NdFeB permanent magnet materials have been widely used in many fields due to their excellent characteristics of high magnetic energy product, high coercivity and high remanence. However, the NdFeB recycling expert, You Waste, said that there is a potential difference between the NdFeB-rich phase and the boron-rich phase in the NdFeB material and the main phase of the magnet alloy, which is easy to form a galvanic cell effect in the use environment and cause electrochemical corrosion on the surface of the material. . The nature of the NdFeB permanent magnet material itself determines that it is susceptible to oxidation corrosion. So is there any way to prevent NdFeB permanent magnets from being corroded?
1. Phosphating：
Phosphating is a chemical and electrochemical reaction to form a phosphate chemical conversion coating process, phosphating has the following purposes:
* Protects the base metal from corrosion to a certain extent.
*Use as a primer before painting to improve film adhesion and corrosion resistance.
* Plays anti-friction and lubricating functions in the process of metal cold working.
2. Electroplating：
Electroplating is the process of plating a thin layer of other metals or alloys on the surface of other metals by electrolysis. Improve wear resistance, electrical conductivity, reflectivity, corrosion resistance and enhance aesthetics. With the exception of neodymium magnets, the outer layers of many coins are electroplated.
3. Electrophoresis：
Under the action of an electric field, charged particles move toward the opposite electrode, which is called electrophoresis. The technique of separating charged particles by their different velocities in an electric field is called electrophoresis. Electrophoresis is one of the anti-corrosion surface treatment technologies widely used in sintered NdFeB and bonded NdFeB permanent magnets. Electrophoretic coating not only has good adhesion with the surface of porous magnet, but also has resistance to salt spray, acid and alkali corrosion
etch characteristics.