A high-boron y-cerium-co co-substituted nanocrystalline material and a preparation method thereof

Abstract

This invention discloses a high-boron Y–Ce–Co co-substituted nanocrystalline material and its preparation method. The general chemical formula of the nanocrystalline material, expressed as a percentage by mass, is: [RE x (Y y Ce 1‑y ) 1‑x ] z Fe 100‑z‑u‑v‑w Co u M v B w The composition is defined as follows: 0 ≤ x ≤ 0.9, 0.05 ≤ y ≤ 0.9, 25 ≤ z ≤ 35, 5 ≤ u ≤ 50, 0 ≤ v ≤ 3, 1.7 ≤ w ≤ 3. This invention utilizes Y–Ce–Co co-substitution to synergistically regulate the lattice occupancy, elemental valence states, and magnetic exchange interactions of the main phase, significantly improving the temperature stability of the Ce-rich system. Addressing the issues of abnormal grain growth and excessive Laves phase precipitation caused by Co introduction, increasing the mass percentage of B significantly enhances the alloy's amorphous forming ability, refines the main phase grains, and suppresses the formation of harmful second phases. Based on this compositional design, a low-linear-velocity melt rapid quenching process (12 to 18 m / s) can directly prepare materials with uniform nanocrystalline structures without subsequent crystallization annealing, achieving high coercivity and high temperature resistance while significantly reducing raw material costs.

Description

Technical Field

[0001] This invention relates to the field of magnetic materials technology, specifically to a high-boron Y–Ce–Co co-substituted nanocrystalline material and its preparation method. This invention utilizes high boron content to control the microstructure, achieving the direct preparation of high-temperature-stability Ce-rich nanocrystalline materials at low cooling rates. Background Technology

[0002] Nd–Fe–B nanocrystalline materials, due to their excellent comprehensive magnetic properties, are widely used in the fabrication of bonded magnets and hot-pressed / hot-deformed magnets. However, traditional Nd–Fe–B materials are highly dependent on the expensive and scarce Nd and Pr elements, resulting in high production costs. To reduce costs and promote the balanced utilization of rare earth resources, the introduction of high-abundance, low-cost Ce elements into the alloy has become an important development direction in the industry. However, the introduction of Ce significantly reduces the saturation magnetization, magnetocrystalline anisotropy field, and Curie temperature of the magnet's main phase, leading to a substantial decrease in the material's room-temperature magnetic properties and temperature stability. Especially in terms of temperature stability, due to Ce₂Fe 14 The Curie temperature of phase B is only 424 K, far lower than that of Nd2Fe. 14 The 585 K of the B phase causes the magnetic properties of Nd–Ce–Fe–B permanent magnet materials to decay sharply with increasing temperature, significantly limiting their application stability in high-temperature environments.

[0003] Existing methods for improving the temperature stability of Ce-rich nanocrystalline materials mainly involve introducing Y and Co elements. These methods utilize the grain-refining effect of Y and Y₂Fe₂. 14The anomalous magnetocrystalline anisotropy temperature coefficient of boron, combined with the significant increase in the Curie temperature of the 2:14:1 main phase by cobalt, can improve temperature stability. However, the introduction of these elements still has limitations: excessive addition of y and cobalt can easily lead to coarsening of the main phase grains, resulting in deterioration of room-temperature magnetic properties; and the introduction of cobalt can easily induce the precipitation of a large amount of RE(Fe, Co)2 type Laves phase. This type of second phase is usually weakly magnetic or non-magnetic, which not only depletes the effective rare earth elements but also destroys the uniformity of the material's microstructure, causing a significant decrease in room-temperature remanence and coercivity. The addition of small amounts of y and cobalt, on the other hand, has very limited effect on improving the material's temperature resistance. In existing technologies, such as patent CN111161949B, a method for preparing Y-Ce co-doped nanocrystalline rare-earth permanent magnets is disclosed. This method involves mixing Y-Ce-containing main powder and auxiliary powder in a certain mass ratio, followed by hot pressing and hot deformation to prepare nanocrystalline rare-earth permanent magnets. While this method can simultaneously improve the magnetic properties and temperature stability of the magnets, the magnetic properties of high-Y-content magnets still deteriorate rapidly, and the improvement in temperature stability is limited. Furthermore, in industrial production, while higher cooling copper roller speeds (e.g., above 30 m / s) are beneficial for grain refinement, they significantly increase the process difficulty and energy consumption. The current technical challenge is how to fully utilize the advantages of Y-Co co-substitution in improving the temperature stability of Ce-rich nanocrystalline materials at low linear speeds, while effectively suppressing the decline in room-temperature magnetic properties caused by microstructural degradation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and to propose a high-boron Y–Ce–Co co-substituted nanocrystalline material and its preparation method.

