THEORY OF METAL-CERAMIC ADHESION

Fully self-consistent, all-electron density functional calculations were carried out for MgO/Ag(100) and MgO/Al(100) interfaces with and without interfacial monolayers of C and S impurities. These first-principles results indicate that both Ag and Al atoms favor the site on top of the O atom. Electron density distributions in the interface regions suggest a significant ionic component to the metal-ceramic bond. There were indications of a metallic/covalent component as well. All adhesion curves were found to accurately obey the universal energy relation. Impurities were found to cause substantial changes in adhesion energies, ranging from 9 to 61%. The contribution of misfit dislocation networks to the work of adhesion was found to be large. Excellent agreement with experiment was found for our computed work of adhesion and contact angle. Finally, application of the Harris functional was found to be accurate, opening the way to systems currently beyond the capability of the fastest computers.