A METHOD OF DISPOSING AN ALUMINUM COATING ON ND-FE-B PERMANENT MAGNETS

摘要

According to the present invention there is provided a method for disposing an aluminum coating on Nd-Fe-B permanent magnets. The method includes the steps of:a) Performing a pre-treatment of the Nd-Fe-B permanent magnets;b) Fixing the Nd-Fe-B permanent magnets on a jig and placing the same in a multi-arc sputtering equipment;c) Evacuating the multi-arc sputtering equipment with a vacuum system until the pressure reaches 1×10^-2Pa to 3×10^-2Pa, then introducing argon gas until the pressure reaches 1×10^-1Pa to 5×10^-1Pa, starting bias voltage treatment of the Nd-Fe-B permanent magnets for 1 to 10 minutes at 800V to 1000V;d) Stopping bias voltage treatment and then evacuating the multi-arc sputtering equipment until the pressure reaches 1×10^-3Pa to 8×10^-3Pa, then refilling argon gas until the pressure reaches 3×10^-1Pa to 5×10^-1Pa, then starting arc deposition from a target source and maintain a DC current between 50A to 70A, turn on bias voltage and maintain voltage between 100V to 200V, and maintain coating the magnets for 0.5 to 5h;e) Cooling down on 20°C to 100°C and taking out the Nd-Fe-B permanent magnets from the multi-arc sputtering equipment; andf) Dipping the Nd-Fe-B permanent magnets into a passivating agent for 1 to 20 minutes and then rinse with water.