CN112309661A - Neodymium-iron-boron magnet and preparation method thereof - Google Patents
Neodymium-iron-boron magnet and preparation method thereof Download PDFInfo
- Publication number
- CN112309661A CN112309661A CN202010859580.5A CN202010859580A CN112309661A CN 112309661 A CN112309661 A CN 112309661A CN 202010859580 A CN202010859580 A CN 202010859580A CN 112309661 A CN112309661 A CN 112309661A
- Authority
- CN
- China
- Prior art keywords
- magnetic material
- material body
- preparing
- coating
- melt
- 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
Images
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
- 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
- H01F41/026—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 protecting methods against environmental influences, e.g. oxygen, by surface treatment
-
- 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
- H01F41/0266—Moulding; Pressing
-
- 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
- H01F41/0293—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 diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/02—Permanent magnets [PM]
- H01F7/0205—Magnetic circuits with PM in general
- H01F7/0221—Mounting means for PM, supporting, coating, encapsulating PM
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Environmental & Geological Engineering (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
- Hard Magnetic Materials (AREA)
Abstract
The invention relates to the field of magnetic materials, in particular to a neodymium iron boron magnet and a preparation method thereof. The utility model provides a neodymium iron boron magnetism material includes magnetism material body and set up in the composite coating on magnetism material body surface, magnetism material body contains the following weight percent's of element: nd: 17-23 wt%, B: 0.5-1.2 wt%, Pr: 6-10 wt%, Dy: 2-5 wt%, Al: 0.3 to 0.9 wt%, Cu: 0.1-0.2 wt%, the balance being Fe; the composite coating comprises an inner coating and an outer coating; the preparation method comprises the following steps: s1, preparing a magnetic material body; s2, preparing an inner coating; s3, preparing an outer coating. The neodymium iron boron magnet has the advantages of excellent corrosion resistance, higher coercive force and higher maximum working temperature. In addition, the preparation method has the advantages of simple operation and convenient mass production.
Description
Technical Field
The invention relates to the field of magnetic materials, in particular to a neodymium iron boron magnet and a preparation method thereof.
Background
The sintered Nd-Fe-B magnet has excellent normal temperature magnetic performance and is one kind of important basic functional material. Remanence Br and coercive force HcjThe magnetic parameters of the basic technology of the magnet are determined not only by the chemical components of the material, but also closely related to the organization structure of the material.
At present, the main methods for preparing the neodymium iron boron magnet comprise smelting alloying, a grain boundary diffusion technology, a double alloy method (comprising a double main phase method) and the like. Wherein, heavy rare earth is added by an alloying method to form a high magnetocrystalline anisotropy (NdDy)2Fe14B hard magnetic phase, which can obviously improve the coercive force of the magnet and reduce the magnetic performance attenuation caused by high temperature.
In addition, the double-alloy method is an effective way for improving the coercive force of the neodymium iron boron magnet, namely, the main phase alloy and the grain boundary phase alloy are respectively prepared, mixed according to a certain proportion, so that the grain boundary phase is uniformly dispersed around the main phase, and the neodymium iron boron magnet is prepared by sintering, tempering and other processes.
However, a chemical electromotive force difference exists between the main phase (-0.515V) and the neodymium-rich phase (-0.65V), so that intergranular corrosion exists between different phases to affect the corrosion resistance of the ndfeb magnet, and meanwhile, Dy atoms and Fe atoms form anti-iron coupling to cause the reduction of residual magnetic induction strength and magnetic energy product, and the magnetic field strength generated by the permanent magnet is also reduced under the extreme environment at high temperature.
Disclosure of Invention
In view of the problems in the prior art, a first object of the present invention is to provide a neodymium iron boron magnetic material, which has the advantages of excellent corrosion resistance, high coercivity and high maximum operating temperature.
The second purpose of the invention is to provide a preparation method of the high-temperature-resistant neodymium-iron-boron magnet, which has the advantages of simple operation and convenience for mass production.
In order to achieve the first object, the invention provides the following technical scheme: the utility model provides a neodymium iron boron magnetism material, includes magnetism material body and set up in the composite coating on magnetism material body surface, magnetism material body contains the following weight percent's of element: nd: 17-23 wt%, B: 0.5-1.2 wt%, Pr: 6-10 wt%, Dy: 2-5 wt%, Al: 0.3 to 0.9 wt%, Cu: 0.1-0.2 wt%, the balance being Fe; the composite coating comprises an inner coating and an outer coating;
the inner coating comprises Cr: 7.3wt%, B: 2.4 wt%, Dy: 4.25 wt%, Gd: 2.7 wt% and the balance Fe; the outer coating comprises graphite: 17.3Wt%, Nb: 2.82 wt%; ti: 23 wt%; SiC: 6.7 percent; mo: 1.13 wt%, the remainder being Ni.
