Morphology, strength and pre-coating effect in YSZ/Nl bonding

The quality of ceramic-metal bond is strongly influenced by the microstructure of the transition region between the ceramic and the metal. Sandwich-like ceramic-metal-ceramic specimens are fabricated by solid state bonding of 3 mol% yttria doped zirconia ceramic with nickel foils. Time dependence of the shear strength of the bonding assembly is evaluated at 900° C under a bonding pressure of 8.17 MPa. An optimum strength is obtained for the bonding time between 10 and 25 minutes. The shear strength is also measured as the function of the bonding pressure and bonding temperature. The dependence of the processing parameters on the shear strength of the bond assembly is investigated on the basis of the morphological development in the ceramic-metal interface. In addition, the effect of a pre-coated Ni film on the strength of YSZ/Ni bonding is discussed.