CN110444385A - A kind of coercitive technique of promotion Nd-Fe-B magnet - Google Patents

A kind of coercitive technique of promotion Nd-Fe-B magnet Download PDF

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Publication number
CN110444385A
CN110444385A CN201910736073.XA CN201910736073A CN110444385A CN 110444385 A CN110444385 A CN 110444385A CN 201910736073 A CN201910736073 A CN 201910736073A CN 110444385 A CN110444385 A CN 110444385A
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China
Prior art keywords
magnet
hydrogen
coercitive
promotion
technique
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CN201910736073.XA
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Chinese (zh)
Inventor
魏中华
陈小平
石晓宁
吴小康
赵栋梁
许丁丁
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Zhejiang Innuovo Magnetics Industry Co Ltd
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Zhejiang Innuovo Magnetics Industry Co Ltd
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Priority to CN201910736073.XA priority Critical patent/CN110444385A/en
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047Alloys characterised by their composition
    • H01F1/053Alloys characterised by their composition containing rare earth metals
    • H01F1/055Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0575Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
    • H01F1/0577Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • H01F41/0293Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)

Abstract

The invention discloses a kind of coercitive techniques of promotion Nd-Fe-B magnet, after needing the magnet being sintered to be cut into the shape of needs, carry out pickling pretreatment;It carries out inhaling hydrogen processing, the suction hydrogen process of magnet is carried out in the container with extraction gas for being connected with recirculated water, the control of hydrogen temperature is inhaled in room temperature, to reduce reacting for hydrogen and magnetic phase, pressure is 0-1MPa, then time 10-30 minute will be coated in magnet surface after heavy rare-earth oxide powder and alcohol mixing and ball milling, place into sintering in vacuum sintering furnace.The invention has the advantages that the magnet of Nd-Fe-B is absorbed protium at room temperature, the Nd-Fe-B magnet on surface layer is set to contain a certain amount of protium, then Dy or Tb oxide is sprayed on to the surface of Nd-Fe-B based sintered magnet, tempering reacts Dy or Tb oxide with the hydrogen in Grain-Boundary Phase first, it is significantly promoted so that magnet coercivity has, while increasing penetration depth.

