CN111968818A - Neodymium-iron-boron permanent magnet and preparation method and application thereof - Google Patents
Neodymium-iron-boron permanent magnet and preparation method and application thereof Download PDFInfo
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- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 40
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 title claims abstract description 35
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- 239000002994 raw material Substances 0.000 claims description 28
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 26
- 230000005291 magnetic effect Effects 0.000 claims description 26
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- 238000010438 heat treatment Methods 0.000 claims description 22
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- 239000012535 impurity Substances 0.000 claims description 8
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- 239000000463 material Substances 0.000 claims description 6
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- 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
- H01F41/0266—Moulding; Pressing
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Hard Magnetic Materials (AREA)
- Powder Metallurgy (AREA)
Abstract
The invention discloses a neodymium iron boron permanent magnet and a preparation method and application thereof. The grain boundary phase and the main phase of the neodymium iron boron permanent magnet have the following structural distribution: the total length of the grain boundary phase in the measuring range is marked as Lm, the total length of the grain boundary phase with the grain boundary width more than or equal to 1 mu m in the measuring range is marked as Ln, and the Lm and the Ln meet the relationship that Ln/Lm is more than or equal to 0.40 and less than or equal to 1; the total length of grain boundary phases with the width between adjacent grain boundary phases being more than or equal to 2 mu m in the measuring range is marked as Lx, Lm and Lx satisfy the relation that Lx/Lm is more than or equal to 0 and less than or equal to 0.2; the total length of the grain boundary phase passing through the EPMA line scanning in the measuring range is represented as Le, the total length of the scanning in the measuring range is represented as LM, and the Le and the LM satisfy the relation of Le/LM <1 > which is more than or equal to 0.40. The high-temperature demagnetization-resistant magnet with high Br, high Hcj, high squareness, specific grain boundary phase and main phase structure is prepared by the method.
Description
Technical Field
The invention belongs to the field of neodymium iron boron magnets, and particularly relates to a neodymium iron boron permanent magnet and a preparation method and application thereof.
Background
The sintered Nd-Fe-B magnet is widely applied to automobile motors, wind power, tractors, compressors and consumer electronic appliances due to the excellent magnetic performance, particularly Br and Hcj. With the development of motors, the performance requirements on sintered neodymium-iron-boron magnets are higher and higher, and particularly, magnets with high Br and high Hcj and higher squareness at working temperature become the requirement trend of novel high-performance motors.
The factors influencing the performance of the neodymium iron boron are many, and the principle is also complex. Structurally, the sintered Nd-Fe-B magnet consists of a main phase Nd2Fe14B and a grain boundary phase composed of an Nd-rich phase and a B-rich phase. The main phase determines the main magnetic performance of the magnet, the existence of the Nd-rich phase can promote the sintering of the magnetic material, so that the magnet is densified, and can play a role in magnetic coupling isolation when being distributed along a grain boundary, thereby being beneficial to the improvement of coercive force and squareness. The Hcj can be improved by enlarging and thickening the grain boundary phase in various ways in engineering. However, the distribution of the grain boundary phase tends to be uneven due to the instability of the grain boundary phase, and the distribution is reflected in magnetic properties such as reduction of Br, reduction of Hcj, and reduction of squareness.
At present, methods for improving the performance of magnets include:
adding heavy rare earth elements such as Tb, Dy, Ho and the like in a formula, so that the Hcj of the magnet can be obviously improved;
a crystal boundary diffusion technology;
thirdly, a grain refining technology;
and fourthly, improving the product performance by adjusting the proportion of the elements such as Cu, Al, Ga, Zr, Ti, B and the like in the formula.
The method is generally applied to development of magnets with different types and different performance requirements, and has advantages, short plates and a large number of patents and academic achievements.
The method is a conventional process method, has simple and mature technology, can effectively improve Hcj, and has the defects of reduction of Br while improving Hcj, scarcity of heavy rare earth element resources and high formula cost;
the method II is a new process method in recent years, uses less heavy rare earth than the method I, improves larger Hcj, has mature technology, has the defects of using heavy rare earth elements, reducing Br and having complex process method.
The method third, can use heavy rare earth element either not or very little, the cost advantage of formulation is obvious, the disadvantage is only suitable for the performance trade mark of certain range, the manufacturing cost is high, have higher requirements for apparatus and process.
The method IV can also use no or little heavy rare earth elements, has advantages of formula cost and manufacturing cost, and has the defect of slightly low performance improvement range.
For example, the results of the research and patent literature for the method (iv) include:
patent document 1(CN105658835B) discloses a low-B rare earth magnet, which is intended to improve squareness of the magnet, and contains Cu: 0.3 to 0.8 at%, Co: 0.3-3 at%, and high Cu phase, low Cu phase and medium Cu phase crystals are formed in the grain boundary in the sintering process, so that the squareness of the magnet is improved, and the demagnetization resistance is improved. However, the content of Cu is too high, which can cause the reduction of the coercive force, and most of Hcj is less than 16kOe from the example; the Co content is low, the temperature resistance of the magnet is poor, and the use requirement of the magnetic steel for the driving motor cannot be met.
