How to enhance the corrosion resistance of NdFeB Magnets through surface treatment?

NdFeB magnets have excellent magnetic properties, but they are susceptible to corrosion in some environments. Appropriate surface treatment can effectively enhance their corrosion resistance.
A common method is electroplating. For example, nickel plating forms a dense nickel layer on the surface of NdFeB magnets through electroplating. Nickel has good corrosion resistance and can isolate the magnet from contact with external corrosive media. In order to further improve the corrosion resistance, multi-layer nickel plating can be used to plate three layers of nickel layers with different texture orientations and cross-stacked. According to the crystal texture growth advantage and dendrite growth control mechanism, cross-densification between layers is achieved, and the interlayer bonding force is enhanced, so as to better resist corrosion.
Chemical plating is also an effective surface treatment method. For example, chemical plating of nickel-phosphorus alloy, this coating has the advantages of good uniformity, high hardness, and strong corrosion resistance. In the process of chemical plating, a layer of nickel-phosphorus alloy is deposited on the surface of the magnet through chemical reaction, which can effectively improve the corrosion resistance of the magnet. Moreover, chemical plating can form a uniform coating on the surface of complex-shaped magnets, and is not limited by shape and size like electroplating.
In addition, passivation treatment can also be used. By immersing the NdFeB magnet in a specific passivation solution, a passivation film is formed on its surface. This passivation film can reduce the activity of the magnet surface, improve its stability in the air, and reduce the reaction with corrosive media such as oxygen and moisture, thereby enhancing corrosion resistance.
Coating protection is also a good choice. For example, organic coatings such as epoxy resin coatings and polyurethane coatings are used. These organic coatings have good water resistance, chemical corrosion resistance and insulation properties. Applying it on the surface of the magnet can form a physical barrier to prevent corrosive media from contacting the magnet. At the same time, organic coatings can also choose different colors and glosses according to needs to meet different usage needs and aesthetic requirements.