The stress dependence of point-defect diffusion to dislocations in 4N-purity polycrystalline material was studied by using shear-wave attenuation and phase velocity methods. Upon maintaining the stress after deformation, the attenuation and velocity approached their non-stressed values. The holding stress was varied from 0 to 12MPa, after applying a 15MPa compressive stress. Time-independent attenuation and stress-induced velocity changes were introduced into the Granato-Hikata-Lücke theory, which established the changes in attenuation and velocity which were caused by point-defect diffusion to dislocations. Good agreement was found between the measurements and the modified theory. The stress-dependence of the recovery-rate was explained in terms of a reduction in the migration energy of the point defects which diffused to dislocations, and the activation volume was calculated for a uniaxial stress. The electromagnetic acoustic resonance technique, which did not involve contact and was highly sensitive, permitted detailed measurements to be made of the attenuation and velocity changes during unloading-holding stress sequences.

Stress-Dependent Recovery of Point Defects in Deformed Aluminum - an Acoustic Damping Study. H.Ogi, A.Tsujimoto, M.Hirao, H.Ledbetter: Acta Materialia, 1999, 47[14], 3745-51