Characterization of tungsten carbide and titanium carbide based cermets for solid oxide fuel cell interconnect application

Electrical conductivity and oxidation behavior studies of cermets were performed. Three samples, titanium carbide HCS with 3 wt% of Ni, titanium carbide with 3 wt% of Ni, and tungsten carbide with 20 wt% of Ni, were ultimately investigated to provide electrical conductivity and oxidation behavior results for potential applications as the interconnect of low temperature SOFC.;While the WC-20wt%Ni cermet was wet milled and hot pressed, the TiC (HCS) and TiC-3wt%Ni samples were both synthesized by patented methods of commercial H.C. Stark and Koc [10, 12], respectively. The sintered cermet samples underwent 100 hours of electrical conductivity measurements in air at 600°C. Sample weight gains were calculated. In addition, X-ray diffraction (XRD), scanning electron microscopy (SEM), and a mechanical hardness test were all performed. These procedures lead to investigation of all sample oxidation behavior.;All tested samples were oxidized, and the oxide scale strongly adhered to each substrate. Further oxidation was prevented from the oxide scale. Electrical conductivity values as high as 1950 S/cm for TiC-3wt%Ni, 1350 for TiC (HCS)-3wt%S/cm, and 350 S/cm for WC-20wt%Ni have been recorded. Decreased electrical conductivity was believed to have occurred from oxide scale formation on the cermet substrate. Both TiC samples resulted in better oxidation resistance and better electrical conductivity than the WC sample, which was heavily oxidized.