What is the best effect of neodymium iron boron magnet surface plating?
Neodymium iron boron magnet due to poor corrosion resistance function, so it is generally necessary to carry out electroplating anti-corrosion, then the problem comes, what should be plated on the surface of the magnet? What’s the best effect?
As for the best effect of neodymium iron boron plating on the surface, we should first know which neodymium iron boron can be plated?
What are the common coatings of NdFeB magnets?
The NdFeB strong magnet coating is generally nickel plated, copper, chromium, gold, black zinc, blue white zinc, epoxy resin, etc. Different electroplating, the color of the magnet surface will vary, and the preservation time will be long and short.
The effects of Ni, Zn, epoxy and Parylene-C coating on magnetic properties of NdFeB magnets in three solutions were studied. The results showed that in acid, alkali and salt environment, the protective effect of polymer coating on magnet was the best, epoxy resin was relatively poor, Ni coating was the second, and Zn coating was relatively poor.
Zinc: the surface looks silver white, can be used for 12-48 hours salt fog. It can be used for bonding some glue (such as ABS). If electroplated, it can be stored for two to five years.
Nickel: it looks like stainless steel color, it is difficult to be oxidized on the surface in the air, and it has good appearance and good gloss. The plating can pass 12-72 hours salt spray test. The disadvantage is that it can not be used for bonding with some glue, which will make the coating fall off. Accelerate oxidation, now the market is mostly nickel copper nickel plating method for 120-200 hours salt spray
Copper: it is mostly found in hardware industry, and Nd-Fe-B industry is rarely used by people, and its appearance is yellow.
Chromium: chromium plating industry is also relatively rare, its electroplating cost is very high, and the company can not accept it, but its corrosion releasing ability is very strong, it is difficult to react with other substances, mainly used in places with strong acid and alkali. This is rarely chosen.
Black zinc: it is to treat the surface of products into black according to the requirements of customers. In the electroplating process, it is mainly based on galvanizing and a layer of black protective film is added through chemical treatment. This film can also be used to protect the products, increase the salt spray time and prolong the oxidation time. But its surface is easy to be scratched and its protection function is lost. There are few people who are now using it, mostly by resin. We will explain below.
Gold: some of the little stalls we saw on the street have yellow gold hand decorations mostly gilded or copper. Gold plating makes the appearance of products look like gold is very beautiful, generally used in the hand decoration industry, our magnet products can also be gilded, used for magnetic hand decoration.
Epoxy resin: it is to add a layer of resin paint on the outside after nickel plating. The industry has only been in the market for nearly two years. It has a rapid development speed. There are many people using various electroplating products. The biggest advantage is that you can achieve the color you want.
PS: the appropriate coating shall be selected according to the unused environment. The coating of the manufacturer is different, the main reason is the chamfering and the length of plating time. In the absence of understanding the magnet plating, we should judge the quality of the coating. In fact, there is a simplest and fast way to see the coating. The brighter the coating means the better the quality. Therefore, when choosing to order the magnet, try to choose the industry to know better famous enterprises to ensure the quality of coating.