It was recalled that dislocation networks could relax coherency stresses at the γ/γ interfaces of the lamellar γ-phase. However, information on these networks was usually incomplete. It was shown here, using a specific example, that a systematic theoretical analysis was required in order to remove some of the uncertainty and yield all possible solutions. It was concluded that, when a periodic planar dislocation network was observed, the long-range stress field and rotation field were completely determined; provided that the positions of the dislocation lines and the Burgers vectors were known with regard to direction, sense and length. When such information was not known, the fundamental equations had to be examined very carefully.

Relaxation of Coherency Stresses by Dislocation Networks in Lamellar γ-TiAl. G.Saada, A.Couret: Philosophical Magazine A, 2001, 81[9], 2109-20