CN113782292B - Yttrium cerium-based rare earth permanent magnetic material with improved temperature stability - Google Patents
Yttrium cerium-based rare earth permanent magnetic material with improved temperature stability Download PDFInfo
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- 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
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- 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
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- 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
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- 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
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Abstract
The invention discloses a yttrium cerium based rare earth permanent magnetic material, which comprises the following components in percentage by mass (R)1‑a‑bYaCeb)x‑(Fe，TM)100‑x‑y‑ByX is more than or equal to 28 and less than or equal to 35, y is more than or equal to 0.95 and less than or equal to 1.2, a is more than or equal to 0.03 and less than or equal to 0.5, and b is more than or equal to 0.03 and less than or equal to 0.5; wherein R is one or the combination of more of Pr, Nd, Ho, Gd, Dy and Tb, and TM is one or the combination of more of B, V, Ti, Co, Cr, Mo, Mn, Ni, Ga, Zr, Ta, Ag, Au, Al, Pb, Cu and Si; according to the invention, by optimizing the microstructure of the main phase crystal grains and regulating the grain boundary phase, the magnetic dilution effect caused by adding yttrium and cerium is reduced, and the coercive force, temperature stability and processability of the material are improved.
Description
Technical Field
The invention belongs to the field of rare earth permanent magnet materials, and particularly relates to a yttrium cerium based rare earth permanent magnet material with improved temperature stability.
Background
In recent years, with the rapid development of industrial robots, intelligent automobiles, wind power generation and other fields, the dosage of Nd-Fe-B permanent magnetic materials is always kept increasing at a high speed. As the application requirements of the neodymium iron boron rare earth permanent magnet in various fields are increased sharply, the requirements on elements such as praseodymium, neodymium, terbium, dysprosium and the like which are in short supply are increased greatly, so that a large amount of rare earth elements such as cerium, lanthanum, yttrium and the like are accumulated, the consumption speed of rare earth mineral resources is increased, and a series of problems such as resource waste, deterioration of ecological environment of a mining area and the like are caused.
Principal phase Y2Fe14B (Js ═ 1.4T, Ha ═ 26kOe) and Ce2Fe14B (Js 1.17, Ha 26kOe) has intrinsic magnetic properties lower than Nd2Fe14B (Js 1.61T, Ha 73kOe), substituting Nd with Y or Ce, inevitably causes deterioration of magnet performance, particularly, a decrease in coercive force. Y and Ce have some special phenomena when they form the main phase: relevant studies show that when Y or Ce replaces Nd to form a main phase, Y tends to enter the main phase, Ce tends to enter a grain boundary phase, and uneven distribution of the Y or Ce main phase can be formed in the grains. Y is2Fe14B magnetocrystalline anisotropy constant K1The positive temperature coefficient is provided in a certain temperature range, and the temperature stability of the magnet can be improved by replacing Nd with Y. Regarding yttrium cerium based rare earth permanent magnet, the applicant's prior patent ZL202010082228.5 discloses a ' high performance yttrium cerium based rare earth permanent magnet and a preparation method ', the permanent magnet includes a grain boundary phase and a main phase of multi-shell structure; the final magnet of the permanent magnet comprises the following components in atomic percentage: re1aRe2bYcCedMeBfFe100-a-b-c-d-e-fRe1 is any one of Pr, Nd and PrNd, Re2 is any one or more than two elements of Dy, Tb, Ho and Gd; m is any one or more than two elements of Cu, Co, Al, Nb, Ga, Zr, Ni and Ti; wherein a is more than or equal to 4.5 and less than or equal to 13.5, b is more than or equal to 0.1 and less than or equal to 5, c is more than or equal to 0.3 and less than or equal to 8.7, d is more than or equal to 0.3 and less than or equal to 8.7, a + b + c + d is more than or equal to 12.5 and less than or equal to 20, c + d is more than or equal to 1.25 and less than or equal to 9, e is more than 0 and less than or equal to 10, f is more than or equal to 5.4 and less than or equal to 7, and the balance of Fe and inevitable impurities; wherein the rare earth Re2 is added by adding grain boundary auxiliary alloy powder, and the grain boundary auxiliary alloy component is Re2 according to atom percentage100-yM’yM' is at least one of Al, Cu, Fe, Co and Ga, y is more than 0 and less than or equal to 90, and the addition amount of the grain boundary auxiliary alloy accounts for 0.1 to 10 weight percent of the total amount of the permanent magnet; in the multi-shell structure, the main phase grain components of the permanent magnet are respectively a high Y phase, a Re1 phase, a high Ce phase and a Re phase from the core to the shell2And (4) phase(s). The prior application improves the magnetic properties and coercive force of the yttrium-cerium-based magnet by adding a grain boundary phase auxiliary alloy, but does not study and improve the temperature stability of the material.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide the yttrium cerium based rare earth permanent magnetic material with improved temperature stability, and the magnetic dilution effect of coercive force can be effectively reduced and the temperature stability and the processing performance can be improved by optimizing and regulating the microstructure of the material.
