Original title:
Effect of Microstructure Change on the Crack Formation of Heat Treated Ti-Al Intermetallic Compound
Authors:
Hasegawa, H. ; Nomura, M. ; Haga, H. ; Dlouhý, Ivo ; Fukutomi, H. Document type: Papers Conference/Event: New Methods of Damage and Failure Analysis of Structural Parts, Ostrava (CZ), 2012-09-10 / 2012-09-14
Year:
2012
Language:
eng Abstract:
Heat treatments were conducted under several conditions in order to clarify the effect of holding temperature, time and cooling rate on microstructure of Ti-46Al-7Nb-0.7Cr-0.2Ni-0.1Si and Ti-45Al-10V (mol%) alloys. Indentation tests were performed in order to understand the effect of beta phase precipitation on crack formation of microstructure controlled Ti-45Al-10V alloy. As for Ti-46Al-7Nb-0.7Cr-0.2Ni-0.1Si alloy, phase condition on several temperatures was estimated experimentally. It is found that the cooling rate where the massive transformation occurs ranges from -300K/s to -5K/s. Furthermore, in order to obtain the fully lamellar structure, the alloy should be cooled slower than -1K/s. As regards the heat treatment on Ti-45Al-10V alloy, fully lamellar structure was formed by cooling from (alfa+gama) two phase state. However, beta precipitates were observed near the lamellar colony boundaries when the material was cooled from (beta+gama) two phase state. Though the cracks are not observed at the specimen cooled at -8x10-2K/s from (alfa+gama) two phase state, the cracks induced by Vickers indentation are observed in most of the heat treated specimens.
Keywords:
beta phase precipitation; crack formation; microstructure control; TiAl intermetallic compound Project no.: ME10117 (CEP) Funding provider: GA MŠk Host item entry: New Methods of Damage and Failure Analysis of Structural Parts, ISBN 978-80-248-2802-2
Institution: Institute of Physics of Materials AS ČR
(web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences. Original record: http://hdl.handle.net/11104/0211308