By adopting the technical scheme, the Nd, B, Pr, Dy, Al, Cu and Fe are adopted as the magnetic material body, so that the prepared magnetic material body has higher coercive force.
Wherein Al is a low-melting-point metal and is 660.37 ℃, and intergranular secondary phases are formed among the Al, Nd, Fe and B, so that the wettability and the corrosion resistance are improved; however, the boiling point of Al is as high as 2467.0 ℃, so that when Ga and Al are added, the liquid phase temperature of the ndfeb magnet can be reduced, and various performances such as spreading and mechanics of the ndfeb magnet are optimized. In addition, after Al is added, alloy grains are refined, meanwhile, the bulk degrees of the Nd-rich phase and the B-rich phase are reduced, the distribution of the Nd-rich phase and the B-rich phase is more dispersed, and therefore the coercive force of the alloy is improved.
Cu can also form an intergranular secondary phase with Nd, Fe and B, thereby further improving the wettability and the corrosion resistance.
The physical and chemical properties of Pr element are close to those of Nd element, the remanence of magnet after adding Pr element is not reduced by adding Dy in large quantity, and Pr element2Fe14B has a higher anisotropy field than Nd2Fe14And B, the coercive force of the magnetic material body can be improved.
Dy element diffuses into the surface layer region of the main phase crystal grains to partially replace Nd element in the surface layer region of the main phase crystal grains to form (Nd, Dy) FeB intermetallic compound, so that the magnetocrystalline anisotropy constant of the defect region of the surface structure of the crystal grains is improved, the epitaxial layer of the main phase crystal grains generates magnetic hardening, and the coercive force of the magnet is obviously improved.
Because Cr, B, Dy, Gd and Fe are used as the inner coating, the coercive force of the magnetic material body is improved; the graphite, Nb, Ti, SiC, Mo and Ni are adopted, so that the corrosion resistance, the wear resistance, the surface hardness and the like of the magnetic material body are improved. The Ni element can be used as an adhesive to wrap graphite, so that the outer coating is attached to the inner coating, and the outer coating has good thermal conductivity, so that the magnetic material body has higher working temperature.
Further, the magnetic material body comprises the following elements in percentage by weight: nd: 17 wt%, B: 0.7 wt%, Pr: 7 wt%, Dy: 3wt%, Al: 0.6 wt%, Cu: 0.1 wt%, the balance being Fe.
Further, the magnetic material body further comprises Co: 0.1-0.15 wt%.
By adopting the technical scheme, the Co can be matched with Cu and Al to compensate each other in performance, so that the overall performance of the neodymium iron boron magnet is improved. In addition, Co is diffused into the surface layer region of the main phase crystal grains to partially replace Nd element in the surface layer region of the main phase crystal grains to form an (Nd, Co) FeB intermetallic compound, so that the magnetocrystalline anisotropy constant of the defect region of the surface structure of the crystal grains is improved, the epitaxial layer of the main phase crystal grains generates magnetic hardening, and the coercive force of the magnet is obviously improved.
In order to achieve the second object, the invention provides the following technical scheme: a preparation method of a neodymium iron boron magnetic material comprises S1 and preparation of a magnetic material body, and comprises the following specific steps:
s1.1, mixing materials:
mixing Nd, B, Pr, Dy, Al, Cu, Fe and Co in proportion into magnetic material mixed powder;
s1.2, smelting and melt spinning:
smelting the magnetic material mixed powder at 1550-1600 ℃, pouring the molten liquid on the surface of a rotating melt-spun metal rod, and melt-spinning to obtain a melt-spun sheet;
s1.3, hydrogen crushing powder:
crushing the melt-spun piece by hydrogen, and then preparing the melt-spun piece into micro powder in an air flow mill;
s1.4, directional profiling:
uniformly mixing the micro powder under the protection of nitrogen, and then pressing and forming to obtain a blank;
s1.5, metallurgical sintering:
sintering the blank for 4-5h at the sintering temperature of 1010-1070 ℃, preserving heat for 2-3h, cooling to 900 ℃, performing aging treatment, preserving heat for 2-3h at the primary aging temperature of 870-960 ℃, and cooling to 150 ℃; the secondary aging temperature is 540-630 ℃, and the magnetic material body is obtained after the temperature is kept for 7-12h and then cooled to room temperature.
