Recovery Creep in Materials Hardened by a Second Phase

A recovery creep model, based upon previous theories by McLean and co-workers, has been developed for creep in materials hardened by a second phase. According to the model the increased creep strength in these materials is caused by a decrease in the recovery rate, and this in turn is due to a decrease of the driving force for the recovery process and of the mobility of the climbing dislocations involved in the process. It is shown that the model can account for the very large stress-dependence of the creep-rate often found for alloys hardened by a second phase. Another support for the model is the observation that changes in the creep-rate for materials in different states of precipitation-hardening are entirely due to changes in the recovery rate.