Preparation method of neodymium-iron-boron magnet with adjustable grain boundary

A technology of NdFeB and grain boundaries, which is applied in the direction of magnetic objects, inductors/transformers/magnets manufacturing, magnetic materials, etc., can solve the problem that the magnets do not provide effective control of grain boundaries, etc., and achieve reduced production costs and simple experimental conditions. Effect

Active Publication Date: 2020-12-25
YANTAI DONGXING MAGNETIC MATERIALS INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above-mentioned magnets do not give effective control of grain boundaries.

Method used

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  • Preparation method of neodymium-iron-boron magnet with adjustable grain boundary
  • Preparation method of neodymium-iron-boron magnet with adjustable grain boundary
  • Preparation method of neodymium-iron-boron magnet with adjustable grain boundary

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0050] 1) Take the NdFeB magnet intermediate, the intermediate satisfies the total amount of Pr, Nd, and Ce at 34.67wt%, the ratio of Pr / Nd is 0.16, the Tb content is 1.13wt%, and the total amount of Al, Cu, Ga, and Mg is 2.22wt%, Cu / Al is 1.26, Cu / Ga is 6, the total of Co, Ti, Zn, Sn is 1.42wt%, B content is 1.04wt%, and the high temperature diffusion of NdFeB magnet is 900℃×10 h, the heating rate is 5 °C / min, the aging temperature is 480 °C × 8 h, Ar gas positive pressure circulation cooling, and the cooling pressure is 1500 mbar.

[0051] 2) NdFeB permanent magnet performance: a magnet with an intrinsic coercivity Hcj of 29 Koe, a remanence Br of 12.5 kGs, and a grain boundary width of 800 nm.

Embodiment 2

[0053] 1) Take the NdFeB magnet intermediate, the intermediate meets the total amount of Pr, Nd, and Ce is 32.79 wt%, the ratio of Pr / Nd is 0.05, the Dy content is 0.98 wt%, and the total amount of Al, Cu, Ga, and Mg is 1.62 wt%, Cu / Al is 0.53, Cu / Ga is 2.5, the total of Co, Ti, Zn, Sn is 1.47 wt%, B content is 1.08 wt%, and the high temperature diffusion of NdFeB magnet is 940℃×8 h, the heating rate is 4°C / min, the aging temperature is 500°C×6 h, Ar gas positive pressure circulation cooling, and the cooling pressure is 1000 mbar.

[0054] 2) NdFeB permanent magnet performance: the intrinsic coercive force Hcj is 27 Koe, the remanence Br is 13.2 kGs, and the grain boundary width is 300 nm. See the backscattered electron picture, such as image 3 .

Embodiment 3

[0056] 1) Take the NdFeB magnet intermediate, the intermediate satisfies the total amount of Pr, Nd, Ce is 37.75 wt%, the ratio of Pr / Nd is 0.53, the total amount of Al, Cu, Ga, Mg is 2.35 wt%, Cu / Al is 0.16, Cu / Ga is 0.75, Mg / Al is 1.11, the total amount of Co, Ti, Zn, and Sn is 1.5wt%, and the B content is 1.1wt%. The high temperature diffusion of NdFeB magnet is 850℃×20 h , the heating rate is 6°C / min, the aging temperature is 460°C×10 h, Ar gas positive pressure circulation cooling, and the cooling pressure is 3000 mbar.

[0057] 2) NdFeB permanent magnet performance: the intrinsic coercive force Hcj is 24Koe, the remanence Br is 12.8 kGs, and the grain boundary width is 600 nm. See the backscattered electron picture, such as Figure 4 .

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Abstract

The invention relates to a preparation method of a neodymium-iron-boron magnet with an adjustable grain boundary. The performance of the neodymium-iron-boron magnet is controlled through regulation ofthe grain boundary, a diffusion source and the neodymium-iron-boron magnet form a neodymium-iron-boron magnet intermediate, the chemical components of the neodymium-iron-boron magnet intermediate areexpressed, in percentage by mass, as [R1xR2yR3<1-x-y>]aMbBcFe<100-a-b>, wherein x is greater than or equal to 0.8 and less than or equal to 1, y is greater than or equal to 0 and less than or equal to 0.08, a is greater than or equal to 32 and less than or equal to 38, b is greater than or equal to 0.5 and less than or equal to 7, c is greater than or equal to 0.9 and less than or equal to 1.2, R1 refers to one or more of Nd, Pr and Ce, R2 refers to one or more of La and Sm, R3 refers to one or more of Tb, Dy and Ho, M refers to multiple groups of Al, Cu, Ga, Ti, Co, Mg, Zn, Nb, Mo and Sn, and then the neodymium-iron-boron magnet intermediate is charged into a furnace and subjected to high-temperature aging treatment. The coercive force performance of the heavy-rare-earth-free magnet canbe higher than 25 kOe, and the coercive force performance of the heavy-rare-earth-containing magnet after treatment can be higher than 29 kOe.

Description

technical field [0001] The invention belongs to the technical field of NdFeB magnets, in particular to a method for preparing NdFeB magnets with adjustable grain boundaries, which improves the coercivity of NdFeB sintered permanent magnets. Background technique [0002] NdFeB sintered permanent magnets, known as the "Magnetic King", have been widely used since their birth and have been deeply rooted in modern society. They are widely used in high-tech fields such as electronic information, medical equipment, new energy vehicles, household appliances, and robots. . With the rapid development of informatization and industrialization, high-performance magnets have become a current research hotspot. [0003] In 2005, Nakamura reported a simple and rapid increase in coercive force by using heavy rare earth oxide and fluoride powders, that is, "grain boundary diffusion technology". With the development of diffusion technology, two diffusion mechanisms are formed, namely hardenin...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02C22C38/06C22C38/16C22C38/14C22C38/10C22C38/12
CPCH01F41/0253H01F41/0266H01F41/0293C22C38/005C22C38/06C22C38/16C22C38/002C22C38/14C22C38/10C22C38/12C22C38/008H01F1/0577
Inventor 王传申杨昆昆彭众杰丁开鸿
Owner YANTAI DONGXING MAGNETIC MATERIALS INC
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