CN111029128A - Rapid heat treatment method of rare earth permanent magnet - Google Patents

Rapid heat treatment method of rare earth permanent magnet Download PDF

Info

Publication number
CN111029128A
CN111029128A CN201911423935.XA CN201911423935A CN111029128A CN 111029128 A CN111029128 A CN 111029128A CN 201911423935 A CN201911423935 A CN 201911423935A CN 111029128 A CN111029128 A CN 111029128A
Authority
CN
China
Prior art keywords
permanent magnet
rare earth
earth permanent
equal
heat treatment
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201911423935.XA
Other languages
Chinese (zh)
Inventor
王新华
李美勋
金佳莹
陶永明
严密
魏中华
赵栋梁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Zhejiang Innuovo Magnetics Industry Co Ltd
Original Assignee
Zhejiang University ZJU
Zhejiang Innuovo Magnetics Industry Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU, Zhejiang Innuovo Magnetics Industry Co Ltd filed Critical Zhejiang University ZJU
Priority to CN201911423935.XA priority Critical patent/CN111029128A/en
Publication of CN111029128A publication Critical patent/CN111029128A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus 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
    • H01F41/02—Apparatus 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
    • H01F41/0253—Apparatus 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets 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
    • H01F1/04—Magnets 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
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B

Abstract

The invention discloses a rapid heat treatment method of a rare earth permanent magnet material. The method uses an improved spark plasma sintering technology, and adds an electric insulating layer material with better heat conductivity between an SPS die and a sample and between an electrode and the sample, thereby avoiding the direct action of current and a permanent magnet and carrying out rapid and transient heat treatment on the rare earth permanent magnet. The invention aims to realize annealing, improve the organization structure, reduce the stray field at the interface, reduce the reverse magnetization nucleation area and improve the coercive force of the magnet while avoiding the growth of crystal grains in the magnet through rapid heat treatment.

