Method for preventing NdFeB permanent magnet from being corroded

Abstract

The invention discloses a method for preventing an NdFeB permanent magnet from being corroded, which comprises: cleaning and drying a plated part; removing fine impurities from the surface of the plated part by argon ion bombardment; and plating a layer of aluminum film on the surface of the plated part by multi-arc ion aluminum plating. In the invention, a layer of uniform aluminum film is plated on the surface of the NdFeB permanent magnet by multi-arc ion aluminum plating, so the corrosion resistance of the NdFeB permanent magnet is improved and the service life of the NdFeB permanent magnet is prolonged.

Description

technical field [0001] The invention relates to an anticorrosion method for NdFeB permanent magnets, in particular to an anticorrosion method for NdFeB permanent magnets realized by adopting a multi-arc ion aluminum plating method on the NdFeB permanent magnets. Background technique [0002] At present, NdFeB (NdFeB) permanent magnets have replaced the traditional Sm-based rare earth permanent magnets because of their excellent magnetic properties, low price and sufficient resource reserves, and are recognized as the most promising permanent magnet materials. It has played an important role in the fields of electronics, machinery, transportation, communication, electric power, national defense, medical treatment, petroleum, mineral processing and mining, environmental protection and industrial production. Although NdFeB permanent magnets have many of the above advantages, their biggest disadvantage is poor corrosion resistance. Nd is a very active element, and Nd causes NdFe...

AI Technical Summary

Problems solved by technology

On the one hand, Ni plating needs to be in contact with the acidic plating solution. When in contact with the acidic plating solution, the surface layer of the NdFeB permanent magnet reacts with the acid, making the NdFeB permanent magnet loose, and the NdFeB permanent magnet after the Ni layer is plated from the outer surface No problem can be seen, but in the actual use process, the NdFeB permanent magnet with Ni layer will appear blistering and peeling

On the other hand, transgranular microcracks are often formed on the surface of NdFeB permanent magnets during processing. During the Ni plating process, these microcracks absorb hydrogen and become a hydrogen-containing embrittlement layer under the Ni layer, and the hydrogen-containing embrittlement layer will cause Destruction of Ni layer

In short, the problems of blistering, peeling, and hydrogen-containing embrittlement layer will not only make the corrosion resistance of NdFeB permanent magnets insufficient, but also reduce the bonding force between Ni layer and NdFeB permanent magnets, resulting in a decline in the magnetic properties of NdFeB permanent magnets.

Moreover, since the Ni layer is mainly used to isolate the environment of the NdFeB permanent magnet, it is required that the Ni layer cannot have pores. Therefore, the Ni layer must reach a certain thickness. However, the Ni element is a ferromagnetic material, and the thicker the Ni layer is, the better it will be. The adverse effect of magnetic properties is greater

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