On the occurrence of extrinsic stacking faults in some copper-base and silver-base alloys

The earlier X-ray data of stacking-fault probabilities in some cold-worked Cu-base and Ag-base alloys have been reanalysed to detect the presence of extrinsic faults. Results indicate that these are present in the alloys having higher solute content. The probability of their occurrence increases with the increase of the valency of the solutes and with the increase of intrinsic faults and decrease of twin faults. However, in certain cases, the measured twin-fault probabilities not only decrease, but become unreasonably large and negative. The observations are in accordance with recent findings on the occurrence of extrinsic faults in cold-worked face-centred cubic alloys.