Stacking fault propagation from a coherent twin boundary

Abstract

Stacking faults nucleated at an annealing twin boundary in pure nickel are analysed by electron microscopy. The formation of the stacking faults is qualitatively explained in terms of the forces acting on the partial dislocations in the annealing twin boundary and in the matrix. The critical factors are found to be the orientation of the driving stress with respect to the Burgers vectors of the Shockley dislocations and the large change in stacking fault energy between the twin boundary and the matrix.