Activation energy of creep in 〈001〉-oriented superalloy CMSX-4 single crystals

The available experimental data on the creep behaviour of the two-phase nickel-base superalloy CMSX-4 single crystals show that the activation 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 〈001〉-oriented nickel base superalloy single crystals taking into account dislocation slip, dynamic recovery, migration of the γ/γ′ interfaces and coarsening of the rafted structure has been developed. The simulated creep curves and the predicted values of the activation energy are in reasonable agreement with the experimental findings of Schneider and Mughrabi [1].