In order to achieve the purpose, the invention provides the following technical scheme:
a yttrium cerium based rare earth permanent magnetic material with improved temperature stability, the composition of the permanent magnetic material is (R) by mass percentage1-a-bYaCeb)x-(Fe，TM)100-x-y-ByX is more than or equal to 28 and less than or equal to 35, y is more than or equal to 0.95 and less than or equal to 1.2, a is more than or equal to 0.03 and less than or equal to 0.5, and b is more than or equal to 0.03 and less than or equal to 0.5; wherein R is one or the combination of more of Pr, Nd, Ho, Gd, Dy and Tb, and TM is one or the combination of more of B, V, Ti, Co, Cr, Mo, Mn, Ni, Ga, Zr, Ta, Ag, Au, Al, Pb, Cu and Si;
the permanent magnet material comprises a grain boundary phase and a main phase, wherein the grains of the main phase comprise yttrium-cerium-containing main phase grains and yttrium-cerium-free main phase grains, the component fluctuation of the yttrium-cerium-free main phase grains is within 5%, and the yttrium-cerium-containing main phase grains have the following segregation microstructure: the yttrium-cerium-containing main phase crystal grain comprises a crystal grain inner layer and a crystal grain outer layer, wherein the crystal grain outer layer comprises a hard magnetic shell layer; the grain inner layer comprises yttrium-rich island regions and cerium-rich island regions, the yttrium-rich island regions are distributed at the positions, close to the core, of the grain inner layer, and the cerium-rich island regions are distributed at the positions, close to the grain outer layer, of the grain inner layer.
The permanent magnet material is prepared by mixing rare earth-poor yttrium cerium-based alloy powder and rare earth-rich alloy powder without yttrium cerium.
The permanent magnetic material is prepared by the following steps:
(1) preparing rare earth-lean yttrium cerium-based alloy powder, wherein the mass percentage of the alloy powderIs Ya1Ceb1(PrNd)c1(Fe，M)balBy1Wherein a is not less than 1 and not more than 1 and not more than 20, b is not less than 1 and not more than b1 and not more than 20, c1 and not more than 20 are not less than 0.5 and not more than 0.95 and y1 and not more than 1.2, and alloy fine powder with the average particle size of 2-5 mu m is obtained;
(2) preparing rare earth-rich alloy powder, wherein the mass percent of the alloy powder is (PrNd)c2HREd(Fe，M)balBy2HRE is one or more of Ho, Tb, Dy and Gd, wherein c2 is more than or equal to 1 and less than or equal to 35, d is more than or equal to 0 and less than or equal to 15, y2 is more than or equal to 0.95 and less than or equal to 1.2, and alloy fine powder with the average particle size of 2-5 mu m is obtained;
(3) mixing the prepared rare earth-poor yttrium cerium-based powder with the rare earth-rich powder according to the weight ratio of 100-55: 1-40;
(4) carrying out orientation molding on the uniformly mixed powder in a 1.8-2T magnetic field press, and carrying out isostatic pressing at 180-220 MPa to obtain a green body;
(5) and sintering the green body in a vacuum sintering furnace, and then tempering under a protective atmosphere.
The magnetocrystalline anisotropy field of the hard magnetic shell layer is 20% -50% higher than that of the inner layer of the crystal grains.
The grain boundary phase composition between different main phase grains of the permanent magnetic material has the following segregation: the content of yttrium cerium element in a grain boundary phase among the yttrium cerium-rich main phase grains is higher than that in a grain boundary phase among the yttrium cerium-free main phase grains.
The content of yttrium cerium element in a grain boundary phase among the yttrium cerium-rich main phase grains is 5-20% higher than that of yttrium cerium in a grain boundary phase among the yttrium cerium-free main phase grains.
The permanent magnet material comprises the following components in percentage by mass: the total amount of the rare earth is 30-31.6, wherein Y is 4.66-8, Ce is 4.66-8, PrNd is 14-21.64, and Ho is 0-0.84.
The temperature coefficient of remanence of the permanent magnetic material is as follows: the temperature of 20-100 ℃ is-0.10%/DEG C to-0.04%/DEG C, and the intrinsic coercive force temperature coefficient of the permanent magnetic material is as follows: the temperature of the mixture is between-0.70%/DEG C and-0.40%/DEG C at the temperature of between 20 and 100 ℃; the density value of the permanent magnetic material is 7.20-7.55 g/cm 3.
