Metal/ceramic interfaces: A microscopic analysis

This contribution treats the fundamental and practical aspects of the analysis of interfaces between metals and ceramic materials. It is shown that, in principle at least, it is possible to assess the bond strength by investigating the atomic structure of the dislocation cores. We have chosen to exemplify our approach with the misfit-dislocation structures at two, crystallographically different, systems, i.e. cube-on-cube and cube-on-non cube interfaces. It turns out that from high-resolution transmission electron microscopy observations in combination with computer modelling studies a qualitative insight can be obtained about the bonding behaviour between these dissimilar materials. In general we may conclude that there is a fair correlation between the atomistic and linear elastic continuum description of interface dislocations. However, it is shown that the linear elastic continuum approach cannot account for the possible configurations at an interface with misfit, because it does not include the effects of different bonding strengths on the interface structure. This contribution directs also to some future experimental work. Segregation of other elements might affect the local bond strength which may become manifest in the experimental observations of atomic structure.