Liquid-phase oxidation joining of oxide ion conducting ceramics via Al/heat resistant alloy/Al multilayer interlayers

A joining technique for oxide ion conducting ceramics, such as yttria-stabilized zirconia, was developed, utilizing oxidation of transiently formed aluminum melt. Two yttria-stabilized zirconia (YSZ) blocks were joined via Al/Ni alloy/Al interlayers at 1273 to 1473 K for 3.6 to 28.8 ks in a vacuum (< 0.2 Pa) with an applied load of 80 MPa. The average fracture strength increased with increasing the joining time and temperature. A strong four-point bend strength of 170 MPa was obtained for the specimen joined at 1473 K for 14.4 ks, which was fractured at YSZ block. Alumina interlayer, which is expected to act as a protective layer for further oxidation of Ni alloy, was formed between YSZ and Ni alloy in the specimen after joining.