Common coatings for magnets

The magnetic coating treatment is mainly aimed at the special working environment of magnets. For example, the working environment of motor magnets and iron remover magnets is relatively humid, so surface coating treatment is required. At present, the main coating technologies for magnets include: zinc plating, colored zinc plating, nickel plating, black nickel plating, nickel copper nickel plating, gold plating, silver plating, and epoxy resin plating.

The surface coating treatment of neodymium iron boron magnets requires different electroplating processes based on the product's usage characteristics and storage time. The most common electroplating processes are galvanizing and nickel plating. The surface color of each electroplating layer is different. Each has its own advantages and disadvantages.

Galvanized: The surface appears silver white and can be used for 12-48 hours of salt spray. It can be used for bonding with some adhesives, such as AB glue. If electroplated well, it can be stored for two to five years, and its advantage is that it is relatively inexpensive.

Black zinc plating: It is the process of treating the surface of the product to black according to customer requirements. In terms of electroplating technology, it mainly involves adding a layer of black protective film through chemical treatment on the basis of galvanizing. This film can also protect the product, increase salt spray time, and extend oxidation time. However, the surface is highly susceptible to scratches and loses its protective effect.

Nickel plating: It appears to have a stainless steel luster and is difficult to oxidize on the surface in the air. It has a beautiful appearance and good glossiness. Electroplating can withstand a 12-72 hour salt spray test. Its disadvantage is that it cannot be bonded with some adhesives, which will cause the coating to peel off and accelerate oxidation. Currently, nickel copper nickel electroplating is commonly used in the market. This electroplating method does 120-200 hours of salt spray, but its electroplating cost is relatively high.

Gold and silver plating: commonly used in magnetic jewelry, magnetic jewelry is mostly in gold yellow and silver white. The appearance of gold-plated magnets looks as beautiful as gold and is commonly used in the handicraft industry. Our products can also be gold-plated for magnetic handicrafts.

Electroplating with epoxy resin: It is the process of adding a layer of resin paint on the outside of a magnet after nickel plating, and its biggest advantage is that it can prolong the time of salt spray testing.

Chromium plating: Chromium plating is generally rare, as it is believed that its chromium plating process has strong corrosion resistance and is difficult to react with other substances. It is generally used in harsh working environments with strong acidity and alkalinity. The electroplating cost is very high, which most companies cannot accept, so there are very few people who choose it.