China Courage Permanent Magnet Manufacturer 
Choosing the proper coating is very important for rare-earth neodymium magnets because these magnets are very susceptible to oxidation and corrosion, especially in environments that are wet or contain corrosive substances. Below are some of the common types of coatings for permanent magnets as well as recommended application environments.
The following table provides the types of coatings common to neodymium magnets, their thicknesses, how long they can withstand salt spray, as well as their costs, and characteristics.
Nickel Plating (Ni-Cu-Ni)
It is one of the most common plating for NdFeB magnets, which provides good protection against corrosion, available in matte and bright, usually silver-white in appearance, can pass 24 hours salt spray test, recommended for most indoor and light outdoor applications.
Black Nickel
Black nickel is a special nickel plating, by adding nickel sulfate, nickel chloride, sodium sulfate, boric acid and other additives to the plating bath, and then by adjusting the pH and temperature of the plating solution, it can generate black or dark gray nickel plating, with unique visual effects, corrosion resistance is not as good as nickel-copper-nickel, and is mainly used for occasions that require a special appearance effect and a certain corrosion resistance.
Electroless Nickel
The appearance of chemical nickel is not much different from nickel-copper-nickel from the photo, you can click on the product "Electroless Nickel Coated Small Cylindrical Neodymium Magnet 2 x 2mm" to see, it has a better protection than nickel-copper-nickel, suitable for applications that require very high corrosion resistance, such as the automotive industry, aerospace, medical equipment and other fields.
Galvanized (Zinc)
This is an affordable plating option that does not provide as much protection as nickel-copper-nickel with three layers. Related types of zinc plating are colored zinc, blue and white zinc, which provide different visual effects and can be used for decorative purposes, and are recommended for cost-sensitive applications.
Epoxy Coating
Epoxy resin coating has better corrosion resistance than nickel-copper-nickel, with a variety of appearances, we mainly see black, gray, in fact, it can also be blue, white, green, red, etc. Bonded neodymium magnets are mainly chosen for this type of coating, which is recommended for long-term exposure to harsh environments for applications such as marine environments or areas with high humidity.
Gold Plating
Gold plating on NdFeB surfaces has a very beautiful appearance, shiny appearance, good electrical conductivity and corrosion resistance, suitable for luxury jewelry and decorations, as well as applications requiring high electrical conductivity.
Chrome Plating
Chromium has high hardness, neodymium magnet surface chrome plating can improve the magnet surface hardness and wear resistance, prolong the service life, suitable for applications that require high surface hardness and wear resistance, such as the automotive industry, industrial equipment, the choice of chrome plating customers really not much.
Polymer Coating - Parylene
Paraline is a high performance polymer coating that does not change the original color (grey) of NdFeB magnets and provides excellent protection, especially in acid, alkali and salt environments.
When selecting the coating for neodymium magnets, the main considerations are environmental conditions, cost, mechanical properties, electrical conductivity, aesthetic requirements, if you need help you can contact us to provide you with advice.
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