Geometric aspects of low energy metal-ceramic interphase boundaries

Abstract

Geometric models relating the energy of heterophase boundaries including metal-ceramic interfaces to their atomic structure can be based on the static distortion wave concept. This approach allows to separate the energetic from the substrate-induced strain contribution of commensurate and incommensurate boundary structures. The lock-in energy is gained when both crystallites are properly oriented, e.g. when the reciprocal lattice vectors of both lattices are equal and the strain energy term can be neglected. However, the chemical interaction and interfacial entropy are important as well for the structural stability evaluation and can be approximated on the basis of the universal binding energy relation. These relationships are discussed and compared with experimental resutls.