S2, preparing an inner coating, which comprises the following steps:
s2.1, mixing materials:
proportioning Cr, B, Dy, Gd and Fe into inner coating mixed powder according to a proportion;
s2.2, evaporation:
putting the mixed powder of the inner coating into an evaporation furnace, heating, melting, evaporating, cooling, and uniformly attaching to the magnetic material body to form a metal film;
s3, preparing an outer coating, which comprises the following steps:
s3.1, mixing materials:
proportionally mixing graphite, Nb, Ti, SiC, Mo and Ni into external coating mixed powder;
s3.2, ball-milling and agglomerating:
grinding the outer coating mixed powder, and adding absolute ethyl alcohol as a binder to uniformly mix to prepare an agglomerate;
b3.3, preparing a preset layer;
under the protection of inert gas, cleaning an oxidation layer and oil stains on the surface of the inner coating layer by using ultrasonic waves, uniformly coating the agglomerates on the surface of the magnetic material body to form a preset layer, and drying the preset layer in the shade indoors;
b3.4 laser cladding
Introducing argon gas as a protective gas, carrying out laser cladding on the magnetic material body and the agglomerates, wherein the laser output power is 1.5-2.3 kW, the scanning speed is 4-8 mm/s, the diameter of a light spot is 3mm, the argon gas flow is 6-8L/min, the lap joint rate is 25-35 wt%, after cladding, covering a cladding area with an aluminum silicate heat-insulating material, and slowly cooling; after cladding, covering a cladding area by using an aluminum silicate heat-insulating material, and slowly cooling.
By adopting the technical scheme, the magnetic material body can be prepared by S1, the inner coating is prepared by S2 and then is attached to the magnetic material body by evaporation to form a metal film, and the outer coating is further prepared by S3 and is coated on the inner coating by laser cladding.
Heavy rare earth metal is taken as a substitute phase to enter the main phase through evaporation, and a continuous region with high rare earth content is formed at the boundary of the main phase, so that the coercive force of the magnetic material body is greatly improved, and meanwhile, after the grain boundary is permeated by the heavy rare earth, the grain boundary rare earth-rich phase is more continuous and clearer, and the isolation exchange coupling effect is more effective. As a result, the coercive force is greatly improved, the remanence is hardly reduced, the use amount of heavy rare earth is reduced, and the production cost is greatly saved. In the process of grain boundary diffusion treatment, Dy elements are diffused into the surface layer region of the main phase crystal grains to partially replace Nd elements in the surface layer region of the main phase crystal grains to form an (Nd, Dy) FeB intermetallic compound, so that the magnetocrystalline anisotropy constant of the defect region of the surface structure of the crystal grains is improved, the epitaxial layer of the main phase crystal grains is subjected to magnetic hardening, and the coercive force of the magnet is obviously improved.
Laser cladding is a rapid heating and melting process, B is a typical ferrite forming element, Cr has a body-centered cubic lattice structure, the content of B, Cr at a grain boundary is high due to the effect of component segregation, and CrB are subjected to rapid cooling2The grain boundary is enriched in B, Cr, and the nucleation is started, and the long needle shape is rapidly grown by shearing. Moreover, after the first strip-shaped needle-shaped strengthening structure is formed, other strip-shaped CrB and CrB are catalyzed2And nucleation is continuously carried out in other directions, so that needle-shaped reinforced tissues in all directions can be quickly formed, the dislocation motion is hindered, the structural strength of the inner coating and the outer coating is further improved, and the structural strength of the neodymium iron boron magnetic material is further improved.
Further, the magnetic material body further comprises S1.6 nitriding treatment after the step S1.5 of metallurgical sintering: polishing the magnetic material body and immersing the magnetic material body in absolute ethyl alcohol for ultrasonic cleaning; and drying, putting into an ion nitriding furnace, and nitriding for 7 h.
By adopting the technical scheme, the alloy elements of the nitrided magnetic material body form various alloy nitrides, so that the nitrided layer with good physical and chemical properties is formed on the surface of the magnetic material body, the wear resistance and the corrosion resistance are improved, and the nitrided magnetic material can stably work at a higher working temperature.
Further, in step S1.2, the upper thread speed of the metal melt-spun roll is 3 m/S.
By adopting the technical scheme, the prepared melt-spun sheet has proper thickness, so that the subsequent hydrogen breaking of the melt-spun sheet into micro powder with uniform particle size is facilitated, and the subsequently prepared magnetic material body has higher coercive force and higher maximum working temperature.
Further, in the step S1.2, after the melt-spun sheet is broken, a liquid antioxidant and graphite in a weight ratio of 6:2 are added, wherein the liquid antioxidant consists of benzotriazole and petroleum ether in a volume ratio of 8: 92.
