Direct measurements of stacking-fault energies from observations of dislocation nodes

From measurements of the radius of curvature of extended dislocation nodes observed by transmission electron microscopy, stacking-fault energies have been determined for a number of copper and silver base aluminium and zinc solid solution alloys and also for a number of nickel-cobalt alloys. Rough estimates of about 40, 25 and 150 erg cm −2 respectively can be made of the stacking-fault energies of copper, silver and nickel. The accuracy of the measurement and the possibility of segregation of solute atoms to stacking faults are discussed.