A high coercivity rare earth permanent magnet preparation method integrating oscillating thermal deformation and infiltration

Abstract

The invention provides a method for preparing a high-coercivity rare earth permanent magnet integrating oscillating thermal deformation and penetration, which comprises the following steps: putting rare earth permanent magnet powder into a vacuum induction hot press to heat and keep it warm, and performing hot pressing treatment to produce After the hot pressing is completed, the magnet does not need to be cooled and then heated up, and directly enters the thermal deformation process, and performs a hot extrusion process to prepare an anisotropic permanent magnet ring; the magnetic ring is demolded and sputtered. The two surfaces perpendicular to the easy magnetization direction of the magnet are sputtered and infiltrated; after sputtering, they are treated at a constant temperature to obtain a rare earth permanent magnet with high coercive force. The integrated forming and infiltration process of hot pressing-thermal deformation-infiltration proposed by the present invention adopts an oscillating deformation treatment process in the forming link to improve the forming ability, avoid the cooling and heating of the magnet and magnetic ring after hot pressing and thermal deformation, and then benefit Realize grain refinement, improve the coercive force and thermal deformation capacity of the magnetic ring, improve forming efficiency and yield, and reduce loss.

Description

technical field [0001] The invention relates to the field of manufacturing and processing of rare earth permanent magnet materials, in particular to a method for preparing a high coercivity rare earth permanent magnet integrating oscillation thermal deformation and infiltration. Background technique [0002] The rare earth permanent magnet ring with radiation orientation is the core device material of advanced equipment such as servo motors and CNC machine tools. The traditional method of preparing magnetic rings is mostly based on the bonding process, but the bonding process produces isotropic magnets, and because of the addition of a large amount of epoxy resin, it not only affects the improvement of magnetic properties, but also affects the working temperature of the magnet. The improvement; the sintering process is difficult to prepare permanent magnetic ring structures with different shapes, heights and thicknesses. [0003] Therefore, the preparation of rare earth per...

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Problems solved by technology

Usually, the heat-deformable permanent magnet ring is first heated to a high temperature and then isothermally hot-pressed. After cooling down, the isotropic magnet is removed from the mold, and then the magnet is put into the mold for preparing the magnetic ring, heated to a certain temperature and kept warm. , making the magnet enter the hot extrusion deformation process to prepare an anisotropic rare earth permanent magnet ring. At the same time, Liu et al. The magnet is infiltrated to further increase the coercive force, but the unavoidable multiple heating-cooling-heating-cooling-heating-heating process in the whole process makes the internal stress inside the magnet unable to be released, making the magnet easy to crack or In addition, the repeated heating-cooling process is not conducive to the microscopic and refined structure of the magnet. Therefore, it is necessary to adopt effective technical means to complete the release of internal stress, uniform stress-strain distribution and The purpose of improving the coercive force

Invention patent (Application No.: 201911416220.1) proposes "an integrated preparation method of intermittent hot-pressing-heat-deformed rare earth permanent magnet ring", which can relieve internal stress through intermittent methods, but because of its intermittent The process is still in the pressure-holding loading stage, and the release degree of internal stress and the improvement of formability are relatively limited.

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