Study on fracture mechanisms of TiAl alloys by in-situ tensile tests

	Study on fracture mechanisms of TiAl alloys by in-situ tensile tests
	Cao, R.1; Chen, J. H.1; Zhang, J.2
	2007
关键词	TiAl alloy fracture process fracture mechanism
卷号	353-358
页码	34-+
英文摘要	Combining in-situ tensile tests with detailed observations of fracture surfaces of a two-phase TiAl alloy, the fracture process and fracture mechanisms of TiAl alloys are investigated. 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, In specimens with a slit notch, most cracks are initiated directly from the notch root and extended along lamellar interfaces. The main crack can be stopped or deflected into a delamination mode by a barrier grain with a lamellar interface orientation deviated from the direction of crack propagation. In this case, new cracks are nucleated along lamellar interfaces of grains with favorable orientation ahead the barrier grain. The main crack and a new crack are then linked by the translamellar cleavage fracture of the barrier grain with increasing applied load. In order to extend the main crack, further increases of the applied load are needed to move the high stress region into the ligament until final fracture. The process of a new crack nucleation with a bridging ligament formation decreases the crack propagation resistance rather than increases it.
会议录	PROGRESSES IN FRACTURE AND STRENGTH OF MATERIALS AND STRUCTURES, 1-4
会议录出版者	TRANS TECH PUBLICATIONS LTD
会议录出版地	KREUZSTRASSE 10, 8635 DURNTEN-ZURICH, SWITZERLAND
语种	英语
资助项目	National Nature Science Foundation of China[50471109]
WOS研究方向	Materials Science
WOS记录号	WOS:000252246300006
内容类型	会议论文
源URL	[http://119.78.100.223/handle/2XXMBERH/38204]
专题	材料科学与工程学院
通讯作者	Cao, R.
作者单位	1.Lanzhou Univ Technol, State Key Lab Adv Nonferrous Met Mat, Lanzhou 730050, Peoples R China 2.Cent Iron & Steel Res Inst, Beijing 100081, Peoples R China
推荐引用方式 GB/T 7714	Cao, R.,Chen, J. H.,Zhang, J.. Study on fracture mechanisms of TiAl alloys by in-situ tensile tests[C]. 见:.