| 摘要 |
PURPOSE:To further improve the hardness of an anodic oxide film formed on an Al material by successively subjecting the anodic oxide film to immersion in an aq. sulfuric acid soln., washing with water, vacuum drying and heating. CONSTITUTION:An anodic oxide film formed on an Al material in an electrolytic bath is immersed in an aq. sulfuric acid soln. to dissolve and remove hydrate in the pores in the oxide film and the soft part of the oxide film. The Al material is well washed with water. When it is not well washed, the oxide film is deteriorated by residual sulfuric acid with the lapse of time. The Al material is then put in an atmosphere under <=10Torr reduced pressure to evaporate the water in the oxide film and the readsorption of water on the dried oxide film is prevented by heating. Thus, a stable anodic oxide film having higher hardness and adsorbing little water is obtd. |