Description

Rapid heat treatment method of rare earth permanent magnet
Technical Field
The invention relates to the field of permanent magnets, in particular to a rapid heat treatment method of a rare earth permanent magnet.
Background
The third generation rare earth permanent magnet neodymium iron boron has the advantages of high remanence, high coercivity and high magnetic energy product, and is widely applied to the fields of power electronics, communication information, transportation, medical equipment, military and the like. However, the temperature stability of the neodymium iron boron is relatively poor, and the thermal demagnetization effect is obvious. The improvement of the coercivity is an important solution to meet the application of complex service environments. To a certain extent, the smaller the neodymium iron boron crystal grain is, the higher the coercive force of the magnet is. However, along with the refinement of the crystal grains, the number of the interfaces is increased, the defect density at the interfaces is high, the relaxation and reconstruction phenomena of atoms are more likely to occur, and a high stray field is presented. The heat treatment is an effective method for optimizing a grain boundary region, reducing the defect density at an interface and improving the coercive force. However, the conventional heat treatment technology has a slow heating speed and a long heat treatment period, and is easy to cause abnormal growth of crystal grains, and the effect of improving the magnetic performance is limited. Therefore, a rapid thermal processing method is urgently needed, which can provide large driving force, improve the distribution of grain boundary phases, reduce the reverse magnetization nucleation sites and improve the coercivity while avoiding the growth of crystal grains.
Especially for the high-abundance rare earth permanent magnet which has gained wide attention in recent years, due to the difference of physicochemical properties between lanthanum cerium yttrium rare earth element and didymium, new grain boundary phase including REFE is easy to be precipitated at the grain boundary under the high lanthanum cerium yttrium substitution amount2、RE2O3And the like, the number of the grain boundaries is more, the environment of the grain boundaries is more complicated, and the requirement on heat treatment is higher. Therefore, for high-abundance rare earth permanent magnets, the interdiffusion of rare earth elements, the growth of crystal grains and the distribution and evolution of crystal boundaries need to be controlled in the heat treatment process so as to meet the commercial requirements.
The Spark Plasma Sintering (SPS) technology can realize rapid temperature rise, the whole period is relatively short, and abnormal growth of crystal grains and diffusion precipitation of elements in the magnet in the long-time temperature rise, heat preservation and temperature reduction processes can be avoided. However, rare earth permanent magnets belong to metal-based multi-phase alloys, and have strong conductivity, and in the heat treatment process, conducted current passes through the magnet and reacts with the permanent magnet material, and the generated polarization effect and the like have uncontrollable influences on element diffusion, grain boundary distribution and magnetic performance.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a rapid heat treatment method of rare earth permanent magnet.
The invention is characterized in that the rapid heat treatment is carried out on the rare earth permanent magnet by using discharge plasma sintering, and the magnet comprises the following components (A) in percentage by mass1-xRx)yQbalMzBwWherein A is one or more elements of Nd, Pr, Dy, Tb, Gd, Ho and Sm, R is one or more elements of La, Ce and Y, Q is one or more elements of Co, Fe and Ni, M is one or more elements of Al, Co, Cr, Cu, Ga, Mn, Mo, Nb, Ni, Si, Ta, Ti, V and Zr, x is more than or equal to 0 and less than or equal to 0.8, Y is more than or equal to 26 and less than or equal to 36, z is more than or equal to 0 and less than or equal to 3, and w is more than or equal to 0.8 and less than or equal to 1.3.
Electric insulation layers with good heat conduction performance are added between the SPS die and the rare earth permanent magnet and between the electrode and the rare earth permanent magnet, the die conducts electricity and generates heat, heat is conducted into a sample through the heat conduction insulation layers, rapid temperature rise is achieved, and the rare earth permanent magnet is subjected to heat treatment.
In a preferred embodiment of the present invention, the material of the electrical insulation layer with good thermal conductivity is alumina Al2O3Zirconium oxide ZrO2Silicon carbide SiC and silicon nitride Si3N4Or aluminum nitride AlN.
As a preferred scheme of the invention, the pressure applied to the rare earth permanent magnet in the rapid heat treatment is 2-50 MPa. More preferably, the pressure is 5 to 20 MPa.
As a preferred scheme of the invention, the temperature rise speed in the rapid heat treatment is 20-400 ℃/min, and the heat preservation time is 5-180 min. More preferably, the temperature rising speed is 50-300 ℃/min, and the heat preservation time is 20-120 min.
As a preferred scheme of the invention, the temperature in the rapid heat treatment is 400-1000 ℃. More preferably, the temperature in the rapid heat treatment is 500-800 ℃.
Compared with the prior art, the invention has the following beneficial effects: the invention adopts the rapid heat treatment of the spark plasma sintering equipment, although the rare earth permanent magnetic alloy is a conductor, the influence of current on the performance of the magnet is avoided while the rapid temperature rise is realized by adding the heat conduction and electric insulation material in the middle, so that the relatively rapid heat treatment is realized, the abnormal growth of crystal grains is avoided, the residual stress in the magnet is released, the defect at the crystal boundary is consumed, and the coercive force of the magnet is improved.
Detailed Description
The present invention is further illustrated by the following examples, but is not limited to the following examples:
example 1:
the magnet comprises (by mass percent) Nd0.5Ce0.5]30.5FebalAl1B1. Placing the magnet into SPS mold, and adding aluminum oxide Al between SPS mold and sample and between electrode and sample2O3And the thin layer realizes rapid heating treatment. The pressure applied in the rapid heat treatment process is 2MPa, the temperature rise speed is 100 ℃/min, the heat preservation time is 15min, and the heat treatment temperature is 600 ℃. The magnetic property of the magnet is Br＝13.0kGs，Hcj＝11.5kOe，(BH)max＝40.1MGOe
Example 2:
the magnet comprises the following components in percentage by mass [ Pr%0.1Nd0.4Ce0.5]30.5FebalAl0.5Cu0.2Co0.5Nb0.15B1. Placing the magnet into SPS mold, and adding aluminum oxide Al between SPS mold and sample and between electrode and sample2O3And the thin layer realizes rapid heating treatment. The pressure applied in the rapid heat treatment process is 5MPa, the temperature rise speed is 100 ℃/min, the heat preservation time is 40min, and the heat treatment temperature is 600 ℃. The magnetic property of the magnet is Br＝13.1kGs，Hcj＝12.5kOe，(BH)max＝41.1MGOe
Example 3:
the magnet comprises (by mass percent) Nd0.7Ce0.3]31.2FebalAl0.5Zr0.15Ga0.3B0.95. And (3) placing the magnet into an SPS (semi-spherical surface sintering) mold, and adding an aluminum nitride (AlN) thin layer between the SPS mold and the sample and between the electrode and the sample to realize rapid heating treatment. The pressure applied in the rapid heat treatment process is 20MPa, the temperature rise speed is 200 ℃/min, the heat preservation time is 60min, and the heat treatment temperature is 680 ℃. The magnetic property of the magnet is Br＝13.5kGs，Hcj＝13.5kOe，(BH)max＝44.3MGOe。
Example 4:
the magnet comprises the following components in percentage by mass [ Pr%0.17Nd0.68Ce0.1La0.05]30.8FebalCo0.2Cu0.2Zr0.15B1. And (3) putting the magnet into an SPS (semi-spherical permanent magnet) mold, and adding a silicon carbide SiC thin layer between the SPS mold and the sample and between the electrode and the sample to realize rapid heating treatment. The pressure applied in the rapid heat treatment process is 15MPa, the temperature rise speed is 300 ℃/min, the heat preservation time is 60min, and the heat treatment temperature is 800 ℃. The magnetic property of the magnet is Br＝13.7kGs，Hcj＝14.6kOe，(BH)max＝46.0MGOe。

