CN116612956A - Cerium-containing neodymium-iron-boron magnet with core-shell structure and preparation method and application thereof - Google Patents
Cerium-containing neodymium-iron-boron magnet with core-shell structure and preparation method and application thereof Download PDFInfo
- Publication number
- CN116612956A CN116612956A CN202310639204.9A CN202310639204A CN116612956A CN 116612956 A CN116612956 A CN 116612956A CN 202310639204 A CN202310639204 A CN 202310639204A CN 116612956 A CN116612956 A CN 116612956A
- Authority
- CN
- China
- Prior art keywords
- iron
- magnetic powder
- cerium
- equal
- component
- 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
Links
- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 75
- 229910052684 Cerium Inorganic materials 0.000 title claims abstract description 58
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 title claims abstract description 58
- 239000011258 core-shell material Substances 0.000 title claims abstract description 34
- 238000002360 preparation method Methods 0.000 title abstract description 7
- 239000006247 magnetic powder Substances 0.000 claims abstract description 72
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 42
- 239000002994 raw material Substances 0.000 claims abstract description 37
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 claims abstract description 16
- 239000002344 surface layer Substances 0.000 claims abstract description 8
- 238000005496 tempering Methods 0.000 claims description 40
- 238000005245 sintering Methods 0.000 claims description 36
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 24
- 238000002156 mixing Methods 0.000 claims description 22
- 150000002910 rare earth metals Chemical class 0.000 claims description 22
- 238000003723 Smelting Methods 0.000 claims description 18
- 239000000126 substance Substances 0.000 claims description 16
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 14
- 238000000227 grinding Methods 0.000 claims description 14
- 229910052739 hydrogen Inorganic materials 0.000 claims description 14
- 239000001257 hydrogen Substances 0.000 claims description 14
- 229910052746 lanthanum Inorganic materials 0.000 claims description 7
- 229910052733 gallium Inorganic materials 0.000 claims description 6
- 229910052706 scandium Inorganic materials 0.000 claims description 6
- 229910052720 vanadium Inorganic materials 0.000 claims description 6
- 229910052727 yttrium Inorganic materials 0.000 claims description 6
- 238000000498 ball milling Methods 0.000 claims description 4
- 230000006698 induction Effects 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 3
- 238000010248 power generation Methods 0.000 claims description 3
- 238000000462 isostatic pressing Methods 0.000 claims description 2
- 230000005291 magnetic effect Effects 0.000 abstract description 22
- 229910052779 Neodymium Inorganic materials 0.000 abstract description 12
- 239000000696 magnetic material Substances 0.000 abstract description 2
- 239000012071 phase Substances 0.000 description 34
- 229910045601 alloy Inorganic materials 0.000 description 20
- 239000000956 alloy Substances 0.000 description 20
- 239000000843 powder Substances 0.000 description 20
- 238000004321 preservation Methods 0.000 description 15
- 239000013078 crystal Substances 0.000 description 14
- 239000000203 mixture Substances 0.000 description 12
- 239000000463 material Substances 0.000 description 10
- 229910052751 metal Inorganic materials 0.000 description 10
- 239000002184 metal Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 238000000465 moulding Methods 0.000 description 5
- 238000009826 distribution Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 229910052692 Dysprosium Inorganic materials 0.000 description 2
- 229910052777 Praseodymium Inorganic materials 0.000 description 2
- 229910052771 Terbium Inorganic materials 0.000 description 2
- 230000005347 demagnetization Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000007712 rapid solidification Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
-
- 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
- H01F1/0571—Alloys 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
- H01F1/0575—Alloys 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
- H01F1/0577—Alloys 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
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/64—Electric machine technologies in electromobility
Abstract
The application discloses a cerium-containing neodymium-iron-boron magnet with a core-shell structure, and a preparation method and application thereof, and belongs to the technical field of magnetic materials. The raw materials of the cerium-containing neodymium-iron-boron magnet comprise a component A and a component B; the component A is low-rare-earth high-Ce neodymium iron boron magnetic powder A; the component B is high-rare-earth high-Pr neodymium-iron-boron magnetic powder B; the cerium-containing neodymium-iron-boron magnet has a microscopic grain core-shell structure; the high Ce neodymium-iron-boron phase is enriched in the main phase grains of the cerium-containing neodymium-iron-boron magnet to form a core structure of the cerium-containing neodymium-iron-boron magnet; the high Pr NdFeB phase is enriched on the surface layer of the main phase grains of the cerium-containing NdFeB magnet, so that the shell structure of the cerium-containing NdFeB magnet is formed. The core-shell structure of the (Nd, ce) -Fe-B magnet has excellent magnetic performance and thermal stability, and especially the coercive force is improved by more than 2 times.
Description
Technical Field
The application belongs to the technical field of magnetic materials, and particularly relates to a cerium-containing neodymium-iron-boron magnet with a core-shell structure, and a preparation method and application thereof.
