Development and characterization of coatings on interconnector (Cr-ODS) used in SOFCs

Abstract

Oxidation behavior of aluminide coated Cr-ODS alloy having different coating thicknesses was investigated at temperatures ranging from 800-950 degrees C in air. Coating degradation due to rapid Al diffusion into the matrix resulting in Kirkendall porosity was characteristic of all coated alloys. The microhardness of the alloy was substantially increased due to Al diffusion. Pre-oxidation was found to be an effective means of reducing rapid growth of Al coating into the substrate. The aluminide coating modified with Co+Ni showed less tendency towards void formation at the sites where the coating was adhered. Silicide coating did not show any enhancement in the microhardness of the alloy or Kirkendall porosity as a result of Si diffusion. From this study, it has been found that an effective silicide coating for Cr-ODS alloy can be produced by selecting suitable coating parameters.