An in situ transmission electron microscopy study was performed on ultrafine-grained aluminium during tensile loading and unloading in the micro-yield regime. The goal was to assess the reasons for the unusually large inelastic backflow that had been observed earlier during unloading on ultrafine-grained material, as compared to that of conventional grain size material. It was noted that in particular edge dislocations emitted by sources within the grains during loading run back into the dislocation sources and disappeared during unloading, explaining at least semi-quantitatively the rather large inelastic back-flow in ultrafine-grained material.

In situ TEM Observations of Reverse Dislocation Motion upon Unloading of Tensile-Deformed UFG Aluminium. F.Mompiou, M.Legros, D.Caillard, H.Mughrabi: Journal of Physics - Conference Series, 2010, 240[1], 012137