Forming die and method for preparing high-performance radial neodymium-iron-boron magnet

Abstract

The invention discloses a forming die and method for preparing a high-performance radial neodymium-iron-boron magnet. The forming die comprises a female die with an oval cavity, an elastic element, amagnetism gathering plate made of a near-permeability material, an upper pressing head, a lower pressing head, an inner hole core rod, a female die sliding block, an elastic element and the like, wherein the upper pressing head and the lower pressing head are made of nonmetal diamagnetic materials. A mixed liquid additive containing a dispersing agent, an antioxidant, a release agent, nitride andthe like is added in a pulse spraying manner during three-dimensional stirring, so that the formability and fluidity of powder are improved; a multi-time magnetization opposite progressive pre-pressing process is adopted, so that automatic pressing and demolding of a radial circular ring are realized, and cracking of the magnet due to uneven density is avoided; and the oxygen content of the magnetis effectively reduced, so that nitrides are distributed at a grain boundary, the growth of crystal grains is inhibited, the crystal grains are effectively refined, the intrinsic coercivity of the neodymium magnet is improved, and the radial ring neodymium magnet with low cost and high performance is prepared.

Description

technical field [0001] The invention relates to a molding die and method for preparing a high-performance radial ring neodymium magnet, and is particularly suitable for the preparation of a high-performance and high coercivity sintered NdFeB radial ring magnet. Background technique [0002] At present, there is a strong demand for 100,000-150,000-rpm high-speed motors in high-lift water pumps, vacuum cleaners, hair dryers, and mite removers. Higher speeds can be converted into greater suction, and the working time and service life of the power supply are also longer. . Such high-speed motors generally use radially oriented sintered NdFeB magnetic rings, and radial cylinders can be directly molded, but it is difficult to directly mold radial rings. Due to the anisotropy of NdFeB magnetic crystals, radial products are easy to crack, and direct molded radial rings are more likely to crack and deform. The final product is a perfect circular inner hole. At present, the radial c...

AI Technical Summary

Problems solved by technology

This kind of high-speed motor generally uses radially oriented sintered NdFeB magnetic rings, and radial cylinders can be directly molded, but it is difficult to directly mold radial rings

Due to the anisotropy of NdFeB magnetic crystals, radial products are easy to crack, and direct molded radial rings are more likely to crack and deform

The final product is a perfect circular inner hole. At present, the radial circular ring is generally produced by making a radial cylinder first, and then drilling the inner hole. This method causes waste of some materials in the inner hole; while some high-speed Motor products need to use radial ring magnets with elliptical inner holes, and have high requirements for the concentricity of the long and short axes of the elliptical inner holes of the magnets. The final product with elliptical inner holes can only be processed by electric pulses. This processing method costs very high

At present,

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