Patent ID: 7086934

Claim:
A process for treating surfaces of rare earth metal-based permanent magnets, comprising the steps of removing an oxide layer formed on a surface of each of the rare earth metal-based permanent magnets using a blasting apparatus which comprises a tubular barrel formed of a mesh net for accommodation of work pieces and supported circumferentially outside a center axis of a support member rotatable about said center axis, for rotation about said center axis, so that said tubular barrel can be rotated about said center axis of said support member by rotating said support member, and an injection nozzle disposed to inject a blast material against the work pieces from the outside of said tubular barrel rotated about said center axis, wherein at least one of said tubular barrel and said support member for supporting said tubular barrel is detachably mounted; removing said tubular barrel containing the rare earth metal-based permanent magnets with the oxide layers removed therefrom, or said support member for supporting said tubular barrel from said blasting apparatus; and attaching said tubular barrel or said support member to a vapor deposited film forming apparatus, where a metal film is formed on the surface of each of the rare earth metal-based permanent magnets by a vapor deposition process.