Stacking Fault Energies of α‐CuAl Alloys

Stacking fault energy of Cu‐2at% Al has been estimated to be 83 erg/cm 2 (± 30%) by faulted dipole method and by extended nodes measurements. Using this value, and those obtained by Howie and Swann, the stacking fault energy of copper is estimated to be 94 erg/cm 2 . It is shown that the variation of stacking fault energy of Cu‐Al alloys with concentration is given approximately as γ CuAl = γ Cu exp { K [ C /(1+ C )] 2 }, where C = X / X 0 , X being the alloying concentration in at% and X 0 the solubility limit in at% at high temperature, and K is a constant ≈ ‐ 10.2.