By adopting the technical scheme, the liquid antioxidant is compounded with the graphite according to the weight ratio of 6:2, so that the graphite is conveniently carried to the surface of the melt-spun sheet and coats the crushing sites of the melt-spun sheet, the melt-spun sheet is prevented from being oxidized, and the contact between air and powder is isolated. Graphite is a lubricant, so that the probability of oxidation of the powder can be reduced, the friction among the powder can be reduced, and the degree of orientation of the powder can be improved. In addition, the graphite can also be used as a reducing agent in the subsequent high-temperature sintering process, so that the reduction effect on the powder is achieved, the oxygen element in the powder is removed, and the graphite is separated from the powder in the form of carbon dioxide, so that the influence on the magnetism of the magnet body is avoided.
Further, the liquid antioxidant consists of benzotriazole and petroleum ether in a volume ratio of 8: 92.
By adopting the technical scheme, the benzotriazole is a high-efficiency antioxidant and has the effects of rust prevention and lubrication.
Further, in step S3.3, before the magnetic material body is coated with the agglomerate, under the protection of inert gas, the oxide layer and the oil stain on the surface of the magnetic material body are cleaned by ultrasonic waves.
Through adopting above-mentioned technical scheme, utilize the ultrasonic wave to clear up oxide layer and greasy dirt and oxide layer, when ultrasonic vibration reaches an atmospheric pressure at the sound wave pressure that greasy dirt and oxide layer propagated, the sound wave pressure peak value of ultrasonic wave just can reach vacuum or negative pressure, clears up the thin slice surface through the ultrasonic wave, and the clearance is more thorough, and clears up the back through the ultrasonic wave, and the thin slice surface does not have the residue because of ultrasonic wave clearance production, and the clearance is effectual.
In conclusion, the invention has the following beneficial effects:
firstly, as the composite coating is adopted, the coercive force of the magnetic material body is improved through the inner coating, and meanwhile, the magnetic attenuation caused by high temperature can be reduced, so that the magnetic material body has higher maximum working temperature; corrosion resistance and wear resistance of magnetic material body are improved by outer coating
Secondly, the method of the invention uses heavy rare earth metal as a substitute phase to enter the main phase by evaporation, and forms a continuous area with high rare earth content at the boundary of the main phase, thereby greatly improving the coercive force of the magnetic material body, and simultaneously, after the grain boundary is infiltrated by the heavy rare earth, the grain boundary rare earth-rich phase is more continuous and clearer, and the method is more effective for the isolation exchange coupling effect. As a result, the coercive force is greatly improved, the remanence is hardly reduced, the use amount of heavy rare earth is reduced, and the production cost is greatly saved. In the process of grain boundary diffusion treatment, Dy elements are diffused into the surface layer area of the main phase crystal grains to partially replace Nd elements in the surface layer area of the main phase crystal grains to form an (Nd, Dy) FeB intermetallic compound, so that the magnetocrystalline anisotropy constant of the defect area of the surface structure of the crystal grains is improved, the main phase crystal grain epitaxial layer generates magnetic hardening, and the coercive force of the magnet is obviously improved.
Thirdly, the outer coating and the inner coating are combined through laser cladding, and the corrosion resistance and the abrasion resistance of the magnetic material body are improved through the cooperation of the inner coating and the outer coating.
Drawings
Fig. 1 is a flow chart of a method provided herein.
Detailed Description
The present invention will be described in further detail with reference to the following drawings and examples.
Example 1
The utility model provides a neodymium iron boron magnetism material, includes magnetism material body and set up in the composite coating on magnetism material body surface, composite coating includes undercoating and overcoating.
The magnetic material body comprises the following elements in percentage by weight: nd: 17 wt%, B: 0.6 wt%, Pr: 6.0 wt%, Dy: 2 wt%, Al: 0.3 wt%, Cu: 0.1 wt%, Co: 0.1 wt% and the balance Fe.
The inner coating comprises Cr: 7.3wt%, B: 2.4 wt%, Dy: 4.25 wt%, Gd: 2.7 wt% and the balance Fe; the outer coating comprises graphite: 17.3Wt%, Nb: 2.82 wt%; ti: 23 wt%; SiC: 6.7 percent; mo: 1.13 wt%, the remainder being Ni.
A preparation method of a neodymium iron boron magnetic material comprises S1 and preparation of a magnetic material body, and comprises the following specific steps:
s1.1, mixing materials:
the raw materials needed by the magnetic material body are purchased in advance, and Nd, B, Pr, Dy, Al, Cu, Fe and Co are mixed into magnetic material mixed powder according to the proportion.
