An anti-oxidation treatment method for sintered NdFeB material and its antioxidant

An antioxidant and treatment method technology, applied in the direction of magnetic materials, inorganic material magnetism, magnetic objects, etc., can solve the problems of unfavorable energy saving and consumption reduction, increase equipment, process, material, energy costs, etc., and achieve the effect of simple and easy preparation

Inactive Publication Date: 2015-11-18
宁波永久磁业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

General gas protection is to fill high-purity nitrogen or argon into highly airtight equipment, which can avoid oxidation to a certain extent, but increases equipment, process, material, and energy costs, which is not conducive to energy saving and consumption reduction

Method used

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  • An anti-oxidation treatment method for sintered NdFeB material and its antioxidant
  • An anti-oxidation treatment method for sintered NdFeB material and its antioxidant
  • An anti-oxidation treatment method for sintered NdFeB material and its antioxidant

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] The sintered NdFeB magnets are prepared by the usual sintering method (protective atmosphere process), that is, the conventional jet mill is used, the powder is mixed with nitrogen protective gas, the compression molding is also carried out in an atmosphere filled with argon, and the sintering adopts high vacuum sintering. Three samples were prepared by this method.

[0013] The method (antioxidant process) of the present invention is the same as the method for preparing sintered NdFeB by the usual sintering method, except that 0.05% of the antioxidant benzotriazole and 99.95% of petroleum ether of the present invention are added during jet milling. The powder mixing is carried out in a closed air atmosphere, and the compression molding is also carried out in an air atmosphere. The sintering adopts a low vacuum of 10 Pa. The initial stage of sintering is controlled at a temperature of 180 ° C for 1.5 hours, and the removal of antioxidants is carried out. This method is u...

Embodiment 2

[0019] The sintered NdFeB magnet is prepared by the usual sintering method (protective atmosphere process), and the method is the same as in Example 1.

[0020] The method (antioxidant process) of the present invention is the same as the method for preparing sintered NdFeB by the usual sintering method, except that 5% of the antioxidant benzotriazole of the present invention and 95% of petroleum ether are added during jet milling. After jet milling, the powder mixing is carried out in a closed air atmosphere, and the compression molding is also carried out in an air atmosphere. The sintering adopts a low vacuum of 100 Pa, and the initial stage of sintering is controlled at a temperature of 300°C for 2.5 hours. Antioxidants are removed. Methods Three samples were prepared.

[0021] The magnetic properties of the NdFeB materials prepared by the above two methods were tested, and the results are shown in Table 2.

[0022] Table 2 Test results of magnetic properties of sintered N...

Embodiment 3

[0026] The sintered NdFeB magnet is prepared by the usual sintering method (protective atmosphere process), and the method is the same as in Example 1.

[0027] The method (antioxidant process) of the present invention is the same as the method for preparing sintered NdFeB by the usual sintering method, except that 0.05% of the antioxidant benzotriazole and 99.95% of petroleum ether of the present invention are added during jet milling. After jet milling, the powder mixing is carried out in a closed air atmosphere, and the compression molding is also carried out in an air atmosphere. The sintering adopts a low vacuum of 100 Pa, and the initial stage of sintering is controlled at a temperature of 300 ° C for 1.5 hours. The removal of antioxidants is carried out. Methods Three samples were prepared.

[0028] The magnetic properties of the NdFeB materials prepared by the above two methods were tested, and the results are shown in Table 3.

[0029] Table 3 Test results of magneti...

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Abstract

The invention discloses an anti-oxidation treatment method for sintering a nd-fe-b material and an antioxidant. The anti-oxidation treatment method comprises the following steps of: in a jet milling stage, injecting the antioxidant into the nd-fe-b material in a spray manner, wherein the antioxidant is evenly coated by magnetic powder during jet milling; sealing and mixing the powder under an air condition; carrying out compression molding in an air atmosphere; and sintering under a low vacuum condition to obtain a blank. Anti-oxidation auxiliaries used are benzotriazole and petroleum ether the volume ratios of which are respectively 0.05-5% and 99.95-95%. According to the invention, requirements for preparation environment are reduced, the preparation is simple and flexible, energy saving and consumption reduction effects are achieved, and a finished magnet has properties similar to those of materials prepared in a non-air atmosphere.

Description

technical field [0001] The invention relates to an antioxidant and a treatment method for preparing sintered NdFeB materials, belonging to the field of magnetic materials. Background technique [0002] Sintered NdFeB permanent magnet materials have high remanence, coercive force and large magnetic energy product, and have been widely used in modern industry and electronic technology. The sintered NdFeB permanent magnet material is formed by metal casting through hydrogen breaking, jet milling, powder mixing, pressing, and vacuum sintering. The casting sheet starts to produce metal powder in the jet mill stage. The metal powder has high activity and is easy to oxidize and burn in the series of processes such as jet mill, powder mixing, pressing and sintering, which will greatly reduce the remanence, coercive force, and The magnetic properties of materials such as magnetic energy product. Therefore, preventing oxidation is a key technology in the preparation of sintering. ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F1/057H01F1/08
Inventor 任春德周鸿波李建忠金伟洋任荷芬张英海宋小明
Owner 宁波永久磁业有限公司
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