Structures atomiques de dislocations à l'intersection de fautes d'empilement dans un cristal c.f.c. à base (Ni, Co)

Abstract

Abstract A (Ni, Co)-based two-phase superalloy has been plastically deformed at room temperature, producing various dislocation and stacking-fault configurations in the f.c.c. matrix. The structures of some dislocation cores were observed at atomic scale using high-resolution electron microscopy, namely a (b = ⅓〈110〉 stair-rod and (b = ⅙〈112〉 Shockley partials at the intersections of crossing intrinsic or extrinsic faults. The displacement fields of the surrounding atomic columns are found to be in good agreement with the fields calculated using anisotropic elasticity theory, except quite close to the cores of the dislocations.