Preparation method and product of high-abundance rare earth sintered NdFeB magnets controlled by grain boundary multilayer structure

Abstract

The invention discloses a preparation method of a high-abundance rare earth sintered neodymium-iron-boron magnet capable of regulating and controlling a grain boundary multi-layer structure and a product prepared by the preparation method, and aims at solving the problems that the grain boundary strengthening effect is single and waste of heavy rare earth resources is serious due to the fact that fine regulation and control on the grain crystal structure cannot be achieved by an existing method, and limited rare earth resources are greatly consumed along with a dramatic increase in the dosage of the magnet. According to the preparation method, preparation of the high-abundance rare earth sintered neodymium-iron-boron magnet capable of regulating and controlling the grain boundary multi-layer structure is achieved by adopting a double-alloy process and a second sintering technology. The prepared magnet has a double main phase structure and has an Nd2Fe14B main phase and an (La, Nd)2Fe14B / (Ce, Nd)2Fe14B main phase at the same time; and the grain boundary phase has a multi-layer grain boundary structure of a heavy rare earth thin shell layer / a high-potential grain boundary center layer containing high-abundance rare-earth / another heavy rare earth thin shell layer. According to the preparation method, overall improvement of the magnetic property and the corrosion resistance of the magnet is achieved through fine regulation and control on the grain crystal structure on the basis of achieving full utilization of the high-abundance rare earth; and the preparation method has relatively high application value and economic value.

Description

technical field [0001] The invention relates to the field of permanent magnet materials, in particular to a preparation method of a high-abundance rare earth sintered NdFeB magnet and its product, which can realize the regulation and control of the multi-layer structure of the grain boundary. A preparation method and product of a rare earth sintered NdFeB magnet. Background technique [0002] NdFeB permanent magnet materials have excellent magnetic properties and are ideal materials for manufacturing high-efficiency, small-volume, and light-weight magnetic functional devices. They have been widely used in electric bicycles, automobile motors, computer hard drives, electronic toys, and electric tools. And other products, as well as audio equipment, communication products, consumer electronics, medical equipment, home appliances, magnetic separation equipment and other fields, its products have high grade, high added value and wide application range. Especially in the applica...

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Problems solved by technology

[0007] The purpose of the present invention is to aim at the inability to finely regulate the grain boundary structure in the existing methods, resulting in a single grain boundary strengthening effect and serious waste of heavy rare earth resources, and with the sharp increase in the amount of magnets, it will lead to a large amount of limited rare earth resources Consumption problem, provide a preparation method of high-abundance rare earth sintered NdFeB magnets controlled by grain boundary multilayer structure and its products

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