字: 鋁鋰合金 變形斷裂機(jī)制 原位觀察
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
