The generalized stacking fault energies, Rice-criterion ductilities, and twinnabilities of selected Ni-x solid-solution alloys (x = Nb, W, Mn, Fe, Cu) were calculated using density functional theory to elucidate how alloying alters the mechanical properties of pure Ni. Relative to Ni, the alloys have smaller stacking fault energies (γsf), similar ductilities, and a greater tendency to undergo deformation twinning. The results were compared to experimental studies of the mechanical properties of nanocrystalline Ni alloys from the literature, and it was suggested that the higher strain-hardening rate recently reported for nanocrystalline-Ni-Cu (relative to nanocrystalline-Ni-Fe) did not arise from differences in γsf, but from a higher dislocation density caused by more facile dislocation nucleation.

Generalized Stacking Fault Energies, Ductilities and Twinnabilities of Ni and Selected Ni Alloys. D.J.Siegel: Applied Physics Letters, 2005, 87[12], 121901 (3pp)