Method for improving remanence and intrinsic coercive force of permanent magnetic ferrite

Abstract

The invention discloses a method for improving remanence and intrinsic coercive force of permanent magnetic ferrite. The method comprises the following steps: (1) burdening, namely taking pre-sintering material powder of permanent magnetic ferrite, and adding calcium carbonate and sodium chloride, so as to obtain pre-sintering material mixed powder of the permanent magnetic ferrite; (2) ball-milling, namely adding water, and carrying out ball-milling until the mean particle size is smaller than or equal to 0.95mu m, so as to obtain permanent magnetic ferrite slurry; (3) participating and filtering, namely participating the slurry, and filtering to obtain forming slurry; (4) shaping by injection molding, namely injecting the forming slurry into a mold, and carrying out extrusion forming under a magnetic field condition, so as to obtain shaped green bodies; and (5) sintering, namely sintering the shaped green bodies at 1100-1200 DEG C, so as to obtain permanent magnetic ferrite blanks. According to the method disclosed by the invention, through adding calcium carbonate and sodium chloride in the ball-milling process, the remanence of the permanent magnetic ferrite is improved, and relatively high intrinsic coercive force is kept, so that the high-performance permanent magnetic ferrite of which Br is 4300-4400 GS and Hcj is 4600-4900 Oe is prepared.

Description

technical field [0001] The invention relates to a method for improving the magnetic properties of permanent magnet ferrite, in particular to a method for improving the remanence and intrinsic coercive force of permanent magnet ferrite. Background technique [0002] In recent years, with the continuous improvement of product miniaturization, light weight, thinner and environmental protection and energy saving requirements, higher requirements have been put forward for the performance of permanent ferrite materials. M-type permanent magnet ferrite belongs to the hexagonal crystal system. It is used as an important permanent magnet because of its high uniaxial magnetic crystal anisotropy, superior cost performance, high Curie temperature and chemical stability. Materials and magnetic recording materials are widely used in various fields such as home appliances, computers, automobiles, and communications. Exploring and developing high-performance permanent magnet ferrite mater...

AI Technical Summary

Problems solved by technology

[0004] In the case of adding alumina, chromium oxide, and kaolin alone or in combination, the intrinsic coercive force Hcj of the magnet increases continuously with the increase of the addition amount, but when the total weight of these materials exceeds the weight of the main raw material of the permanent magnet ferrite When the content is 0.3%, the remanence of permanent magnet ferrite will be significantly reduced. Therefore, it is difficult to effectively improve the comprehensive performance of the magnet under the condition of obtaining high intrinsic coercive force Hcj by adding alumina, chromium oxide, and kaolin alone or in combination.