High temperature interface reactions of TiC, TiN, and SiC with palladium and rhodium

Reactions of TiC, TiN, and SiC with palladium and rhodium at temperatures up to 1600 °C were examined using bulk diffusion couple experiments. Intermetallic phases at the ceramic–metal interfaces were observed using scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and transmission electron microscopy (TEM). The reactivity of the ceramics with these platinum group metals follows the order SiC ≫ TiC > TiN, and reactivity of the metals follows the order Pd > Rh. TiN–Pd interfaces were unique in that no intermetallic phase formation was observed at any of the annealing times and temperatures. The formation of distinct intermetallic phases at the SiC–Rh and TiC–Rh interfaces followed a non-parabolic behavior.