Preparation method of full-compact nanometer compound rare earth permanent magnetic material

Abstract

The invention provides a preparation method of full-density nanometer composite rare earth permanent magnetic material, comprising the process steps as follows: (1) non-crystal nanometer rare earth permanent magnetic powder is put into a reaction chamber where inert gas is pumped into so as to eliminate air in the reaction chamber; subsequently, the inert gas is taken as carrier gas; pentacarbonyl iron steam is brought into the reaction chamber and carries out chemical vapour deposition under the vibration condition; the pentacarbonyl iron steam is decomposed so as to generate elementary substance Fe which is deposited on the surface of the rare earth magnetic powder so as to form the rare earth permanent magnetic powder / elementary substrate Fe composite magnetic powder; (2) the rare earth permanent magnetic powder / elementary substrate Fe composite magnetic powder is put into a discharging plasma sintering device or an induction sintering device so as to carry out vacuum pressurization sintering, thus obtaining the full-density nanometer composite rare earth permanent magnetic material. The method of the invention can not only prepare the full-density nanometer dual-phase composite magnetic body with high performance, but also has simple technology and low cost.

Description

technical field [0001] The invention belongs to the field of composite rare earth permanent magnet materials, and in particular relates to a preparation method of a nanometer two-phase composite rare earth permanent magnet material. Background technique [0002] Nano two-phase composite rare earth permanent magnet material utilizes the high saturation magnetization of the soft magnetic phase and the high magnetocrystalline anisotropy of the hard magnetic phase to obtain excellent magnetic properties, and is an important functional material. The traditional preparation method of nano-two-phase composite permanent magnet materials is the bonding method. The nano-composite magnet obtained by this method contains a large amount of non-magnetic binder, and it is difficult to densify, which seriously affects the magnetic properties of the material. [0003] The preparation of full-dense nanocomposite rare earth permanent magnets usually adopts sintering method, including direct si...

AI Technical Summary

Problems solved by technology

Although this method can obtain nanocomposite magnetic powder with uniform distribution of soft and hard magnetic phases, it has the following problems: 1. Due to the need to use an ultrasonic device, the cost is greatly increased; 2. The NdFeB magnetic powder needs to be immersed in an organic solvent for coating. Therefore, organic solvent must remain between the surface of NdFeB magnetic powder and the elemental iron in the coating layer, which will affect the performance of the magnet; 3. The composite magnetic powder needs to be centrifugally separated and washed, and the process is relatively complicated

However, magnetron sputtering, pulsed laser spraying and electroplating have strict requirements on equipment and complex processes, and the cost is too high, and the plating solution in electroplating is difficult to handle, which is not conducive to environmental protection; before electroless plating, the substrate material needs to be activated, Sensitization and other pre-plating treatment, therefore, the more active Nd-rich phase is easy to corrode, only about 1 / 4 to 1 / 3 of the powder particles can be plated with soft magnetic materials, the efficiency is very low, and the composite magnetic powder after electroless plating is also Separation and washing are required, chemical liquids need to be treated, and non-magnetic chemical reagents will inevitably remain in the composite magnetic powder, resulting in a decrease in the magnetic properties of the magnet

Images