Stacking-fault strengthening

Abstract

Abstract The energy of an extended dislocation is decreased if the energy of the stacking fault formed between its component partial dislocations is reduced. It is suggested that such an effect may influence the yield stress of an alloy containing coherent precipitates of lower stacking-fault energy than the matrix. The proposal is examined quantitatively for face-centred cubic metals, and its significance for aluminium and copper base alloys assessed. The effect is most marked in matrices of high stacking-fault energy containing unstable precipitates.