Method for preparing corrosion resistance rare earth permanent-magnetic material

A rare-earth permanent magnet and corrosion-resistant technology, which is applied in the fields of magnetic materials, inorganic material magnetism, inductor/transformer/magnet manufacturing, etc., can solve the problems of corrosion resistance constraints, easy corrosion, and limited improvement space, and achieve improved corrosion resistance , reduced weight loss, superior corrosion resistance

Inactive Publication Date: 2007-08-29
NANJING UNIV OF SCI & TECH
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Problems solved by technology

Although this method of changing performance through material compounding can improve the corrosion resistance of the material, the root cause of the corrosion resistance of rare earth permanent magnet materials is that the rare earth-rich intermetallic compound acts as a grain boundary phase, and thi

Method used

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  • Method for preparing corrosion resistance rare earth permanent-magnetic material

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Example Embodiment

[0015] Example 1:

[0016] 1) Prepare the main and auxiliary alloy ingots separately, the atomic percentage composition of the main alloy is Nd: 9.5%, Dy: 1.5%,

[0017] Fe: 81.5%, B: 5.5%, Al: 2%, the atomic percentage composition of the auxiliary alloy is Nd: 59.9%, Co:

[0018] 29.9%, Al: 9.9%, Dy: 0.1%, Fe: 0.1%, Cu: 0.1%.

[0019] 2) The main and auxiliary alloys are powdered separately, and the average particle diameter is made by the junior high school fine crushing under the protection of nitrogen atmosphere

[0020] It is about 6.5μm powder.

[0021] 3) Mix the main and auxiliary alloy powders in a weight ratio of 9:1, while adding 3% of the total weight of the alloy

[0022] Ethylene oxide alkyl ether and 1% gasoline are uniformly mixed into a mixed powder in a mixer.

[0023] 4) Pass the mixed powder through a magnetic field orientation pressing press for the first time under 8MPa pressure and 1.7T orientation magnetic field

[0024] Forming, and then secondary pressing...

Example Embodiment

[0029] Example 2:

[0030] 1) Prepare the main and auxiliary alloy ingots respectively. The atomic percentage composition of the main alloy is Nd: 9%, Dy: 1%, Pr: 1%, Tb: 1%, Fe: 78%, Co: 4%, B: 6%, the atomic percentage composition of the auxiliary alloy is Nd: 30%, Pr: 10%, Dy: 10%, Co: 29.9%, Fe: 0.1%, Al: 10%, Cu: 5%, Ga: 5%.

[0031] 2) The main and auxiliary alloys are powdered separately. Through the junior high school fine crushing under the protection of nitrogen atmosphere, powder with an average particle diameter of about 6.5μm is produced.

[0032] 3) Mix the main and auxiliary alloy powders in a weight ratio of 9:1, while adding the antioxidant polyethylene oxide alkyl ether accounting for 3% of the total weight of the alloy powder and gasoline accounting for 1% of the total weight of the alloy powder in the mixer. Mix evenly into a mixed powder.

[0033] 4) The mixed powder is firstly compressed and molded by a magnetic field orientation pressing machine under a pres...

Example Embodiment

[0036] Example 3:

[0037] 1) Prepare the main and auxiliary alloy ingots separately, the atomic percentage composition of the main alloy is Nd: 7%, Dy: 3%, Tb: 2%, Fe: 78%, Co: 4%, B: 6%, auxiliary alloy The atomic percentage composition of Nd: 40%, Pr: 15%, Fe: 5%, Co: 25%, Al: 10%, Cu: 2%, Ga: 2%, Nb: 1%.

[0038] 2) The main and auxiliary alloys are powdered separately. Through the junior high school fine crushing under the protection of nitrogen atmosphere, the powder with an average particle diameter of about 5.5μm is produced.

[0039] 3) Mix the main and auxiliary alloy powders in a weight ratio of 88:12, and add the antioxidant polyethylene oxide alkyl ether which accounts for 3% of the total weight of the alloy powder and gasoline which accounts for 1% of the total weight of the alloy powder. Mix evenly into a mixed powder.

[0040] 4) The mixed powder is firstly compressed and molded by a magnetic field orientation pressing machine under a pressure of 8 MPa and an orien...

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Abstract

This invention discloses a preparation method for anti-corrosion rare earth magnet material characterizing that it takes the optimized grain-boundary phase design as the starting point on the basis of a dual alloy method to select Nd base alloy with high crystal forming ability as the assist alloy and reduces the temperature of the press mold blank in a quartz container to room temperature from over grain-boundary phase melting point with the water extraction way to get enough cooling rate and guarantee the non-grain-boundary phase, compared with the material of the same composition prepared by ordinary method, the weightlessness of this invented material reduces over 30% after testing the weightlessness of the material by laying it for 96 hours under 121deg.C, 2 atmosphere and 100% humid environment to show the advanced performance of anti-corrosion.

Description

a technical field [0001] The invention relates to a preparation method of a magnetic material, in particular to a preparation method of a corrosion-resistant rare earth permanent magnet material. Two background technology [0002] At present, sintered NdFeB rare earth permanent magnet materials prepared by powder metallurgy technology have been widely used in many fields such as electronics, automobiles, computers, electric power, machinery, energy, environmental protection, national defense, and medical equipment due to their excellent magnetic properties. The sintered NdFeB rare earth permanent magnet material is mainly composed of a matrix phase and a rare earth-rich phase. Among them, the atomic ratio of the matrix phase is close to Nd:Fe:B=2:14:1, which constitutes the main phase of the microstructure, while the rare earth-rich phase, also known as the grain boundary phase, is distributed along the grain boundary and plays an exchange coupling role. It is beneficial to...

Claims

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Application Information

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IPC IPC(8): H01F41/02H01F1/057H01F1/08C22C1/04C21D1/00C21D11/00
Inventor 徐锋陈光杜宇雷皋萍
Owner NANJING UNIV OF SCI & TECH
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