Effects of hydrostatic pressure on Stage III recovery in irradiated and cold-worked molybdenum

The Stage III recovery temperature is lowered when irradiated or cold-worked molybdenum is annealed under pressure. In irradiated samples, the pressure effect can be explained in terms of an activation volume, negative in sign, which decreases in magnitude with increasing fluence. For cold-worked molybdenum, the pressure effects are not compatible with the activation volume hypothesis. This suggests that recovery mechanisms for the two types of damage can not be considered identical, the differences probably arising from substructure features characteristic of the damage states