A discrete dislocation model was used to rationalize the stability of interface dislocation configurations in particle-strengthened alloys having microstructures like those found in monocrystalline superalloys; where large cubes of ordered γ’-phase (1μ) were separated by thin channels (0.1μ). The model combined 3 elements which contributed to the overall stress state. These were an external constant applied stress, coherency stresses (due to misfit between matrix and particle) and stresses which were associated with dislocations. The Peach-Koehler forces on interface dislocations were calculated on the basis of this overall stress state. The calculations were performed by using a 2-dimensional model for a (110) projection of the overall microstructural scenario. The stability of simple dislocation arrays at the γ/γ’ interface was studied with regard to the interaction of 2 octahedral slip systems in the thin γ-channels. When compared with the case where only one octahedral slip system was activated, simultaneous glide in 2 octahedral slip systems further decreased the number of dislocation loops which could enter the channel in each of the 2 slip systems.

Static Dislocation Interactions in Thin Channels between Cuboidal Particles. A.Dlouhý, M.Probst-Hein, G.Eggeler: Materials Science and Engineering A, 2001, 309-310, 278-82