Ho-Kyung Kim, Sung-Hoon Kim, Chang-Young Hyun
June 11, 2013
In this study, the hydrogen embrittlement technique was employed in order for the direct observation of entire cavities on exposing grain boundary facets in a Ni3Al alloy. Also, stereo pair SEM micrographs were used to investigate the effects of inclined angle of grain boundary on cavity growth, by comparing relative positions of features on the stereo pair. Many of cavities at 65% of the rupture time are on the verge of coalescing with other cavities. Cavities on inclined boundaries had grown for longer time than those on transverse boundaries. Thus, the time to cavity coalescence on transverse facets are lower bound of the material lifetime. And, overall damage was found to have the value of about 0.6 at rupture.