A preparation method and device for reducing the magnetic declination angle of sintered NdFeB

A magnetic declination and NdFeB technology, which is applied in the field of preparation and device for reducing the magnetic declination of sintered NdFeB, can solve the problems of uncontrollable production, reduction of magnetic declination of magnets, and damage of magnet performance, so as to improve the material Effects of Utilization, Declination Angle Reduction, and Capability Enhancement

CN104493158BActive Publication Date: 2017-07-21NINGBO KETIAN MAGNET CO LTD +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2017-07-21

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Abstract

A method for preparing a permanent magnet for reducing the magnetic declination of sintered NdFeB, including batching-smelting-powder-making-forming-sintering, adding additives to improve the fluidity of powder during the powder-making process, increasing the magnetic field strength H during the forming process, Reduce the mold orientation length L, increase the cross-sectional area A in the direction of the vertical magnetic force line, put the powder of the mixture into the molding mold of the press, and adjust the molding mold on the mold bracket to be at the center of the coil magnetic pole, so that the pressed powder is in the molding During the orientation pressing process, it is at the center of the coil magnetic field. By adjusting the comprehensive effect of four related parameters, the magnetic declination of the prepared sintered NdFeB magnetic material is reduced from 10 degrees to 3 degrees, and the utilization rate of materials with qualified magnetic declination is 35% increased to more than 60%, greatly reducing production costs and improving economic benefits.
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Description

technical field

[0001] The invention relates to a permanent magnet manufacturing method and a device thereof, in particular to a manufacturing method and a device for reducing the magnetic declination of sintered NdFeB. Background technique

[0002] Sintered NdFeB permanent magnet materials have been widely used in the field of motor manufacturing due to their excellent magnetic properties. Theoretically, the magnetic pole axis on the physical shape of the NdFeB permanent magnet should coincide with the magnetic pole direction after the magnet is magnetized, but due to the influence of various factors during the magnet preparation process, especially the molding process and processing technology, the actual physical shape of the magnet There is an angle between the magnetic pole axis on the magnet and the magnetic pole direction after the magnet is magnetized, and this angle is the magnetic declination angle φ. Due to the existence of magnetic declination, the non-magnetize...

Examples

Embodiment 1

[0021] The finished product specification is 20mm×4mm×9mm↓ (orientation direction), the production process of the brand N40 product.

[0022] Ingredients: according to the following composition ratio weight ingredients, praseodymium neodymium alloy 30.2% by weight, gadolinium 2.0% by weight, boron 1.03% by weight, aluminum 0.64% by weight, zirconium 0.3% by weight, copper 0.02% by weight, and the balance is iron and other impurities, Wherein in the praseodymium neodymium alloy, praseodymium accounts for 25% by weight, neodymium accounts for 75% by weight, boron is added in the state of BFe alloy, the boron content is 19%, and the iron content is 81%; Gadolinium is added in the state of GdFe alloy, and the content of gadolinium is 75%. The iron content is 25%.

[0023] Melting: Put the prepared raw materials into a vacuum induction furnace, vacuum the induction furnace to 4.5-5Pa, heat and melt until the raw materials in the furnace turn red, close the vacuum valve, fill in arg...

Embodiment 2

[0042] The finished product specification is Φ100mm×3mm↓ (orientation direction), the production process of the brand N38 product.

[0043] Ingredients: According to the following composition ratio weight ingredients, praseodymium neodymium alloy 31% by weight, gadolinium 2.5% by weight, boron 1.02% by weight, aluminum 0.64% by weight, zirconium 0.1% by weight, copper 0.02% by weight, and the balance is iron and other impurities, Wherein in the praseodymium neodymium alloy, praseodymium accounts for 25% by weight, neodymium accounts for 75% by weight, boron is added in the state of BFe alloy, the boron content is 19%, and the iron content is 81%; Gadolinium is added in the state of GdFe alloy, and the content of gadolinium is 75%. The iron content is 25%.

[0044] Melting: Put the prepared raw materials into the vacuum induction furnace, vacuum the induction furnace to 4.0-4.5Pa, heat and melt until the raw materials in the furnace turn red, close the vacuum valve, fill with a...

Embodiment 3

[0063] The finished product specification is Φ21mm×3mm↓ (orientation direction), the production process of the brand N45 product.

[0064] Ingredients: Ingredients are prepared according to the weight ratio of the following ingredients: 28% neodymium, 1.02% boron, 1.0% dysprosium, 1.5% holmium, 0.2% aluminum, 1.5% gadolinium, 0.4% niobium, 0.2% copper, 0.2% cobalt, 0.1% gallium , iron and other impurities are 65.88%, of which boron is added in the state of BFe alloy, the content of boron is 19%, and the content of iron is 81%; holmium is added in the state of alloy with HoFe purity of 99.50%, the content of holmium is 80%, and the content of iron is 20% Gadolinium is added in the state of GdFe alloy, the content of gadolinium is 75%, and the content of iron is 25%; niobium is added in the state of NbFe alloy, of which the content of niobium is 65% and the content of iron is 35%.

[0065] Melting: Put the prepared raw materials into the vacuum induction furnace, vacuum the induct...