Background
In recent years, sintered NdFeB permanent magnet materials are widely applied to various industries of national economy such as instruments and meters, microwave communication, wind power generation, electric automobiles and the like due to extremely high coercivity and magnetic energy product. However, the traditional neodymium iron boron material consumes a large amount of rare and expensive resources such as praseodymium (Pr), neodymium (Nd), dysprosium (Dy), terbium (Tb) and the like, so that a large amount of backlog of high-abundance rare earth elements such as cerium (Ce), lanthanum (La) and the like which are extracted by associated exploitation is caused, and the rare earth resources in China are extremely unbalanced in utilization. The high abundance rare earth element Ce is the highest in the crust, the total amount of the high abundance rare earth element Ce exceeds 40% of the total rare earth amount, and meanwhile, the price of the Ce element is less than 1/30 of that of Nd and Pr, and is only about 1/100 of that of Tb and Dy. Therefore, from the viewpoints of reducing the cost of the magnet and promoting the balance utilization of rare earth resources, the preparation of (Nd, ce) -Fe-B permanent magnet material by replacing Nd with Ce becomes a research hot spot in recent years.
A great deal of research shows that the coercive force, the residual magnetization, the maximum magnetic energy product and the like of the (Nd, ce) -Fe-B magnet are rapidly reduced along with the increase of the Ce content, and the reasons mainly comprise the following aspects: first of all because of Ce 2 Fe 14 Intrinsic properties of B (mu) 0 M s ＝1.17T，μ 0 H A ＝2.6T，T c =424K) is much lower than Nd 2 Fe 14 Intrinsic properties of B (mu) 0 M s ＝1.6T，μ 0 H A ＝7.3T，T c =585K), ce doped p Nd 2 Fe 14 The main phase B causes magnetic dilution; secondly, ce-Fe-B can generate a large amount of weak ferromagnetic hetero-phase in the rapid solidification processCeFe 2 The hard magnetic property of the (Nd, ce) -Fe-B magnet is greatly damaged by the nucleation center which is formed by the agglomeration at the triangular grain boundary of the magnet and becomes an anti-magnetization domain in the anti-magnetization process; in addition, the thin-walled grain boundary phase of the (Nd, ce) -Fe-B magnet contains a large amount of Ce element, so that the chemical composition and phase structure of the grain boundary phase are changed, the fluidity, wettability to the main phase and the like of the grain boundary phase are reduced, and continuous and uniform thin-walled grain boundaries cannot be formed to magnetically isolate the main phase grains, so that the coercive force of the (Nd, ce) -Fe-B magnet is reduced.
Disclosure of Invention
According to one aspect of the application, a cerium-containing neodymium-iron-boron magnet with a core-shell structure, a preparation method and application thereof are provided, and the technical problem of coercivity reduction of the cerium-containing neodymium-iron-boron magnet is mainly solved.
In one aspect, the application provides a cerium-containing NdFeB magnet with a core-shell structure, wherein the raw materials of the cerium-containing NdFeB magnet comprise a component A and a component B;
the component A is low-rare-earth high-Ce neodymium iron boron magnetic powder A;
the component B is high-rare-earth high-Pr neodymium-iron-boron magnetic powder B;
the cerium-containing neodymium-iron-boron magnet has a microscopic grain core-shell structure;
the high Ce neodymium-iron-boron phase is enriched in the main phase grains of the cerium-containing neodymium-iron-boron magnet, so that a core structure of the cerium-containing neodymium-iron-boron magnet is formed;
the high Pr NdFeB phase is enriched on the surface layer of the main phase grains of the cerium-containing NdFeB magnet, so that the shell structure of the cerium-containing NdFeB magnet is formed.
The process of forming the core-shell structure of the present application is shown in FIG. 1.
The inventor discovers that the key of obtaining the high-performance (Nd, ce) -Fe-B magnet is to regulate and control the spatial distribution of Ce element in the magnet during scientific research experiments, so that Ce with weaker intrinsic performance 2 Fe 14 The B phase is enriched in the main phase crystal grains of the cerium-containing neodymium-iron-boron magnet and simultaneously inhibits or consumes CeFe at the triangular grain boundary of the magnet 2 The mixed phase is obtained, a continuous and uniform thin-wall grain boundary phase is obtained, and the magnetic isolation effect of the grain boundary on main phase grains is enhanced; can solve the problemsGreatly improves the magnetic performance of the cerium-containing neodymium-iron-boron magnet and is popularized and applied in a large scale.
The application designs the magnetic powder with low rare earth and high Ce and high rare earth and high Pr components, adopts a double main phase method to obtain a magnet, and utilizes the rare earth-rich phase in the high rare earth and high Pr components to form flowing liquid phase to wrap main phase grains with high Ce in the heat treatment process, so that the Ce is formed 2 Fe 14 The B phase is enriched in the main phase grains of the cerium-containing neodymium-iron-boron magnet, (Nd, pr) 2 Fe 14 The B phase is enriched on the surface layer of the main phase crystal grain of the cerium-containing neodymium-iron-boron magnet to form a crystal grain inner core shell structure with a high anisotropic field surface layer, meanwhile, the surplus Pr element forms a thin-wall crystal boundary phase among the main phase crystal grains of the cerium-containing neodymium-iron-boron magnet, so that an effective magnetic isolation effect is achieved on the main phase crystal grains of the cerium-containing neodymium-iron-boron magnet, and the coercive force of the cerium-containing neodymium-iron-boron magnet is finally improved.
