Additive and method for improving performance of permanent magnetic ferrite

Abstract

The invention discloses an additive and method for improving the performance of permanent magnetic ferrite. The additive is composed of calcium carbonate, quartz sand, and silicon carbide. The method comprises the following steps: (1) adding a permanent magnetic ferrite pre-sintered material into a ball mill, at the same time, adding the additive, then adding water, and carrying out ball-milling to obtain permanent magnetic ferrite slurry; (2) filtering the permanent magnetic ferrite slurry to obtain permanent magnetic ferrite filtered slurry; (3) filling the permanent magnetic ferrite filtered slurry into a mould, and pressing the permanent magnetic ferrite filtered slurry under a pressure of 350 to 500 kg / cm2 and a magnetic field strength of 450 to 950 kA / m so as to obtain a permanent magnetic ferrite blank; (4) sintering the obtained permanent magnetic ferrite blank for 0.5 to 3.0 hours at a temperature of 1150 to 1250 DEG C to obtain permanent magnetic ferrite. The additive cost is low, the raw material resources are wide, pricy additives such as rare earth elements, cobalt oxide, and the like are not needed; compared with the prior art, the magnetic performance of the obtained permanent magnetic ferrite is more excellent, and the performance to cost ratio is higher.

Description

technical field [0001] The invention specifically relates to an additive and a method for improving the magnetic properties of permanent ferrite. Background technique [0002] Permanent ferrite is a non-metallic magnetic material, which can generate a stable magnetic field only by providing magnetization energy once from the outside, so as to continuously provide magnetic energy to the outside. Permanent magnet ferrite is mainly used in various motor equipment and speakers, etc. At present, the widely used permanent magnet ferrite materials use iron oxide and strontium carbonate as raw materials, and high-performance permanent magnet ferrite materials also need to add cobalt oxide And rare earth oxides to improve magnetic properties. [0003] The magnetic performance indicators of permanent ferrite mainly include remanence (Br) and intrinsic coercive force (Hcj). The higher the two indicators, the better the performance of the magnet, and the remanence is proportional to th...

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Problems solved by technology

[0005] At present, when producing high-performance permanent magnet ferrite, many enterprises adopt the method of adding calcium carbonate, quartz sand, lanthanum oxide and cobalt oxide to improve the performance of the magnet. However, due to the high price of cobalt oxide, it greatly increases the cost of materials Therefore, all companies are looking for cheaper and more effective additives to replace cobalt oxide

[0006] CN104446519A discloses a dispersant and method for improving the magnetic performance of permanent magnet ferrite. It adopts the method of adding dispersant to realize the improvement of magnetic performance. Although the experimental effect close to the present invention can be obtained by using dispersant, due to the added The dispersant will expand and decompose in the initial sintering stage of the product (below 300°C), which will cause the blank to crack. Therefore, the addition of dispersant will have a certain impact on the qualified rate of the product

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