Abstract: The Al₂O₃-based seals were prepared by tape casting process using Al₂O₃ and Al fine powders as primary starting materials. The materials’ hermetic properties were tested in simulative environment of the sealing of planar ITSOFC, and the materials after hermetic property test were characterized by X-ray diffraction and scanning electron microscope. The results show the flexible Al₂O₃-based seals are successfully prepared by appropriate tape casting process. The Al₂O₃-based seals have favorable sealing characteristics even though the compressive stresses are quite low. The leak paths are reduced and the tortuosity of leak paths are aggrandized when Al fine powders are added into Al₂O₃-based seals, which enhance the materials’ hermetic property and mid-term stabilities. It is feasible that Al₂O₃-based seals with 10wt%--20wt% Al fine powders prepared by tape casting are used as sealing materials for the planar ITSOFCs.

Key words: solid oxide fuel cell, seal, Al₂O₃, tape casting