NICKEL-ALUMINA BONDS - MECHANICAL-PROPERTIES RELATED TO INTERFACIAL CHEMISTRY

Mechanical properties of solid state bonded Ni-Al2O3 interfaces have b een investigated as a function of several bonding parameters (temperat ure, pressure, time) and purity of the starting alumina. It has been s hown that they depend upon the plastic deformation of the metal, on th e damages induced at the ceramic surface and on both the nature and am ount of interfacial phase that appears during the bonding process. Acc ording to the processing conditions used, the nickel aluminate spinel has not been found at the interface, but it has been shown that bondin g arises from the magnesium aluminate spinel or sodium magnesium silic ate and that nickel silicide is formed on the nickel side of the bond near by the interface.