Claims (6)

1. A rapid thermal processing method of a rare earth permanent magnet, characterized in that the rapid thermal processing of the rare earth permanent magnet is carried out by using discharge plasma sintering, the rapid thermal processing is carried out by the following method: and electric insulating layers with better heat conduction performance are added between the SPS die and the rare earth permanent magnet and between the electrode and the rare earth permanent magnet, heat is conducted into the sample through the heat conduction insulating layers, rapid temperature rise is realized, and the rare earth permanent magnet is subjected to heat treatment.
2. The rapid thermal processing method for rare earth permanent magnet according to claim 1, wherein the composition of the rare earth permanent magnet is (A) in mass percent1-xRx)yQbalMzBwWherein A is one or more elements of Nd, Pr, Dy, Tb, Gd, Ho and Sm, R is one or more elements of La, Ce and Y, and Q is Co,Fe. One or more elements in Ni, M is one or more elements in Al, Co, Cr, Cu, Ga, Mn, Mo, Nb, Ni, Si, Ta, Ti, V and Zr, x is more than or equal to 0 and less than or equal to 0.8, y is more than or equal to 26 and less than or equal to 36, z is more than or equal to 0 and less than or equal to 3, and w is more than or equal to 0.8 and less than or equal to 1.3.
3. The rapid thermal processing method of rare-earth permanent magnet according to claim 1, wherein the electrically insulating layer having a good thermal conductivity is made of alumina Al2O3Zirconium oxide ZrO2Silicon carbide SiC and silicon nitride Si3N4Or aluminum nitride AlN.
4. The method according to claim 1, wherein the pressure applied to the rare earth permanent magnet in the rapid thermal treatment is 2 to 50 MPa.
5. The method according to claim 1, wherein the temperature rise rate in the rapid thermal treatment is 20 to 400 ℃/min, and the holding time is 5 to 180 min.
6. The method according to claim 1, wherein the temperature in the rapid thermal treatment is 400 to 1000 ℃.
CN201911423935.XA 2019-12-31 2019-12-31 Rapid heat treatment method of rare earth permanent magnet Pending CN111029128A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911423935.XA CN111029128A (en) 2019-12-31 2019-12-31 Rapid heat treatment method of rare earth permanent magnet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911423935.XA CN111029128A (en) 2019-12-31 2019-12-31 Rapid heat treatment method of rare earth permanent magnet

Publications (1)

Publication Number Publication Date
CN111029128A true CN111029128A (en) 2020-04-17

Family

ID=70201879

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911423935.XA Pending CN111029128A (en) 2019-12-31 2019-12-31 Rapid heat treatment method of rare earth permanent magnet

Country Status (1)

Country Link
CN (1) CN111029128A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112927920A (en) * 2021-03-05 2021-06-08 西安交通大学 Pressurizing heat treatment method for improving magnetic property of 2:17 type Sm-Co sintered magnet
CN113130200A (en) * 2021-04-26 2021-07-16 浙江大学 Method for improving magnetic property of Ce-Y-rich rare earth permanent magnet

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1358595A (en) * 2001-11-16 2002-07-17 清华大学 Method for making rareearth permanent magnet material by discharge plasma sintering
CN1549867A (en) * 2001-09-03 2004-11-24 �Ѻ͵繤��ʽ���� Rare earth magnet alloy ingot, manufacturing method for the same, R-T-B type magnet alloy ingot, r-t-b type magnet, r-t-b type bonded magnet, r-t-b type exchange spring magnet alloy ingot, r-t-b type
CN101266859A (en) * 2008-01-08 2008-09-17 上海大学 Method for quick sintering of micro-crystal ferrite magnetic core part
CN102744406A (en) * 2012-05-16 2012-10-24 华南理工大学 Method for preparing fully dense anisotropic nanocrystalline neodymium-iron-boron (NdFeB) bulk magnet material
CN103081037A (en) * 2011-06-24 2013-05-01 日东电工株式会社 Rare earth permanent magnet and method for manufacturing rare earth permanent magnet
EP2869311A1 (en) * 2013-10-29 2015-05-06 Institute Jozef Stefan Method of manufacturing fully dense Nd-Fe-B magnets with enhanced coercivity and gradient microstructure
US20160322136A1 (en) * 2015-04-30 2016-11-03 Jozef Stefan Institute METAL-BONDED RE-Fe-B MAGNETS

