Effects of protective coating prepared by atmospheric plasma spraying on planar SOFC interconnect

In the planar design of intermediate temperature solid oxide fuel cell (ITSOFC), a metallic interconnect is used to separate the single cells. Fe-16Cr alloy is a promising metallic interconnect material and a disadvantage of it is the high-temperature oxidation and corrosion at the surface of the cathode side leading to rapid cell degradation. In this paper, a dense La_0.8Sr_0.2MnO_3-σ(LSM) perovskite coating was deposited on the surface of the metallic interconnects prepared by atmospheric plasma spraying (APS). The main process factors and their effect on protective coatings were discussed. The appropriate process parameters were determined in the experiment. It was found that heat treatment after APS is an effective method for reducing the porosity in the coating. After heat-treatment, the LSM coatings with porosity of less than 1% were obtained. By spraying LSM protective coatings, the oxidation rate of Fe-16Cr alloy in air at 1073 K was lowered by 76%.