Fabrication method for surface electroplating coating layer of NdFeB rare-earth permanent magnet

Abstract

The invention belongs to the technical field of corrosion-prevention surface processing, and particularly relates to a fabrication method for a surface electroplating coating layer of an NdFeB rare-earth permanent magnet. The fabrication method comprises the steps of firstly, pre-processing a surface of the NdFeB rare-earth permanent magnet; secondly, performing vacuum pumping on the NdFeB rare-earth permanent magnet; and finally, electroplating by employing an ultrasonic wave electroplating groove. By the fabrication method, expansion and bubbles of a plating layer caused by a hydrogen evolution effect are prevented, the corrosion prevention performance of the surface coating layer of the NdFeB rare-earth permanent magnet is improved, an existing NdFeB electroplating corrosion-prevention technology is expected to be substituted, and thus, the fabrication method has a very wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of anti-corrosion surface treatment, in particular to a method for preparing an electroplating coating on the surface of an NdFeB rare earth permanent magnet. Background technique [0002] NdFeB rare earth permanent magnets are used more and more for their excellent magnetic properties, and are widely used in automobile motors, elevator motors, energy-saving motors, medical nuclear magnetic resonance imaging, computer hard drives, mobile phone vibration motors, audio, Motors for hybrid vehicles, wind turbines, etc. [0003] Since NdFeB rare earth permanent magnets are easy to oxidize, surface coating treatment is generally required in the use of the above-mentioned NdFeB rare earth permanent magnets. At present, the widely used coating method is mainly electroplating, electroplating zinc, electroplating nickel, electroplating nickel copper nickel and so on on the NdFeB substrate. However, NdFeB magnets are...

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Problems solved by technology

There will be hydrogen evolution effect during the pretreatment and electroplating process, and the generated hydrogen will infiltrate and adsorb in the micropores on the surface of the substrate. When the concentration is high, the adsorbed hydrogen will overflow due to expansion, which will generate a pressure on the coating, causing the coating to protrude from the substrate, forming bulging and foaming, resulting in failure of the coating and seriously affecting the anti-corrosion ability of the coating.

Since the surface of the NdFeB substrate contains a large number of micropores, the porosity is determined by the preparation process, and the hydrogen evolution effect is inevitable in the electroplating process, so the electroplating quality of rare earth permanent magnets can not be compared with the electroplating quality of ordinary metal substrates. This shortcoming It also severely restricts its further application in the fields of electrical machinery, electronics, aerospace, etc.

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