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1549867A (en) * 2001-09-03 2004-11-24 �Ѻ͵繤��ʽ���� Rare earth magnet alloy ingot, manufacturing method for the same, R-T-B type magnet alloy ingot, r-t-b type magnet, r-t-b type bonded magnet, r-t-b type exchange spring magnet alloy ingot, r-t-b type
CN1358595A (en) * 2001-11-16 2002-07-17 清华大学 Method for making rareearth permanent magnet material by discharge plasma sintering
CN101266859A (en) * 2008-01-08 2008-09-17 上海大学 Method for quick sintering of micro-crystal ferrite magnetic core part
CN103081037A (en) * 2011-06-24 2013-05-01 日东电工株式会社 Rare earth permanent magnet and method for manufacturing rare earth permanent magnet
CN102744406A (en) * 2012-05-16 2012-10-24 华南理工大学 Method for preparing fully dense anisotropic nanocrystalline neodymium-iron-boron (NdFeB) bulk magnet material
EP2869311A1 (en) * 2013-10-29 2015-05-06 Institute Jozef Stefan Method of manufacturing fully dense Nd-Fe-B magnets with enhanced coercivity and gradient microstructure
US20160322136A1 (en) * 2015-04-30 2016-11-03 Jozef Stefan Institute METAL-BONDED RE-Fe-B MAGNETS

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112927920A (en) * 2021-03-05 2021-06-08 西安交通大学 Pressurizing heat treatment method for improving magnetic property of 2:17 type Sm-Co sintered magnet
CN112927920B (en) * 2021-03-05 2022-05-06 西安交通大学 Pressurizing heat treatment method for improving magnetic property of 2:17 type Sm-Co sintered magnet
CN113130200A (en) * 2021-04-26 2021-07-16 浙江大学 Method for improving magnetic property of Ce-Y-rich rare earth permanent magnet
CN113130200B (en) * 2021-04-26 2022-06-17 浙江大学 Method for improving magnetic property of Ce-Y-rich rare earth permanent magnet

Similar Documents

Publication Publication Date Title
TWI751789B (en) NdFeB MAGNET MATERIAL, RAW MATERIAL COMPOSITION, PREPARATION METHOD AND APPLICATION
JP5856953B2 (en) Rare earth permanent magnet manufacturing method and rare earth permanent magnet
CN101266855B (en) Rare earth permanent magnetism material and its making method
WO2015078362A1 (en) Low-b rare earth magnet
CN102496437B (en) Anisotropic nanocrystal complex-phase compact block neodymium-iron-boron permanent-magnet material and preparation method thereof
WO2016086398A1 (en) Method for preparing high-coercivity sinterednd-fe-b and product obtained thereby
JP4702547B2 (en) Functionally graded rare earth permanent magnet
WO2016201944A1 (en) Preparation method of ndfeb magnet having low melting point light rare-earth-copper alloy at grain boundary
TWI595519B (en) Rare earth permanent magnet manufacturing method
TWI569294B (en) Manufacture of rare earth permanent magnets
JP2012069819A (en) Permanent magnet and permanent magnet motor and power generator using the same
CN111063536B (en) Grain boundary diffusion method suitable for bulk rare earth permanent magnet material
JP2011049441A (en) Method for manufacturing r-t-b based permanent magnet
KR20090091203A (en) Permanent magnet and method for producing permanent magnet
CN103123843A (en) Preparation method for fine grain anisotropy densified neodymium iron boron permanent magnet
CN111029128A (en) Rapid heat treatment method of rare earth permanent magnet
JP4700578B2 (en) Method for producing high resistance rare earth permanent magnet
EP2801985A1 (en) Neodymium-based rare-earth permanent magnet and process for producing same
CN109859920A (en) A kind of highly resistance corrosion richness high abundance rare-earth permanent magnet and preparation method
JP4951703B2 (en) Alloy material for RTB-based rare earth permanent magnet, method for manufacturing RTB-based rare earth permanent magnet, and motor
JP5288276B2 (en) Manufacturing method of RTB-based permanent magnet
EP2506270B1 (en) Permanent magnet and manufacturing method for permanent magnet
KR20220041189A (en) R-T-B type permanent magnet material, raw material composition, manufacturing method, application
CN108777204B (en) Preparation method of samarium-iron-nitrogen permanent magnet powder
CN1061163C (en) Double-phase rare-earth-iron-boron magnetic powder and its prepn. method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20200417