Catalytic behavior of plasma-sprayed Al–Al2O3 coatings doped with metal oxides

Reactive plasma spraying of aluminum and Al(OH)3 powders with oxide additives, CuO and Cr2O3, was investigated. An arc-plasma spray gun was constructed with the injection of powders into the plasma torch both internally and externally. The spraying was done at atmospheric pressure in a working gas comprising an argon/air mixture. The resulting oxide-doped Al–Al2O3 coatings, which were 30–50 μm thick, were investigated by X-ray diffraction and scanning electron microscopy. Their catalytic behavior was identified observing by the combustion effect of propane in a tube furnace.