On the attractive particle–dislocation interaction in dispersion-strengthened material

Abstract

The combined climb–detachment process, controlled by “interfacial pinning’ of dislocations by the attractive incoherent dispersoid particles, is critically analysed. The athermal detachment stress is recalculated (i) within the framework of the Fleischer–Friedel weak point-obstacle approximation and (ii) taking into account the particle-spacing /climb statistics. Thus inadequate restrictions of the successful model of Arzt, Rösler and Wilkinson (ARW) can be eliminated. The predicted creep thresholds cover the range from 0.13 to 0.45 (Gb/L) and are, therefore, considerably lower than the values of the ARW estimate.