화학공학소재연구정보센터
Materials Science Forum, Vol.426-4, 1655-1659, 2003
The influence of microstructure and residual stress on pre-yield cracking in TiAl-based alloys
Cylindrical samples of Ti44Al8Nb1B (at%) have been tested in tension and the tendency for pre-yield cracking has been assessed using acoustic emission combined with microscopic examination of the surfaces before and after testing. The influence of surface preparation on pre-yield cracking of the tensile samples has been investigated. This has been correlated with the magnitude of any residual stresses associated with the different surface preparation. It has been found that although the surface preparation is important, the microstructure is the most significant factor in influencing pre-yield cracking. Thus fully lamellar samples always show pre-yield cracking, but duplex structured samples never do. Work in progress on the Ti45Al8Nb0.2C suggests that the microstructure in these alloys also dominates the behaviour. These data will be reported at the meeting.