Optionally, the chemical formula of the low-rare-earth high-Ce neodymium iron boron magnetic powder A is shown as formula I:
(RE x Ce y ) α B β M γ N δ Fe 100-α-β-γ-δ a formula I;
wherein x and y are mass percent, x+y=1 and y is more than or equal to 0.20 and less than or equal to 1;
the weight percentage of alpha is more than or equal to 20 and less than or equal to 40, beta is more than or equal to 0 and less than or equal to 3, gamma is more than or equal to 0 and less than or equal to 10, and delta is more than or equal to 0 and less than or equal to 10;
RE is rare earth element, RE is selected from at least one of La, ce, pr, nd, pm, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc;
m in the formula I is selected from at least one of Co, ni, mn, cr, cu, zn, ti, V, zr, nb;
n in formula I is selected from at least one of Ga, al, sn, ge.
Optionally, the chemical formula of the high rare earth high Pr neodymium iron boron magnetic powder B is formula II:
(R m Pr n ) a B b M c N d Fe 100-a-b-c-d the method comprises the steps of carrying out a first treatment on the surface of the A formula II;
wherein m and n are mass percent, m+n=1 and n is more than or equal to 0.30 and less than or equal to 1;
in terms of mass percent, a is more than or equal to 20 and less than or equal to 90,0, b is more than or equal to 3, c is more than or equal to 0 and less than or equal to 10, and d is more than or equal to 0 and less than or equal to 10;
r is a rare earth element, and R is at least one selected from La, ce, pr, nd, pm, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc;
m in the formula II is selected from at least one of Co, ni, mn, cr, cu, zn, ti, V, zr, nb;
n in formula II is selected from at least one of Ga, al, sn, ge.
Alternatively, the mass of the component A and the mass of the component B are respectively m A And m B The ratio of the component A to the total mass of the component A and the component B is k=m A /(m A +m B ) The value range of k is more than 0 and less than 1.
Optionally, k is more than 0.2 and less than 0.98.
Optionally, k is more than 0.4 and less than 0.95.
Alternatively, k is selected from any value or range of values between any two of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.78, 0.8, 0.85, 0.86, 0.9, 0.93, 0.95, 0.97, 0.98, 0.99.
In a second aspect, the application provides a preparation method of the cerium-containing neodymium-iron-boron magnet, which comprises the following steps:
s1: obtaining magnetic powder A and magnetic powder B;
s2: the magnetic powder A and the magnetic powder B are mixed and then are subjected to orientation forming to prepare a magnet blank;
s3: and sintering and tempering the green blank to obtain the cerium-containing neodymium-iron-boron magnet with the core-shell structure.
Optionally, the method for obtaining the magnetic powder a in step S1 includes: preparing raw materials of each component according to the raw material proportion of the magnetic powder A, mixing the raw materials of each component, and sequentially carrying out quick setting smelting, hydrogen breaking and air flow grinding to obtain the magnetic powder A;
or preparing raw materials of each component according to the raw material proportion of the magnetic powder A, and after mixing the raw materials of each component, carrying out induction smelting, and then carrying out mechanical crushing and/or ball milling to obtain the magnetic powder A.
Optionally, the method for obtaining the magnetic powder B in step S1: preparing raw materials of each component according to the raw material proportion of the magnetic powder B, mixing the raw materials of each component, and sequentially carrying out quick setting smelting, hydrogen breaking and air flow grinding to obtain the magnetic powder B;
or preparing raw materials of each component according to the raw material proportion of the magnetic powder B, and after mixing the raw materials of each component, carrying out induction smelting, and then carrying out mechanical crushing and/or ball milling to obtain the magnetic powder B.
Optionally, in step S2, the magnetic powder a and the magnetic powder B are shaped into a magnet blank through isostatic pressing orientation.
Optionally, in step S1, the ratio of the magnetic powder a to the total mass of the magnetic powder a and the magnetic powder B is k=m A /(m A +m B ) The value range of k is more than 0 and less than 1.
Optionally, k is more than 0.2 and less than 0.98.
Optionally, k is more than 0.4 and less than 0.95.
Optionally, k is more than 0.5 and less than 0.95.
Alternatively, k is selected from any value or range of values between any two of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.78, 0.8, 0.85, 0.86, 0.9, 0.93, 0.95, 0.97, 0.98, 0.99.
Optionally, the sintering temperature in the step S3 is 900-1200 ℃;
the sintering time is 1-10 h;
the vacuum degree of sintering is 1X 10 -4 ～1×10 -2 Pa。
Optionally, the sintering temperature is selected from any value or range of values between any two of 900 ℃, 950 ℃, 1000 ℃, 1050 ℃, 1100 ℃, 1150 ℃, 1200 ℃.
