How To Remove Impurities From Finished NdFeB Products?
The processing of NdFeB magnets is basically carried out under vacuum conditions, and impurities are not easily mixed. Since the chemical properties of NdFeB permanent magnet materials are relatively active, impurities are incorporated during the oxidation of the metal. Therefore, the finished product needs to be electroplated and coated. However, the quality of electroplating coating has a close relationship with its pretreatment. This processing technology generally includes degreasing, rust removal and activation. In this pretreatment process, if one of the them is not cleaned, it may cause problems such as foaming and peeling of the plating layer. If such defective NdFeB magnet parts are mounted on the equipment, it is likely to cause the entire machine to malfunction.
The forged metal material is more precise than the NdFeB permanent magnet material, and the NdFeB permanent magnet material is a microporous material, and its porosity brings many difficulties and time consuming to the preplating treatment.How to remove dirt from the pores is an important matter except removing alkali, acid, and dirt from the surface of the workpiece.
For low-grade permanent magnet materials that are generally less demanding, the previous pretreatment processes are: alkaline degreasing-washing-pickling-washing-surface activation plating. This kind of process is relatively simple,but it has high requirements for degreasing agent, and it needs special degreasing agent for NdFeB. The formula of this degreasing and degreasing agent is complicated, and there are many kinds of raw materials required, and the preparation process foruser is very troublesome. Since the emergence of high-power ultrasonic cleaners in industrial production, these problems have been solved one by one. The unique cavitation effect of ultrasonic cleaning can make the alkaline and acidic substances remaining in the micropores of the permanent magnet material better removed!
The most powerful magnets available, Sintered NdFeB is produced by powder metallurgical process with chemical composition of Nd2Fe14B, which are hard, brittle and easily corrode, involving the sintering of compacts under vacuum. Poorest corrosion resistance of all commercial magnetic material. Grinding and slicing possible; very reactive with moisture and oxygen; coating may be applied depending on the expected environment. The sintered NdFeB magnet has high remanence, high coercive force, high energy product and high ratio between performance value and product cost. It may be easily formed into various sizes. The intrinsic coercive force is over 30,000 Oe. Neodymium magnets lose -0.09 ~ -0.13% of Br/°C. Their working stability is under 80°C for low Hci. Neodymium magnets and above 200°C for high Hci Neodymium magnets. The highest (BH)max reaches up to 51MGOe . The choice of Strip casting and HDDR technology in our factory allows us to make high performance NdFeB over N52 possible. Surface treatments have been developed that allow the sintered NdFeB magnet to be used in most applications. The treatments include gold, nickel, zinc and tin plating and epoxy resin coating.