Grain boundaries and propagation of slip bands

Deformation experiments were performed on three different Fe-4at%Si bicrystals. Synchrotron radiation topography in situ and post mortem was used to investigate the influence of grain boundaries (GB) on slip transmission and to study the interaction of slip dislocations with the GB. It was found that the GB forms a strong barrier in all cases and the slip transfer cannot be fully explained by geometric relations of Burgers vectors and slip planes in the two grains. To explain the results of experiments the internal stresses near the GB due to accumulated slip dislocations produced in one grain and stopped at the GB and image forces due to the grain boundary were calculated. The structure of GB has been studied by conventional TEM.