Optionally, the sintering time is selected from any value or range of values between any two of 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10 h.
Optionally, the sintering vacuum degree is 1×10 -4 、1×10 -3 、1×10 -2 Any value or any of PaMeaning a range of values between the two.
Optionally, the tempering in step S3 includes a primary tempering and a secondary tempering:
the temperature of the primary tempering is 800-1000 ℃; the primary tempering time is 1-6 h;
the temperature of the secondary tempering is 400-650 ℃; the secondary tempering time is 1-6 h.
Optionally, the temperature of the primary tempering is selected from any value or a range of values between any two of 800 ℃, 810 ℃, 820 ℃, 830 ℃, 840 ℃, 850 ℃, 860 ℃, 870 ℃, 880 ℃, 890 ℃, 900 ℃, 910 ℃, 920 ℃, 930 ℃, 940 ℃, 950 ℃, 1000 ℃.
Optionally, the primary tempering time is any value of 1h, 2h, 3h, 4h, 5h, 6h or a range of values between any two.
Optionally, the temperature of the secondary tempering is any value or a range of values between any two of 400 ℃, 420 ℃, 440 ℃, 460 ℃, 480 ℃, 500 ℃, 520 ℃, 540 ℃, 560 ℃, 580 ℃, 600 ℃, 610 ℃, 620 ℃, 630 ℃, 640 ℃, 650 ℃.
Optionally, the secondary tempering time is any value of 1h, 2h, 3h, 4h, 5h, 6h or a range of values between any two.
In a third aspect, the application provides application of the cerium-containing neodymium-iron-boron magnet in instruments and meters, microwave communication, wind power generation and electric automobiles.
Compared with the prior art, the application has the following beneficial effects:
the application utilizes the rare earth-rich phase in the magnetic powder B to form flowing liquid phase in the heat treatment process to wrap the main phase grains (Ce) of the magnetic powder A 2 Fe 14 B) Make Ce 2 Fe 14 The phase B is enriched in the main phase crystal grains of the cerium-containing neodymium-iron-boron magnet, and the main phase crystal grains (Nd, pr) of the magnetic powder B 2 Fe 14 The B phase is enriched on the surface layer of the main phase crystal grain to form the NdFeB permanent magnet material with the crystal grain inner core shell structure with the high anisotropic field surface layer.
The core-shell structure designed in the cerium magnet can not only optimize element distribution and microstructure in the magnet, but also greatly improve coercive force of the cerium magnet, obtain the (Nd, ce) -Fe-B magnet with excellent magnetic property and thermal stability, realize the purpose of balanced utilization of rare earth resources and reduce the cost of the neodymium-iron-boron magnet, and have important theoretical significance and application value.
Drawings
Fig. 1 is a schematic diagram of a core-shell structure formed by magnetic powder a and magnetic powder B according to an embodiment of the present application;
FIG. 2 is a graph showing the room temperature demagnetization curves of the magnets provided in examples 1-5 and the comparative example;
fig. 3 is a microstructure and element distribution diagram of the magnets provided in examples 1-5 and comparative examples.
Detailed Description
The present application is described in detail below with reference to examples, but the present application is not limited to these examples.
Unless otherwise indicated, all starting materials in the examples of the present application were purchased commercially.
The Ce45 magnet of the application represents that the cerium element accounts for 45 percent of the total mass of rare earth elements in the magnet, and the numbers behind the element symbol Ce represent the mass percent.
The embodiment of the application has the same formula as the low-rare-earth high-Ce neodymium iron boron magnetic powder A as formula I:
(RE x Ce y ) α B β M γ N δ Fe 100-α-β-γ-δ a formula I;
wherein x and y are mass percent, x+y=1 and y is more than or equal to 0.20 and less than or equal to 1;
the weight percentage of alpha is more than or equal to 20 and less than or equal to 40, beta is more than or equal to 0 and less than or equal to 3, gamma is more than or equal to 0 and less than or equal to 10, and delta is more than or equal to 0 and less than or equal to 10;
RE is rare earth element, RE is selected from at least one of La, ce, pr, nd, pm, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc;
m in formula I is selected from at least one of Co, ni, mn, cr, cu, zn, ti, V, zr, nb, and N is selected from at least one of Ga, al, sn, ge.
The chemical formula of the high-rare-earth high-Pr neodymium iron boron magnetic powder B in the embodiment of the application is shown as formula II:
(R m Pr n ) a B b M c N d Fe 100-a-b-c-d the method comprises the steps of carrying out a first treatment on the surface of the A formula II;
wherein m and n are mass percent, m+n=1 and n is more than or equal to 0.30 and less than or equal to 1;
in terms of mass percent, a is more than or equal to 20 and less than or equal to 90,0, b is more than or equal to 3, c is more than or equal to 0 and less than or equal to 10, and d is more than or equal to 0 and less than or equal to 10;
r is a rare earth element, and R is at least one selected from La, ce, pr, nd, pm, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc;
m in formula II is selected from at least one of Co, ni, mn, cr, cu, zn, ti, V, zr, nb, and N is selected from at least one of Ga, al, sn, ge.