[0005] This method effectively solves the problems of grain growth and excessive Laves phase precipitation caused by Y–Ce–Co co-substitution by increasing the boron content, significantly improving the temperature coefficient while ensuring room-temperature magnetic properties. This opens up a new technical path for preparing Ce-rich nanocrystalline materials with high temperature resistance. The nanocrystalline magnets prepared by this invention, with high Y–Ce–Co substitution, possess high coercivity and high temperature stability, and require no crystallization heat treatment step.

[0006] This invention first provides a high-boron Y–Ce–Co co-substituted nanocrystalline material, the main phase of which is an Nd–Fe–B type tetragonal structure, and its general chemical formula expressed in mass percentage is: [RE x (Y y Ce 1-y ) 1-x ] z Fe 100-z-u-v-w Co u M v B wWhere RE is one or more of the rare earth elements La, Pr, Nd, Gd, Tb, Dy, Ho, and Er; M is one or more of the elements Al, Cr, Cu, Ga, Mn, Mo, N, Nb, P, Pb, Sb, Sn, Si, Ta, Ti, V, W, Zn, and Zr; and x, y, z, u, v, and w, expressed as mass percentages, satisfy the following relationships: 0 ≤ x ≤ 0.9, 0.05 ≤ y ≤ 0.9, 25 ≤ z ≤ 35, 5 ≤ u ≤ 50, 0 ≤ v ≤ 3, and 1.7 ≤ w ≤ 3. B accounts for 1.7% to 3% of the total mass of the material. The nanocrystalline material is prepared by a melt rapid quenching process. The melt rapid quenching process involves spraying melt onto a rotating roller with a surface linear velocity of 12 to 18 m / s, and the melt directly solidifies into a material with a nanocrystalline structure.

[0007] The microstructure of the material is a uniform nanocrystalline structure obtained directly by a rapid quenching process, with an average size of 10~100 nm for the main phase grains.

[0008] This invention suppresses the coarsening of the main phase grains and the formation of the Laves phase caused by the introduction of Co at a cooling roller linear speed of 12~18 m / s, achieving direct ribbon formation without crystallization annealing. Therefore, preferably, the nanocrystalline material is directly condensed into ribbons through the melt rapid quenching process without crystallization annealing.

[0009] The present invention also provides a method for preparing the aforementioned high-boron Y–Ce–Co co-substituted nanocrystalline material, which includes the following steps:

[0010] 1) Ingredients: Weigh out the elemental metals RE, Y, Ce, Fe, Co, M and Fe-B master alloy raw materials with a purity of not less than 99.5% according to the mass percentage ratio of the general chemical formula. Among them, RE is one or more of the rare earth elements La, Pr, Nd, Gd, Tb, Dy, Ho and Er, and M is one or more of the elements Al, Cr, Cu, Ga, Mn, Mo, N, Nb, P, Pb, Sb, Sn, Si, Ta, Ti, V, W, Zn and Zr.

[0011] 2) Smelting: The prepared raw materials are placed in a smelting furnace and smelted under the protection of inert gas to obtain alloy ingots with uniform composition;

[0012] 3) Rapid quenching of melt: After the alloy ingot is crushed, it is placed in a melting container with nozzles. After induction melting, the spraying pressure is controlled at 0.05~0.2 MPa, and the melt is sprayed onto a rotating roller with a surface linear velocity of 12~18 m / s. The melt is directly solidified into a material with a nanocrystalline structure.

[0013] According to a preferred embodiment of the present invention, the induction melting in step 2) includes multiple repetitive and identical melting operations. Each melting operation is as follows: first, the raw materials are fully melted into a liquid; after confirming that all metal raw materials have melted into a liquid, magnetic stirring is started and melting is continued for 4-5 minutes; then, the alloy liquid is cooled into a solid. After the previous melting operation is completed, the cooled solid alloy is turned over, and then the melting operation is repeated. Preferably, the induction melting stage in step 2) is repeated 3-5 times.

