Thermal Growth Cu1.2Mn1.8O4 Spinel Coatings on Metal Interconnects for Solid Oxide Fuel Cell Applications

A novel cobalt-free Cu1.2Mn1.8O4 spinel coating is prepared and evaluated for the metal interconnect of solid oxide fuel cell. Mn-35Cu and Co-35Mn alloy coatings are deposited on 430 SS substrate and then in-situ oxidized in air at 750 degrees C for 100 h. XRD results confirm that Cu1.2Mn1.8O4 spinel with some Mn2O3 is formed, and the average thickness of the coating is 70-80 mu m according to cross section image. Spinel oxide coating is compact and has good adherence to the substrate, and very low Cr and Fe contents are detected in the coating. A small area specific resistance of 8.7 Omega m cm(2) is achieved at 800 degrees C for the composited Cu1.2Mn1.8O4 spinel coating, which is much less than that of the composited (Co,Mn)(3)O-4 spinel coating. The research indicates that the Cu1.2Mn1.8O4 coating evolved by the high-energy micro-arc alloying process is a promising coating material for the metallic interconnects.