Surface treatment method of NdFeB permanent magnet material and its products

Abstract

The invention relates to a surface treatment method of a neodymium iron boron permanent magnet material and a product thereof. The surface treatment method includes the steps that an aluminum and rare earth alloy layer is plated on the neodymium iron boron permanent magnet material in a vacuum plating mode, then the neodymium iron boron permanent magnet material is subjected to vitrification treatment and coated with an epoxy layer in an electrophoretic painting mode, and the neodymium iron boron permanent magnet material with the surface treated is obtained after curing. Electrophoretic paint tank liquid comprises epoxy resin and color paste. The surface of the neodymium iron boron permanent magnet material with the surface treated is sequentially plated with the aluminum and rare earth alloy layer, the vitrification layer and the epoxy layer from inside to outside, and the bonding force between the plating layers and between the aluminum and rare earth alloy layer and the base neodymium iron boron permanent magnet material is obviously improved. The surface of the neodymium iron boron permanent magnet material with the surface treated is flat, smooth, uniform, compact, free of pitting, bubbles and scales, the corrosion resistance is obviously improved, the corrosion resistance time of a salt spray test is above 1680 h, and the corrosion resistance requirements for the neodymium iron boron permanent magnet material in severe environments such as offshore wind power generation and high-temperature deserts are met. The invention further provides a neodymium iron boron permanent magnet material product manufactured through the surface treatment method.

Description

technical field [0001] The invention relates to the technical field of surface treatment and protection, in particular to a surface treatment method of an NdFeB permanent magnet material and a product thereof. Background technique [0002] Neodymium iron boron (NdFeB) permanent magnet materials have excellent magnetic properties and high cost performance, and they play an important role in various fields of the national economy. However, the NdFeB permanent magnet material is a multi-phase structure, and the electrochemical potential of each phase is different, making it extremely easy to corrode in acidic, salt spray and humid environments. At present, the surface protection of NdFeB permanent magnet materials is an effective method to improve the corrosion performance of NdFeB permanent magnet materials. The method of surface protection can significantly improve its corrosion resistance without compromising its magnetic properties, and the cost is low. [0003] The surfa...

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Problems solved by technology

[0004] Chinese patent 201010280103.X discloses a surface treatment method of mechanical galvanized aluminum-nickel plating of NdFeB permanent magnet materials. The salt spray performance of the obtained aluminum-zinc-nickel coating is better than that of electrogalvanized and electroplated copper layers, but this method requires Copper is pre-plated first to ensure the bonding force

Chinese patent 201010606023.9 ​​discloses the composite protective process of vacuum aluminum plating and electrophoretic coating for NdFeB magnets and a NdFeB magnet with a composite protective layer. The patent points out that the coating obtained by this method has good corrosion resistance, and the results of the salt spray test The corrosion resistance time exceeds 1000 hours, but the salt spray resistance of the coating obtained by this method mainly depends on the epoxy coating, and the salt spray performance is basically close to the limit value of the epoxy coating, and it is difficult to improve it

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