Investigation of chemical bonding at metal-ceramic interfaces

We present a comparative ab-initio study of atomic and electronic properties of Al/TiC(N) and Al/VC(N) interfaces performed using DFT with the projector-augmented-wave method. The most stable configuration of metal film on the ceramic substrate was determined. The work of separation of metallic films in dependence on cleavage plane was calculated. The analysis of the electronic properties confirms a stronger interaction in the case of the Al top position over metalloid which indicates the dominant role of the covalent contribution in the chemical bonding at these interfaces. We demonstrate that point defects at the interface (metal, carbon and nitrogen vacancies) change the adhesion at the metal-ceramic interfaces significantly and cause redistribution of the electron properties across the interface.