Microstructure of Fe–25Cr/(La, Ca)CrO3 composite interconnector in solid oxide fuel cell operating conditions

A 20 μm thick coating of La0.8Ca0.2CrO3 perovskite on Fe–25Cr steel substrates was obtained by the screen-printing method. The interaction of the (La, Ca)CrO3 coating with the steel substrate occurring during oxidation in air at 1073 K for 200 h was investigated. The microstructure, phase and chemical analyses of the coating after oxidation were examined. It has been revealed that the metal substrate–coating interfacial zone has a two-layer structure built of mainly FeCr2O4 and LaCrO3, which provide the electric contacts between the interconnector material and the film, thus creating conditions for prolonged exploitation of solid oxide fuel cells.