Method for producing Nd2Fe14B/Fe double-phase nano crystal composite permanent-magnetic materials

Abstract

The preparation method of Nd2Fe14B / Fe biphase nanocrystalline composite permanent magnetic material belongs to the magnetism material field. Currently it is impossible that the ideal model of soft and hard magnetic phase is conformed at the same time that the block is densified. The specific steps are as follow. In the protection of inert gas, Nd2Fe14B hard magnetic powder below 5 mum is dispersed in decane. After adding Fe (CO) 5, the Fe weight rate of Nd2Fe14B and Fe (CO) 5 is 9:1 and cool it below 0DEG C. Open the supersonic generator, adjust the power to 100-240W and let it react for 1-3h. Centrifugate, remove the liquid and clean it with pentane. After pentane volatilizes, Nd2Fe14B / Fe coating nanometer composite magnetic powder is obtained. Put the magnetic powder into the mould and put it in the plasma fritting furnace. The pressure is 30-1000MPa. In the gas of Ar, the temperature increases in the speed of 40-100DEG C / min to 500-700DEG C. The fritting time is 2-10min. Cool down with the furnace. The invention prepares fully dense, massive, biphase, nanometer and composite magnet. The crystal grain is small and distributes uniformly.

Description

technical field [0001] A preparation of Nd 2 Fe 14 A method for B / Fe dual-phase nanocrystalline composite permanent magnet material, which belongs to the preparation of magnetic materials [0002] technology field. Background technique [0003] Nanocrystalline dual-phase magnets contain both hard and soft magnetic phases. Calculated according to the principle of micromagnetism, if there is sufficient exchange coupling between the hard magnetic phase and the soft magnetic phase, the magnet will not only have the high coercive force of the hard magnet but also maintain the high saturation magnetization of the soft magnet, so it has a great High magnetic energy product. Whether it is from the perspective of magnetic properties or production costs, nanocrystalline dual-phase magnetic materials have important application prospects. Nd 2 Fe 14 Maximum Magnetic Energy Product (BH) of B / α-Fe Series Nano-Dual Phase Rare Earth Permanent Magnets max The theoretical value is 800...

AI Technical Summary

Problems solved by technology

[0004] At present, the preparation methods of the material mainly include the melt rapid quenching method and the mechanical alloying method. Although many scientists have continuously improved the two methods, the actual magnetic properties of the nanocomposite magnetic materials are different from the theoretical magnetic properties. There is still a big gap between them, and most of the researches are concentrated on powder materials, and the progress on the preparation of bulk materials has been relatively slow, mainly because the grain size is larger than the intermediary size of the exchange coupling between soft and hard magnetic phases, and the soft and hard magnetic phases The crystal grains of the hard magnetic phase are not in good contact with each other and the distribution is uneven. The biggest difficulty is that the densification of the bulk cannot be achieved while satisfying the ideal model of the soft and hard magnetic phase, resulting in insufficient exchange coupling between the soft and hard magnetic phases. full

Images