The temperature coefficient of remanence of the permanent magnetic material is as follows: the temperature of 20-100 ℃ is-0.10%/DEG C to-0.12%/DEG C, and the intrinsic coercive force temperature coefficient of the permanent magnetic material is as follows: the temperature of the mixture is between-0.69%/DEG C and-0.78%/DEG C at 20 ℃ to 100 ℃; the density value of the permanent magnetic material is 7.47-7.51 g/cm 3.
The preparation method of the yttrium cerium based rare earth permanent magnetic material comprises the following steps:
(1) preparing rare earth-lean yttrium cerium-based alloy powder, wherein the mass percent of the alloy powder is Ya1Ceb1(PrNd)c1(Fe，M)balBy1Wherein a is not less than 1 and not more than 1 and not more than 20, b is not less than 1 and not more than b1 and not more than 20, c is not less than 0.5 and not more than c1 and not more than 20, and y is not less than 0.95 and not more than y1 and not more than 1.2, and alloy fine powder with the average particle size of 2-5 mu m is obtained;
(2) preparing rare earth-rich alloy powder, wherein the mass percent of the alloy powder is (PrNd)c2HREd(Fe，M)balBy2HRE is one or more of Ho, Tb, Dy and Gd, wherein c2 is more than or equal to 1 and less than or equal to 35, d is more than or equal to 0 and less than or equal to 15, y2 is more than or equal to 0.95 and less than or equal to 1.2, and alloy fine powder with the average particle size of 2-5 mu m is obtained;
(3) mixing the prepared rare earth-poor yttrium cerium-based powder with the rare earth-rich powder according to the weight ratio of 100-55: 1-40;
(4) carrying out orientation molding on the uniformly mixed powder in a 1.8-2T magnetic field press, and carrying out isostatic pressing at 180-220 MPa to obtain a green body;
(5) and sintering the green body in a vacuum sintering furnace, and then tempering under a protective atmosphere.
In the step (1), raw material proportioning is carried out according to the components of the lean rare earth yttrium cerium-based alloy powder, the raw materials are polished to remove surface oxide skin and impurities before proportioning and weighing, a rapid hardening sheet is prepared from the raw materials in a rapid hardening furnace, the average thickness of the rapid hardening sheet is 0.1-0.5 mm, hydrogen crushing is carried out in a hydrogen crushing furnace to obtain hydrogen crushing coarse powder, the hydrogen crushing coarse powder is mixed in a powder mixer for 2 +/-0.5 h and then subjected to airflow milling, the pressure of the airflow milling gas is 0.5 +/-0.1 MPa, and the rotating speed of a grading wheel is 3500rpm, so that alloy fine powder with the average particle size of 2-5 mu m is obtained.
In the step (2), raw material proportioning is carried out according to the components of the rare earth-rich alloy powder, raw materials are polished to remove surface oxide skin and impurities before proportioning and weighing, a quick-setting sheet is prepared in a quick-setting furnace, the average thickness of the quick-setting sheet is 0.3-0.6 mm, hydrogen crushing is carried out in a hydrogen crushing furnace to obtain hydrogen crushing coarse powder, the hydrogen crushing coarse powder is mixed in a powder mixer and then is subjected to airflow milling, the airflow milling gas pressure is 0.8Mpa, the rotating speed of a grading wheel is 4500rpm, and alloy fine powder with the average particle size of 2-3 mu m is obtained.
In the step (3), after mixing, adding a lubricant according to 0.05-0.2% of the total weight, and mixing the powder for 5 +/-0.5 h, wherein after fully mixing the powder, the mixed powder has rare earth-poor yttrium cerium-based powder particles and rare earth-rich alloy powder particles without yttrium cerium.
In the step (5), the sintering temperature is 1050 +/-20 ℃, the sintering time is 2 +/-0.5 h, and the vacuum degree is always better than 10 in the sintering process-3Pa, then carrying out primary tempering at 880 +/-50 ℃, and carrying out secondary tempering at 480 +/-20 ℃, wherein the primary tempering is carried out for 2 +/-0.5 h, the secondary tempering is carried out for 3 +/-0.5 h, and the tempering is carried out in the argon protective atmosphere.
In the step (2), the (PrNd) is prepared by the following chemical coprecipitation-reduction methodc2HREd(Fe，M)balBy2Rare earth-rich alloy powder: respectively reacting chlorides RECl of rare earth elements3、FeCl3And BCl3Respectively dissolving in deionized water to form aqueous solution of chloride; will then be rich in (OH)-Adding the root solution into a chloride solution to form three types of chloride coprecipitates, and separating the coprecipitates from the solution by using filter paper; calcining the precipitate obtained by separation to obtain an oxide; then reducing the oxide in hydrogen to obtain the final alloy powder, wherein the powder granularity of the alloy is 500 nm.
