It is important to protect neodymium magnets as they will oxidize quickly without a protective coating. The following is the current introduction of all coatings
1. Nickel-plated coating
Nickel plated magnets and the most common coating on most magnets on the market. This coating is typically applied as a three-layer coating (nickel-copper-nickel) with copper in between. It's perfect for indoor/outdoor use as long as it's moisture-resistant. Nickel finish is also available as black nickel in a shiny dark grey/charcoal color.
2. Chemical nickel coating
Electroless nickel is similar to normal nickel except that it is almost completely resistant to alkalis, salt/brine solutions, chemical and petroleum environments, and all types of hydrocarbons, solvents, ammonia solutions and acids. This makes electroless nickel an excellent choice for magnets requiring corrosion resistance.
3. Galvanized coating
Zinc is usually used as a single coat. It offers excellent performance as a corrosion resistant coating at an economical price. As the zinc begins to oxidize, it forms a layer of zinc oxide that helps protect the magnet.
4. Epoxy resin coating
The epoxy coating is mostly black and covers the triple nickel coating (Ni-Cu-Ni-Epoxy). It provides excellent performance in outdoor applications where corrosion resistance is required. This coating is softer than other coatings and scratches easily, which can expose the underlying layers and cause the magnet to corrode. Epoxy coatings are available in a variety of colors.
5. Gold-plated coating
Gold coating is available as a very thin layer of 24k gold overlaying the nickel coating. If you want to lower the cost of gold-plated magnets, you can use gold dye, but the color is not as bright as real gold. This type of coating is often found in magnetic therapy applications.
6. Silver coating
Silver plating is popular in medical applications. Silver plating exhibits good corrosion resistance, biocompatibility and inherent resistance to bacteria.
7. Plastic, Rubber coating
The plastic coating is super durable and highly corrosion resistant. It prevents magnets from cracking due to impact and prevents corrosion by creating a waterproof barrier between the magnet and the element. This type of coating comes in any color and is more expensive than other types because it requires the use of injection molds. The plastic coating is mostly 1mm thick and does degrade the magnet due to its thickness.
8. Everlube coating
Everlube is an aluminized barrier coating for maximum corrosion protection when applied to rare earth magnets. The coating is extremely durable and has excellent chemicals and corrosion resistance to a wide range of substances.
9. Teflon coating
Teflon is extremely elastic and can withstand various harsh environments. It is highly corrosion resistant. Teflon coatings do not perform well with adhesives and are not recommended for these types of applications. Teflon coating is available in a variety of colors.
10. Parylene coating
Parylene is an ultra-thin, pinhole-free polymer coating that provides superior abrasion resistance and improved abrasion resistance. It is commonly used in medical equipment, electronics, transportation and defense/aerospace applications.