Sintered ndfeb permanent magnets, as promoting the advancement of modern technology and society is one of the important material, widely used in the following areas: computer hard drives, nuclear magnetic resonance imaging (fmri) permanent magnet motor, electric cars, wind power generation, industry, consumer electronics (CD, DVD, mobile phones, audio, duplicator, scanners, cameras, camera, fridge, TV, air conditioning, etc.) and the magnetic force, magnetic levitation, magnetic mechanical transmission industry. Since 1985, it has been industrialized in Japan, China, Europe and The United States simultaneously. In the past 30 years, the global permanent magnet material industry has been developing rapidly, with continuous record breaking magnetic properties and increasing material varieties and brands. With the expansion of the market, its manufacturers are also increasing, and many customers are inevitably trapped in such confusion, how to judge the pros and cons of the product?

The most comprehensive judgment method: 1. 2. Magnet size; Three, magnet coating.

First of all, the guarantee of magnet performance comes from the control of the raw material production process

1. According to the requirements of manufacturing high-grade, intermediate or low-grade sintered Ndfeb, choose and purchase raw materials according to the raw material composition stipulated by national standards.

2. The performance and quality of the magnet are directly determined by the advanced production technology. The most advanced technologies are scale ingot (SC) technology, hydrogen crushing (HD) technology and air flow grinding (JM) technology. Small capacity vacuum induction furnace (10kg, 25kg, 50kg) has been replaced by large capacity (100kg, 200kg, 600kg, 800kg) vacuum induction furnace. StripCasting fast casting technology has gradually replaced large ingot (ingot with cooling thickness greater than 20-40mm), hydrogen crushing (HD) technology and air flow grinding (JM) have replaced jaw crusher, disc mill and ball mill (wet powder) to ensure the uniformity of powder and facilitate liquid phase sintering and grain refinement.

3. In terms of magnetic field orientation, China is the only country in the world that adopts two-step pressing molding. In the orientation, it adopts small pressure vertical molding and finally adopts quasi-isostatic pressing molding, which is one of the most important characteristics of China's sintered Ndfeb industry.

4. Moreover, it is very important to monitor the quality of the production process, which can be controlled by measuring the thickness of SC slices and the size distribution of JM powder particles. The quality of the product depends on the control of the production process, but the customer must be very confused, how to judge the performance of the product I bought? The Chinese Academy of Metrology has developed various types of magnetic parameters measuring instruments for permanent magnet materials. Pulsed magnetic field magnetometer (PFM) is a test instrument for testing ultra-high coerced permanent magnets, which are mainly used in the field of electric vehicles and large permanent magnet motors. The customer can select the NdFeb brand he needs according to the magnet parameters Br(remanence), Hcb(coercivity), Hcj(intrinsic coercivity) and (BH) Max (maximum magnetic energy product). At the same time, these four parameters are the standards to determine whether the product is produced according to the customer's requirements.