Effect of thermal-sprayed Mn_1.5Co_1.5O₄ coating on oxidation suppression of metallic interconnects

Metallic interconnects are less expensive, more conductive and able to form complex shapes than ceramic interconnects for SOFC applications. Most metallic interconnects use alloys containing chromium. At elevated temperatures, chromia scales react with cathode and degrade its performance. Manganese cobalt oxide ((Mn,Co)₃O₄, (MCO), with spinel structure is found to be a good material to form a protective coating for metallic interconnects. In this study, the high-temperature ferritic stainless steel Crofer 22H and nickel-chromium alloy Inconel 625 were thermally sprayed with MCO, and the oxidation, scale structure, and resistance of metallic substrates were investigated using XRD, TEM and SEM.