Sintered neodymium-iron-boron preparation method capable of improving intrinsic coercivity and anticorrosive performance

A technology of intrinsic coercive force and NdFeB, applied in the direction of magnetic objects, magnetic materials, inorganic materials, etc., can solve the problem of high corrosion resistance and process requirements, and achieve high amorphous forming ability, low melting point, and reduced weight loss Effect

Active Publication Date: 2011-10-19
NANJING UNIV OF SCI & TECH +1
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  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However with Nd 65 co 25 al 15 The formation ability of auxiliary alloy glass as the main body is relatively limited, and on this basis, the realization of grain boundary amorphization and improvement of corrosion resistance requires high process requirements

Method used

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  • Sintered neodymium-iron-boron preparation method capable of improving intrinsic coercivity and anticorrosive performance
  • Sintered neodymium-iron-boron preparation method capable of improving intrinsic coercivity and anticorrosive performance
  • Sintered neodymium-iron-boron preparation method capable of improving intrinsic coercivity and anticorrosive performance

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preparation example Construction

[0019] In conjunction with the accompanying drawings, the present invention improves the intrinsic coercivity and corrosion resistance of the sintered NdFeB preparation method, comprising the following steps:

[0020] Step 1, preparing the main NdFeB alloy, preparing the NdFeB main alloy into alloy ingots or using the quick-setting casting process to prepare cast sheets, and performing homogenization heat treatment on the alloy ingots; homogenizing the heat treatment temperature on the alloy ingots The temperature is 950-1150°C, and the time is 3-20h.

[0021] Step 2, preparation auxiliary alloy, the atomic percentage of auxiliary alloy is (Ce-La-Pr-Nd) 100-x-y-z co x al y m z , where M is one or a mixture of two or more of Ga, Cu, Nb, 20≤x≤30, 5≤y≤15, 0≤z≤5, each rare earth element in the total composition of the auxiliary alloy is hundreds of atoms The content is: Ce: 25-30%; La: 20-25%; Pr: 0-5%; Nd: 5-15%.

[0022] Step 3, smelting the auxiliary alloy to obtain the au...

Embodiment 1

[0029] Step 1, preparation of NdFeB main alloy, the atomic ratio of its composition is Nd 12.6 Dy 1.4Al 2.3 Cu 0.2 Nb 0.4 B 6.5 Fe 76.6 , using a water-cooled copper mold to cast the main alloy into an NdFeB alloy ingot, and perform a vacuum heat treatment for homogenizing the composition of the alloy ingot at 1000 ° C for 8 hours.

[0030] Step 2, preparation auxiliary alloy, the atomic percentage of auxiliary alloy is Ce 29 La 22 PR 3.5 Nd 10.5 co 25 Al 10 .

[0031] Step 3: Smelting the auxiliary alloy to obtain auxiliary alloy ingots, preparing quick-setting flakes by using the quick-setting flake preparation process, the roll speed is 40m / s, heat-treating the auxiliary alloy strips at 400°C for 20 minutes in vacuum, and then cooling to room temperature.

[0032] Step 4, performing hydrogen explosion crushing on the main and auxiliary alloys respectively, and performing dehydrogenation treatment at 550° C. for 2 hours.

[0033] Step 5, mix the hydrogen crushed...

Embodiment 2

[0039] Step 1, preparation of NdFeB main alloy, the atomic ratio of its composition is Nd 12.6 Dy 1.4 Al 2.3 Cu 0.2 Nb 0.4 B 6.5 Fe 76.6 , using the quick-setting casting process to cast the main alloy into NdFeB alloy castings.

[0040] Step 2, preparation auxiliary alloy, the atomic percentage of auxiliary alloy is Ce 25 La 20 Nd 5 co 30 Al 15 Ga 5 .

[0041] Step 3: Melt the auxiliary alloy to obtain auxiliary alloy ingots, prepare quick-setting flakes by using the quick-setting flake preparation process, the roll speed is 5m / s, heat-treat the auxiliary alloy flakes at 200°C for 1 hour in vacuum, and cool to room temperature.

[0042] Step 4, performing hydrogen explosion crushing on the main and auxiliary alloys respectively, and performing dehydrogenation treatment at 500° C. for 4 hours.

[0043] Step 5. Mix the hydrogen crushed powder of the main and auxiliary alloys in a weight ratio of 88:12, and add 0.05% lubricant, 1% antioxidant, and 1% gasoline in a w...

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Abstract

The invention discloses a sintered neodymium-iron-boron preparation method capable of improving intrinsic coercivity and anticorrosive performance. On the basis of a double-alloy preparation process, Ce-enriched multicomponent rare-based alloy with high amorphous forming ability is used as an auxiliary alloy, and the decrystallizatoin of crystal boundary phase structure is realized by gas quenching cooling in a sintering tempering process. In the invention, the intrinsic coercivity is obviously improved, the anticorrosive weight loss is greatly reduced, the magnetic performance and anticorrosive performance are high, and the method can be widely used in the field of production of high-performance anticorrosive sintered neodymium-iron-boron material.

Description

technical field [0001] The invention relates to a preparation method of sintered NdFeB, in particular to a preparation method of sintered NdFeB which improves intrinsic coercive force and corrosion resistance. Background technique [0002] Sintered NdFeB has the highest saturation energy product and the largest intrinsic coercive force among existing permanent magnet materials, and is widely used in many fields such as electronics, automobiles, computers, electric power, machinery, energy, environmental protection, national defense, and medical equipment. Applications. Sintered NdFeB material is prepared by powder metallurgy process, and its microstructure mainly includes the main phase (close to Nd 2 Fe 14 Phase B) and rare earth-rich phase (Note: There is also a boron-rich phase, which can be ignored when the atomic percentage of boron in sintered NdFeB is less than 6.5%). The rare earth-rich phase formed during the sintering process is generally distributed at the grai...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C33/02C22C38/00H01F1/057H01F1/08
Inventor 徐锋陈光卢国文朱海南管宏胜杨义恒范从平
Owner NANJING UNIV OF SCI & TECH
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