SYNTHESIS AND THERMAL-PROPERTIES OF NI-ALLOY AL2O3 CERMETS FOR INTERCONNECTOR MATERIALS IN SOLID OXIDE FUEL-CELLS/

Ni-alloy/Al2O3 cermets are considered for interconnector materials of solid oxide fuel cells. In this study the sintering behaviour of cerme ts and their thermal expansion in dependence upon the Al2O3 content we re investigated. Sintering in vacuum at 1340 degrees C gave samples wi th a relative density up to 95.5%. Thermal expansion coefficients were calculated from expansion curves of various cermet compositions. Cerm ets with high metallic content showed only small deviations from coeff icients calculated from the rule of mixtures, whereas cermets with hig her Al2O3 contents showed significantly lowered thermal expansion coef ficients ranging from 10 x 10(-6)/K down to 8.3 x 10(-6)/K for pure A1 (2)O(3).