The invention provides a novel structure of a yttrium cerium based rare earth permanent magnetic material by optimizing the microstructure of a magnet, wherein a hard magnetic shell layer with a high magnetocrystalline anisotropy field is arranged at the periphery of a main phase crystal grain and an uneven distribution region of the magnetocrystalline anisotropy field is arranged inside the main phase crystal grain, the hard magnetic shell layer with the high magnetocrystalline anisotropy field is distributed around the crystal grain which is easy to nucleate in the process of reverse magnetization, the nucleation field can be improved, short-range interaction between local regions with different intrinsic magnetism is realized, and the movement and the growth of a reverse magnetic domain can be inhibited. Therefore, the invention can effectively reduce the decrease of coercive force caused by the substitution of praseodymium-neodymium element by yttrium-cerium element, and simultaneously improve the temperature stability and the processing performance of the magnet.
Compared with the prior art, the invention has a novel microstructure, thereby having remarkable effects of enhancing the temperature stability and improving the coercive force of the yttrium-cerium-based magnet and having the following beneficial effects:
1) by optimizing the microstructure of the main phase crystal grain, a hard magnetic shell layer is formed outside the yttrium-cerium-based main phase crystal grain, in addition, yttrium-rich and cerium-rich areas exist inside the crystal grain, the hard magnetic shell layer outside the crystal grain can improve the nucleation field of a reverse magnetic domain during reverse magnetization, different areas have different magnetocrystalline anisotropy fields, short-range interaction exists, the expansion and the movement of the reverse magnetic domain can be hindered, and therefore the coercive force of a magnet can be effectively improved.
2) By jointly adding yttrium and cerium, the synergistic effect of two elements is exerted, the problem of low temperature stability of a cerium magnet is solved, the working temperature of a high-abundance magnet is improved, the problem that the yttrium element is rarely applied to a permanent magnet material for a long time is solved, and the batch application of yttrium in the field of rare earth permanent magnets is realized.
3) The permanent magnet material is prepared by directly using abundant yttrium cerium with large reserves and low price as a raw material, so that the production cost is reduced, the balanced utilization of rare earth resources is promoted, and the precious rare earth resources are protected.
Drawings
Fig. 1 is a schematic distribution diagram of powder particles obtained after mixing a rare earth-poor yttrium-cerium-based alloy and rare earth-rich yttrium-cerium-free alloy powder in a preparation process of a yttrium-cerium-based permanent magnetic material of the invention.
FIG. 2 is a schematic view of the microstructure of the final product of the yttrium-cerium-based permanent magnetic material of the present invention, wherein A is a main phase grain, B is a grain boundary phase, 1 is an R-Fe-B main phase, 2 is an R-Fe-B hard magnetic shell, 3 is a composition uniformity region, 4 is a Y-rich segregation region, and 5 is a Ce-rich segregation region.
FIG. 3 is a microscopic morphology image of a yttrium cerium-based magnet according to the present invention under a scanning electron microscope.
Fig. 4 is a demagnetization curve of the yttrium-cerium-based magnet of the present invention. (magnetic Properties corresponding to alloy A in example 1)
Detailed Description
The present invention will be further described with reference to the following drawings and specific examples, but the present invention is not limited to the following examples.
The invention provides a yttrium cerium based rare earth permanent magnet material, wherein main phase grains of the permanent magnet material comprise yttrium cerium containing main phase grains and yttrium cerium free main phase grains; the yttrium-cerium-containing main phase crystal grains comprise a crystal grain inner layer and a crystal grain outer layer; the outer layer of the crystal grains comprises a hard magnetic shell layer; the magnetocrystalline anisotropy field of the hard magnetic shell layer is higher than that of the grain inner layer; the grain inner layer comprises yttrium-rich island regions and cerium-rich island regions; the yttrium-rich island regions are distributed on the grain inner layer close to the core; the cerium-rich island regions are distributed on the inner layer of the crystal grains close to the outer layer of the crystal grains; the composition of the yttrium cerium-free main phase grains is uniform.
The yttrium cerium based rare earth permanent magnet material has the advantages that grain boundary phase components among different main phase grains are uneven, and the content of yttrium cerium element in a grain boundary phase among the yttrium cerium rich main phase grains is larger than that of yttrium cerium in a grain boundary phase among the non-yttrium cerium containing grains.
The yttrium cerium based rare earth permanent magnetic material comprises the following components of (R)1-a-bYaCeb)x-(Fe，TM)100-x-y-ByX is more than or equal to 28 and less than or equal to 35, y is more than or equal to 0.95 and less than or equal to 1.2, a is more than or equal to 0.03 and less than or equal to 0.5, and b is more than or equal to 0.03 and less than or equal to 0.5; wherein R is one or the combination of more of Pr, Nd, Ho, Gd, Dy and Tb, and TM is one or the combination of more of B, V, Ti, Co, Cr, Mo, Mn, Ni, Ga, Zr, Ta, Ag, Au, Al, Pb, Cu and Si.
