Fabricating a MnCo coating to improve oxidation resistance and electrical conductivity of Crofer22H alloy as SOFC interconnect

The oxidation kinetic behavior of Crofer22H alloy at 700-800 degrees C was investigated. Due to the high oxidation rate exhibited at 800 degrees C, the xCr-MnCo dual-structured spinel coating was prepared by magnetron sputtering. The element diffusion behavior of the coating/alloy system was changed by control the formation of Cr layer with different thicknesses on the surface. Appropriately increase the thickness of Cr barrier layer can effectively hinders the Fe outward diffusion and improve the antioxidant performance. Fe doped into Mn-Co spinel increased the electron hopping in the crystal structure. Higher electron hopping and thin Cr2O3 layer reduced the electron resistance.