Deformation processes in the vicinity of metal—ceramic interfaces

The deformation processes in the vicinity of Pt-NiO metal—ceramic interfaces tested by the periodic cracking method were investigated by electron microscopy. Cracks in the NiO thin film were suggested to result from a mechanism where dislocations propagate from the interface and react to form immobile dislocations which act to nucleate microcracks. Some distance away from the cracks in the NiO, a dense wall of dislocations was present in the Pt about 1 μm away from and parallel to the interface, with a low dislocation-density region between the wall and the metal—ceramic interface. The formation of the dislocation wall is explained qualitatively by considering reactions between dislocations originating from the bulk Pt and the interface.