Super-dislocations in the γ' phase of the fourth-generation single-crystal superalloy were characterized after creep rupture at a stress of 137MPa and various temperatures. The number of slip dislocations increased upon increasing the creep temperature from 1100 to 1150C. The predominant cutting mode of the γ' phase involved dislocation pairs coupled by an antiphase boundary. Common super-dislocations in the γ' phase exhibited a screw nature; with Burgers vectors of <011> or <101>. Also observed in the γ' phase were 60° or screw super-dislocations in either the [110] or [1¯10] directions, and [001] edge super-dislocations. Stacking faults arose from the dissociation of super-dislocations. These super-dislocations were related to damage of the rafted structure of the superalloy.

Slip Geometry of Dislocations Related to Cutting of the γ' Phase in a New Generation Single-Crystal Superalloy. J.X.Zhang, T.Murakumo, Y.Koizumi, T.Kobayashi, H.Harada: Acta Materialia, 2003, 51[17], 5073-81