Mesoporous-material-added zinc-plated neodymium-iron-boron magnet and preparation method thereof

Abstract

The invention discloses a mesoporous-material-added zinc-plated neodymium-iron-boron magnet which is composed of the following components in percentage by mass: 25-35% of Pr-Nd, 1-2% of B, 0.1-1% of Al, 0-0.2% of Cu, 1-2% of Co, 0.1-0.3% of Ga, 0.1-1% of Nb, 0-0.1% of Zr, 0.1-1% of mesoporous silicon dioxide, and the balance of Fe and small amounts of inevitable impurities in the material. By starting with the neodymium-iron-boron magnet raw material powder ground by an air flow grinder, the micron-sized raw material powder is directly coated and plated by zinc, thereby enhancing the oxidation resistance of the neodymium-iron-boron raw material. By adding the mesoporous silicon dioxide, the nano component and neodymium-iron-boron magnet main phase are compounded into the grain boundary phase, thereby enhancing the coercivity of the magnet on the premise of keeping the magnetic remanence basically constant; and the produced neodymium-iron-boron magnet has the advantages of uniform crystal form structure, excellent corrosion resistance, obviously higher machinability, excellent oxidation resistance and high coercivity.

Description

technical field [0001] The invention relates to the technical field of rare earth permanent magnet materials, in particular to a galvanized NdFeB magnet added with mesoporous materials and a preparation method thereof. Background technique [0002] NdFeB permanent magnet material, as the latest result of the development of rare earth permanent magnet materials, is known as the magnet king because of its excellent magnetic properties. It is the permanent magnet with the strongest magnetic force at present, and its maximum magnetic energy product is 10 times higher than that of ferrite. Above, it has the advantages of small size, light weight, extremely high magnetic energy product and coercive force, and high energy density, which makes NdFeB permanent magnet materials widely used in modern industry and electronic technology. [0003] In recent years, with the rapid development of NdFeB magnets in many fields, sintered NdFeB magnets have been widely used in various aspects du...

AI Technical Summary

Problems solved by technology

Due to the interaction of van der Waals force, London force and magnetic force among the raw material powders of micron-sized NdFeB magnets, the powders are agglomerated into secondary powder particles and small particle groups are formed, resulting in poor fluidity and difficult orientation of the powders, which eventually lead to neodymium Iron-boron permanent magnet materials have disadvantages such as low Curie temperature, poor temperature characteristics, and easy to be oxidized and corroded.

[0004] Chinese invention patent CN 105702405A is the first to add nano-scale mesoporous materials to NdFeB magnet materials to improve its microstructure and structural defects, thereby increasing its coercive force and working temperature. Its advantages lie in simple processing technology and uniform crystal structure 1. The magnet material has strong coercive force and good temperature resistance, but it does not improve the shortcoming that NdFeB magnets are easily oxidized and corroded. For this reason, the present invention starts with the NdFeB magnet raw material powder after airflow grinding, and the micron Grade raw material powder is first galvanized on the surface, and the surface of the particles is coated with a layer of nano-scale zinc layer, and then mixed with mesoporous silica for subsequent processes, so as to comprehensively improve the shortcomings of NdFeB magnets