A preparation method of a high-performance heavy rare earth Nd-Fe-B magnet

A neodymium-iron-boron, heavy rare earth technology, applied in the direction of magnetic objects, inductor/transformer/magnet manufacturing, magnetic materials, etc. The effect of increasing intrinsic coercivity, reducing consumption and reducing the magnitude of reduction

Inactive Publication Date: 2019-01-11
ZHEJIANG DONGYANG DMEGC RARE EARTH MAGNET CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this technical method will cause a large decrease in the remanence of the magnet, and at the same time, the consumption of heavy rare earth elements such as Dy and Tb will increase, and the manufacturing cost of the product will increase.
[0004] Applying the double alloy process, adding a certain amount of oxides, fluorides, hydride powders or alloy powders of Dy and Tb heavy rare earth elements in the powder preparation process can also effectively improve the intrinsic coercive force of the magnet, but if the process The control is not suitable, heavy rare earth elements such as Dy and Tb are difficult to achieve grain boundary aggregation and distribution, which leads to a significant decrease in the remanence of the magnet to a certain extent, and increases the consumption of heavy rare earth elements

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] (1) Prepare the RTM alloy according to the following formula through the quick-setting process, and then prepare the RTM alloy powder with an average particle size of about 2.0 μm by hydrogen breaking and jet milling; R is selected from Tb, T is selected from Fe, and M is selected from Al ; The mass percentages of Tb, Fe, Al in the powder are 80%, 15% and 5% respectively;

[0027] (2) Prepare the N50H magnet blank through the steps of smelting, powder making, molding and sintering, and process it into a size of 50×30×2mm (2mm is the orientation direction);

[0028] (3) Put the RTM alloy powder and 50×30×2mm N50H magnet blank together in a vacuum rotary furnace and evacuate to 10 -2 Below Pa, after heating to 700°C for 4 hours of pre-infiltration, a layer of RTM alloy powder with a weight of about 1% is adhered to the surface to obtain an N50H magnet semi-finished product, which is separated from the remaining RTM alloy powder;

[0029] (4) Put the pre-infiltrated N50H ...

Embodiment 2

[0035] (1) Prepare the RTM alloy according to the following formula through the quick-setting process, and then prepare the RTM alloy powder with an average particle size of about 2.5 μm through the hydrogen breaking and jet milling process; R is selected from Dy, T is selected from Co, and M is selected from Cu ; The mass percentages of Dy, Co and Cu in the powder are 75%, 20% and 5% respectively;

[0036] (2) The N40SH magnet blank is obtained through smelting, powder making, molding and sintering steps, and processed into a size of 60×20×3mm (3mm is the orientation direction);

[0037] (3) Put the RTM alloy powder and 60×20×3mm N40SH magnet blank together in a vacuum rotary furnace and evacuate to 10 -2 Below Pa, heat to 680°C for 3.5 hours of pre-infiltration, make the surface adhere to a layer of RTM alloy powder with a weight of about 1.5%, and obtain a N40SH magnet semi-finished product, which is separated from the remaining RTM alloy powder;

[0038] (4) Put the pre-i...

Embodiment 3

[0044] (1) Prepare the RTM alloy according to the following formula through the quick-setting process, and then prepare the RTM alloy powder with an average particle size of about 2.8 μm by hydrogen breaking and jet milling; R is selected from Nd, T is selected from Co, and M is selected from Al ; The mass percentages of Nd, Co and Al in the powder are 70%, 20% and 10% respectively;

[0045] (2) The N52 magnet blank is obtained through the steps of smelting, powder making, molding and sintering, and processed into a size of 55×25×2.5mm (2.5mm is the orientation direction);

[0046] (3) Put the RTM alloy powder and 55×25×2.5mm N52 magnet blank together in a vacuum rotary furnace and evacuate to 10 -2Below Pa, heat to 720°C for 4.5 hours of pre-infiltration, make the surface adhere to a layer of RTM alloy powder with a weight of about 1.8%, and obtain a N52 magnet semi-finished product, which is separated from the remaining RTM alloy powder;

[0047] (4) Put the pre-infiltrated...

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Abstract

The invention relates to the technical field of magnetic materials, in particular to a preparation method of high-performance heavy rare earth Nd-Fe-B magnet, comprising the following steps: (1) placing RTM alloy powder and Nd-Fe-B blank in a vacuum rotary furnace for pre-penetration treatment to obtain a semi-finished Nd-Fe-B product with an RTM alloy powder layer adhered on the surface; (2) high-performance heavy rare earth NdFeB magnet is obtained by high-temperature diffusion and heat treatment of NdFeB semi-finished product. As that heavy rare earth is diffuse at the grain boundary of theneodymium iron boron magnet, the intrinsic coercivity of the neodymium iron boron magnet is remarkably improved, the consumption quantity of the heavy rare earth element is obviously reduced, and thereduction range of the original remanence and the maximum magnetic energy product of the neodymium iron boron magnet is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of magnetic materials, in particular to a preparation method of a high-performance heavy rare-earth neodymium-iron-boron magnet. Background technique [0002] Sintered NdFeB magnets are an important class of basic functional materials with a wide range of applications. With the rapid development of high-tech fields such as wind power generation equipment, electric vehicles, hybrid vehicles, frequency conversion electrical devices, and industrial energy-saving motors, there is a demand for sintered NdFeB magnets with high magnetic properties, high operating temperature, and high operating stability. growing day by day. High intrinsic coercivity is a basic condition for sintered NdFeB magnets to have high operating temperature and high working stability. [0003] At present, adding heavy rare earth elements such as Dy and Tb in the alloy preparation process is the main technical means to significantly improv...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02H01F1/057
CPCH01F1/0577H01F41/0293
Inventor 黎龙贵卢慧斌胡烈平李超
Owner ZHEJIANG DONGYANG DMEGC RARE EARTH MAGNET CO LTD
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