S1.2, smelting and melt spinning:
putting the magnetic material mixed powder into a vacuum smelting furnace, smelting at 1550-1600 ℃, pouring molten liquid on the surface of a melt-spun metal rod with the upper line speed of 2-4m/s, and melt-spinning to obtain a melt-spun sheet;
s1.3, hydrogen crushing powder:
crushing the melt-spun piece by using hydrogen, preparing the melt-spun piece into micro powder in an airflow mill, and adding a liquid antioxidant and graphite in a weight ratio of 6:2, wherein the liquid antioxidant consists of benzotriazole and petroleum ether in a volume ratio of 8: 92;
s1.4, directional profiling:
uniformly mixing the micro powder under the protection of nitrogen, and then pressing and forming to obtain a blank;
s1.5, metallurgical sintering:
sintering the blank for 4-5h at the sintering temperature of 1010-1070 ℃, preserving heat for 2-3h, cooling to 900 ℃, performing aging treatment, preserving heat for 2-3h at the primary aging temperature of 870-960 ℃, and cooling to 150 ℃; the secondary aging temperature is 540-630 ℃, and the magnetic material body is obtained after the temperature is kept for 7-12h and then cooled to room temperature.
S1.6, nitriding treatment:
polishing the magnetic material body with gold photographic paper, and using Cr3O3Polishing the magnetic material body by using polishing powder, and immersing the polished magnetic material body in absolute ethyl alcohol for ultrasonic cleaning; and drying, putting into an ion nitriding furnace, and nitriding for 7 h. And obtaining the magnetic material body. The application adopts an ion nitriding furnace with the model of LDMC-A, and the specific operation is as follows: vacuumizing the ion nitriding furnace until the air pressure in the furnace is lower than 10Pa, and introducing hydrogen to remove impurities on the surface of the magnetic material body; removing deviceAnd introducing nitrogen after impurity removal, and cooling the magnetic material body to room temperature under the protection of the nitrogen.
S2, preparing an inner coating, which comprises the following steps:
s2.1, mixing materials:
pre-purchasing raw materials required by an inner coating, and proportioning Cr, B, Dy, Gd and Fe powder into inner coating mixed powder according to a proportion; the concrete proportion is as follows: cr: 7.3wt%, B: 2.4 wt%, Dy: 4.25 wt%, Gd: 2.7 wt% and the balance Fe;
s2.2, evaporation:
putting the inner coating mixed powder into an evaporation furnace, heating the evaporation furnace to 450 ℃, preserving heat for two hours, heating the evaporation furnace to 2250 ℃, heating, melting and evaporating the inner coating mixed powder, cooling and uniformly attaching the inner coating mixed powder to a magnetic material body to form a metal film;
s2.3, permeation treatment:
and (3) performing permeation treatment on the evaporated magnetic material body for 4 hours at the temperature of 950 ℃ in vacuum.
S3, preparing an outer coating, which comprises the following steps:
s3.1, mixing materials:
the graphite, Nb, Ti, SiC, Mo and Ni are proportioned into the external coating mixed powder according to the specific proportion: 17.3Wt%, Nb: 2.82 wt%; ti: 23 wt%; SiC: 6.7 percent; mo: 1.13 wt%, the remainder being Ni.
S3.2, ball-milling and agglomerating:
grinding the outer coating mixed powder by using a ball mill, wherein the rotating speed of the ball mill is 220r/min, a ball milling medium is a stainless steel ball with the diameter of 8mm, grinding the outer coating mixed powder for 20 minutes, and adding absolute ethyl alcohol as a binder to uniformly mix the mixture after grinding to prepare an agglomerate;
b3.3, preparing a preset layer;
uniformly coating the agglomerates on the surface of the magnetic material body to form a preset layer with the thickness, and drying the preset layer indoors in the shade;
b3.4 laser cladding
Introducing argon gas as a protective gas, carrying out laser cladding on the magnetic material body and the agglomerates, wherein the laser output power is 1.5-2.3 kW, the scanning speed is 4-8 mm/s, the diameter of a light spot is 3mm, the argon gas flow is 6-8L/min, the lap joint rate is 25-35 wt%, after cladding, covering a cladding area with an aluminum silicate heat-insulating material, and slowly cooling; after cladding, covering a cladding area by using an aluminum silicate heat-insulating material, and slowly cooling.
Examples 2 to 4
Examples 2-4 based on the method of example 1, the contents of the components of the magnetic material body were adjusted, and the specific adjustment is shown in table one below.
TABLE Components and component content tables of examples 1-4
| Example 1 | Example 2 | Example 3 | Example 4 | |
| Nd | 17 | 19 | 21 | 23 |
| B | 0.6 | 0.5 | 1.0 | 1.2 |
| Pr | 6 | 7 | 9 | 10 |
| Dy | 2 | 3 | 4 | 5 |
| Al | 0.3 | 0.4 | 0.6 | 0.9 |
| Cu | 0.1 | 0.12 | 0.17 | 0.20 |
| Co | 0.1 | 0.12 | 0.13 | 0.15 |
| Fe | 73.9 | 69.86 | 64.1 | 59.55 |
Example 5
The difference from example 1 is that the magnetic material body is not subjected to S1.7 nitriding treatment after S1.6 aging treatment.