Patent document 2(CN106024254A) discloses a low B neodymium iron boron magnet having M at grain boundary triple point2Boride phase, no B-rich phase, and R-Fe (Co) -M in grain boundary phase1Phase and/or R-M1And the width of a grain boundary phase is at least more than or equal to 10nm and is averagely more than or equal to 50nm, so that a better magnetic isolation effect is achieved, and high coercivity is obtained. However, the proportional relationship among elements such as B, Co, Cu, Zr, and Ti is not optimal, and high Br and coercive force cannot be obtained at the same time, and a good squareness index cannot be obtained.
Aiming at the method IV, the existing research results and patent documents are adjusted from different element combinations to form a certain organization structure and performance. However, at present, no evidence indicates that the achievement which can be applied to high Br and high Hcj products exists, and the practical application significance is not great. Moreover, there is no clear achievement of the correspondence between the organization structure, the formula and the performance.
Disclosure of Invention
The invention provides a neodymium iron boron permanent magnet, which comprises a main phase and a grain boundary phase, wherein the grain boundary phase and the main phase have the following structural distribution:
marking the total length of a grain boundary phase as Lm in a measuring range, marking the total length of the grain boundary phase with the inter-phase width (namely the grain boundary width) of adjacent grain boundaries being more than or equal to 1 mu m in the measuring range as Ln, wherein Lm and Ln meet the relationship that Ln/Lm is more than or equal to 0.40 and less than or equal to 1; for example 0.45. ltoreq. Ln/Lm. ltoreq.0.9, preferably 0.50. ltoreq. Ln/Lm. ltoreq.0.8, exemplary 0.462, 0.50, 0.55, 0.56, 0.60, 0.65, 0.70, 0.78;
marking the total length of grain boundary phases within the measuring range as Lm, and marking the total length of the grain boundary phases with the width between adjacent grain boundary phases being more than or equal to 2 mu m within the measuring range as Lx, wherein Lm and Lx satisfy the relation that Lx/Lm is more than or equal to 0 and less than or equal to 0.2; for example 0. ltoreq. Lx/Lm. ltoreq.0.19, preferably 0. ltoreq. Lx/Lm. ltoreq.0.18, exemplary 0.15, 0.16, 0.17, 0.18, 0.19, 0.2;
marking the total length of a crystal boundary phase passed by EPMA line scanning in a measuring range as Le, and marking the total length of scanning in the measuring range as LM, wherein Le and LM meet the relationship of Le/LM <1 > which is more than or equal to 0.40; for example 0.45. ltoreq. Le/LM. ltoreq.0.8, preferably 0.50. ltoreq. Le/LM. ltoreq.0.7, exemplary 0.45, 0.50, 0.55, 0.56, 0.60, 0.65.
In the present invention, Lm represents the total length of the grain boundary phase within the test range as indicated by the dotted line in FIG. 7.
As indicated by the dotted line in FIG. 8, Ln1 represents the length of the grain boundary phase with a grain boundary width of 1 μm or more, and Ln is the total length of these grain boundary phases satisfying the same conditions as those of Ln1, i.e., Ln1+ Ln2+ Ln3+ … … + Lnn.
As indicated by the broken line in fig. 9, Lx1 represents the length of the grain boundary phase having a grain boundary width of 2 μm or more, and Lx is the total length of these grain boundary phases satisfying the same conditions as Lx1, i.e., Lx1+ Lx2+ Lx3+ … … + Lxx.
LM represents the total length of the scan in the measurement range, i.e. the total length on the abscissa of the left images of fig. 4 and 6;
le represents the total length of the grain boundary phase passed by the EPMA line scan in the measurement range, and Ch3 on the left side of FIGS. 4 and 6 is the waveform of Nd, and the total length of the grain boundary phase is the width of the peak.
According to an embodiment of the invention, the main phase has R2Fe14B structure, R represents rare earth element. Preferably, R is selected from Nd, or Nd and at least one of the following rare earth elements: pr, Dy, Tb and Ho.
According to an embodiment of the present invention, the grain boundary phase contains an R-rich phase and a B-rich phase.
According to the neodymium iron boron permanent magnet formed in the way, Le/LM is more than or equal to 0.40, so that sufficient paramagnetic or diamagnetic grain boundary phases exist between main phase grains, and the generated magnetic isolation effect can effectively improve the demagnetization resistance of the magnet in a high-temperature environment. The proportion of the grain boundary with the grain boundary width exceeding 1 mu m to the total length of the grain boundary is not less than thirty percent, so that the rare earth-rich grain boundary phase is effectively and uniformly distributed in the whole magnet, the invalid segregation of the rare earth-rich phase is avoided, the hard contact of main phase grains caused by incomplete cladding of a non-magnetic phase is reduced, and the magnetic penetration is effectively reduced, which is obviously different from the common magnet that the rare earth-rich grain boundary phase is generally enriched by three or more than three R-containing grain boundary phases2Fe14And a grain boundary triple point region surrounded by the main phase grains of the B structure.
According to an embodiment of the present invention, the total content of C and O in the ndfeb permanent magnet is 2800ppm or less, for example 2500ppm or less. Preferably, the C content is 1200ppm or less, for example 1100ppm or less. Preferably, the O content is 1600ppm or less, for example 1400ppm or less. The low C, O content can inhibit the influence of the elements enriched in the grain boundary phase on the squareness and the coercive force of the magnet.
