Abstract
The critical misfit for dislocation creation and the equilibrium distance of misfit dislocations in nickel-based superalloys with high volume fraction of the ordered phase were calculated using anisotropic elastic theory. It is shown that incorrect use of Brook's formula for determining the misfit from dislocation distances in these alloys has frequently led to wrong results in the literature. The results are compared with experimental data for aged samples of SRR 99. Indications for a cubic-to-tetragonal phase transition of the γ′-phase of SRR 99 at high temperature were found.
