In-situ SEM/EBSD observation of abnormal grain growth in electrodeposited nanocrystalline nickel

An in-situ SEM/EBSD technique has been applied to observe initial-stage and late-stage abnormal grain growth in electrodeposited nanocrystalline nickel with the aim of obtaining a comprehensive understanding of the dynamics of abnormal grain growth. We found that the late-stage abnormal grain growth occurred in an anisotropic manner such that the area of faceted {001} planes increased, and the faceted interface migrated by step motion. During abnormal grain growth, low-angle boundary and low-R CSL boundaries such as σ3 and σ9 were found to migrate more slowly than random boundaries. As a result, small grains that possessed a CSL relation with the abnormally growing grain were often embedded into the abnormal grain. Initial-stage and late-stage abnormal grain growth both obeyed a parabolic growth law. © Carl Hanser Verlag GmbH & Co. KG.