According to the embodiment of the invention, the raw materials for preparing the neodymium iron boron permanent magnet comprise:
r: 12-16 at%, R having the choice as described above;
B：5-6at％；
t comprises M1, M2, Fe and Co; wherein, M1: 0.5 to 1.5 at%, M1 is selected from transition metal elements containing Cu and Ga; m2: 0.05 to 0.3 at%, M2 is at least one of Nb, Zr and Ti; co: 0.5-8 at%;
the balance of Fe and inevitable impurities;
the atomic number of the elements simultaneously satisfies the following conditions:
14.5＜([Fe]+[Co])/([B]-[M2]×2))＜17.5；
2.5＜[R]/([B]-[M2]×2)＜3.5；
cu is more than 0 and less than or equal to 0.3at percent, Ga is more than 0 and less than or equal to 0.3at percent, and [ Cu ]/[ Ga ] is more than or equal to 0.5 and less than or equal to 1.
In the present application, at% ([ the number of atoms ]/[ the total number of atoms in the molecule ].
According to an embodiment of the invention, the R content is 13-15 at%, such as 12 at%, 13 at%, 14 at%, 15 at%, 16 at%.
According to an embodiment of the invention, the B content is 5.2-5.8 at%, such as 5 at%, 5.2 at%, 5.4 at%, 5.5 at%, 5.6 at%, 5.8 at%, 6 at%.
According to an embodiment of the invention, M1 is present in an amount of 0.6-1.4 at%, such as 0.5 at%, 0.6 at%, 0.7 at%, 0.8 at%, 0.9 at%, 1.0 at%, 1.2 at%, 1.4 at%, 1.5 at%.
According to an embodiment of the present invention, M1 may further contain at least one of Si, Al, Zn, Mn. Illustratively, M1 contains Cu, Ga and Al.
According to an embodiment of the invention, the M2 content is 0.08-0.26 at%.
According to an embodiment of the present invention, said M2 is selected from Zr.
According to an embodiment of the invention, the Co content is 1-6 at%.
According to an embodiment of the invention, 14.7 ≦ ([ Fe ] + [ Co ])/([ B ] - [ M2] x 2)) ≦ 17.0, as well as 14.9 ≦ ([ Fe ] + [ Co ])/([ B ] - [ M2] x 2)) ≦ 16.5, illustratively, ([ Fe ] + [ Co ])/([ B ] - [ M2] x 2))) 14.94, 15.00, or 15.10.
According to an embodiment of the invention 2.55 < [ R ]/([ B ] - [ M2] × 2) < 3.3, as well as 2.6 < [ R ]/([ B ] - [ M2] × 2) < 3.1, exemplarily, [ R ]/([ B ] - [ M2] × 2) ═ 2.67, 2.69 or 2.79.
According to an embodiment of the invention, 0.1 at% Cu.ltoreq.0.25 at%, for example 0.15 at% Cu.ltoreq.0.20 at%.
According to an embodiment of the invention, 0.1 at% Ga. ltoreq.0.25 at%, for example 0.15 at% Ga. ltoreq.0.20 at%.
According to an embodiment of the invention 0.6 ≦ Cu/[ Ga ] ≦ 0.9, illustratively, [ Cu ]/[ Ga ] ≦ 0.66 or 0.82.
According to an embodiment of the present invention, the impurity contains C, S, O, N and the like.
According to the embodiment of the invention, the neodymium iron boron permanent magnet is prepared from the raw materials.
According to the embodiment of the invention, the squareness degree of the neodymium iron boron permanent magnet is more than or equal to 0.95.
The invention strictly limits the content of each element in the magnet raw material, and specifically comprises the following steps: the content of R is too low, so that enough grain boundary phases cannot be formed to achieve the magnetic isolation effect, and the coercive force is reduced; the content of R is too high, the volume proportion of the main phase is low, and Br is reduced. The content of B is too low, the volume proportion of the main phase is small, and Br is low; the content of B is too high, a B-rich phase is formed in a grain boundary, and Br and coercive force are reduced. The addition of a proper amount of metal M can achieve the effects of refining grains, improving coercive force and replacing heavy rare earth, but the content of M1 is too high, so that the volume ratio of a main phase is reduced, Br is reduced, and excessive R-Fe (Co) -M1 phase is easy to form, so that the squareness of the magnet is poor. The content of M2 is low, the sintering uniformity of the magnet is poor, and the squareness is poor due to easy overburning; the content of M2 is high, a higher sintering temperature is needed for achieving dense sintering of the magnet, and the feasibility of industrial production is poor. The Co content is low, and the temperature resistance is poor; the content of Co is high, and the coercive force is reduced. By using less Co, Cu and Ga contents, a uniform and continuous grain boundary phase with moderate thickness is formed. Under the condition, the magnet has high Br and Hcj, and the squareness degree is more than or equal to 0.95 at the working temperature.
The invention also provides a preparation method of the neodymium iron boron permanent magnet, which comprises the following steps:
1) pressing the alloy powder in a magnetic field to obtain a pressed blank; wherein the alloy powder is prepared from materials containing the raw materials;
2) and sintering and aging the pressed compact to obtain the neodymium iron boron permanent magnet.
According to an embodiment of the present invention, in step 1), the preparation process of the alloy powder includes: the alloy powder is obtained by carrying out hydrogen crushing and airflow milling treatment on an alloy sheet prepared from the raw materials. Wherein, the hydrogen breaking and air flow grinding treatment can adopt the operation known in the field. Preferably, the alloy sheet has a thickness of 0.1-0.5mm, preferably 0.15-0.40mm, for example 0.20-0.35 mm.
