In the practical application of sintered magnets, a type of material that mainly utilizes the magnetic properties possessed by the material becomes a magnetic material. It includes hard magnetic materials, soft magnetic materials, magneto-optical materials, magnetic bubble materials and magnetic refrigeration materials, the largest amount of hard magnetic materials and soft magnetic materials. Radial orientation of the ring on the development of permanent magnet motor is of great significance, the market prospects are impressive. However, the biggest problem encountered in the development of such products is the product easy to crack, the yield is low.
Sintered magnet is currently the largest commodity magnet, the program is generally melting - alloy ingot grinding - milling - magnetic field orientation forming - sintering - tempering aging - magnetization testing. NdFeB sintered permanent magnet properties depend on the intrinsic magnetic and microstructure, NdFeB alloy was discovered in 1983 in Japan and the United States NdFeB alloy, known as the third generation of permanent magnet materials. It has many kinds of preparation methods, sintering method, reduction diffusion method, melt quenching method, bonding method, etc., commonly used is the sintering method.
Permanent magnet RMI-CT MRI equipment used in the past, ferrite magnets, magnet weight 50 tons, now using the latest NdFeB permanent magnet material, the magnetic field strength has doubled, the image sharpness is greatly improved, and Save a lot of raw materials. Each NMR imager needs 0.5-3 tons of NdFeB permanent magnets, calculated according to the annual market demand of 1,000 in the world market. The annual magnet needs 500-3000 tons. At present, the United States and Germany, Siemens and Siemens have MRI production base in China.