The yttrium cerium based rare earth permanent magnetic material has the following remanence temperature coefficient: the temperature of 20-100 ℃ is-0.10%/DEG C to-0.04%/DEG C, and the intrinsic coercive force temperature coefficient of the permanent magnetic material is as follows: the temperature of 20-100 ℃ is-0.70%/DEG C to-0.40%/DEG C; the density value of the permanent magnetic material is 7.20-7.55 g/cm 3.
Example 1
(1) Preparing rare earth-lean yttrium cerium-based alloy powder, and expressing the mass percent of the alloyFormula is Y8Ce8(PrNd)14(Fe，M)balB1.1The raw materials are proportioned according to the components, the raw materials are polished to remove surface oxide skin and impurities before being proportioned and weighed, the raw materials are prepared into a rapid hardening sheet in a rapid hardening furnace, the average thickness of the rapid hardening sheet is 0.1-0.5 mm, then hydrogen crushing is carried out in a hydrogen crushing furnace to obtain hydrogen crushing coarse powder, the hydrogen crushing coarse powder is mixed in a powder mixer for 2 hours and then subjected to airflow milling, the airflow milling gas pressure is 0.5MPa, and the rotation speed of a grading wheel is 3500rpm, so that alloy fine powder with the average particle size of 2-5 mu m is obtained;
(2) preparing rare earth-rich alloy powder, wherein the expression of the mass percent of the alloy is (PrNd)32Ho2(Fe，M)balB1.1The method comprises the following steps of proportioning raw materials according to the components, grinding the raw materials to remove surface oxide skin and impurities before proportioning and weighing, preparing a quick-setting sheet in a quick-setting furnace from the raw materials, wherein the average thickness of the quick-setting sheet is 0.3-0.6 mm, then carrying out hydrogen crushing in a hydrogen crushing furnace to obtain hydrogen crushing coarse powder, mixing the hydrogen crushing coarse powder in a powder mixer, and then carrying out jet milling at the gas pressure of 0.8Mpa and the rotating speed of a grading wheel of 4500rpm to obtain alloy fine powder with the average particle size of 2-3 mu m;
(3) mixing the prepared rare earth poor powder and rare earth rich powder according to the weight ratio of 100:0, 85:15, 70:30 and 55:45, adding a lubricant according to one thousandth of the total weight after mixing, and finally mixing the powder for 5 hours, wherein the distribution of the two kinds of powder is shown in figure 1 after fully mixing the powder;
(4) carrying out orientation molding on the uniformly mixed powder in a 2T magnetic field press, and carrying out isostatic pressing at 200MPa to obtain a green body;
(5) sintering the green body in a vacuum sintering furnace at 1050 deg.C for 2h, wherein the vacuum degree is always better than 10-3Pa, performing primary tempering at 880 ℃, performing secondary tempering at 480 ℃, and performing primary tempering and heat preservation for 2 hours and secondary tempering and heat preservation for 3 hours, wherein the tempering is performed in an argon protective atmosphere. The different types of rare earth elements of the final magnet are in proportion in table 1.
TABLE 1
The final magnet was cut to test a sample size of D10 x 10, wherein the height direction was the magnetization direction, and the room temperature demagnetization curve of the sample column after saturation magnetization and the temperature coefficients of remanence and coercivity between room temperature and 100 ℃ were measured, and the results are shown in table 2.
TABLE 2
Comparative example 1
Preparing materials according to the components of the formulas of the alloys A-D shown in the table 1 in the example 1, polishing raw materials to remove surface oxide skins and impurities before smelting, preparing quick-setting sheets in a quick-setting furnace, wherein the thickness of the quick-setting sheets is 0.1-0.5 mm, then performing hydrogen crushing in a hydrogen crushing furnace to obtain hydrogen crushed coarse powder, mixing the hydrogen crushed coarse powder in a powder mixer for 2 hours, and then performing airflow milling, wherein the airflow milling gas pressure is 0.5MPa, and the rotation speed of a grading wheel is 3500rpm, so as to obtain alloy fine powder with the average particle size of 2-5 mu m; adding one thousandth of lubricant into the alloy fine powder and then mixing the powder for 5 hours; carrying out orientation molding on the alloy fine powder in a 2T magnetic field press, and carrying out isostatic pressing at 200MPa to obtain a green body; sintering the green body in a vacuum sintering furnace at 1050 deg.C for 2h, wherein the vacuum degree is always better than 10-3Pa, performing primary tempering at 880 ℃, performing secondary tempering at 480 ℃, and performing primary tempering and heat preservation for 2 hours and secondary tempering and heat preservation for 3 hours, wherein the tempering is performed in an argon protective atmosphere. The magnetic property data obtained are shown in Table 3.