Furthermore, the alloy sheet is prepared from the raw materials through melting and rapid hardening melt-spinning.
According to an embodiment of the present invention, the alloy powder obtained by the jet milling treatment has an SMD particle diameter (surface average particle diameter) of 1.5 to 3.5. mu.m, for example, 2.0 to 3.0. mu.m.
According to an embodiment of the invention, the alloy powder obtained from the jet milling process has an X10 ≥ 0.8 μm, for example X10 ≥ 1.2 μm, with 1.23 μm, 1.28 μm being exemplary.
Wherein X10 represents the particle size corresponding to the cumulative percentage of the particle distribution reaching 10%, i.e., the volume fraction of particles smaller than this particle size is 10% of the total particles.
According to an embodiment of the invention, the alloy powder obtained by the jet milling treatment has an X100. ltoreq.24 μm, for example X100. ltoreq.20 μm, with 15 μm, 18 μm being exemplary.
Wherein, X100 represents the corresponding particle size value when the cumulative distribution percentage reaches 100%, that is, the particle size of all the particles is not larger than the particle size, and the number of the particles larger than the particle size value is 0.
According to an embodiment of the present invention, at least one of an antioxidant and a lubricant may be further contained in the alloy powder. Wherein the antioxidant and lubricant may be selected from agents known in the art, and in amounts known in the art.
According to an embodiment of the invention, the sintering is performed in a vacuum heat treatment furnace.
According to an embodiment of the invention, the sintering temperature is 900-1100 ℃, such as 950-1070 ℃, and is exemplarily 1060 ℃, 1070 ℃, 1075 ℃.
According to an embodiment of the invention, the sintering time is 3-8h, such as 3.5-6h, exemplary 4 h.
According to an embodiment of the invention, the aging treatment comprises: and after sintering, cooling to room temperature, heating to 750-plus-one temperature of 850 ℃, preserving heat for 2-5h, cooling to room temperature, heating to 500-plus-one temperature of 600 ℃, preserving heat for 2-5h, and cooling to room temperature to obtain the neodymium-iron-boron permanent magnet. Preferably, the aging treatment comprises: and after sintering, cooling to room temperature, heating to 780-plus-830 ℃, preserving heat for 3-4h, cooling to room temperature, heating to 530-plus-580 ℃, preserving heat for 3-4h, and cooling to room temperature to obtain the neodymium-iron-boron permanent magnet.
Wherein the cooling rate is 5-12 deg.C/min, such as 6-10 deg.C/min, and exemplary is 6 deg.C/min, 8 deg.C/min, and 10 deg.C/min.
According to an exemplary scheme of the invention, the preparation method of the neodymium iron boron permanent magnet comprises the following steps:
step a) preparing R-T-B alloy raw materials, which comprises the following steps:
r: 12-16 at%, R having the choice as described above;
B：5-6at％；
t comprises M1, M2, Fe and Co; wherein, M1: 0.5 to 1.5 at%, M1 is selected from transition metal elements containing Cu and Ga; m2: 0.05 to 0.3 at%, M2 is at least one of Nb, Zr and Ti; co: 0.5-8 at%;
the balance of Fe and inevitable impurities;
the atomic number of the elements simultaneously satisfies the following conditions:
14.5＜([Fe]+[Co])/([B]-[M2]×2))＜17.5；
2.5＜[R]/([B]-[M2]×2)＜3.5；
cu is more than 0 and less than or equal to 0.3at percent, Ga is more than 0 and less than or equal to 0.3at percent, and [ Cu ]/[ Ga ] is more than or equal to 0.5 and less than or equal to 1;
step b), mixing and melting the alloy raw materials, and obtaining an alloy rapid hardening sheet through rapid hardening and strip throwing;
step c), performing hydrogen breaking and air flow grinding treatment on the alloy quick-setting sheet to prepare alloy powder with SMD (surface mounted device) of 1.5-3.5 micrometers;
step d) pressing the alloy powder in a magnetic field to obtain a pressed blank;
optionally, at least one of an antioxidant and a lubricant is contained or not contained in the alloy powder;
and f) sintering and aging the pressed blank in a vacuum heat treatment furnace to obtain the neodymium iron boron permanent magnet.
The invention also provides application of the neodymium iron boron permanent magnet in automobile motors, wind power, tractors, compressors, consumer electronic appliances and the like.
The invention has the beneficial effects that:
the inventor of the application finds that in the sintered rare earth permanent magnet prepared by the prior art, the grain boundary phase is often intensively distributed at the grain boundary three-phase point, so that excessive segregation of rare earth elements is caused, the magnetic isolation effect of the grain boundary phase is not favorably exerted, and more heavy rare earth Dy and Tb elements must be added for preparing the permanent magnet with high Br, high Hcj and high squareness. The permanent magnet prepared by the invention improves the distribution of a grain boundary phase and a main phase by adjusting the element proportion, increases the wettability of the grain boundary phase while improving the proportion of the grain boundary phase to a certain extent, improves the distribution characteristics of the grain boundary phase, has a specific structure of the grain boundary phase and the main phase, and can remarkably improve the coercive force of the magnet and improve the high-temperature characteristic of the magnet while maintaining high Br by more uniform distribution, thereby reducing about 1 percent of Dy dosage in a formula compared with the prior art while realizing the same magnetic performance. The magnet has high Br and high Hcj, and the squareness of the magnet is more than or equal to 0.95 at the working temperature of the motor, so that the demagnetization resistance of the driving motor in high-temperature operation can be met. Namely, the high-temperature demagnetization-resistant magnet which is high in Br, Hcj and squareness and has a specific grain boundary phase and a main phase structure is prepared by the method.
