ACTIVATION-ENERGY OF CREEP IN [001]-ORIENTED SUPERALLOY CMSX-4 SINGLE-CRYSTALS

The available experimental data on the creep behaviour of the two-phas e nickel-base superalloy CMSX-4 single crystals show that the activati on energy of the steady-state creep is much higher than the activation energies of self-diffusion in both the phases. A model of creep in [0 01]-oriented nickel base superalloy single crystals taking into accoun t dislocation slip, dynamic recovery, migration of the gamma/gamma' in terfaces and coarsening of the rafted structure has been developed. Th e simulated creep curves and the predicted values of the activation en ergy are in reasonable agreement with the experimental findings of Sch neider and Mughrabi [1]. (C) 1997 Elsevier Science S.A.