[0014] According to a preferred embodiment of the present invention, the induction melting in step 3) is achieved by high-frequency induction heating with a heating rate of 10~300 ℃ / s, heating the alloy ingot to 1100~1550 ℃ and holding it for 1~10 min to make the melt composition uniform.

[0015] According to a preferred embodiment of the present invention, the rotating roller in step 3) is a metal roller, the material of which is selected from pure copper, chromium zirconium copper alloy or beryllium copper alloy.

[0016] According to a preferred embodiment of the present invention, in step 3), the surface linear velocity of the rotating roller is 14~16 m / s (preferably 15 m / s).

[0017] According to a preferred embodiment of the present invention, during the spraying process in step 3), the distance between the spray nozzle and the surface of the rotating roller is controlled to be 0.3~2.0 mm.

[0018] The high-boron Y–Ce–Co co-substituted nanocrystalline material provided by this invention can be used to prepare bonded permanent magnets and hot-pressed hot-deformed permanent magnets that have high magnetic properties, high temperature resistance, and low cost, and can be used in magnetic electronic components such as automotive electronics, industrial robots, energy-saving home appliances, sensors, and drone power systems.

[0019] Compared with existing technologies, the technical concept of this invention lies in achieving a synergistic improvement in the room-temperature magnetic properties and temperature stability of Ce-rich nanocrystalline materials by controlling the boron content and introducing the synergistic regulatory effect of Y–Ce–Co co-substitution. Its technical advantages are specifically reflected in the following three aspects:

[0020] 1) Y-Co Synergistic Enhancement of Temperature Stability: In Ce-rich systems, Ce substitution for Nd significantly reduces the Curie temperature and magnetic properties of the material. This invention, through the joint introduction of Y and Co, utilizes the substitution of Fe atoms by Co to enhance interatomic exchange interactions within the main phase, thereby significantly increasing the Curie temperature. Simultaneously, Y₂Fe 14The temperature coefficient of the anomalous magnetocrystalline anisotropy field of B can further improve the temperature stability of Y–Ce–Co co-substituted nanocrystalline magnets. It also has a synergistic effect with Co, playing a beneficial role in the fine structure control of Ce valence state and element occupancy, and effectively improving the remanence retention rate and coercivity stability of the material under high temperature environment.

[0021] 2) Suppression of "Co Side Effects" by High Boron Content: While the introduction of Co is beneficial for improving temperature stability, Co significantly deteriorates the amorphous forming ability of the alloy and readily promotes the formation of RE(Fe, Co)2-type Laves phases during rapid quenching. These harmful phases consume rare earth elements and deteriorate magnetic properties. The B content of traditional Nd–Fe–B magnets is generally limited to 0.8 to 1.3%, while this invention increases the mass percentage of B content to 1.7 to 3%. By significantly enhancing the amorphous forming ability of the alloy melt and thus controlling the solidification path, this invention effectively suppresses the nucleation process of the Laves phase, refining the grains while ensuring that the alloy is mainly composed of a 2:14:1 hard magnetic phase. Simultaneously, the nonferromagnetic boron-rich phase and amorphous structure formed in the alloy can pin the domain walls, thereby improving magnetic properties.

[0022] 3) Achieving direct ribbon formation at low linear speeds: In conventional Nd–Fe–B production, obtaining nanocrystals typically requires extremely high linear speeds (>30 m / s) to obtain amorphous ribbons followed by necessary crystallization heat treatment to achieve a uniform nanocrystalline structure. Alternatively, nanocrystals can be directly obtained at medium linear speeds (20 to 25 m / s), but the resulting ribbon exhibits poor uniformity from the roller-attached surface to the free surface. This invention, at a relatively low cooling rate of approximately 14–16 m / s, utilizes the retardation effect of a high-boron formulation on atomic diffusion to directly obtain a uniform nanocrystalline structure of 10–100 nm without the need for crystallization heat treatment. This not only simplifies the production process and reduces equipment wear and energy consumption but also avoids the non-uniform grain growth that may result from subsequent heat treatment. Attached Figure Description

[0023] Figure 1 The X-ray powder diffraction results are shown for Example 3 and Comparative Examples 3-5.

