Preliminary evidence suggested that the presence of grain boundaries, with misorientations that were described by low-Σ CSL relationships, had an appreciable effect upon bulk plasticity. An increase in the frequency of so-called special boundaries, and special triple junctions, improved the ductility by a factor of 3. This was accompanied by a decrease of similar magnitude in the flow stress. Scanning electron microscopy indicated that the presence of so-called grain boundaries, in sufficient quantities, encouraged delocalization in plastic flow as shown by a tendency for these microstructures to undergo diffuse necking in response to an applied strain. Further evidence clearly suggested that the extent to which triple junctions contribute to polycrystalline plasticity depended upon their defect structure.

On the Role of Intercrystalline Defects in Polycrystal Plasticity E.M.Lehockey, G.Palumbo, K.T.Aust, U.Erb, P.Lin: Scripta Materialia, 1998, 39[3], 341-6