Orientation Gradients at Boundaries in Micron-Sized Bicrystals


  • The authors would like to thank Prof. F. Mücklich, Dr. F. Soldera, and C. Pauly for helpful supports for preparing the thin film samples and Dr. M. Marx for fruitful discussions. The support of this work by the Deutsche Forschungsgemeinschaft (DFG) is gratefully acknowledged.


In micron-sized Ni bicrystals, after compression tests, orientation gradients are measured by electron back scattering diffraction (EBSD). The results clearly show that EBSD can be used to study dislocation pile-ups at boundaries. Using bicrystals with single and multiple slip orientations our results show that with decreasing the size of the pillars the orientation changes due to cross-slip decreases and the orientation changes at the boundary increases. This directly indicates a change in the hardening mechanism when the probability of dislocation–dislocation interaction decreases due to source-limited plasticity in the bicrystals with diameters below approximately two microns.