Adoucissement d'un superalliage base nickel sous-vieilli en fatigue oligocyclique

Like most of the alloys containing shearable precipitates, the under-aged Waspaloy hardens in low-cycle fatigue to a maximum stress and presents a subsequent softening period. Although this phenomenon is known to be due to repeated precipitate shearing by dislocations, the softening corresponds to a decrease of the kinematic hardening. Microscopic observations lead to understand the physical origin of the softening and the importance of the reversibility.