Drawings
FIG. 1 is a comparison of EPMA of example 1.
FIG. 2 is a comparison of EPMA of comparative example 1.
Fig. 3 is an EPMA line scan image of example 1.
FIG. 4 is the EPMA line scan DATA of example 1.
Fig. 5 is an EPMA line scan image of comparative example 1.
Fig. 6 is an EPMA line scan DATA of comparative example 1.
Figure 7 is a schematic view of Lm.
Fig. 8 is a schematic view of Ln 1.
Fig. 9 is a schematic diagram of Lx 1.
Detailed Description
The technical solution of the present invention will be further described in detail with reference to specific embodiments. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.
Unless otherwise indicated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.
Apparatus and device
The grain boundary phase and main phase structure analysis method comprises the following steps: and scanning the fracture of the blank by using EPMA, processing the CP Image of the EPMA by using Image PRO software, and analyzing the width, the length and the like of the grain boundary.
The particle size of the magnetic powder is tested by a particle size distribution instrument of laser diffraction.
Example 1
(1) Preparing materials: various raw materials required in this example were prepared, the atomic percentages of the raw materials being 11.1% Nd, 2.9% Pr, 0.2% Dy, 2.24% Co, 0.37% Al, 0.16% Cu, 0.19% Ga, 0.12Zr, 5.55% B, and the balance being iron and unavoidable impurities. The formulation composition is shown in table 1.
(2) The raw materials are melted at high frequency in Ar atmosphere and poured on a quenching roller to prepare an alloy quick-setting sheet, and the thickness of the sheet is 0.15-0.40 mm.
(3) The alloy was pulverized by hydrogenation and then jet-milled, and the resulting magnetic powder had a particle size SMD of 2.8 μm, X10 of 1.28 μm and X100 of 18 μm.
(4) The above air current is milled into powder and added with 0.2 wt% of lubricant of raw materials, then mixed and molded under the environment of an orientation field with the magnetic field intensity of 2T.
(5) And (3) placing the blank into a vacuum sintering furnace, carrying out heat preservation treatment at 1070 ℃ for 4h, cooling to room temperature at the speed of 10 ℃/min, heating to 850 ℃ for heat preservation treatment for 3h, cooling to room temperature at the speed of 6 ℃/min, heating to 540 ℃ for heat preservation treatment for 4h, cooling to room temperature at the speed of 8 ℃/min, and cooling to obtain the neodymium iron boron blank.
(6) The blank was sampled D10-10mm and tested for magnetic properties.
(7) And (3) preparing a blank sample to be EPMA, analyzing the characteristics of a main phase and a grain boundary phase, and carrying out quantitative analysis by image analysis software.
Comparative example 1
(1) The proportion of the ingredients is different: 11.24 atomic% of Nd, 2.88 atomic% of Pr, 0.86 atomic% of Dy, 1.69 atomic% of Co, 0.25 atomic% of Al, 0.14 atomic% of Cu, 0.14 atomic% of Ga, 0.09 atomic% of Zr, 6.09 atomic% of B, and the balance of Fe and inevitable impurities. The formulation composition is shown in table 1.
Table 1: formulations of example 1 and comparative example 1 (unit: at%)
Note: k1 ═ ([ Fe ] + [ Co ])/([ B ] - [ N ] × 2), K2 ═ R ]/([ B ] - [ N ] × 2).
(2) Smelting, pulverizing and pressing the raw materials into a green body according to the same process as the example 1, putting the green body into a vacuum sintering furnace, carrying out heat preservation treatment at 1075 ℃ for 4 hours, cooling to room temperature at the speed of 10 ℃/min, heating to 850 ℃ for heat preservation treatment for 3 hours, cooling to room temperature at the speed of 6 ℃/min, heating to 500 ℃ for heat preservation treatment for 4 hours, cooling to room temperature at the speed of 8 ℃/min, and cooling to obtain the neodymium iron boron blank.
The magnetic properties and metallographic characterization results for example 1 and comparative example 1 are given in table 2 below, fig. 1 to 6:
table 2: metallographic characteristic analysis and magnetic performance index
The formula system changes, the corresponding phase-change temperature of the magnet can also shift, the optimal sintering process of the formula system is correspondingly adjusted according to the change of the phase-change temperature of the magnet, and the sintering processes of the embodiment and the comparative example are the optimal processes under the formula.
As can be seen from tables 1 and 2, the formulation of example 1 has 0.66 at% less Dy than comparative example 1, and the contents of Co, Cu, Zr, Al, and B are adjusted at the same time, Hcj is equivalent to the comparative example, and Br is slightly higher than the comparative example.
From the metallographic characteristics of fig. 1 and fig. 2, the grain boundary phase of example 1 occupies a higher amount of Ln/Lm, and the grain boundary phase, particularly the two-phase grain boundary, is clearer and more uniform. The above characteristics are also demonstrated in the EPMA images of fig. 3 and 4, which also confirms that the example 1 formulation can produce magnets with the specified characteristics and that the magnets have excellent Br, Hcj and squareness.
