Fracture behavior of notched specimens of TiAl alloys |
| |
Authors: | J H Chen R Cao J Zhang G Z Wang |
| |
Affiliation: | (1) State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou, Gansu, 730050, China;(2) High Temperature Material Research Division, Central Iron and Steel Research Institute, Beijing, 100081, China |
| |
Abstract: | Fracture behavior of a two-phase TiAl alloy was investigated using notched specimens. Fracture surfaces and metallographic
sections of surviving notch in double notched specimens are observed. The fracture process of notched specimens of TiAl alloys
was described as that several inter-lamellar cracks initiate and extend directly from the notch root and propagate preferentially
along the interfaces between lamellae and stop at various obstacles. With increasing applied load, cracks connect with each
other and propagate further by translamellar cracks. The toughening mechanisms, which make the main crack difficult to propagate
or cause it to be stopped, could be reducing the driving force for crack propagation. The higher toughness of near fully lamellar
microstructure than that of finer duplex microstructure is attributed to the path of crack propagation. On the fracture surfaces
of the finer duplex microstructure, more low-energy-spending interlamellar fracture facets are observed, which means that
it is easier for crack to bypass a fine duplex lamellar grain with lamellae perpendicular to the main crack and to take a
interlamellar path. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|