| 摘要 |
PURPOSE:To form simply a hygroscopic film of the oxide of Al or its alloy at a low cost by immersing Al or its alloy in an aqueous ammonia soln. having a specified concn. at a specified temp. CONSTITUTION:Al or its alloy is immersed in a 1-4% aqueous ammonia soln. at 60-90 deg.C to form a hygroscopic surface film of the oxide of Al or its alloy. This oxide film is equal to an alumite film formed by anodic oxidation in hygroscopicity, and it is less expensive than the alumite film. |
