Fabrication and Characterization of Al-Fe Coating for the Wet-Seal Area of Separator for Molten Carbonate Fuel Cells (MCFC) by the Laminating of Al Foil

Abstract

The separator of the molten carbonate fuel cells (MCFC) has the major corrosion problems, especially wet-seal area, because this part contacts directly with the corrosive molten carbonate electrolyte. For the protection of the wet-seal area, aluminization method is developed recently. Coated aluminum reacts with the molten carbonate and forms the LiAlO2 having high corrosion resistance, high melting point, no electrical conductivity and no dissolution in molten carbonate. In this study, 50㎛ thickness aluminum foil was applied to form the Al-Fe coating layer on the AISI316L by using the laminating method. Laminating of aluminum foil on AISI 316L was performed at 630°C for 5h in Ar atmosphere using a jig and diffusion heat treatment was carried out at 700°C, 750°C and 800°C for 3h in Ar atmosphere respectively. This method simplified the existing complicated process and has a great advantage of low-cost mass production compared to other methods like PVD, CVD and spray coating.