Interaction of Slip Bands with Grain Boundary - in situ TEM Observation

摘要

Mechanism of the slip transmission across the grain boundaries was studied on 23 bicrystals of Fe-4at%Si by transmission electron microscopy. In situ straining experiments as well as post mortem observations were performed. Three distinct events were observed in dependence on the angle a between the slip and grain boundary planes, namely transformation of the tertiary slip system in one grain into the secondary slip system in the other grain for α≈ 90°, cross slip of dislocations of the primary slip system into the {112} plane parallel to the grain boundary for α≈21°, and an abrupt formation of a sub-grain boundary in one grain for α≈ 49°. Reasons for these diverse phenomena will be discussed in terms of interactions between the slip dislocations and the grain boundary dislocations.