TABLE 3
It can be found by analyzing the magnetic property data in example 1 and comparative example 1 that the magnetic property of example 1 is significantly superior to that of comparative example 1 because a hard magnetic shell layer and a composition non-uniform region are formed inside the material by controlling the microstructures of the main phase and the grain boundary phase.
Example 2
Y was prepared by the same method as in the step (1) in example 18Ce8(PrNd)14(Fe，M)balB1.1The average particle size of the alloy powder is 2-5 μm. Preparation (PrNd) by chemical coprecipitation-reduction32HRE2(Fe，M)balB1.1The alloy powder (HRE ═ Ho, Tb, Dy, Gd one or several combination), mainly comprises rare earth element chloride RECl3、FeCl3And BCl3Dissolving in deionized water to form chloride aqueous solution, and enriching with (OH)-Adding the root solution into a chloride solution to form three types of chloride coprecipitates, separating the coprecipitates from the solution by using filter paper, calcining the precipitate obtained by separation to obtain an oxide, and reducing the oxide in hydrogen to obtain final alloy powder, wherein the powder granularity of the alloy is 500 nm. Mixing the two alloy powders according to a ratio of 85:15, adding one thousandth of lubricant, and putting the mixture on a powder mixer for fully mixing, wherein the powder mixing time is 5 hours; carrying out orientation molding on the alloy fine powder in a 2T magnetic field press, and carrying out isostatic pressing at 200MPa to obtain a green body; sintering the green body in a vacuum sintering furnace at 1050 deg.C for 2h, wherein the vacuum degree is always better than 10-3Pa, performing primary tempering at 880 ℃, performing secondary tempering at 480 ℃, and performing primary tempering and heat preservation for 2 hours and secondary tempering and heat preservation for 3 hours, wherein the tempering is performed in an argon protective atmosphere.
The magnetic property of the material is tested as follows: br 12.68kGs Hcj 8.82kOe, (BH) max 27.65MGOe, αBr＝-0.10％/℃，βHcj-0.68%/deg.C, density p 7.47g/cm3。
Claims (15)
1. A permanent-magnet material of yttrium-cerium-based rare earth with improved temperature stability, characterized in that the composition of the permanent-magnet materialBy mass percent of (R)1-a-bYaCeb）x-（Fe，TM）100-x-y-ByX is more than or equal to 28 and less than or equal to 35, y is more than or equal to 0.95 and less than or equal to 1.2, a is more than or equal to 0.03 and less than or equal to 0.5, and b is more than or equal to 0.03 and less than or equal to 0.5; wherein R is one or the combination of more of Pr, Nd, Ho, Gd, Dy and Tb, and TM is one or the combination of more of B, V, Ti, Co, Cr, Mo, Mn, Ni, Ga, Zr, Ta, Ag, Au, Al, Pb, Cu and Si;
the permanent magnet material has a grain boundary phase and a main phase, wherein the crystal grains of the main phase comprise yttrium-cerium-containing main phase crystal grains and yttrium-cerium-free main phase crystal grains, and the yttrium-cerium-containing main phase crystal grains have the following segregation microstructure: the yttrium-cerium-containing main phase crystal grain comprises a crystal grain inner layer and a crystal grain outer layer, wherein the crystal grain outer layer comprises a hard magnetic shell layer; the grain inner layer comprises yttrium-rich island regions and cerium-rich island regions, the yttrium-rich island regions are distributed at the position, close to the core, of the grain inner layer, and the cerium-rich island regions are distributed at the position, close to the grain outer layer, of the grain inner layer;
the permanent magnet material is prepared by mixing and sintering rare earth-poor yttrium cerium-based alloy powder and rare earth-rich alloy powder, wherein the mass percentage of the rare earth-poor yttrium cerium-based alloy powder is Ya1Ceb1（PrNd）c1（Fe，M）balBy1Wherein a is not less than 1 and not more than 1 and not more than 20, b is not less than 1 and not more than b1 and not more than 20, c1 and not more than 0.5 and not more than 20, and y1 and not more than 0.95 and not more than 1.2; the mass percentage of the rare earth-rich alloy powder is (PrNd)c2HREd（Fe，M）balBy2，HRE is one or more of Ho, Tb, Dy and Gd, wherein c2 is more than or equal to 1 and less than or equal to 35, d is more than or equal to 0 and less than or equal to 15, and y2 is more than or equal to 0.95 and less than or equal to 1.2; the rare earth-poor yttrium cerium-based alloy powder has a larger particle size than the rare earth-rich alloy powder; the rare earth total amount of the rare earth-lean yttrium-cerium-based alloy powder is less than the rare earth total amount of the rare earth-rich alloy powder.