Description

A kind of coercitive technique of promotion Nd-Fe-B magnet
Technical field
The present invention relates to a kind of coercitive techniques of promotion Nd-Fe-B magnet.
Background technique
Sintered NdFeB magnet has high coercivity and magnetic energy product.Meanwhile sintered magnet microstructure and magnetic property Uniformity consistency is good.So sintered NdFeB industrialized production ability is high.Chinese manufacturing enterprise has reached 170 according to statistics More families, total production capacity have reached 3 hundreds of millions tons.It is widely used in new-energy automobile, railway transportation equipment, space flight and aviation dress In the tradition such as standby, smart grid, energy-saving industrial motor and novel industry.But the Curie temperature of sintered NdFeB is low, temperature is steady Qualitative difference constrains the application of neodymium iron boron.The coercivity for improving sintered magnet, the temperature stabilization for increasing magnet is developing new opplication Important channel.
Improving the coercitive main method of sintered magnet is to add heavy rare earth Dy and Tb element, Dy/Tb substitution in neodymium iron boron Nd element in magnet is formed (Nd, Dy/Tb)2Fe14B phase.The magnetocrystalline anisotropy field of the magnetism phase is greater than neodymium-iron-boron Body can effectively improve magnet coercivity.But (Nd, Dy/Tb)2Fe14The remanent magnetism of B phase is low, and then influences the remanent magnetism of magnet And maximum magnetic energy product.Therefore, reduce (Nd, Dy/Tb)2Fe14Ratio of the B phase in magnet, makes it be distributed in Nd2Fe14Outside B phase Layer is formed (Nd, Dy/Tb)2Fe14B phase surrounds Nd2Fe14The core-shell structure of B, to increase the forming core field of magnet.The advantages of nucleocapsid It is that coercivity increases the amplitude that obvious, remanent magnetism reduces and becomes smaller, reduces heavy rare earth usage amount.
Grain boundary decision is the method for realizing the structure.By the oxide containing heavy rare earth, fluoride, alloy, metal adsorption On the moderate sintered magnet surface of thickness, after tempering, Dy/Tb enters the outer layer of crystal boundary and magnetic phase.
Method about grain boundary decision has " magnetron sputtering method ", " vapour deposition process ", " electrodeposition process ", " electrophoresis " and " cladding process " " spray coating method " etc..Wherein, the equipment cost of magnetron sputtering and vapour deposition process is high, production efficiency is low.Electrodeposition process It is by (Dy)2(OH)5NO3·nH2The compound depositions such as O are spread after heat resolve to the surface of magnet, the width that coercivity improves It spends small.The raw material that electrophoresis uses is fluoride, is currently in laboratory stage.Cladding process and spray coating method are low for equipment requirements, There are many factories to use the industrialization the method achieve grain boundary decision at present.The raw material one that cladding process and spray coating method use As be fluoride or oxide.Hydride is also used in cladding process part.The preparation method of fluoride is the fluorination of oxide, together Oxide is compared, and fluoride increases process procedure and pollution environment.Hydride be heavy rare earth element hydrogenation, be crushed preparation and At, stability is poor, and it is inflammable in air, it needs to operate in the extremely low environment of oxygen content.So the use of oxide being directly work The optimal selection that industry metaplasia produces.But the diffusion depth directly using the heavy rare earth of oxide is low.In order to improve diffusion depth, have It reports CaH2It is spread with after the hybrid reaction of oxide, this CaH2With the reaction rate of oxide, expansion is largely affected Depth is dissipated, is difficult to carry out industrialized production.
Summary of the invention
The purpose of the present invention is to provide a kind of coercitive techniques of promotion Nd-Fe-B magnet to be made using simple technique With common reagent, grain boundary decision is carried out, the coercivity of magnet is improved.
In order to solve the above-mentioned technical problem, the present invention is achieved by the following technical solutions: a kind of promotion Nd-Fe-B magnetic The coercitive technique of body, comprising the following steps:
A, after the magnet being sintered being needed to be cut into the shape of needs, pickling pretreatment is carried out;
B, it carries out inhaling hydrogen processing, the suction hydrogen process of magnet is carried out in the container with extraction gas for being connected with recirculated water, The control of hydrogen temperature is inhaled in room temperature, to reduce reacting for hydrogen and magnetism phase, pressure 0-1MPa, time 10-30 minute;
C, the powder of heavy rare-earth oxide is mixed with alcohol, then carries out ball milling, ball milling granularity is 50nm-300nm;
D, the heavy rare-earth oxide powder that step C is obtained is applied to the magnet surface of step B in air, waits nature dry It is dry;