Example 2
(1) Preparing materials: the various raw materials required for this example were prepared, and the atomic percent composition of the ingredients is shown in table 3.
(2) The raw materials are melted at high frequency in Ar atmosphere and poured on a quenching roller to prepare an alloy quick-setting sheet, and the thickness of the sheet is 0.15-0.40 mm.
(3) The alloy was pulverized by hydrogenation and then jet-milled, and the resulting magnetic powder had a particle size SMD of 2.7 μm, X10 of 1.23 μm and X100 of 15 μm.
(4) The above air current is milled into powder and added with 0.3 wt% of lubricant of raw materials, then mixed and molded under the environment of an orientation field with the magnetic field intensity of 2T.
(5) And (3) placing the blank into a vacuum sintering furnace, carrying out heat preservation treatment at 1075 ℃ for 4h, cooling to room temperature at the speed of 10 ℃/min, heating to 800 ℃ for 3h, cooling to room temperature at the speed of 6 ℃/min, heating to 580 ℃ for 4h, cooling to room temperature at the speed of 8 ℃/min, and cooling to obtain the neodymium iron boron blank.
(6) The blank was sampled D10-10mm and tested for magnetic properties. See table 4.
(7) And (3) preparing a blank sample to be EPMA, analyzing the characteristics of a main phase and a grain boundary phase, and carrying out quantitative analysis by image analysis software. See table 4.
Comparative example 2
(1) The proportion of the ingredients is different: the formulation composition is shown in table 3.
(2) Smelting, pulverizing and pressing the raw materials into a green body according to the process, putting the green body into a vacuum sintering furnace, carrying out heat preservation treatment at 1065 ℃ for 4h, cooling to room temperature at the speed of 10 ℃/min, heating to 850 ℃ for heat preservation treatment for 3h, cooling to room temperature at the speed of 6 ℃/min, heating to 500 ℃ for heat preservation treatment for 4h, cooling to room temperature at the speed of 8 ℃/min, and cooling to obtain the neodymium iron boron blank.
Table 3: formulations of example 2 and comparative example 2 (unit at%)
Note: k1 ═ ([ Fe ] + [ Co ])/([ B ] - [ N ] × 2), K2 ═ R ]/([ B ] - [ N ] × 2).
Table 4: metallographic characteristic analysis and magnetic performance index
As can be seen from tables 3 and 4, the formulation of example 2 has 0.40 at% less Dy than comparative example 2, but has equivalent Br, and the Hcj example has about 70kA/m higher.
Example 3
(1) Preparing materials: the raw materials required for this example were prepared and the formulation composition is shown in Table 5.
(2) The raw materials are melted at high frequency in Ar atmosphere and poured on a quenching roller to prepare an alloy quick-setting sheet, and the thickness of the sheet is 0.15-0.40 mm.
(3) The alloy was pulverized by hydrogenation and then jet-milled to obtain a magnetic powder having a particle size SMD of 2.9 μm, X10 of 1.28 μm and X100 of 18 μm.
(4) The above air current is milled into powder and added with 0.3 wt% of lubricant of raw materials, then mixed and molded under the environment of an orientation field with the magnetic field intensity of 2T.
(5) And (3) placing the blank into a vacuum sintering furnace, carrying out heat preservation treatment at 1060 ℃ for 4h, cooling to room temperature at the speed of 10 ℃/min, heating to 800 ℃ for heat preservation treatment for 3h, cooling to room temperature at the speed of 6 ℃/min, heating to 560 ℃ for heat preservation treatment for 4h, cooling to room temperature at the speed of 8 ℃/min, and cooling to obtain the neodymium iron boron blank.
(6) The blank was sampled D10-10mm and tested for magnetic properties. See table 6.
(7) And (3) preparing a blank sample to be EPMA, analyzing the characteristics of a main phase and a grain boundary phase, and carrying out quantitative analysis by image analysis software. See table 6.
Comparative example 3
(1) The proportion of the ingredients is different: the formulation composition is shown in table 5.
(2) Smelting, pulverizing and pressing the raw materials into a green body according to the process of the embodiment 3, putting the green body into a vacuum sintering furnace, carrying out heat preservation treatment at 1080 ℃ for 4 hours, cooling to room temperature at the speed of 10 ℃/min, heating to 850 ℃ for heat preservation treatment for 3 hours, cooling to room temperature at the speed of 6 ℃/min, heating to 520 ℃ for heat preservation treatment for 4 hours, cooling to room temperature at the speed of 8 ℃/min, and cooling to obtain the neodymium iron boron blank.