2. The yttrium-cerium-based rare earth permanent magnetic material of claim 1, wherein the permanent magnetic material is prepared by mixing rare earth-poor yttrium-cerium-based alloy powder and rare earth-rich alloy powder without yttrium-cerium.
3. The yttrium-cerium-based rare earth permanent magnetic material of claim 2, wherein the permanent magnetic material is prepared by the following steps:
(1) preparing rare earth-poor yttrium cerium-based alloy powder to obtain alloy fine powder with the average particle size of 2-5 mu m;
(2) preparing rare earth-rich alloy powder to obtain alloy fine powder with the average particle size of 2-3 mu m;
(3) mixing the prepared rare earth-poor yttrium cerium-based powder with the rare earth-rich powder according to the weight ratio of 100-55: 1-40;
(4) carrying out orientation molding on the uniformly mixed powder in a 1.8-2T magnetic field press, and carrying out isostatic pressing at 180-220 MPa to obtain a green body;
(5) and sintering the green body in a vacuum sintering furnace, and then tempering under a protective atmosphere.
4. The yttrium-cerium-based rare earth permanent magnetic material of claim 1, wherein the magnetocrystalline anisotropy field of the hard magnetic shell layer is 20% to 50% higher than that of the inner layer of grains.
5. The yttrium-cerium-based rare earth permanent magnetic material according to claim 1, wherein the grain boundary phase composition between different main phase grains of the permanent magnetic material has the following segregation: the content of yttrium cerium element in a grain boundary phase among the yttrium cerium-rich main phase grains is higher than that in a grain boundary phase among the yttrium cerium-free main phase grains.
6. The yttrium-cerium-based rare earth permanent magnetic material according to claim 5, wherein the content of yttrium-cerium element in a grain boundary phase between the yttrium-cerium-rich main phase grains is 5 to 20% higher than that in a grain boundary phase between the yttrium-cerium-free main phase grains.
7. The yttrium-cerium-based rare earth permanent magnetic material of claim 1, wherein the permanent magnetic material comprises the following components in percentage by mass: the total amount of the rare earth is 30-31.6, wherein Y is 4.66-8, Ce is 4.66-8, PrNd is 14-21.64, and Ho is 0-0.84.
8. The yttrium-cerium-based rare earth permanent magnetic material according to claim 1, wherein the temperature coefficient of remanence of the permanent magnetic material is: the temperature of 20-100 ℃ ranges from-0.10%/DEG C to-0.04%/DEG C, and the intrinsic coercive force temperature coefficient of the permanent magnet material is as follows: at 20-100 ℃, the temperature is-0.70%/DEG C to-0.40%/DEG C; the density value of the permanent magnetic material is 7.20-7.55 g/cm 3.
9. The yttrium-cerium-based rare earth permanent magnetic material according to claim 1, wherein the temperature coefficient of remanence of the permanent magnetic material is: the temperature of 20-100 ℃ ranges from-0.10%/DEG C to-0.12%/DEG C, and the intrinsic coercive force temperature coefficient of the permanent magnet material is as follows: 20-100 ℃ is-0.69%/DEG C to-0.78%/DEG C; the density value of the permanent magnetic material is 7.47-7.51 g/cm 3.
10. A method for preparing a yttrium-cerium-based rare earth permanent magnetic material according to claim 1, comprising the steps of:
(1) preparing rare earth-lean yttrium cerium-based alloy powder, wherein the mass percent of the alloy powder is Ya1Ceb1（PrNd）c1（Fe，M）balBy1Wherein a is not less than 1 and not more than 1 and not more than 20, b is not less than 1 and not more than b1 and not more than 20, c is not less than 0.5 and not more than c1 and not more than 20, and y is not less than 0.95 and not more than y1 and not more than 1.2, and alloy fine powder with the average particle size of 2-5 mu m is obtained; wherein the pressure of the grinding gas of the jet mill is 0.5 +/-0.1 MPa, and the rotating speed of the grading wheel is 3500 rpm;
(2) preparing rare earth-rich alloy powder, wherein the mass percent of the alloy powder is (PrNd)c2HREd（Fe，M）balBy2，HRE is one or more of Ho, Tb, Dy and Gd, wherein c2 is more than or equal to 1 and less than or equal to 35, d is more than or equal to 0 and less than or equal to 15, y2 is more than or equal to 0.95 and less than or equal to 1.2, and alloy fine powder with the average particle size of 2-3 mu m is obtained; wherein the pressure of grinding gas of the jet mill is 0.8MPa, and the rotating speed of the grading wheel is 4500 rpm;
(3) mixing the prepared rare earth-poor yttrium cerium-based powder with the rare earth-rich powder according to the weight ratio of 100-55: 1-40;
(4) carrying out orientation molding on the uniformly mixed powder in a 1.8-2T magnetic field press, and carrying out isostatic pressing at 180-220 MPa to obtain a green body;
(5) and sintering the green body in a vacuum sintering furnace, and then tempering under a protective atmosphere.
