SURFACE TREATMENT OF RARE EARTH METAL MAGNET POWDER

摘要

PURPOSE:To prevent the deterioration of magnet powder due to oxidation during kneading and due to aging by immersing the powder in a coupling agent soln. and applying an AC magnetic field so as to perfectly coat the surface of the powder. CONSTITUTION:A coupling agent is dissolved in a proper solvent to prepare a coupling agent soln. A vessel 2 is placed in a hollow coil 1, permanent magnet powder 3 is put in the vessel 2 and a prescribed amt. of the coupling agent soln. 4 is added. AC of about 50-60 Hz is supplied to the coil 1 to generate an AC magnetic field in the coil 1. The coagulated magnetic particles 3 are perfectly separated and vibrated by the AC magnetic field and the coupling agent soln. 4 reaches the entire surfaces of the particles 3 to perfectly coat the surfaces of the particles 3. By this surface treatment, the oxidation resistance of the rare earth metal magnet powder is improved.