The thermal stability of extrinsic grain-boundary dislocations in near Σ = 11 grain boundaries was investigated in bi-crystalline thin foils which contained various levels of impurities. The results showed that the extrinsic grain-boundary dislocation accommodation kinetics depended strongly upon the degree of segregation. This was related to the orientation plane of the grain boundary, and to the extrinsic grain-boundary dislocation line orientation in the grain boundary plane. Their effect was interpreted mainly in terms of intergranular diffusion. They supported the conclusion that no geometrical criterion could predict grain-boundary behavior, particularly in the presence of grain boundary segregation.

Thermal Stability of Extrinsic Dislocations in Near Σ11 Grain Boundaries in Nickel W.A.Swiatnicki, S.Poulat, L.Priester, B.Decamps, M.W.Grabski: Acta Materialia, 1998, 46[5], 1711-7