Ab-initio study of interfacial strength and misfit dislocations in eutectic composites: NiAl/Mo

The electronic structure and fracture energy characteristics of the NiAl/Mo interface have been investigated by the full-potential linear muffin-tin orbital method. We optimized the crystal geometry of the coherent interface and calculated the ideal work of adhesion and interfacial shear energies. For the first time, based on ab-initio calculations, the structure and energy of misfit dislocations were determined within the Peierls-Nabarro model with a generalized restoring force law. The bonding at the coherent interface is found to be close to that of bulk NiAl, but the appearance of the misfit dislocations leads to a drastic weakening of the NiAl/Mo interface. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.