Dislocation interaction with a Σ = 3 grain boundary in body-centered cubic Fe-4at%Si was investigated by means of in situ transmission electron microscopy. The dislocations, whose Burgers vector belonged to the grain-boundary plane, cross-slipped out of their slip-band, and did not form stress concentrations. No slip transfer through the grain boundary was observed at this stage. The trapped dislocations exerted a back-force on the new incoming dislocations, and either stopped them or pushed them to the sides of the slip band. An apparently short-ranged behavior of this force was attributed to surface effects. Easy cross-slip in body-centered cubic metals led to a spreading of the tip of a slip band, and the stress concentration which might overcome the grain-boundary resistance lost its advantage.

Dislocation Interaction with a S = 3 Grain Boundary Observed by in situ TEM. T.Vystavel, A.Jacques, A.Gemperle, J.Gemperlová, A.George: Materials Science Forum, 1999, 294-296, 397-400