A high-performance la/ce/y-rich rare earth permanent magnet based on rare earth hydride addition and its preparation method

Abstract

The invention discloses a rare earth hydride addition based high-performance La / Ce / Y-rich rare earth permanent magnet and a preparation method thereof. A mutli-alloy technique is adopted, the primary alloy is rich in La / Ce / Y, and the secondary alloy is rare earth hydride. During sintering and heat treatment, a hard magnetic shell layer surrounding principal phase boundaries is formed, and the comprehensive magnetic performance of the rare earth permanent magnet can be improved. The invention provides a method for efficiently utilizing abundant rare earth La / Ce / Y, the magnet cost is greatly reduced, and the comprehensive magnetic performance of the rare earth permanent magnet can be ensured.

Description

technical field [0001] The invention relates to the field of rare earth permanent magnet materials, in particular to a high-performance La / Ce / Y rich rare earth permanent magnet based on the addition of rare earth hydrides and a preparation method thereof. Background technique [0002] The third-generation rare-earth permanent magnet material NdFeB has a high magnetic energy product unmatched by other permanent magnets, so it is known as the "king of permanent magnets" and is an indispensable strategic functional material in various fields of military and civilian in modern society. From 1996 to 2008, the global output of sintered NdFeB increased from 6,000 tons to 63,000 tons, maintaining an average annual growth rate of nearly 10% (YangLuo.Proc.20th Int.Workshop on Rare Earth Permanent Magnets and Their Applications.2008, 27) . Taking 2010 as an example, the market share of NdFeB in the world's permanent magnets reached 62% (the statistics are provided by the US Magnetic M...

AI Technical Summary

Problems solved by technology

The addition of heavy rare earth mainly includes the following two ways: one is smelting addition, that is, directly adding Dy or Tb metal during the smelting process, but it will cause magnetic dilution effect, resulting in a significant reduction in remanence; the other is grain boundary diffusion, that is, through sputtering Heavy rare earth compounds are coated on the surface of magnets by methods such as spraying, vapor deposition, and surface coating. During sintering or heat treatment, the heavy rare earth elements diffuse to the surface of the crystal grains to form a magnetic hard shell, and the heavy rare earth elements will not enter the main body too much. Magnetic dilution is caused in the phase grains, but this method is only suitable for small pieces of magnets due to the limitation of diffusion depth, and is not suitable for mass production