Abstract
Hot-stage electron microscopy is used to study the annealing behaviour of lattice dislocations in high-angle grain boundaries in Ni, Ni 5% Al, austenitic stainless steel and Al 0·9 % Mg. The observations indicate that individual dislocations are incorporated in a boundary by a spreading of their cores or a dissociation into partial dislocations with small Burgers vectors. This process results in a rearrangement of the grain boundary structure by grain boundary diffusion. It is shown that this process enables a random grain boundary to incorporate more than 1012 dislocations cm−2 at the recrystallization temperature.