摘要 |
<p>The present invention provides an Fe-B-R based permanent magnet, which has a chemical conversion coating film formed on its surface with an aluminum film interposed therebetween, the chemical conversion coating film containing at least one of titanium and zirconium, phosphorus, oxygen and fluorine as constituting elements, and a process for producing such an Fe-B-R based permanent magnet. In the permanent magnet, the chemical conversion coating film is adhered firmly to the magnet with the aluminum film interposed therebetween and hence, the magnet is excellent in corrosion resistance. Even if the magnet is left to stand for a long time under high-temperature and high-humidity conditions of a temperature of 80 DEG C and a relative humidity of 90 %, the magnet exhibits a stable high magnetic characteristic which cannot be deteriorated. Moreover, the film is free from hexa-valent chromium.</p> |