(1.湖南省農(nóng)業(yè)機械鑒定站， 長沙 410004;
2.石油大學(華東)機械系， 東營 257062)
摘 要: 研究了2091鋁鋰合金超塑變形的斷裂行為。 掃描電鏡觀察表明， 2091鋁鋰合金超塑變形中存在晶內斷裂，光學金相觀察表明斷裂試樣存在較活躍的動態(tài)再結晶和較多的大軸徑比晶粒，透射電鏡觀察發(fā)現(xiàn)斷裂試樣內部存在較多的晶內位錯。 研究表明，由于再結晶縮小了大軸徑比晶粒的橫截面使其在超塑變形的晶粒轉動中受到很大的彎曲應力而造成了晶內斷裂。
關鍵字: 關鍵詞: 鋁鋰合金 超塑變形 斷裂
（1.Agricultural Machinery Appraisement Station of Hunan Province,Changsha 410004, P. R. China
2.University of Petroleum,Dongying 257062, P. R. China）
Abstract:The fracture behaviors in superplastic deformation of 2091 Al-Li alloy have been investigated. SEM observations indicated that interior fracture existed in superplastic deformation of 2091 Al-Li alloy. Optical metallography observations also indicated that there were active dynamic recrystallization and a lot of grains with great ratio of longitudinal size with latitudinal size in fracture specimen. TEM observations found that lots of interior dislocations were created in fracture specimen. It is indicated that interior fracture in superplastic deformation of 2091 Al-Li alloy is caused by great bending stress created by grain rotation due to cross section size of grains with great ratio of longitudinal size with latitudinal size decreased by recrystallization.
Key words: Al-Li alloy superplastic deformation fracture