[0024] Figure 2 This is a scanning electron microscope image of Comparative Example 3;

[0025] Figure 3 Here is a scanning electron microscope image of Example 3;

[0026] Figure 4 The transmission electron microscopy nanobeam electron diffraction results for Example 3 are shown below.

[0027] Figure 5 The result is the Fast Fourier Transform of high-resolution transmission electron microscopy in Comparative Example 3;

[0028] Figure 6 This is a bright-field image obtained by transmission electron microscopy in Example 6. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments:

[0030] Example 1:

[0031] According to the nominal component [Nd 0.5 (Y 0.1 Ce 0.9 ) 0.5 ] 30.5 Fe bal Co5Al 0.2 B 1.7 The mass percentage ratio of elemental metals Nd, Y, Ce, Fe, Co, and Fe-B master alloy raw materials with a purity of 99.5% was weighed. The prepared raw materials were placed in a melting furnace and first melted completely into a liquid. After confirming that all metal raw materials had melted into a liquid, magnetic stirring was turned on and melting was continued for 5 minutes. Then, the alloy liquid was cooled into a solid. After the previous melting operation was completed, the cooled solid alloy was turned over, and the melting operation was repeated 5 times to obtain an alloy ingot with uniform composition. The alloy ingot was broken and placed in a melting container with nozzles. The alloy ingot was heated to 1300 °C by high-frequency induction and held for 1 minute to ensure uniform melt composition. The injection pressure was controlled at 0.1 MPa, and the melt was sprayed onto a rotating roller with a surface linear velocity of 15 m / s. During the spraying process, the distance between the nozzle and the surface of the rotating roller was controlled at 0.6 mm. The melt directly solidified into a material with a nanocrystalline structure. The corresponding magnetic measurement results show that its magnetic properties are: H cj =1.15 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.16% / ℃ and -0.35% / ℃, respectively.

[0032] Comparative Example 1:

[0033] The difference between Comparative Example 1 and Example 1 lies in their composition; the other preparation methods are the same as in Example 1. The composition of Comparative Example 1 is [Nd...]. 0.5 Ce 0.5 ] 30.5 Fe bal Co5Al 0.2 B 1.7 The corresponding magnetic measurement results show that its magnetic properties are: H cj =1.05T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.20% / ℃ and -0.4% / ℃, respectively.

[0034] Example 2:

[0035] Example 2 differs from Example 1 in that it contains different components; the other preparation methods are the same as in Example 1. The component of Example 2 is [Nd...]. 0.5 (Y 0.15 Ce 0.85 ) 0.5 ] 30.5 Fe bal Co5Al 0.2 B 1.7 The corresponding magnetic measurement results show that its magnetic properties are: H cj =1.18 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.15% / ℃ and -0.34% / ℃, respectively.

[0036] Comparative Example 2:

[0037] The difference between Comparative Example 2 and Example 2 lies in their composition; the other preparation methods are the same as in Example 2. The composition of Comparative Example 2 is [Nd...]. 0.5 (Y 0.15 Ce 0.85 ) 0.5 ] 30.5 Fe bal Al 0.2 B 1.7 The corresponding magnetic measurement results show that its magnetic properties are: H cj =1.15 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.17% / ℃ and -0.39% / ℃, respectively.

[0038] Example 3:

[0039] Example 3 differs from Example 1 in its composition; the other preparation methods are the same as in Example 1. The composition of Example 3 is [Nd...]. 0.5 (Y 0.15 Ce 0.85 ) 0.5 ] 30.5 Fe bal Co 40 Ga 0.3 B 2.5 The corresponding magnetic measurement results show that its magnetic properties are: H cj =0.95 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.06% / ℃ and -0.36% / ℃, respectively; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 427 ℃ are -0.11% / ℃ and -0.22% / ℃, respectively.

[0040] Comparative Example 3:

[0041] The difference between Comparative Example 3 and Example 3 lies in their composition; the other preparation methods are the same as in Example 3. The composition of Comparative Example 3 is [Nd...]. 0.5 (Y 0.15 Ce 0.85 ) 0.5 ] 30.5 Fe bal Co 40 Ga 0.3 B1, the corresponding magnetic measurement results show that its magnetic properties are: H cj =0.52 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.15% / ℃ and -0.44% / ℃, respectively; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 427 ℃ are -0.22% / ℃ and -0.38% / ℃, respectively.

