TitleOxidation Resistant Coating for Niobium by Combining Hot Dipping
in Molten Aluminum Coating and Anodic Oxidation
Author(s)Takeshi F. Kumon
Publication/PublisherJ. Jpn. Inst. Metals, Vol.59, No.9, (1995) pp.
日本金属学会誌 第59巻 第9号 (1995) pp. 967-972.
AbstractThe combination of hot dipping in molten aluminum and the
subsequent anodic oxidation to dense Al2O3 films was studied to prepare an
oxidation-resistant coating on niobium surface. By immersing Nb into a molten Al
bath, granular NbAl3 was precipitated and improved the coherency of the film to
the substrate. Amorphous Al2O3 was formed by anodic oxidation of the Al layer
and crystallized to corrosion resistant alpha-Al2O3 by the subsequent heat
treatment. The Nb substrate after this combined treatment did not form any
niobium oxides even after heating in air for 64.8ks at 1073K, and the oxygen
increment in the Nb bulk was suppressed below 400 mass ppm.