Preparation method for R-Fe-B-series sintering magnet

A sintered magnet, r-fe-b technology, used in magnetic objects, inductor/transformer/magnet manufacturing, magnetic materials, etc., can solve the adhesion between sintered magnets and heavy rare earth materials, strict and high operating system requirements, and coating adhesion. To achieve the effect of improving coercivity, good diffusion effect and tight contact

Inactive Publication Date: 2014-04-23
YANTAI ZHENGHAI MAGNETIC MATERIAL CO LTD
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AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved by this invention is to provide a kind of preparation method of R-Fe-B series sintered magnet, this method has overcome the oxide or fluoride slurry coating method coating adhesion of Tb or Dy in the prior art The problem of poor and complicated operation overcomes the problems of strict requirements on the operating system, low processing efficiency and high cost of using the evaporation method, and avoids the problem of adhesion between sintered magnets and heavy rare earth materials caused by the use of existing methods

Method used

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  • Preparation method for R-Fe-B-series sintering magnet

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Effect test

Embodiment 1

[0038] The content of neodymium, praseodymium, dysprosium, terbium, electrolytic iron, cobalt, copper, gallium, aluminum, zirconium and boron by weight percentage: Nd-24.3%, Pr-5%, Dy-0.5%, Fe-68.29%, Co -0.5%, Cu-0.13%, Ga-0.1%, Al-0.1%, Zr-0.12%, B-1% ratio, pouring is completed in a vacuum melting furnace under an inert gas environment, the pouring temperature is 1450°C, and the quenching roll The rotation speed is 60r / min, and the thickness of the obtained scales is about 0.3mm; the scales are made into powders with an average particle size of 3.0μm after HD powder milling and jet milling; they are oriented and pressed in a magnetic field of 15kOe to make compacts; The compact was placed in a sintering furnace under an Ar atmosphere, and sintered at 1070° C. for 5 hours to obtain a green compact. The green compact was aged at 500° C. for 5 hours to obtain a sintered blank. Process the sintered blank into a 50M magnet with a size of 40mm*20mm*4mm by machining, denoted as M ...

Embodiment 2

[0045] The same smelting, powder making, pressing, heat treatment, wire cutting, and spraying methods as in Example 1 were used to prepare 50M magnetic sheets. Dry the 50M sintered magnet (40mm*20mm*4mm) after degreasing, pickling, activation and deionized water washing, put the sintered magnet in 20 pieces*10 pieces into the thermal spraying sealed box, and spray on the surface of the sintered magnet A 20 μm thick DyTb alloy layer containing 60% Dy; after spraying one side, the sintered magnet can be turned over with a glove box, and a 20 μm thick DyTb alloy layer is sprayed on the other side. The sintered magnet after thermal spraying treatment was placed in a vacuum sintering furnace, treated at 900°C in an Ar atmosphere of 5kPa for 48h, then aged at 500°C for 5h, and cooled to room temperature by Ar. Open the door of the vacuum sintering furnace to get the sintered magnet M 3 . Its performance is shown in Table 2.

[0046] Table 2M 3 , M 1 and M 0 Magnetic performanc...

Embodiment 3

[0050] The same smelting, powder making, pressing, heat treatment and wire cutting methods as in Embodiment 1 were used to prepare 50M magnetic sheets. Dry the 50M sintered magnet (40mm*20mm*4mm) after degreasing, pickling, activation and washing with deionized water, put 20 pieces*10 pieces of sintered magnet into the thermal spray vacuum box, and spray on the surface of the sintered magnet A 20 μm thick DyTb alloy layer containing 80% Dy; after spraying one side, turn the sintered magnet over, and spray the same 20 μm thick DyTb layer on the other side. The sintered magnet after thermal spraying treatment was placed in a vacuum sintering furnace, treated at 880°C for 24h, then aged at 500°C for 5h, and cooled to room temperature with Ar gas. Open the door of the vacuum sintering furnace to get the magnet M 4 . After measurement and analysis, its performance is shown in Table 3.

[0051] The same smelting, powder making, pressing, heat treatment and wire cutting methods as...

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Abstract

The invention relates to a preparation method for an R-Fe-B-series sintering magnet. The preparation method for the R-Fe-B-series sintering magnet comprises the following steps of firstly, preparing an R-Fe-B-series sintering magnet with the thickness of 1-10mm by using the conventional method; secondly, spraying DyTb alloy with the thickness of 10-200 micrometers and the Dy mass percent of 60%-90% on the surface of the sintering magnet in a sealing box at an Ar gas protective atmosphere by using a thermal spraying method; and finally, placing the sintering magnet with the DyTb alloy on the surface in a vacuum sintering furnace, and performing heat treatment on the sintering magnet in a vacuum or Ar gas protective atmosphere at the temperature of 750-1000 DEG C so that heavy rare earth elements such as Tb and Dy enter the sintering magnet along a crystal boundary by diffusion. The DyTb alloy is sprayed on the surface of the sintering magnet by using the thermal spraying method, the problem of waste on resources due to high volatility of the Dy is solved, a phenomenon that production only depends on the heavy rare earth Tb with quite low content is avoided, the treatment speed is high, the coating is uniform, the yield is high, and the coercivity of the magnet after heat treatment is performed on the magnet is greatly improved.

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] R-Fe-B series rare earth sintered magnets have developed rapidly since their discovery due to their high strength, excellent magnetic properties, and low cost. They are widely used in computer hard disks, hybrid vehicles, medical care, wind power and other industries. field. [0003] Coercive force is an important index to measure the magnetic properties of rare earth sintered magnets. The traditional method to improve the coercive force of magnets is to add pure metals or alloys of rare earth raw materials Tb or Dy during the smelting process. Since most of Tb or Dy enters the main phase, and only a small part is distributed in the grain boundary to contribute to the improvement of the coercive force of the magnet, resulting in low utilization of Tb or Dy. Due to the relativ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02H01F1/057H01F7/02B22F3/16
Inventor 于永江李广军孙秀彦魏蕊侯晓红
Owner YANTAI ZHENGHAI MAGNETIC MATERIAL CO LTD
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