R-T-B type sintered permanent magnet

Abstract

The invention discloses an R-T-B type sintered permanent magnet. The sintered permanent magnet is characterized in that contents of impurity elements are controlled in the preparation process to enable that C is less than or equal to 800ppm, O is less than or equal to 800ppm and N is less than or equal to 200ppm in the sintered magnet; the microstructure of the magnet comprises an R2T14B main phase, a crystal boundary phase and a triangular region 1, wherein the crystal boundary phase refers to a separation part between two main phase crystal particles; the crystal boundary phase comprises a first crystal boundary phase in the direction of easy orientation axis of the magnet and a second crystal boundary phase perpendicular to the direction of easy orientation axis of the magnet; the crystal structures of the two types of crystal boundaries are both face-centered cubic structures; the triangular region 1 is a rare earth-rich phase with high content of Al+Ga elements, and the rare earth-rich phase is an amorphous phase, wherein the component atomic percentages satisfy the relation as follows: Pr+Nd is greater than or equal to 65% and less than or equal to 88%; Al+Ga is greater than or equal to 10% and less than or equal to 25%; O is less than or equal to 10%; and other elements Fe+Cu+Co is less than or equal to 2%. By virtue of the magnet structure, coercivity can be greatly improved.

Description

Technical field: [0001] The invention relates to the technical field of sintered permanent magnets, in particular to an R-T-B rare earth sintered permanent magnet with a novel microstructure. Background technique: [0002] At present, R-T-B (R refers to a single or combination of certain rare earth elements, such as Pr, Nd, Dy, Tb, etc.; T refers to a single or combination of certain transition metals, such as Fe, Co, etc.; B refers to B or N element) series of sintered permanent magnet materials are more and more widely used in wind power generation, air conditioning, elevators and new energy vehicles. Due to the high price of heavy rare earth elements Dy and Tb, they can be obtained without adding heavy rare earths or adding less heavy rare earths. High coercivity magnets are in increasing demand. [0003] In order to save the use of heavy rare earths and maximize the coercive force of the magnet, the diffusion technology of pure metals, two-phase or multi-phase alloys of...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome above-mentioned deficiencies in prior art, and provide a kind of R-T-B type sintered permanent magnet; Under certain conditions, a sintered NdFeB magnet with a specific microstructure and composition is obtained, with higher coercive force

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