Example 6
The difference from example 1 is that the upper thread speed of the melt-spun metal roll was 5 m/s.
Example 7
The difference from example 1 is that the liquid antioxidant and graphite were not added after the melt spun sheet was made into a fine powder.
Example 8
The difference from example 1 is that the magnetic material body is not subjected to ultrasonic cleaning of the oxide layer and the oil stain on the surface of the body after the aging treatment of S1.6.
Example 9
The difference from example 1 is that no Co element was added.
Comparative example
Comparative example 1
The difference from example 1 is that no composite coating was provided.
Comparative example 2
The difference from example 1 is that no overcoat layer was provided.
Performance test
The neodymium iron boron magnets prepared in the examples 1 to 9 and the comparative examples 1 and 2 are measured for coercive force and Curie temperature according to the detection standard GB/T13560-;
performing a neutral salt spray test on the neodymium iron boron magnetic material, performing a spray salt spray test on a test material by using a sodium chloride aqueous solution with the concentration of 5 wt%, wherein the test temperature is 35 ℃, and the weight loss rate is used as a detection basis;
performing wear resistance test on the neodymium iron boron magnetic material, using an ML-10 type wear testing machine, wherein the fabric is 100-mesh corundum abrasive paper, measuring the mass after one wear every 10min under the state that a pressing block is 500g, and taking the wear weight loss as a detection basis; see table two below for the results of the measurements.
TABLE II examination results of examples 1 to 9 and comparative examples 1 to 2
Referring to table two, when comparing the detection results of examples 1 to 9 with the detection results of comparative examples 1 to 2, the application can synergistically improve the coercive force and the curie temperature of the neodymium iron boron magnet by arranging the composite coating on the magnet body, so that the neodymium iron boron magnet can work and operate at a higher working temperature.
Comparing the detection results of examples 1 to 4 with those of example 5, the nitriding treatment can enhance the corrosion resistance and wear resistance of the ndfeb magnet, and the ndfeb magnet can be operated at a higher operating temperature.
Comparing the detection results of the embodiments 1 to 4 with the detection result of the embodiment 6, when the upper thread speed of the melt-spun metal is 3m/s, the thickness of the melt-spun sheet is proper, so that the melt-spun metal is conveniently and subsequently broken into fine powder with uniform particle size by hydrogen, and the subsequently prepared magnetic material body has higher coercive force and Curie temperature and can work and operate at higher working temperature. When the upper thread speed of the metal melt-spun is 5m/s, the coercive force and Curie temperature of the subsequently prepared magnetic material body are relatively low.
Comparing the test results of examples 1 to 4 with those of example 7, the addition of the liquid antioxidant and graphite can improve the overall performance of the ndfeb magnet, thereby improving the highest working temperature, wear resistance and corrosion resistance thereof.
Comparing the detection results of the embodiments 1 to 4 and the embodiment 8, the magnetic material body is subjected to ultrasonic cleaning of the oxide layer and the oil stain on the surface of the blank after aging treatment, and the overall performance of the neodymium iron boron magnet can be improved, so that the highest working temperature, the highest wear resistance and the highest corrosion resistance of the neodymium iron boron magnet are improved.
Comparing the detection results of examples 1 to 4 with the detection result of example 9, the addition of the Co element can improve the coercive force and the curie temperature of the neodymium iron boron magnet.
The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.
Claims (9)
1. The utility model provides a neodymium iron boron magnetism material, its characterized in that, including magnetism material body and set up in the compound coating on magnetism material body surface, magnetism material body contains the following weight percent's of element: nd: 17-23 wt%, B: 0.5-1.2 wt%, Pr: 6-10 wt%, Dy: 2-5 wt%, Al: 0.3 to 0.9 wt%, Cu: 0.1-0.2 wt%, the balance being Fe; the composite coating comprises an inner coating and an outer coating;
the inner coating comprises Cr: 7.3wt%, B: 2.4 wt%, Dy: 4.25 wt%, Gd: 2.7 wt% and the balance Fe;
the outer coating comprises graphite: 17.3Wt%, Nb: 2.82 wt%; ti: 23 wt%; SiC: 6.7 percent; mo: 1.13 wt%, the remainder being Ni.
2. The ndfeb magnet according to claim 1, wherein the magnet body contains the following elements in weight percent: nd: 17 wt%, B: 0.7 wt%, Pr: 7 wt%, Dy: 3wt%, Al: 0.6 wt%, Cu: 0.1 wt%, the balance being Fe.
3. The ndfeb magnet according to claim 1 or 2, wherein the magnet body further comprises a binder comprising Co: 0.1-0.15 wt%.