Example 1
Designing a low rare earth high Ce component A: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder A;
the chemical formula of the component A: [ (PrNd) 0.5 Ce 0.5 ] 29.5 B 0.98 Co 0.5 Zr 0.2 Al 0.1 Ga 0.1 Fe bal (Ce50)；
Designing a high rare earth and high Pr component B: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder B;
the chemical formula of the component B: pr (Pr) 45 B 0.7 Ti 0.5 Ga 4 Fe bal (Pr45)；
The two prepared magnetic powders are mixed according to the mass ratio m A /(m A +m B ) And (2) preparing a ratio of 0.6, uniformly mixing, performing magnetic field orientation molding to prepare a green body, and then placing the green body into a high-vacuum sintering furnace for high-temperature sintering and tempering treatment to finally obtain the cerium-containing neodymium-iron-boron magnet with the core-shell structure.
The specific sintering and tempering process comprises the following steps: vacuum degree of 1X 10 -4 Pa, sintering temperature is 1020 ℃, and sintering heat preservation time is 4h; the primary tempering temperature is 900 ℃, and the heat preservation time is 2 hours;the secondary tempering temperature is 500 ℃, and the heat preservation time is 2 hours.
The prepared magnet is placed in an open-circuit PFM permanent magnet material measuring system, and the magnetic performance is measured as follows: b (B) r ＝10.80kGs，H cj ＝16.39kOe，(BH) max ＝27.57MGOe。
Example 2
Designing a low rare earth high Ce component A: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder A;
the chemical formula of the component A: [ (PrNd) 0.5 Ce 0.5 ] 29.5 B 0.98 Co 0.5 Zr 0.2 Al 0.1 Ga 0.1 Fe bal (Ce50)，
Designing a high rare earth and high Pr component B: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder B;
the chemical formula of the component B: pr (Pr) 45 B 0.7 Ti 0.5 Ga 4 Fe bal (Pr45)；
The two prepared magnetic powders are mixed according to the mass ratio m A /(m A +m B ) And (2) preparing a ratio of 0.7, uniformly mixing, performing magnetic field orientation molding to prepare a green body, and then placing the green body into a high-vacuum sintering furnace for high-temperature sintering and tempering treatment to finally obtain the cerium-containing neodymium-iron-boron magnet with the core-shell structure.
The specific sintering and tempering process comprises the following steps: vacuum degree of 1X 10 -4 Pa, sintering temperature is 1020 ℃, and sintering heat preservation time is 4h; the primary tempering temperature is 900 ℃, and the heat preservation time is 2 hours; the secondary tempering temperature is 500 ℃, and the heat preservation time is 2 hours.
The prepared magnet is placed in an open-circuit PFM permanent magnet material measuring system, and the magnetic performance is measured as follows: b (B) r ＝11.47kG，H cj ＝14.47kOe，(BH) max ＝30.84MGOe。
Example 3
Designing a low rare earth high Ce component A: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder A;
the chemical formula of the component A: [ (PrNd) 0.5 Ce 0.5 ] 29.5 B 0.98 Co 0.5 Zr 0.2 Al 0.1 Ga 0.1 Fe bal (Ce 50); designing a high rare earth and high Pr component B: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder B;
the chemical formula of the component B: pr (Pr) 45 B 0.7 Ti 0.5 Ga 4 Fe bal (Pr45)；
The two prepared magnetic powders are mixed according to the mass ratio m A /(m A +m B ) And (2) preparing a ratio of 0.78, uniformly mixing, performing magnetic field orientation molding to prepare a green body, and then placing the green body into a high-vacuum sintering furnace for high-temperature sintering and tempering treatment to finally obtain the cerium-containing neodymium-iron-boron magnet with the core-shell structure.
The specific sintering and tempering process comprises the following steps: vacuum degree of 1X 10 -4 Pa, sintering temperature is 1020 ℃, and sintering heat preservation time is 4h; the primary tempering temperature is 900 ℃, and the heat preservation time is 2 hours; the secondary tempering temperature is 500 ℃, and the heat preservation time is 2 hours.
The prepared magnet is placed in an open-circuit PFM permanent magnet material measuring system, and the magnetic performance is measured as follows: b (B) r ＝11.27kG，H cj ＝15.03kOe，(BH) max ＝29.60MGOe。
Example 4
Designing a low rare earth high Ce component A: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder A;
the chemical formula of the component A: [ (PrNd) 0.5 Ce 0.5 ] 29.5 B 0.98 Co 0.5 Zr 0.2 Al 0.1 Ga 0.1 Fe bal (Ce50)；
Designing a high rare earth and high Pr component B: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder B;
the chemical formula of the component B: pr (Pr) 45 B 0.7 Ti 0.5 Ga 4 Fe bal (Pr45)；
The two prepared magnetic powders are mixed according to the mass ratio m A /(m A +m B ) And (2) preparing a cerium-containing NdFeB magnet with a core-shell structure of crystal grains by the proportion of 0.86, uniformly mixing, performing magnetic field orientation molding to prepare a green body, and then placing the green body into a high-vacuum sintering furnace for high-temperature sintering and tempering treatment.
