Variations of the dislocation density, with stacking-fault energy, were measured in shock-deformed Cu and Cu-Al alloys. Differential scanning calorimetry was used to measure the stored energy; from which the dislocation density was estimated. The energy which was released during recrystallization in the differential scanning calorimetry experiments was attributed mainly to the annihilation of dislocations; with the energy contributions arising from recovery, deformation twins and point-defects considered to be relatively small. The dislocation density in 10GPa shock-deformed samples first increased and then decreased with increasing Al content (decreasing stacking-fault energy), while the dislocation density in 35GPa shock-deformed samples first decreased and then remained constant with increasing Al content. This variation in dislocation density in the shock-deformed materials was attributed to the nature of shock-deformation, the influence of stacking-fault energy upon dislocation storage mechanisms, and the tendency to deformation twinning.

The Variation of Dislocation Density as a Function of the Stacking Fault Energy in Shock-Deformed FCC Materials. A.Rohatgi, K.S.Vecchio: Materials Science and Engineering A, 2002, 328[1-2], 256-66