4. The method for preparing the neodymium-iron-boron magnetic material of any one of claims 1 to 3, which is characterized by comprising the steps of S1 and preparing a magnetic material body, wherein the steps comprise:
s1.1, mixing materials:
mixing Nd, B, Pr, Dy, Al, Cu, Fe and Co in proportion into magnetic material mixed powder;
s1.2, smelting and melt spinning:
smelting the magnetic material mixed powder at 1550-1600 ℃, pouring the molten liquid on the surface of a rotating melt-spun metal rod, and melt-spinning to obtain a melt-spun sheet;
s1.3, hydrogen crushing powder:
crushing the melt-spun piece by hydrogen, and then preparing the melt-spun piece into micro powder in an air flow mill;
s1.4, directional profiling:
uniformly mixing the micro powder under the protection of nitrogen, and then pressing and forming to obtain a blank;
s1.5, metallurgical sintering:
sintering the blank for 4-5h at the sintering temperature of 1010-1070 ℃, preserving heat for 2-3h, cooling to 900 ℃, performing aging treatment, preserving heat for 2-3h at the primary aging temperature of 870-960 ℃, and cooling to 150 ℃; the secondary aging temperature is 540-630 ℃, and the magnetic material body is obtained after the temperature is kept for 7-12h and then cooled to room temperature;
s2, preparing an inner coating, which comprises the following steps:
s2.1, mixing materials:
proportioning Cr, B, Dy, Gd and Fe into inner coating mixed powder according to a proportion;
s2.2, evaporation:
putting the mixed powder of the inner coating into an evaporation furnace, heating, melting, evaporating, cooling, and uniformly attaching to the magnetic material body to form a metal film;
s3, preparing an outer coating, which comprises the following steps:
s3.1, mixing materials:
proportionally mixing graphite, Nb, Ti, SiC, Mo and Ni into external coating mixed powder;
s3.2, ball-milling and agglomerating:
grinding the outer coating mixed powder, and adding absolute ethyl alcohol as a binder to uniformly mix to prepare an agglomerate;
b3.3, preparing a preset layer;
uniformly coating the agglomerates on the surface of the magnetic material body to form a preset layer, and drying the preset layer in the shade indoors;
b3.4 laser cladding
Introducing argon gas as a protective gas, carrying out laser cladding on the magnetic material body and the agglomerates, wherein the laser output power is 1.5-2.3 kW, the scanning speed is 4-8 mm/s, the diameter of a light spot is 3mm, the argon gas flow is 6-8L/min, the lap joint rate is 25-35 wt%, after cladding, covering a cladding area with an aluminum silicate heat-insulating material, and slowly cooling; after cladding, covering a cladding area by using an aluminum silicate heat-insulating material, and slowly cooling.
5. The method for preparing the neodymium iron boron magnetic material according to the claim 4, characterized in that the magnetic material body further comprises S1.6 nitriding treatment after S1.5 metallurgical sintering: polishing the magnetic material body and immersing the magnetic material body in absolute ethyl alcohol for ultrasonic cleaning; and drying, putting into an ion nitriding furnace, and nitriding for 7 h.
6. The method for preparing a neodymium iron boron magnetic material according to claim 4, characterized in that in step S1.2, the upper line speed of the melt-spun metal roller is 3 m/S.
7. The method for preparing a neodymium iron boron magnetic material according to claim 4, characterized in that in step S1.2, after the melt-spun sheet is broken, a liquid antioxidant and graphite are added in a weight ratio of 6: 2.
8. The method for preparing the neodymium-iron-boron magnetic material according to claim 7, wherein the liquid antioxidant is composed of benzotriazole and petroleum ether in a volume ratio of 8: 92.
