The impact of heavy-ion produced defects on the mobility of dislocations, dislocation sources and newly generated dislocations in 304 stainless steel were discovered by performing irradiation and deformation experiments in real time in the transmission electron microscope. Dislocations mobile prior to irradiation were effectively locked in position by the irradiation, but the irradiation had no discernible impact on the ability of a source to generate dislocations. The motion and mobility of a dislocation was altered by the irradiation. It becomes irregular and jerky and the mobility increased slowly with time as the radiation-produced defects were annihilated locally. Channels created by dislocations ejected from grain boundary dislocation sources were found to have a natural width, as the emission sites within the boundary were spaced close together. Finally, the distribution of dislocations, basically, an inverse dislocation pile-up, within a cleared channel suggested a new mechanism for generating high local levels of stress at grain boundaries.

Effect of Ion Irradiation-Produced Defects on the Mobility of Dislocations in 304 Stainless Steel. M.Briceño, J.Fenske, M.Dadfarnia, P.Sofronis, I.M.Robertson: Journal of Nuclear Materials, 2011, 409[1], 18-26