The sintered neodymium iron boron strong magnetic coating includes nickel, copper, chromium, gold, zinc, black zinc, and epoxy resin. The surface plating is not the same, its color is also different, and its storage time is also different. Each has its advantages and disadvantages.
1) Zinc: The surface looks silvery white, it can be used as salt spray for 12-48 hours, and can be used for bonding with some glues (such as AB glue) such as sintered neodymium iron boron strong magnetic plating can be stored for two to five years , Its advantage is that the price is relatively low.
2) Nickel: It looks like the color of stainless steel, the surface is difficult to be oxidized when left in the air, and the appearance is good, and the gloss is good. The electroplating can pass the salt spray test for 12-72 hours. The disadvantage is that it cannot be used for bonding with some glue, which will cause the coating to fall off. Accelerate the oxidation. At present, the nickel-copper-nickel electroplating method is mostly used in the market for 120-200 hours of salt spray, but the electroplating cost is relatively high.
3) Copper: It is mostly found in the hardware industry. The sintered NdFeB magnet is rarely used, and its appearance is yellow.
4) Chromium: Chromium electroplating industry is also relatively rare, and its electroplating cost is very high, and the average company cannot accept it. However, it has a strong ability to release corrosion, and it is difficult to react with other substances. It is mainly used in places with strong pH and domestic product prices are relatively low, so few people choose.
5) Black zinc: According to customer requirements, the surface of the product is treated to black. In terms of electroplating process, a black protective film is added through chemical treatment on the basis of galvanizing. This film can also protect the product. , Increase the salt spray time and prolong the oxidation time. But its surface is easily scratched and loses its protective effect. There are very few people in use now, and most of them are replaced by resin. We have explained below.
6) Gold: This industry is very popular nowadays. The yellow gold jewelry of some stalls we see on the street is mostly gilded or copper. Gold-plating makes the product look very beautiful like gold. It is generally used in the jewelry industry. Our products can also be gold-plated for magnetic jewelry.
7) Epoxy resin: The effect of NI, ZN, epoxy resin, and PARYLENE-C coating on the magnetic properties of NdFeB magnets in three solutions has been compared and studied.
Polymer material>Epoxy resin>NI coating>ZN coating
It is to add a layer of resin paint on the outside of the product after nickel plating. This industry has only had a market in the past two years, and its development speed is very fast. Nowadays, many people use various electroplating products, and its advantage is that you can do what you want. The color you want.
Therefore, according to different needs, choose different colors for the coating of sintered NdFeB magnets.