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A kind of preparation method of r-fe-b system sintered magnet

A sintered magnet, r-fe-b technology, applied in the direction of magnetic objects, inductance/transformer/magnet manufacturing, magnetic materials, etc., to achieve the effects of reducing production costs, simple operation process, and improving coercive force

Active Publication Date: 2016-04-13
YANTAI ZHENGHAI MAGNETIC MATERIAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a method for preparing R-Fe-B sintered magnets, which overcomes the problem of low speed of Dy or Tb infiltration by using Dy or Tb oxide or fluoride slurry coating method , simple operation, low cost, and greatly improved the performance of the magnet

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] In a vacuum or inert gas environment, pouring is completed in a vacuum melting furnace, and cast on a quenching roll at 1500 ° C to form scales with a thickness of 0.1 to 0.5 μm. The speed of the quenching roll is 60 r / min; Formed into powder with an average particle size of 3.5 μm; oriented and pressed in a magnetic field of 15KOe to make a green body; put the green body into a sintering furnace under an Ar atmosphere, and sinter at 1100°C for 5 hours to obtain a green body, and the green body was sintered at 500°C Aging at high temperature for 5 hours to obtain a sintered billet.

[0034] Wash the 50M sintered billet (40mm*20mm*4mm) with NaOH alkali solution and deionized water, and then dry it. Mix 50g of dysprosium oxide powder with 50mL of ethanol to make a slurry, apply it evenly on the surface of the sintered billet, and dry it to obtain The dysprosium oxide coating is 5-20 μm; then a layer of 100 μm sodium metal is evaporated on the surface of the dysprosium oxi...

Embodiment 2

[0039]In a vacuum or inert gas environment, pouring is completed in a vacuum melting furnace, and cast on a quenching roll at 1500 ° C to form scales with a thickness of 0.1 to 0.5 μm. The speed of the quenching roll is 60 r / min; Formed into powder with an average particle size of 3.5 μm; oriented and pressed in a magnetic field of 15KOe to make a green body; put the green body into a sintering furnace under an Ar atmosphere, and sinter at 1100°C for 5 hours to obtain a green body, and the green body was sintered at 500°C Aging at high temperature for 5 hours to obtain a sintered billet.

[0040] Wash the 50M sintered billet (40mm*20mm*4mm) with NaOH alkali solution and deionized water, and then dry it. Mix 50g of dysprosium fluoride powder and 50mL of ethanol to make a slurry, apply it evenly on the surface of the sintered billet, and dry it. Finally, a dysprosium fluoride coating of 5-20 μm is obtained; then a layer of 100 μm sodium metal is vapor-deposited on the surface of...

Embodiment 3

[0045] In a vacuum or inert gas environment, pouring is completed in a vacuum melting furnace, and cast on a quenching roll at 1500 ° C to form scales with a thickness of 0.1 to 0.5 μm. The speed of the quenching roll is 60 r / min; Formed into powder with an average particle size of 3.5 μm; oriented and pressed in a magnetic field of 15KOe to make a green body; put the green body into a sintering furnace under an Ar atmosphere, and sinter at 1100°C for 5 hours to obtain a green body, and the green body was sintered at 500°C Aging at high temperature for 5 hours to obtain a sintered billet.

[0046] Wash the 50M sintered billet (40mm*20mm*4mm) with NaOH alkali solution and deionized water, and then dry it. Mix 50g of terbium oxide powder and 50mL of ethanol to make a slurry, apply it evenly on the surface of the sintered billet, and dry it A terbium oxide coating of 5-20 μm is obtained; then a layer of 100 μm sodium is vapor-deposited on the surface of the terbium oxide depositi...

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Abstract

The invention relates to a manufacturing method of R-Fe-B series sintered magnets and belongs to the field of rare earth permanent magnetic materials. The manufacturing method includes the steps of smelting, powder manufacturing, compression, thermal treatment and the like. A neodymium iron boron magnet processed by the method is not changed much in residual magnetism and magnetic energy product, and coercive force is improved greatly. Compared with that Nd in the magnet is used for replacing Dy or Tb in Dy or Tb compound coated on the surface of the magnet, the manufacturing method has the advantage that the Dy or Tb is replaced at the low temperature by using potassium or sodium as a reducing agent, uniformity of a coating is improved, Dy and Tb seepage speed is improved greatly, and seepage layer thickness is increased greatly. The manufacturing method of R-Fe-B series sintered magnets is simple in operation process, uses low-price potassium or sodium, and greatly reduces production cost. Generated low-melting-point potassium or sodium compound is separated from a workpiece directly before Dy or Tb seepage, and the low-melting-point potassium or sodium compound cannot penetrate the magnet to influence performance of the magnet.

Description

technical field [0001] The invention relates to a preparation method of an R-Fe-B system sintered magnet, belonging to the field of rare earth permanent magnet materials. Background technique [0002] In recent years, the NdFeB magnet industry has developed rapidly and has been widely used in electronics, machinery and other fields instead of magnets and ferromagnets. Due to its high strength, small size, light weight, and high magnetism, NdFeB magnets play an important role in products such as hard disks, nuclear magnetic resonance (MRI), motors, electric vehicles, and wind turbines. Dy and Tb are commonly used additives in NdFeB permanent magnets, which can combine with the main phase Nd 2 Fe 14 Partial substitution of Nd in the B grain edge occurs, thereby improving the grain boundary structure and significantly increasing the coercive force of the magnet. [0003] Dysprosium or terbium can be added in various ways and have different effects on magnet performance. Bec...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F41/02H01F1/057C22C38/00C22C33/02
Inventor 于永江赵军涛孙秀彦李广军李咚咚史丙强
Owner YANTAI ZHENGHAI MAGNETIC MATERIAL CO LTD