Fracture mechanism of a tial alloy

	Fracture mechanism of a tial alloy
	Chen, J.H.1 ; Cao, R.1 ; Zhang, J.2; Wang, G.Z.1
	2005
会议名称	11th International Conference on Fracture 2005, ICF11
会议录名称	11th International Conference on Fracture 2005, ICF11
卷号	6
页码	3974-3979
会议日期	March 20, 2005 - March 25, 2005
会议地点	Turin, Italy
出版者	International Congress on Fracture
摘要	Combining with in-situ tensile tests, the macro-results of 3PB tests and detailed observations of fracture surfaces and remaining cracks in unloaded precracked specimens of a two-phase TiAl alloy, results of series investigations on the fracture mechanisms of a TiAl alloy are summarized. The results reveal that Cracks prefer to initiate and propagate along lamellar interfaces, which are the weakest link in the near fully lamellar microstructure. The interlamellar strength calculated is less than the translamellar strength. The tensile stress is the driving force for crack initiation and propagation. The inverse relationship between ductility and fracture toughness of finer duplex and coarser near fully lamellar microstructures is caused by the difference of the crack propagation path taken by the crack in the tensile test and in the bending test of precracked specimens where the sampling volume is different. On the fracture surfaces of the coarse near fully lamellar microstructure, less low-energy interlamellar fracture facets are observed, which means that it is more difficult for the crack to bypass the coarser near fully lamellar grain with unfavorable direction and to take the interlamellar path. But in tensile tests, due to the much larger sampling volume, the cracks take the weakest path and show an inferior ductility in a coarse grain microstructure. The toughening mechanisms, which make propagation of the main crack difficult to propagate or cause it to be stopped, could be: Reducing the driving force by blunting of crack tip; Bifurcation of the crack tip; Deflection of the crack by lamellae and formation of a diffuse zone of microcracks; Stopping the crack at the boundary of a grain with unfavorable orientation or γ grains and forcing the crack to bypass the barrier grain and take a tortuous path, or cross the barrier grain spending more energy.
关键词	Aluminum alloys Binary alloys Crack propagation Ductility Fracture toughness Metal testing Microcracks Microstructure Tensile strength Tensile testing Titanium alloys Blunting of crack tips Crack initiation and propagation Crack propagation path In-situ tensile test Interlamellar strength Inverse relationship Precracked specimens Toughening mechanisms
收录类别	EI
语种	英语
EI入藏号	20124815728159
EI主题词	Crack tips
来源库	Compendex
分类代码	541.2 Aluminum Alloys - 542.3 Titanium and Alloys - 951 Materials Science
文献类型	会议论文
条目标识符	https://ir.lut.edu.cn/handle/2XXMBERH/117106
专题	材料科学与工程学院_特聘教授组材料科学与工程学院
作者单位	1.College of Materials Science and Engineering, State Key Laboratory for New Materials of Non-Ferrous Metal, Lanzhou University of Technology, Lanzhou, 730050, China; 2.High Temperature Material Research Division, Central Iron and Steel Research Institute, Beijing, 100081, China
第一作者单位	兰州理工大学
推荐引用方式 GB/T 7714	Chen, J.H.,Cao, R.,Zhang, J.,et al. Fracture mechanism of a tial alloy[C]:International Congress on Fracture,2005:3974-3979.