The transformation mechanisms of abnormal grain growth in nanocrystalline Ni were studied extensively by transmission electron microscopy (TEM). A combination of in situ TEM annealing and ex situ annealing followed by TEM 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