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 mu m 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.