Table 5: formulations of example 2 and comparative example 2 (unit at%)
Note: k1 ═ ([ Fe ] + [ Co ])/([ B ] - [ N ] × 2),
K2＝[R]/([B]-[N]×2)。
table 6: metallographic characteristic analysis and magnetic performance index
As can be seen from tables 5 and 6, example 3 has 0.59 at% less Dy than the comparative example 3 formulation, equivalent Br, and about 50kA/m higher Hcj example.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A neodymium iron boron permanent magnet, which comprises a main phase and a grain boundary phase, and is characterized in that the grain boundary phase and the main phase have the following structural distribution:
marking the total length of a grain boundary phase as Lm in a measuring range, marking the total length of the grain boundary phase with the inter-phase width (namely the grain boundary width) of adjacent grain boundaries being more than or equal to 1 mu m in the measuring range as Ln, wherein Lm and Ln meet the relationship that Ln/Lm is more than or equal to 0.40 and less than or equal to 1;
marking the total length of grain boundary phases within the measuring range as Lm, and marking the total length of the grain boundary phases with the width between adjacent grain boundary phases being more than or equal to 2 mu m within the measuring range as Lx, wherein Lm and Lx satisfy the relation that Lx/Lm is more than or equal to 0 and less than or equal to 0.2;
and thirdly, the total length of the grain boundary phase passing through the EPMA line scanning in the measuring range is marked as Le, the total length of the scanning in the measuring range is marked as LM, and the Le and the LM meet the relationship that Le/LM <1 is more than or equal to 0.40.
2. The ndfeb permanent magnet according to claim 1, characterized by 0.45 ≦ Ln/Lm ≦ 0.9.
Preferably, 0.5. ltoreq. Lx/Lm. ltoreq.0.19.
Preferably, 0.45. ltoreq. Le/LM. ltoreq.0.8.
3. A ndfeb permanent magnet according to claim 1 or 2, characterized in that the main phase has the structure R2Fe14B, R representing a rare earth element. Preferably, R is selected from Nd, or Nd and at least one of the following rare earth elements: pr, Dy, Tb and Ho.
Preferably, the grain boundary phase contains an R-rich phase and a B-rich phase.
Preferably, the total content of C and O in the ndfeb permanent magnet is 2800ppm or less, for example 2500ppm or less.
Preferably, the C content is 1200ppm or less, for example 1100ppm or less.
Preferably, the O content is 1600ppm or less, for example 1400ppm or less.
4. The utility model provides a neodymium iron boron permanent magnet which characterized in that, neodymium iron boron permanent magnet's preparation raw materials includes:
r: 12-16 at%, R represents rare earth element;
B：5-6at％；
t comprises M1, M2, Fe and Co; wherein, M1: 0.5 to 1.5 at%, M1 is selected from transition metal elements containing Cu and Ga; m2: 0.05 to 0.3 at%, M2 is at least one of Nb, Zr and Ti; co: 0.5-8 at%;
the balance of Fe and inevitable impurities;
the atomic number of the elements simultaneously satisfies the following conditions:
14.5＜([Fe]+[Co])/([B]-[M2]×2))＜17.5；
2.5＜[R]/([B]-[M2]×2)＜3.5；
cu is more than 0 and less than or equal to 0.3at percent, Ga is more than 0 and less than or equal to 0.3at percent, and [ Cu ]/[ Ga ] is more than or equal to 0.5 and less than or equal to 1.
Preferably, the ndfeb permanent magnet is the ndfeb permanent magnet of any one of claims 1 to 3;
preferably, R has the option as defined in claim 3.
5. A NdFeB permanent magnet according to claim 4, characterized in that R content is 13-15 at%.
Preferably, the B content is 5.2-5.8 at%.
Preferably, the M1 content is 0.6-1.4 at%.
Preferably, M1 further contains at least one of Si, Al, Zn and Mn.
Preferably, the M2 content is 0.08-0.26 at%.
Preferably, the M2 is selected from Zr.
Preferably, the Co content is 1 to 6 at%.
Preferably, 14.7 ≦ ([ Fe ] + [ Co ])/([ B ] - [ M2] x 2)) ≦ 17.0.
Preferably, 2.55 < [ R ]/([ B ] - [ M2 ]. times.2) < 3.3.
Preferably, Cu is 0.1 at% to 0.25 at%.
Preferably, Ga is 0.1 at% to 0.25 at%.
Preferably, 0.6 ≦ Cu/[ Ga ] ≦ 0.9.
Preferably, the impurity contains C, S, O, N or the like.
Preferably, the squareness degree of the neodymium iron boron permanent magnet is more than or equal to 0.95.
6. The method for preparing the neodymium-iron-boron permanent magnet according to any one of claims 1 to 5, characterized by comprising the following steps:
1) pressing the alloy powder in a magnetic field to obtain a pressed blank; wherein the alloy powder is prepared from a material comprising the raw material of claim 5;
2) and sintering and aging the pressed compact to obtain the neodymium iron boron permanent magnet.
7. The method according to claim 6, wherein in the step 1), the preparation process of the alloy powder comprises: the alloy powder is obtained by subjecting an alloy sheet prepared from the raw material according to claim 5 to hydrogen decrepitation and air flow milling.
Preferably, the alloy sheet has a thickness of 0.1-0.5mm, preferably 0.15-0.40mm, for example 0.20-0.35 mm.
Preferably, the alloy sheet is prepared from materials containing the raw materials through melting and rapid hardening and strip spinning.
Preferably, the alloy powder obtained by the jet milling treatment has an SMD particle size of 1.5-3.5 μm.
Preferably, the X10 of the alloy powder obtained by the air flow milling treatment is more than or equal to 0.8 mu m.
Preferably, the X100 of the alloy powder obtained by the air flow milling treatment is less than or equal to 24 mu m.
Optionally, the alloy powder further contains at least one of an antioxidant and a lubricant.
8. The method according to claim 6 or 7, wherein the sintering is performed in a vacuum heat treatment furnace.
Preferably, the sintering temperature is 900-.
