Reed, P.A.S. and Miller, M.D.
Effect of Environment on Notch Fatigue Initiation Resistance in CMSX4.
In, TMS Spring Meeting, San Francisco, USA,
Full text not available from this repository.
Crack initiation at high temperatures has been studied in CMSX4 in both air and vacuum environments, to elucidate the effect of oxidation on the notch fatigue initiation process. In air, crack initiation occurred at sub-surface interdendritic pores in all cases. The sub-surface crack grows initially under vacuum conditions, before breaking out to the top surface. Lifetime is then critically dependent on initiating pore size and distance from the notch root surface. In vacuum conditions, crack initiation has been observed more consistently from surface or close-to-surface pores - indicating that surface oxidation is in-filling/”healing” surface pores or providing significant local stress transfer to shift initiation to sub-surface pores.
Actions (login required)