An increased atomic diffusion during plastic deformation was detected by using an improved rotating-frame nuclear spin resonance technique. The increase was attributed to the effect of excess vacancies which were created by deformation. The 27Al nuclear magnetic resonance experiments were carried out, at various temperatures, on polycrystalline foils of pure Al during deformation at a constant strain rate. An evaluation of the data yielded the actual concentration of excess vacancies as a function of temperature, strain and strain rate. It was found that the results were consistent with a model which described vacancy formation as a function of the applied deformation power density (product of applied stress and strain rate), and vacancy annihilation in terms of their diffusion to dislocations which acted as vacancy sinks.

K.Detemple, O.Kanert, J.T.M.De Hosson, K.L.Murty: Physical Review B, 1995, 52[1], 125-33