E, the dusting magnet that step D is obtained is put into vacuum sintering furnace, reaches 10 to vacuum degree-3When Mpa, start to add Heat carries out ageing treatment, and the temperature of level-one timeliness is 850 DEG C -1000 DEG C, and aging time is 8-10 hours, secondary aging temperature It is 450 DEG C -550 DEG C, aging time is 3-5 hours, obtains finished product.
Preferably, magnet is placed in the container with extraction gas in the step B, reaches 10 to vacuum degree-3When Mpa, Vacuum pump is closed, argon gas is passed through and starts gas washing, be passed through hydrogen after gas washing, when hydrogen pressure is 0.5Mpa, valve is closed, leads to Recirculated water is crossed, cooling tube wall extracts extra hydrogen out, open valve after argon gas gas washing, magnet is taken after reacting 30 minutes Out.Enable surface layer magnet containing the protium of appropriate amount, magnet is in the state of reducing agent when ensuring diffusion.
Preferably, in the step C, the powder of heavy rare-earth oxide is mixed with alcohol 1:1 in mass ratio.
Preferably, 300 revs/min of ball mill rotation revolving speed, Ball-milling Time 36 hours, ball milling granularity 100nm.
Preferably, level-one aging temp is 950 DEG C in the step E, and aging time is 10 hours;Secondary aging temperature is 450 DEG C, aging time is 3 hours.
Preferably, the heavy rare-earth oxide is Dy or Tb oxide.
Compared with prior art, the invention has the advantages that the magnet of Nd-Fe-B is absorbed protium at room temperature, make table The Nd-Fe-B magnet of layer contains a certain amount of protium, Dy or Tb oxide is then sprayed on Nd-Fe-B based sintered magnet Surface, tempering are reacted Dy or Tb oxide with the hydrogen in Grain-Boundary Phase first, are significantly promoted so that magnet coercivity has, simultaneously Increase penetration depth.
Specific embodiment
The embodiment of the present invention is described below in detail, it is intended to be used to explain the present invention, and should not be understood as to of the invention Limitation.
A kind of embodiment promoting the coercitive technique of Nd-Fe-B magnet, comprising the following steps:
A, after the magnet being sintered being needed to be cut into the shape of needs, pickling pretreatment is carried out;
B, it carries out inhaling hydrogen processing, magnet is placed in the container with extraction gas, reaches 10 to vacuum degree-3When Mpa, close Vacuum pump is passed through argon gas and starts gas washing, is passed through hydrogen after gas washing, when hydrogen pressure is 0.5Mpa, valve is closed, by following Ring water, cooling tube wall extract extra hydrogen out, open valve after argon gas gas washing, magnet is taken out after reacting 30 minutes;
C, the powder of Dy or Tb oxide is mixed with alcohol 1:1 in mass ratio, then carries out ball milling, ball mill is walked around certainly 300 revs/min of speed, Ball-milling Time 36 hours, ball milling granularity 100nm;
D, the heavy rare-earth oxide powder that step C is obtained is applied to the magnet surface of step B in air, is waited 20 minutes Left and right spontaneously dries;
E, the dusting magnet that step D is obtained is put into vacuum sintering furnace, reaches 10 to vacuum degree-3When Mpa, start to add Heat carries out ageing treatment, and level-one aging temp is 950 DEG C, and aging time is 10 hours;Secondary aging temperature is 450 DEG C, timeliness Time is 3 hours, obtains finished product.
The result obtained with common manufacturing process in contrast, manufacturing process are as follows: by heavy rare-earth oxide and alcohol It mixes, is placed in the tank of ball mill for 1:1 in mass ratio.Rotation revolving speed is 300 revs/min, ball milling 36 hours, is put down after ball milling Equal granularity is 100nm.
The suspension of heavy rare earth is coated in the surface of magnet, it is 20 minutes dry.
Dried magnet is placed in vacuum sintering furnace, when vacuum degree reaches 10-3Mpa.It begins to warm up, when level-one Imitating temperature is 950 DEG C, and aging time is 10 hours.Secondary aging temperature is 450 DEG C, and aging time is 3 hours.
Remanent magnetism (kGs) Coercivity (kOe) Coercivity rises in value (kOe) Magnetic energy product (MGOe)
Example 13.3 20.4 7.1 48.5
Comparison 13.2 17.2 4.0 47.6
Table 1
It is compared by table, after using technique of the invention, indices are obviously improved, by the magnetic of Nd-Fe-B Body absorbs protium at room temperature, and the Nd-Fe-B magnet on surface layer is made to contain a certain amount of protium, then by Dy or Tb oxide It is sprayed on the surface of Nd-Fe-B based sintered magnet, tempering reacts Dy or Tb oxide with the hydrogen in Grain-Boundary Phase first, so that magnetic Body coercivity, which has, significantly to be promoted, while increasing penetration depth.
Above is only a specific embodiment of the present invention, but technical characteristic of the invention is not limited thereto, Ren Heben Within the field of the present invention, made changes or modifications all cover within the scope of the patent of the present invention the technical staff in field.

