Abstract
Application of existing theories of age-hardening due to ordered phase to the measured strength of Udimet 520 has revealed that the theoretical predictions of particle spacing along a dislocation are lacking in validity and should be elaborated. In this study, distribution of γ′ particles in a slip plane in Udimet 520 was determined on the basis of direct observations of partial dislocation loops formed around particles during creep deformation. Then the sequence of dislocation movement through the array of γ′ particles was examined. The mean particle spacing along a dislocation was determined and expressed as a function of the size and volume fraction of particles and the applied stress. A comparison of the values of particle spacing evaluated in this study with existing theoretical predictions was made.
