MICROSTRUCTURAL CHARACTERISTICS IN NI/ZIRCONIA BONDING

Zirconia with various dopants of Y2O3 and CeO2 was employed in the solid state bonding of an Ni/ceramic assembly. The interfacial microstructure of the bonding assembly was examined by electron microscopy and X-ray diffraction and the bonding strength was evaluated with a tensile test under constant pressure. An intermediate layer was observed in the interface of the 3Y2O3-10CeO2-ZrO2/Ni bonding assembly which revealed that the solid state bonding of Ni/zirconia required the formation of a thin oxide layer to wet the ceramics. In the Ni/zirconia bonding, the growth of NiO was influenced by the dopants in the zirconia. This would, in turn, result in different bonding strengths between ZrO2 and nickel. The highest bonding strength occurred in the 12CeO2-ZrO2/Ni assembly. © 1990 Chapman and Hall Ltd.