The specific sintering and tempering process comprises the following steps: vacuum degree of 1X 10 -4 Pa, sintering temperature is 1020 ℃, and sintering heat preservation time is 4h; the primary tempering temperature is 900 ℃, and the heat preservation time is 2 hours; the secondary tempering temperature is 500 ℃, and the heat preservation time is 2 hours.
The prepared magnet is placed in an open-circuit PFM permanent magnet material measuring system, and the magnetic performance is measured as follows: b (B) r ＝11.71kG，H cj ＝12.44kOe，(BH) max ＝32.09MGOe。
Example 5
Designing a low rare earth high Ce component A: mixing the metal raw materials according to the proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder A;
the chemical formula of the component A: [ (PrNd) 0.5 Ce 0.5 ] 29.5 B 0.98 Co 0.5 Zr 0.2 Al 0.1 Ga 0.1 Fe bal (Ce50)；
Designing a high rare earth and high Pr component B: mixing the metal raw materials in proportion, performing quick setting smelting on the mixture to obtain alloy cast sheets, performing hydrogen breaking on the alloy cast sheets to obtain coarse powder, and performing air flow grinding on the coarse powder to obtain magnetic powder B;
the chemical formula of the component B: pr (Pr) 45 B 0.7 Ti 0.5 Ga 4 Fe bal (Pr45)；
The two prepared magnetic powders are mixed according to the mass ratio m A /(m A +m B ) The mixture is mixed uniformly in a proportion of 0.93,And (3) performing magnetic field orientation molding to prepare a green body, then placing the green body into a high-vacuum sintering furnace for high-temperature sintering and tempering treatment, and finally obtaining the cerium-containing neodymium-iron-boron magnet with the crystal grains having a core-shell structure.
The specific sintering and tempering process comprises the following steps: vacuum degree of 1X 10 -4 Pa, sintering temperature is 1020 ℃, and sintering heat preservation time is 4h; the primary tempering temperature is 900 ℃, and the heat preservation time is 2 hours; the secondary tempering temperature is 500 ℃, and the heat preservation time is 2 hours.
The prepared magnet is placed in an open-circuit PFM permanent magnet material measuring system, and the magnetic performance is measured as follows: b (B) r ＝12.03kG，H cj ＝9.77kOe，(BH) max ＝34.01MGOe。
Comparative example
As a control group, the original cerium-containing magnet with low rare earth and high Ce component was treated according to the same process (compared with the example, no B component, and the cerium-containing neodymium-iron-boron magnet was prepared by using only magnetic powder a), to obtain a control group magnet Ce50.
The prepared magnet is placed in an open-circuit PFM permanent magnet material measuring system, and the magnetic performance is measured as follows: b (B) r ＝12.17kG，H cj ＝5.65kOe，(BH) max ＝29.16MGOe。
FIG. 1 is a graph showing the room temperature demagnetization curves of the magnets obtained in examples 1 to 5 and the comparative example; as can be seen from fig. 1, the demagnetizing curves of the layered composite magnet show smooth curves, which indicate that the magnet structures prepared in examples 1 to 5 of the present application are uniform; as the amount of Pr45 added to the Ce50 magnet increases, the coercivity of the magnet gradually increases, but the remanence and magnetic energy product decrease.
FIG. 2 is a microstructure and element distribution diagram of the magnets obtained in examples 1 to 5 and comparative example; as can be seen from fig. 2, the core-shell structure is not formed in the crystal grains of the comparative example magnet, but after different amounts of Pr45 are added to the Ce50 magnet, the outer layer PrNd-rich core-shell structure and the inner layer Ce-rich core-shell structure are formed on the surface layer of the crystal grains of the magnet, and as the amount of Pr45 increases, the core-shell structure becomes obvious gradually, which indicates that the core-shell structure design scheme of the application is feasible, and the magnetic performance of the cerium-containing neodymium-iron-boron magnet is improved to a certain extent.
The coercive force of the magnets of comparative examples 1-5 and comparative example is about 9-15 kOe; the coercivity of the magnet Ce50 of the comparative example was about 5.65 kOe; as can be seen, the coercivity of the cerium-containing neodymium-iron-boron magnet with the core-shell structure is obviously improved, and even the coercivity is improved by more than 2 times.
While the application has been described in terms of preferred embodiments, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the scope of the application, and it is intended that the application is not limited to the specific embodiments disclosed.
