ndfeb permanent magnet has excellent magnetic properties, but poor corrosion resistance limits its wide application in many fields. Therefore, it is extremely critical to explore effective corrosion resistance optimization strategies.
First of all, surface coating treatment is a common and effective means. The use of electroplated nickel, zinc, chromium and other metal coatings can form a dense protective film on the surface of the permanent magnet to isolate the external environment from contact with the magnet matrix. For example, the electroplated nickel layer can provide good corrosion resistance and decorative properties, and its thickness and uniformity have a significant impact on the protective effect. Generally speaking, a thicker and uniform nickel layer can better block the erosion of corrosive media such as moisture and oxygen.
Secondly, electroless plating is also a feasible method. Electroless nickel-phosphorus alloy coating, due to the presence of phosphorus element, can make the coating have an amorphous structure. This structure can effectively improve the uniformity and corrosion resistance of the coating. Compared with traditional electroplated nickel coating, it can be used in some complex-shaped magnets. It can be covered more evenly, reducing corrosion risks caused by coating defects.
Furthermore, the application of organic coatings is becoming more and more widespread. Organic coatings such as epoxy resin and polyurethane have good flexibility and chemical resistance. Coating it on the surface of ndfeb permanent magnet can not only prevent corrosion, but also buffer external mechanical impact to a certain extent. Before applying the organic coating, the magnet surface needs to be properly pre-treated, such as grinding, degreasing, etc., to enhance the adhesion between the coating and the substrate.
In addition, alloying modification of ndfeb permanent magnet is also an important way to optimize corrosion resistance. Adding appropriate amounts of aluminum, copper, titanium and other elements can change the microstructure of the magnet and form a more stable phase, thus improving its inherent corrosion resistance. For example, the aluminum element can form a dense aluminum oxide protective film on the surface of the magnet to enhance its resistance to corrosive media.
During production and use, controlling environmental humidity and temperature cannot be ignored. Try to store ndfeb permanent magnet in a dry and low-temperature environment to reduce the erosion of the magnet by moisture and high temperature. Because the high temperature and high humidity environment will accelerate the oxidation and corrosion process of the magnet.
In addition, optimizing packaging materials and packaging methods can also play a secondary protective role. Use packaging materials with moisture-proof and oxygen-proof functions, such as aluminum foil composite bags, etc., to seal and package the magnets to reduce the chance of contact with corrosive gases and moisture from the outside.
Finally, for some special application scenarios that require extremely high corrosion resistance, a variety of corrosion resistance optimization strategies can be used comprehensively, such as alloying modification first, and then applying metal coatings and organic coatings in sequence, combined with good Packaging and environmental control to maximize the corrosion resistance of ndfeb permanent magnet, expand its application scope, extend its service life, and ensure the performance stability and reliability of related equipment or products.