Claims (6)

1. a kind of coercitive technique of promotion Nd-Fe-B magnet, it is characterised in that: the following steps are included:
A, after the magnet being sintered being needed to be cut into the shape of needs, pickling pretreatment is carried out;
B, it carries out inhaling hydrogen processing, the suction hydrogen process of magnet is carried out in the container with extraction gas for being connected with recirculated water, inhales hydrogen Temperature control is in room temperature, to reduce reacting for hydrogen and magnetism phase, pressure 0-1MPa, time 10-30 minute;
C, the powder of heavy rare-earth oxide is mixed with alcohol, then carries out ball milling, ball milling granularity is 50nm-300nm;
D, the heavy rare-earth oxide powder that step C is obtained is applied to the magnet surface of step B in air, waits and spontaneously drying;
E, the dusting magnet that step D is obtained is put into vacuum sintering furnace, reaches 10 to vacuum degree-3When Mpa, begin to warm up, into Row ageing treatment, the temperature of level-one timeliness are 850 DEG C -1000 DEG C, and aging time is 8-10 hours, secondary aging temperature 450 DEG C -550 DEG C, aging time is 3-5 hours, obtains finished product.
2. a kind of coercitive technique of promotion Nd-Fe-B magnet as described in claim 1, it is characterised in that: in the step B Magnet is placed in the container with extraction gas, reaches 10 to vacuum degree-3When Mpa, vacuum pump is closed, argon gas is passed through and starts to wash Gas is passed through hydrogen after gas washing, when hydrogen pressure is 0.5Mpa, closes valve, and by recirculated water, cooling tube wall works as reaction After 30 minutes, extracts extra hydrogen out, open valve after argon gas gas washing, magnet is taken out.
3. a kind of coercitive technique of promotion Nd-Fe-B magnet as described in claim 1, it is characterised in that: the step C In, the powder of heavy rare-earth oxide is mixed with alcohol 1:1 in mass ratio.
4. a kind of coercitive technique of promotion Nd-Fe-B magnet as claimed in claim 3, it is characterised in that: ball mill rotation 300 revs/min of revolving speed, Ball-milling Time 36 hours, ball milling granularity 100nm.
5. a kind of coercitive technique of promotion Nd-Fe-B magnet as described in claim 1, it is characterised in that: in the step E Level-one aging temp is 950 DEG C, and aging time is 10 hours;Secondary aging temperature is 450 DEG C, and aging time is 3 hours.
6. a kind of coercitive technique of promotion Nd-Fe-B magnet as described in claim 1, it is characterised in that: the heavy rare earth Oxide is Dy or Tb oxide.
CN201910736073.XA 2019-08-09 2019-08-09 A kind of coercitive technique of promotion Nd-Fe-B magnet Pending CN110444385A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111210987A (en) * 2020-02-01 2020-05-29 厦门钨业股份有限公司 R-T-B magnet material and preparation method and application thereof
CN111223623A (en) * 2020-01-31 2020-06-02 厦门钨业股份有限公司 Large-thickness neodymium iron boron magnetic steel and preparation method thereof

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1701396A (en) * 2003-01-16 2005-11-23 爱知制钢株式会社 Process for producing anisotropic magnet powder
CN2743065Y (en) * 2004-11-03 2005-11-30 徐家发 Neodymium iron boron hydrogen breaking system
US20070079904A1 (en) * 2003-08-27 2007-04-12 Katsuhiko Mori Rare earth magnet powder and method of producing the same
CN102568806A (en) * 2011-12-29 2012-07-11 包头天和磁材技术有限责任公司 Method for preparing rare-earth permanent magnets by infiltration process and graphite box utilized in method
CN104221100A (en) * 2012-03-30 2014-12-17 因太金属株式会社 Ndfeb-based sintered magnet
CN107112125A (en) * 2015-01-09 2017-08-29 因太金属株式会社 The manufacture method of RFeB based sintered magnets

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1701396A (en) * 2003-01-16 2005-11-23 爱知制钢株式会社 Process for producing anisotropic magnet powder
US20070079904A1 (en) * 2003-08-27 2007-04-12 Katsuhiko Mori Rare earth magnet powder and method of producing the same
CN2743065Y (en) * 2004-11-03 2005-11-30 徐家发 Neodymium iron boron hydrogen breaking system
CN102568806A (en) * 2011-12-29 2012-07-11 包头天和磁材技术有限责任公司 Method for preparing rare-earth permanent magnets by infiltration process and graphite box utilized in method
CN104221100A (en) * 2012-03-30 2014-12-17 因太金属株式会社 Ndfeb-based sintered magnet
CN107112125A (en) * 2015-01-09 2017-08-29 因太金属株式会社 The manufacture method of RFeB based sintered magnets

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111223623A (en) * 2020-01-31 2020-06-02 厦门钨业股份有限公司 Large-thickness neodymium iron boron magnetic steel and preparation method thereof
CN111223623B (en) * 2020-01-31 2022-04-05 厦门钨业股份有限公司 Large-thickness neodymium iron boron magnetic steel and preparation method thereof
CN111210987A (en) * 2020-02-01 2020-05-29 厦门钨业股份有限公司 R-T-B magnet material and preparation method and application thereof
CN111210987B (en) * 2020-02-01 2021-11-05 厦门钨业股份有限公司 R-T-B magnet material and preparation method and application thereof

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Application publication date: 20191112