11. The method for preparing a yttrium-cerium-based rare earth permanent magnetic material according to claim 10, wherein in the step (1), the raw material is proportioned according to the components of the rare earth-poor yttrium-cerium-based alloy powder, the raw material is ground to remove surface oxide skin and impurities before being proportioned and weighed, the raw material is prepared into a quick-setting sheet in a quick-setting furnace, the quick-setting sheet has an average thickness of 0.1-0.5 mm, then hydrogen crushing is carried out in a hydrogen crushing furnace to obtain hydrogen crushed powder, and the hydrogen crushed powder is mixed in a powder mixer for 2 +/-0.5 h and then subjected to air milling to obtain alloy fine powder with an average particle size of 2-5 μm.
12. The method for preparing a yttrium-cerium-based rare earth permanent magnetic material according to claim 10, wherein in the step (2), raw material proportioning is performed according to the components of the rare earth-rich alloy powder, the raw materials are polished to remove surface oxide scales and impurities before being proportioned and weighed, the raw materials are prepared into quick-setting tablets in a quick-setting furnace, the average thickness of the quick-setting tablets is 0.3-0.6 mm, hydrogen crushing is performed in a hydrogen crushing furnace to obtain hydrogen crushed powder, and the hydrogen crushed powder is mixed in a powder mixer and then subjected to air milling to obtain alloy fine powder with the average particle size of 2-3 μm.
13. The method of claim 10, wherein in the step (3), the lubricant is added in an amount of 0.05-0.2% by weight of the total weight of the mixed powder, and the mixed powder is mixed for 5 ± 0.5 hours, and the mixed powder has rare earth-poor yttrium cerium-based powder particles and rare earth-rich alloy powder particles without yttrium cerium.
14. The method for preparing the yttrium-cerium-based rare earth permanent magnetic material as claimed in claim 10, wherein in the step (5), the sintering temperature is 1050 ± 20 ℃, the sintering time is 2 ± 0.5h, and the vacuum degree is always better than 10 in the sintering process-3Pa, primary tempering at 880 + -50 deg.C, secondary tempering at 480 + -20 deg.C for 2 + -0.5 hr, and secondary tempering for maintainingThe temperature is 3 +/-0.5 h, and the tempering is carried out in the argon protection atmosphere.
15. The method for preparing the yttrium-cerium-based rare earth permanent magnetic material according to claim 10, comprising the following steps:
in the step (2), the (PrNd) is prepared by the following chemical coprecipitation-reduction methodc2HREd（Fe，M）balBy2Rare earth-rich alloy powder: respectively reacting chlorides RECl of rare earth elements3、FeCl3And BCl3Respectively dissolving in deionized water to form aqueous solution of chloride; will then be rich in (OH)-Adding the root solution into a chloride solution to form three types of chloride coprecipitates, and separating the coprecipitates from the solution by using filter paper; separating the obtained precipitate, and calcining to obtain an oxide; and then reducing the oxide in hydrogen to obtain final alloy powder, wherein the particle size of the alloy powder is 500 nm.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107275027A (en) * | 2017-05-11 | 2017-10-20 | 浙江大学 | Cerium-rich rare earth permanent magnet using yttrium and preparation method thereof |
| WO2018181592A1 (en) * | 2017-03-30 | 2018-10-04 | Tdk株式会社 | Permanent magnet and rotating machine |
| CN111210963A (en) * | 2020-02-07 | 2020-05-29 | 钢铁研究总院 | High-performance yttrium cerium based rare earth permanent magnet and preparation method thereof |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018181592A1 (en) * | 2017-03-30 | 2018-10-04 | Tdk株式会社 | Permanent magnet and rotating machine |
| CN107275027A (en) * | 2017-05-11 | 2017-10-20 | 浙江大学 | Cerium-rich rare earth permanent magnet using yttrium and preparation method thereof |
| CN111210963A (en) * | 2020-02-07 | 2020-05-29 | 钢铁研究总院 | High-performance yttrium cerium based rare earth permanent magnet and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| Atomic scale insights into the segregation/partitioning behaviour in as-sintered multi-main-phase Nd-Ce-Fe-B permanent magnets;Hansheng Chen;《Journal of Alloys and Compounds》;20200719;全文 * |
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