REVIEW OF TWIN AND STACKING-FAULT ENERGIES IN AL, MG AND BE

Twin and stacking fault energies in Al, Mg and Be calculated from the pseudopotential theory are reviewed and classified according to the computational method. For a given pseudopotential, the different methods agree between themselves and give the right order of magnitude as compared with the experimental energy. The energy values are nearly proportional to the number of stacking errors, and therefore in Al gamma t approximately= 1/2 gamma i approximately=1/ 2 gamma e where gamma t, gamma i and gamma e are the twin, intrinsic and extrinsic fault energies respectively.