Atomistic dynamical observation of grain boundary structural changes under electron irradiation

We investigated the structural changes in two grain boundaries with different grain boundary nature during electron irradiation using an atomic-resolution high-voltage electron microscope. It was found that the morphology of one type of grain boundary changed due to boundary movement during the irradiation, whereas another type of grain boundary did not show such structural change. On the other hand, solute segregation was induced in the vicinity of both grain boundaries. It was found that differences between the two grain boundaries, particularly the difference between grain boundary interfacial planes prior to irradiation, caused the different grain boundary migration behavior.