Preferably, the sintering time is 3-8h, such as 3.5-6 h.
Preferably, the aging treatment comprises: and after sintering, cooling to room temperature, heating to 750-plus-one temperature of 850 ℃, preserving heat for 2-5h, cooling to room temperature, heating to 500-plus-one temperature of 600 ℃, preserving heat for 2-5h, and cooling to room temperature to obtain the neodymium-iron-boron permanent magnet.
Preferably, the cooling rate is 5-12 ℃/min.
9. The method according to claim 6, wherein the preparation method of the neodymium iron boron permanent magnet comprises the following steps:
step a) preparing R-T-B alloy raw materials, which comprises the following steps:
r: 12-16 at%, R having the choice as described above;
B：5-6at％；
t comprises M1, M2, Fe and Co; wherein, M1: 0.5 to 1.5 at%, M1 is selected from transition metal elements containing Cu and Ga; m2: 0.05 to 0.3 at%, M2 is at least one of Nb, Zr and Ti; co: 0.5-8 at%;
the balance of Fe and inevitable impurities;
the atomic number of the elements simultaneously satisfies the following conditions:
14.5＜([Fe]+[Co])/([B]-[M2]×2))＜17.5；
2.5＜[R]/([B]-[M2]×2)＜3.5；
cu is more than 0 and less than or equal to 0.3at percent, Ga is more than 0 and less than or equal to 0.3at percent, and [ Cu ]/[ Ga ] is more than or equal to 0.5 and less than or equal to 1;
step b), mixing and melting the alloy raw materials, and obtaining an alloy rapid hardening sheet through rapid hardening and strip throwing;
step c), performing hydrogen breaking and air flow grinding treatment on the alloy quick-setting sheet to prepare alloy powder with SMD (surface mounted device) of 1.5-3.5 micrometers;
step d) pressing the alloy powder in a magnetic field to obtain a pressed blank;
optionally, at least one of an antioxidant and a lubricant is contained or not contained in the alloy powder;
and f) sintering and aging the pressed blank in a vacuum heat treatment furnace to obtain the neodymium iron boron permanent magnet.
10. Use of the ndfeb permanent magnet of any one of claims 1 to 5 in automotive motors, wind power, traction machines, compressors or consumer electronics.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113223801A (en) * | 2021-05-21 | 2021-08-06 | 慈溪市兴发磁业科技有限公司 | High-boron neodymium-iron-boron permanent magnet and preparation method thereof |
| CN113921218A (en) * | 2021-09-22 | 2022-01-11 | 烟台正海磁性材料股份有限公司 | High-remanence neodymium-iron-boron magnet and preparation method and application thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008270699A (en) * | 2007-03-29 | 2008-11-06 | Hitachi Ltd | Rare earth magnet and its manufacturing method |
| CN102696080A (en) * | 2009-12-18 | 2012-09-26 | 丰田自动车株式会社 | Rare earth magnet and manufacturing method therefor |
| CN103915232A (en) * | 2013-01-07 | 2014-07-09 | 昭和电工株式会社 | R-T-B rare earth sintered magnet, alloy for R-T-B rare earth sintered magnet, and method of manufacturing the same |
| CN105118593A (en) * | 2007-06-29 | 2015-12-02 | Tdk株式会社 | Rare earth magnet |
| US20160293303A1 (en) * | 2015-03-31 | 2016-10-06 | Shin-Etsu Chemical Co., Ltd. | R-fe-b sintered magnet and making method |
| CN108417376A (en) * | 2018-02-05 | 2018-08-17 | 宁波松科磁材有限公司 | A kind of Sintered NdFeB magnet preparation method without heavy rare earth |
-
2020
- 2020-09-04 CN CN202010923593.4A patent/CN111968818B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008270699A (en) * | 2007-03-29 | 2008-11-06 | Hitachi Ltd | Rare earth magnet and its manufacturing method |
| CN105118593A (en) * | 2007-06-29 | 2015-12-02 | Tdk株式会社 | Rare earth magnet |
| CN102696080A (en) * | 2009-12-18 | 2012-09-26 | 丰田自动车株式会社 | Rare earth magnet and manufacturing method therefor |
| CN103915232A (en) * | 2013-01-07 | 2014-07-09 | 昭和电工株式会社 | R-T-B rare earth sintered magnet, alloy for R-T-B rare earth sintered magnet, and method of manufacturing the same |
| US20160293303A1 (en) * | 2015-03-31 | 2016-10-06 | Shin-Etsu Chemical Co., Ltd. | R-fe-b sintered magnet and making method |
| CN108417376A (en) * | 2018-02-05 | 2018-08-17 | 宁波松科磁材有限公司 | A kind of Sintered NdFeB magnet preparation method without heavy rare earth |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113223801A (en) * | 2021-05-21 | 2021-08-06 | 慈溪市兴发磁业科技有限公司 | High-boron neodymium-iron-boron permanent magnet and preparation method thereof |
| CN113921218A (en) * | 2021-09-22 | 2022-01-11 | 烟台正海磁性材料股份有限公司 | High-remanence neodymium-iron-boron magnet and preparation method and application thereof |
| CN113921218B (en) * | 2021-09-22 | 2022-11-29 | 烟台正海磁性材料股份有限公司 | High-remanence neodymium-iron-boron magnet and preparation method and application thereof |
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