Method for manufacturing dry-pressing formed sintered permanent ferrite

A permanent magnet ferrite, dry pressing forming technology, applied in the field of magnetic material manufacturing, can solve the problems of difficult automatic forming, product density reduction, complex forming molds, etc. Effect

Inactive Publication Date: 2008-06-25
HENGDIAN GRP DMEGC MAGNETICS CO LTD
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Problems solved by technology

[0005] The present invention provides a method for manufacturing sintered permanent magnet ferrite by dry pressing, aiming at the defects of low production efficiency, complex molding molds, and difficulty in realizing automatic molding in the manufacturing method of sintered permanent magnet ferrite in the existing wet pressing molding technology. The method has the advantages of high production efficiency, simple molding die, and easy realization of automatic molding; the surface of the finished product after molding is smooth and flat, and there is almost no need for trimming, which greatly reduces the workload of subsequent processes
[0007] The present invention also aims at the defect that the existing dry-pressed sintered permanent magnet ferrite has fine pores in the sintered product, resulting in a relative decrease in product density and a decrease in magnetic performance, and provides a method by adding a suitable organic dispersion The manufacturing method of the sintered permanent magnet ferrite which is dry-pressed and formed by using additives and organic binders to effectively improve the coercive force and remanent magnetism of the product

Method used

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  • Method for manufacturing dry-pressing formed sintered permanent ferrite
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  • Method for manufacturing dry-pressing formed sintered permanent ferrite

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] The molecular formula is [Sr 1-x La x [(Fe 3+ a Fe 2+ b ) 12-y co y ]O 19 , where a+b is equal to 1; z is 0.9~1.1; a is 0.97~0.999, b is 0.001~0.03; the range of x and y is: 02 , 0.75wt% CaCO 3 , 18 hours of wet pulverization was carried out in a high-efficiency ball mill, the ratio of ball water to water was set at 1:15:1.2, and the average particle size of the pulverized slurry particles was 0.8 μm.

[0026] Dry the above slurry at a constant temperature of 130°C for 24 hours, weigh 1.6kg of block material, then add 0.8wt% ground camphor powder and 0.5wt% calcium stearate, and fully stir for 5min by a high-speed mixer, A dry-pressed magnetic powder suitable for dry-pressed molding is obtained. The moisture detection content of the dry-pressed magnetic powder is 0.8wt%.

[0027] The above-mentioned dry-pressed magnetic powder is subjected to magnetic field forming, and a forming magnetic field of 10000 Oe is applied in the pressing direction. The obtained mo...

Embodiment 2

[0037] The molecular formula is [Sr 1-x La x [(Fe 3+ a Fe 2+ b ) 12-y co y ]O 19 , where a+b is equal to 1; z is 0.9~1.1; a is 0.97~0.999, b is 0.001~0.03; the range of x and y is: 02 , 0.75wt% CaCO 3 and different contents of polyethylene glycol (PEG800), followed by wet pulverization in a high-efficiency ball mill for 20 hours, and the ratio of material ball to water is set to 1:15:1.2.

[0038] Dry the above slurry at a constant temperature of 130°C for 24 hours, weigh 1.6kg of block material, then add 1.0wt% of ground camphor powder and 0.5wt% of calcium stearate, and fully stir for about 5min with a high-speed mixer , to prepare dry-pressed magnetic powder for dry-pressing. The moisture detection content of the dry-pressed magnetic powder is 0.7wt%.

[0039] The above-mentioned dry-pressed magnetic powder is subjected to magnetic field forming, and a forming magnetic field of 8000 Oe is applied in the pressing direction. The obtained molded body was a cylinder...

Embodiment 3

[0045] The molecular formula is [Sr 1-x La x [(Fe 3+ a Fe 2+ b ) 12-y co y ]O 19 , where a+b is equal to 1; z is 0.9~1.1; a is 0.97~0.999, b is 0.001~0.03; the range of x and y is: 02 , 0.75wt% CaCO 3 , followed by wet pulverization in a high-efficiency ball mill for 20 hours, the ratio of the ball to water was set to 1:15:1.2, and the average particle size of the pulverized slurry particles was 0.8 μm.

[0046] Dry the above-mentioned slurry at a constant temperature of 130°C for 24 hours, weigh 1.6kg / part of block material, first carry out coarse crushing, and then directly add 0.6wt% of ground camphor powder and 0.5wt% of Calcium stearate, for the other part, first dissolve the above-mentioned binder completely in analytical pure alcohol, then add the alcohol solution of the above-mentioned binder to the powdery magnetic powder in the form of spray, and then use a high-speed mixer to The above mixture was fully stirred for about 5 minutes to obtain a dry-pressed m...

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Abstract

The invention relates to a manufacturing method of sintering permanent magnetism ferrite by dry-pressing molding. The method comprises following working procedures: crushing process, the preparation process of dry pressing the magnetic powder, dry pressing process and sinter process. The organic dispersant added in the crushing process is one or a plurality among polyethylene glycol, calcium stearate and calcium gluconate, and the content of the organic dispersant is 0.1wtpercent-1.5wtpercent; the bond added in the he preparation process of dry pressing the magnetic powder is one or a plurality among PVA, polyethylene glycol, camphor and stearate, and the content of the bond is 0.1wtpercent-1.5wtpercent. 1. The manufacturing method of sintering permanent magnetism ferrite by dry-pressing molding of the invention has the advantages of that the productivity effect is high, the molding mould is simple and the automation molding is easy to be realized; the surface of the molded finished product is lubricous and even, the fettling is not needed, and the workload of the post processing is decreased greatly; 2. The manufacturing method of sintering permanent magnetism ferrite by dry-pressing molding of the invention adopts the unique preparation technique of dry pressing the magnetic powder, and the orientation in the process of magnetic field press is relatively good, and the high Br and high HCJ dry-pressing sintering permanent magnetism ferrite is easy to be gained; 3. The manufacturing method of sintering permanent magnetism ferrite by dry-pressing molding of the invention adopts the pre-sintering material with a better performance of ion substitutional main prescription, and a dry-pressing anisotropic sintering permanent magnetism ferrite with a better magnetism performance can be achieved.

Description

technical field [0001] The invention relates to a method for manufacturing sintered permanent magnet ferrite, in particular to a method for manufacturing sintered permanent magnet ferrite formed by dry pressing; it belongs to the field of manufacturing magnetic materials. Background technique [0002] Sintered permanent magnet ferrite has stable magnetic properties and strong demagnetization resistance; it is not easy to rust and does not need to be coated with a protective layer; it is hard and brittle and can be used for special tool processing and cutting; and it is cheap and low in use. Therefore, it is widely used in automobiles, household appliances, industrial automation and other industries. The sintered permanent ferrite is made of hexagonal sintered ferrite magnets, especially the hexagonal magnetoplumbite ferrite is more widely used. The oxide permanent magnet ferrite material is mainly strontium ferrite (SrO·6Fe) with magnetoplumbite hexagonal structure. 2 o 3...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/26C04B35/622
Inventor 杨武国包大新丁伯明叶华胡良权
Owner HENGDIAN GRP DMEGC MAGNETICS CO LTD
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