On the atomic structure of the Nb/Al2O3 interface and the growth of Al2O3 particles

Abstract

The growth mechanism for small precipitates of Al₂O₃ formed by internal oxidation in the Nb–Al₂O₃ interface is studied in detail. The observations show that the Nb (001)/Al₂O₃ (00.1) interface is almost atomically flat and that there are no interface compounds. We suggest that the final layer on the Al₂O₃ side of this interface consists of oxygen atoms. The effects of image forces on misfit dislocations are found to result in a standoff distance between dislocation cores and the interface, in good agreement with the recent theory. The implications of this for the strength of metal-ceramic bonding are discussed.