METHOD FOR MEASURING THICKNESS OF ALUMINUM FILM OF NIODIUM PERMANENT MAGNET

摘要

PURPOSE: A measuring method of the thickness of an aluminum in a niodium permanent magnet is provided to easily, simply and exactly measure the thickness by using the weight difference before and after melting a film with a sodium hydroxide solution. CONSTITUTION: The weight of a niodium permanent magnet coated with an aluminum film is measured. A sodium hydroxide solution is produced. The aluminum film is melted with the sodium hydroxide solution. Remaining materials on the surface of the magnet are removed. The weight of the niodium permanent magnet is measured. The weight of the melted film is calculated by the weight difference before and after melting the film. The thickness of the film is calculated by using the weight.