Thermal growth Cu1.2Mn1.8O4 spinel coatings on metal interconnects for solid oxide fuel cell applications

Abstract

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°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 μm 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 mΩ cm2 is achieved at 800°C for the composited Cu1.2Mn1.8O4 spinel coating, which is much less than that of the composited (Co,Mn)3O4 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.