9. The method for preparing an ndfeb magnetic material according to claim 4, wherein in step S3.3, before the magnetic material body is coated with the agglomerate, an oxidation layer and oil stains on the surface of the inner coating layer are cleaned by ultrasonic waves under the protection of inert gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010859580.5A CN112309661A (en) | 2020-08-24 | 2020-08-24 | Neodymium-iron-boron magnet and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010859580.5A CN112309661A (en) | 2020-08-24 | 2020-08-24 | Neodymium-iron-boron magnet and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112309661A true CN112309661A (en) | 2021-02-02 |
Family
ID=74483680
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010859580.5A Pending CN112309661A (en) | 2020-08-24 | 2020-08-24 | Neodymium-iron-boron magnet and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112309661A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115798905A (en) * | 2022-09-27 | 2023-03-14 | 宁波佳丰磁材科技有限公司 | High-toughness neodymium iron boron magnet and preparation method thereof |
| CN115954174A (en) * | 2022-12-30 | 2023-04-11 | 宁波金轮磁材技术有限公司 | A kind of preparation method and application of NdFeB magnetic material |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110074530A1 (en) * | 2009-09-30 | 2011-03-31 | General Electric Company | Mixed rare-earth permanent magnet and method of fabrication |
| CN103943295A (en) * | 2013-01-21 | 2014-07-23 | 三环瓦克华（北京）磁性器件有限公司 | Sintered nd-fe-b magnet |
| WO2016086397A1 (en) * | 2014-12-04 | 2016-06-09 | 浙江大学 | Method for improving coercive force of sintered neodymium iron boron magnet by adding dysprosium hydrogen compound and product |
| CN108122654A (en) * | 2017-12-21 | 2018-06-05 | 宁波金轮磁材技术有限公司 | A kind of grain boundary decision heavy rare earth neodymium iron boron magnetic materials and preparation method thereof |
| CN111354525A (en) * | 2020-04-10 | 2020-06-30 | 余姚市宏伟磁材科技有限公司 | High-temperature-resistant neodymium-iron-boron magnet and production process thereof |
-
2020
- 2020-08-24 CN CN202010859580.5A patent/CN112309661A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110074530A1 (en) * | 2009-09-30 | 2011-03-31 | General Electric Company | Mixed rare-earth permanent magnet and method of fabrication |
| CN103943295A (en) * | 2013-01-21 | 2014-07-23 | 三环瓦克华（北京）磁性器件有限公司 | Sintered nd-fe-b magnet |
| WO2016086397A1 (en) * | 2014-12-04 | 2016-06-09 | 浙江大学 | Method for improving coercive force of sintered neodymium iron boron magnet by adding dysprosium hydrogen compound and product |
| CN108122654A (en) * | 2017-12-21 | 2018-06-05 | 宁波金轮磁材技术有限公司 | A kind of grain boundary decision heavy rare earth neodymium iron boron magnetic materials and preparation method thereof |
| CN111354525A (en) * | 2020-04-10 | 2020-06-30 | 余姚市宏伟磁材科技有限公司 | High-temperature-resistant neodymium-iron-boron magnet and production process thereof |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115798905A (en) * | 2022-09-27 | 2023-03-14 | 宁波佳丰磁材科技有限公司 | High-toughness neodymium iron boron magnet and preparation method thereof |
| CN115798905B (en) * | 2022-09-27 | 2023-09-01 | 宁波佳丰磁材科技有限公司 | High-strength and high-toughness neodymium-iron-boron magnet and preparation method thereof |
| CN115954174A (en) * | 2022-12-30 | 2023-04-11 | 宁波金轮磁材技术有限公司 | A kind of preparation method and application of NdFeB magnetic material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108122654B (en) | Grain boundary diffusion heavy rare earth neodymium iron boron magnetic material and preparation method thereof | |
| JP4702546B2 (en) | Rare earth permanent magnet | |
| KR20220042194A (en) | R-T-B type permanent magnet material and its manufacturing method and application | |
| CN1898757B (en) | Method for producing rare earth permanent magnet material | |
| CN100594566C (en) | Functionally graded rare earth permanent magnet | |
| JP6586451B2 (en) | Alloy material, bond magnet and method for modifying rare earth permanent magnet powder | |
| JP5093485B2 (en) | Rare earth permanent magnet and manufacturing method thereof | |
| CN114284018B (en) | Neodymium iron boron magnet and its preparation method and application | |
| KR102631761B1 (en) | Neodymium iron boron magnetic material, raw material composition, manufacturing method and application | |
| CN111261355B (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method and application | |
| CN111223627B (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method and application | |
| CN106128673A (en) | A kind of Sintered NdFeB magnet and preparation method thereof | |
| CN110335733B (en) | High-temperature-resistant neodymium-iron-boron magnet and preparation method thereof | |
| CN111210987B (en) | R-T-B magnet material and preparation method and application thereof | |
| CN112309661A (en) | Neodymium-iron-boron magnet and preparation method thereof | |
| KR20220041191A (en) | Neodymium iron boron magnetic material, raw material composition, manufacturing method and application | |
| TWI617676B (en) | R-fe-b based rare-earth sintering magnet compositing praseodymium (pr) and tungsten (w) | |
| CN111524674A (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method and application | |
| WO2016058132A1 (en) | Method for preparing rare earth permanent magnet | |
| CN111540557A (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method and application | |
| CN112768170A (en) | Rare earth permanent magnet and preparation method thereof | |
| CN111524672B (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method and application | |
| CN111613404B (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method and application thereof | |
| CN104425092B (en) | A kind of neodymium-iron-boron magnetic material and preparation method thereof | |
| CN111223628B (en) | Neodymium-iron-boron magnet material, raw material composition, preparation method and application |
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: 20210202 |