Claims (10)
1. The cerium-containing neodymium-iron-boron magnet with the core-shell structure is characterized in that raw materials of the cerium-containing neodymium-iron-boron magnet comprise a component A and a component B;
the component A is low-rare-earth high-Ce neodymium iron boron magnetic powder A;
the component B is high-rare-earth high-Pr neodymium-iron-boron magnetic powder B;
the cerium-containing neodymium-iron-boron magnet has a microscopic grain core-shell structure;
the high Ce neodymium-iron-boron phase is enriched in the main phase grains of the cerium-containing neodymium-iron-boron magnet, so that a core structure of the cerium-containing neodymium-iron-boron magnet is formed;
the high Pr NdFeB phase is enriched on the surface layer of the main phase grains of the cerium-containing NdFeB magnet, so that the shell structure of the cerium-containing NdFeB magnet is formed.
2. The cerium-containing neodymium-iron-boron magnet with a core-shell structure according to claim 1, wherein the chemical formula of the low-rare-earth high-Ce neodymium-iron-boron magnetic powder a is as follows:
(RE x Ce y ) α B β M γ N δ Fe 100-α-β-γ-δ a formula I;
wherein x and y are mass percent, x+y=1 and y is more than or equal to 0.20 and less than or equal to 1;
the weight percentage of alpha is more than or equal to 20 and less than or equal to 40, beta is more than or equal to 0 and less than or equal to 3, gamma is more than or equal to 0 and less than or equal to 10, and delta is more than or equal to 0 and less than or equal to 10;
RE is rare earth element, RE is selected from at least one of La, ce, pr, nd, pm, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc;
m in the formula I is selected from at least one of Co, ni, mn, cr, cu, zn, ti, V, zr, nb;
n in formula I is selected from at least one of Ga, al, sn, ge.
3. The cerium-containing neodymium-iron-boron magnet with a core-shell structure according to claim 1, wherein the chemical formula of the high rare earth high Pr neodymium-iron-boron magnetic powder B is formula II:
(R m Pr n ) a B b M c N d Fe 100-a-b-c-d the method comprises the steps of carrying out a first treatment on the surface of the A formula II;
wherein m and n are mass percent, m+n=1 and n is more than or equal to 0.30 and less than or equal to 1;
in terms of mass percent, a is more than or equal to 20 and less than or equal to 90,0, b is more than or equal to 3, c is more than or equal to 0 and less than or equal to 10, and d is more than or equal to 0 and less than or equal to 10;
r is a rare earth element, and R is at least one selected from La, ce, pr, nd, pm, sm, eu, gd, tb, dy, ho, er, tm, yb, lu, Y and Sc;
m in the formula II is selected from at least one of Co, ni, mn, cr, cu, zn, ti, V, zr, nb;
n in formula II is selected from at least one of Ga, al, sn, ge.
4. The cerium-containing neodymium-iron-boron magnet with a core-shell structure according to claim 1, wherein the mass of the component A and the mass of the component B are respectively m A And m B The ratio of the component A to the total mass of the component A and the component B is k=m A /(m A +m B ) The value range of k is more than 0 and less than 1;
preferably, k is more than 0.2 and less than 0.98;
preferably, k is in the range of 0.4 < k < 0.95.
5. The method for preparing the cerium-containing neodymium-iron-boron magnet with the core-shell structure according to any one of claims 1 to 4, wherein the method comprises the following steps:
s1: obtaining magnetic powder A and magnetic powder B;
s2: the magnetic powder A and the magnetic powder B are mixed and then are subjected to orientation forming to prepare a magnet blank;
s3: and sintering and tempering the green blank to obtain the cerium-containing neodymium-iron-boron magnet with the core-shell structure.
6. The method for preparing a cerium-containing neodymium-iron-boron magnet according to claim 5, wherein the method for obtaining the magnetic powder a in step S1 comprises the steps of: preparing raw materials of each component according to the raw material proportion of the magnetic powder A, mixing the raw materials of each component, and sequentially carrying out quick setting smelting, hydrogen breaking and air flow grinding to obtain the magnetic powder A;
or preparing raw materials of each component according to the raw material proportion of the magnetic powder A, mixing the raw materials of each component, carrying out induction smelting, and then carrying out mechanical crushing and/or ball milling to obtain the magnetic powder A;
optionally, the method for obtaining the magnetic powder B in step S1 includes: preparing raw materials of each component according to the raw material proportion of the magnetic powder B, mixing the raw materials of each component, and sequentially carrying out quick setting smelting, hydrogen breaking and air flow grinding to obtain the magnetic powder B;
or preparing raw materials of each component according to the raw material proportion of the magnetic powder B, and after mixing the raw materials of each component, carrying out induction smelting, and then carrying out mechanical crushing and/or ball milling to obtain the magnetic powder B.
7. The method according to claim 5, wherein in step S2, the magnetic powder a and the magnetic powder B are shaped into a magnet blank by isostatic pressing.
8. The method of claim 5, wherein in step S1, the ratio of the magnetic powder a to the total mass of the magnetic powder a and the magnetic powder B is k=m A /(m A +m B ) The value range of k is more than 0 and less than 1;
optionally, k is more than 0.2 and less than 0.95.
