The transformation mechanisms of abnormal grain growth in nanocrystalline Ni were studied extensively by transmission electron microscopy. A combination of in situ transmission electron microscope annealing and ex situ annealing followed by transmission electron microscopic characterization was used. It was observed that grain boundary migration was both spatially and temporally non-uniform; migration occurred in a series of discrete steps, which were followed by periods of stagnation.

Grain Boundary Migration During Abnormal Grain Growth in Nanocrystalline Ni. G.D.Hibbard, V.Radmilovic, K.T.Aust, U.Erb: Materials Science and Engineering A, 2008, 494[1-2], 232-8