Original Paper(Vol.61 No.6 pp.505-508)

Thermal Behavior of Alumina Coat Layer/Alloy Substrate at Elevated Temperature

Masakuni OZAWA and Ken-ichi ARAKI

Abstract:Thermal behavior ofƒม-Al2O3 coat layer on alloy substrate was examined for forming the catalytic parts used under harsh heat condition. Stable catalytic coat layer was made through a simple dipping-drawing procedure of aqueous ƒม-Al2O3 slurry. Thermal stability of alumina layer and interface was examined by surface area measurement, XRD, and SEM morphology as well as EDS in the temperature range of 800-1200Ž. The phase trasformation and related microstructural development were observed at the surface of alloy substrate and alumina layer. The coat layer was stable, regarding with metastable phase and surface area, on FeCrAl alloy below the temperature of 1200Ž, however macroscopic structure of coated alumina must be improved more.

Key Words:Alumina, Coat layer, Alloy substrate, Thermal stability, Automotive catalyst, Oxidation