9. The method of producing a cerium-containing neodymium-iron-boron magnet according to claim 5, wherein the sintering temperature in step S3 is 900 ℃ to 1200 ℃;
the sintering time is 1-10 h;
the vacuum degree of sintering is 1X 10 -4 ～1×10 -2 Pa；
Optionally, the tempering in step S3 includes a primary tempering and a secondary tempering:
the temperature of the primary tempering is 800-1000 ℃; the primary tempering time is 1-6 h;
the temperature of the secondary tempering is 400-650 ℃; the secondary tempering time is 1-6 h.
10. The application of the cerium-containing neodymium-iron-boron magnet with the core-shell structure in instruments and meters, microwave communication, wind power generation and electric automobiles according to any one of claims 1 to 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310639204.9A CN116612956A (en) | 2023-05-31 | 2023-05-31 | Cerium-containing neodymium-iron-boron magnet with core-shell structure and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310639204.9A CN116612956A (en) | 2023-05-31 | 2023-05-31 | Cerium-containing neodymium-iron-boron magnet with core-shell structure and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116612956A true CN116612956A (en) | 2023-08-18 |
Family
ID=87679816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310639204.9A Pending CN116612956A (en) | 2023-05-31 | 2023-05-31 | Cerium-containing neodymium-iron-boron magnet with core-shell structure and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116612956A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117542601A (en) * | 2023-12-11 | 2024-02-09 | 宁波中杭实业有限公司 | High-toughness high-cerium-content neodymium-iron-boron magnet and preparation method thereof |
-
2023
- 2023-05-31 CN CN202310639204.9A patent/CN116612956A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117542601A (en) * | 2023-12-11 | 2024-02-09 | 宁波中杭实业有限公司 | High-toughness high-cerium-content neodymium-iron-boron magnet and preparation method thereof |
| CN117542601B (en) * | 2023-12-11 | 2024-04-23 | 宁波中杭实业有限公司 | High-toughness high-cerium-content neodymium-iron-boron magnet and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102956336B (en) | A kind of method preparing the sintered Nd-Fe-B permanent magnetic material of compound interpolation gadolinium, holmium and yttrium | |
| CN110047636B (en) | Preparation method of high-coercivity La/Ce-rich sintered magnet | |
| CN104700973B (en) | A kind of rare-earth permanent magnet being made up of the common association raw ore mischmetal of Bayan Obo and preparation method thereof | |
| CN107275027B (en) | Using the cerium-rich rare earth permanent magnet and preparation method thereof of yttrium | |
| JP7470804B2 (en) | Neodymium iron boron magnet material, raw material composition, and manufacturing method | |
| WO2012000294A1 (en) | Neodymium-iron-boron magnet having gradient coercive force and method for producing the same | |
| CN108154986B (en) | Y-containing high-abundance rare earth permanent magnet and preparation method thereof | |
| CN112863848B (en) | Preparation method of high-coercivity sintered neodymium-iron-boron magnet | |
| CN106710768A (en) | Method for improving neodymium, cerium, iron and boron sintered magnet coercivity by adding neodymium hydride | |
| CN111636035A (en) | Heavy rare earth alloy, neodymium iron boron permanent magnet material, raw materials and preparation method | |
| EP3955267A1 (en) | Ndfeb alloy powder for forming high-coercivity sintered ndfeb magnets and use thereof | |
| CN107958760B (en) | Rare earth permanent magnetic material and preparation method thereof | |
| CN112086255A (en) | High-coercivity and high-temperature-resistant sintered neodymium-iron-boron magnet and preparation method thereof | |
| CN116612956A (en) | Cerium-containing neodymium-iron-boron magnet with core-shell structure and preparation method and application thereof | |
| CN113593873A (en) | High-coercivity mixed rare earth permanent magnet material and preparation method thereof | |
| CN111091944B (en) | Lanthanum-cerium-yttrium-rich multi-main-phase fine-grain rare earth permanent magnet material and preparation method thereof | |
| CN103137314A (en) | Method for preparing rare earth-iron-boron permanent magnet | |
| CN107146672A (en) | A kind of superelevation magnetic property sintered Nd-Fe-B permanent magnetic material and preparation method | |
| CN115831519B (en) | Sintered NdFeB permanent magnet | |
| CN109585112B (en) | High-performance rare earth permanent magnetic material with improved crystal structure | |
| CN114823027A (en) | High-boron neodymium-iron-boron permanent magnet material and preparation method thereof | |
| CN114156031A (en) | Neodymium-iron-boron magnet and preparation method thereof | |
| CN114678182A (en) | Low-cost high-performance multi-main-phase rare earth permanent magnet material and preparation method thereof | |
| CN114664507A (en) | High-performance rare earth permanent magnetic material with composite hard magnetic shell structure and preparation method thereof | |
| CN109637768B (en) | Yttrium-containing rare earth permanent magnetic material and preparation method thereof |
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 |