(1.湖南省农业机械鉴定站， 长沙 410004;
2.石油大学(华东)机械系， 东营 257062)
摘 要: 研究了2091铝锂合金超塑变形的断裂行为。 扫描电镜观察表明， 2091铝锂合金超塑变形中存在晶内断裂，光学金相观察表明断裂试样存在较活跃的动态再结晶和较多的大轴径比晶粒，透射电镜观察发现断裂试样内部存在较多的晶内位错。 研究表明，由于再结晶缩小了大轴径比晶粒的横截面使其在超塑变形的晶粒转动中受到很大的弯曲应力而造成了晶内断裂。
关键字: 关键词: 铝锂合金 超塑变形 断裂
（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
