A kind of preparation method of high coercivity neodymium cerium iron boron magnet

Abstract

The invention provides a method for preparing a high-coercivity Nd-Cerium-Fe-Bron magnet. The sintered Nd-Cerium-Fe-Bron magnet is prepared by adopting a dual-main-phase in-situ reaction chemical grain boundary modification technology. The dual-main-phase process, the chemical plating process and the in-situ The combination of reactive grain boundary modification technology makes the high melting point inorganic rare earth compound powder and the copper coating layer on the surface react in situ during the sintering process to generate a low melting point rare earth alloy liquid phase, which promotes liquid phase sintering and increases the density of the magnet. Uniformly improve the physical and chemical properties and distribution of the grain boundary phase, reduce the magnetic exchange coupling between the main phase grains, and at the same time promote the rare earth elements in the liquid phase of the rare earth alloy to diffuse more effectively into the main phase grains of NdFeB and CeriumFeB Substituting neodymium and cerium elements, forming a multi-main phase organization with a core-shell structure, increasing the magnetocrystalline anisotropy field of the main phase, and preparing a high-coercivity NdCer-Fe-B magnet.

Description

technical field [0001] The invention belongs to the technical field of permanent magnet material preparation, in particular to a preparation method of a high-coercivity neodymium-cerium-iron-boron magnet. Background technique [0002] Sintered NdFeB magnets have excellent magnetic properties and have been widely used in the manufacture of core components in high-tech fields such as new energy vehicles, wind power generation, computers, communications, and household appliances. However, with the development of sintered NdFeB magnets and the increasing demand, Nd, Pr, Dy, Tb and other rare earth elements used in the manufacture of NdFeB magnets are consumed in large quantities, and their prices continue to increase, resulting in NdFeB magnets. The price of magnets is getting higher and higher. At the same time, it has caused a large backlog of other low-cost and high-abundance rare earth elements, such as La and Ce, so that my country's rare earth elements cannot be used in a...

AI Technical Summary

Problems solved by technology

Studies have shown that Nd 80 al 20 、Nd 90 Fe 10 The grain boundary addition of such rare earth alloys and inorganic rare earth compounds such as (Nd,Pr)-H can form a continuous and uniform rare earth-rich phase at the grain boundary and a hard magnetic layer on the surface of the main phase grains, which significantly improves the coercive force of the cerium-containing magnet, but At present, it is mainly limited to single-phase Nd-Cer-Fe-B magnets

Moreover, rare earth alloys need to be prepared through additional smelting processes, and then made into alloy powder. The process is more complicated, which greatly increases the production process and increases the production cost; and the melting point of inorganic rare earth compounds is high, and its addition will not only affect the sintering densification, but also affect the production cost. Limit the diffusion of rare earth elements to the main phase grains and reduce the utilization efficiency of rare earth elements