Nickel-alumina bonds: Mechanical properties related to interfacial chemistry

Mechanical properties of solid state bonded Ni-Al2O3 interfaces have been investigated as a function of several bonding parameters (temperature, pressure, time) and purity of the starting alumina. It has been shown that they depend upon the plastic deformation of the metal, on the damages induced at the ceramic surface and on both the nature and amount of interfacial phase that appears during the bonding process. According to the processing conditions used, the nickel aluminate spinel has not been found at the interface, but it has been shown that bonding arises from the magnesium aluminate spinel or sodium magnesium silicate and that nickel silicide is formed on the nickel side of the bond near by the interface.