Method for directly preparing MnZn ferrite material from nanocrystalline MnZn powder

Abstract

The invention discloses a preparation method for directly preparing a high-frequency low-power-consumption material by nanocrystalline MnZn ferrite particles and belongs to the preparation technical field of ferrite magnetic materials. The preparation method comprises the following operation steps: step one: preparing nanocrystalline MnZn powder; step two: pressing into annular biscuit; and step three: sintering into a product. The biscuit pressed in the step two is put in a vacuum furnace, balanced oxygen partial pressure protection is adopted for the biscuit in the heat preservation and cooling processes, and finally the biscuit is naturally cooled to room temperature, thus obtaining the high-frequency low-power-consumption MnZn ferrite. The key point of the preparation lies in combination of quick heating and slow heating in the heating process, which is favorable for elimination and densification of air holes, and causes the crystal particles to be uniform in the processes of slow heating and heat preservation. In the method, the nanocrystalline MnZn powder is prepared by adopting a sol-gel spontaneous combustion method by direct sintering without a presintering re-ball milling process, the cycle is short and the process is relatively simple, thus reducing energy consumption and lowering labor cost. The nanocrystalline MnZn powder particles prepared by the sol-gel method have the advantages of even particles, huge activity, even and non-segregating components and high yield.

Description

technical field [0001] The invention relates to a method for directly firing high-frequency power MnZn ferrite material from nanocrystalline MnZn ferrite powder. The invention belongs to the technical field of ferrite magnetic materials. Background technique [0002] With the development of electronic systems towards planar patching, miniaturization and light weight, the power supply is required to develop towards high frequency, which means that power ferrite is required to develop towards high frequency and low loss. However, MnZn ferrite is cheaper than NiZn ferrite, and has high saturation magnetization, high Curie temperature, and high magnetic permeability. Therefore, it is urgently required to replace NiZn ferrite with MnZn ferrite in some high-temperature applications. frequency field. [0003] The sintering process is the key to prepare high performance MnZn ferrite. To ensure the performance of MnZn power ferrite, we must pay attention to the whole process from ...

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Problems solved by technology

[0004] At present, most manufacturers at home and abroad use the solid-state reaction method to prepare MnZn ferrite. It needs to go through tedious and complicated procedures such as ball milling, pre-sintering, doping, secondary ball milling and sintering. In the above process, impurities are easily introduced and the product quality Guaranteed to be difficult

CN1951865A discloses a low-temperature sintering method, which realizes sintering at a lower temperature, but adopts the solid-state reaction method, which requires pre-burning and then ball milling, resulting in long production cycle and high cost

CN101276668A discloses a preparation method of nanocrystalline soft magnetic manganese-zinc material. Co-precipitation method is used to prepare nano-powder. However, the phase of nano-powder prepared by co-precipitation method is impure, and insufficient washing cannot remove impurity ions. The prepared powder It is easy to delaminate, and the performance after sintering is difficult to guarantee. Its saturation magnetization reaches 899mT, 1027mT, and 989mT in the examples, which is debatable

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