[0042] Comparative Example 4:

[0043] The difference between Comparative Example 4 and Example 3 lies in their composition; the other preparation methods are the same as in Example 3. The composition of Comparative Example 4 is [Nd...]. 0.5 (Y 0.15 Ce 0.85 ) 0.5 ] 30.5 Fe bal Co 40 Ga 0.3 B 3.5 The corresponding magnetic measurement results show that its magnetic properties are: H cj =0.42 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.10% / ℃ and -0.45% / ℃, respectively; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 427 ℃ are -0.20% / ℃ and -0.35% / ℃, respectively.

[0044] Comparative Example 5: The difference between Comparative Example 5 and Example 3 is that the linear velocity of the rotating roller, the composition, and other preparation methods are the same as in Example 3. The linear velocity of Comparative Example 5 is 25 m / s, and the corresponding magnetic measurement results show that its magnetic properties are: H cj =0.25T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.11% / ℃ and -0.48% / ℃, respectively; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 427 ℃ are -0.22% / ℃ and -0.39% / ℃, respectively.

[0045] Example 4:

[0046] Example 4 differs from Example 1 in its composition; the other preparation methods are the same as in Example 1. The composition of Example 4 is [Nd...]. 0.5 (Y 0.15 Ce 0.85) 0.5 ] 30.5 Fe bal Co 50 Cu 0.2 B 2.3 The corresponding magnetic measurement results show that its magnetic properties are: H cj =0.55 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.06% / ℃ and -0.36% / ℃, respectively; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 427 ℃ are -0.11% / ℃ and -0.22% / ℃, respectively.

[0047] Comparative Example 6:

[0048] The difference between Comparative Example 6 and Example 4 lies in their composition; the other preparation methods are the same as in Example 4. The composition of Comparative Example 6 is [Nd...]. 0.5 (Y 0.15 Ce 0.85 ) 0.5 ] 30.5 Fe bal Co 60 Cu 0.2 B 2.3 The corresponding magnetic measurement results show that its magnetic properties are: H cj =0.18 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.05% / ℃ and -0.40% / ℃, respectively; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 427 ℃ are -0.20% / ℃ and -0.35% / ℃, respectively.

[0049] Example 5:

[0050] Example 5 differs from Example 4 in composition, linear velocity, and injection pressure; the other preparation methods are the same as in Example 4. The composition of Example 5 is [Nd...]. 0.5 (Y 0.15 Ce 0.85 ) 0.5 ] 30.5 Fe bal Co 50 Cu 0.2 B2, with a linear velocity of 18 m / s and an injection pressure of 0.12 MPa, has the following magnetic properties as determined by magnetic measurements: H cj =0.54 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.06% / ℃ and -0.35% / ℃, respectively; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 427 ℃ are -0.11% / ℃ and -0.21% / ℃, respectively.

[0051] Comparative Example 7:

[0052] The difference between Comparative Example 7 and Example 5 lies in the linear velocity and the addition of a crystallization heat treatment step; the other preparation methods are the same as in Example 5. The linear velocity of Comparative Example 7 was 25 m / s. The obtained material was placed in a tube furnace under an argon atmosphere for crystallization heat treatment at a temperature of 600 °C for 5 min. Corresponding magnetic measurement results showed that its magnetic properties were: H... cj =0.41 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.07% / ℃ and -0.38% / ℃, respectively; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 427 ℃ are -0.13% / ℃ and -0.26% / ℃, respectively.

[0053] Example 6:

[0054] Example 6 differs from Example 1 in its composition; the other preparation methods are the same as in Example 1. The composition of Example 6 is [Nd...]. 0.5 (Y 0.9 Ce 0.1 ) 0.5 ] 30.5 Fe bal Co5Zr 0.2 B 1.7 The corresponding magnetic measurement results show that its magnetic properties are: H cj =1.26 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.1% / ℃ and -0.31% / ℃, respectively.

[0055] Comparative Example 8:

[0056] The difference between Comparative Example 8 and Example 6 lies in their composition; the other preparation methods are the same as in Example 6. The composition of Comparative Example 8 is [Nd...]. 0.5 (Y 0.95 Ce 0.05 ) 0.5 ] 30.5 Fe bal Co5Zr 0.2 B 1.7 The corresponding magnetic measurement results show that its magnetic properties are: H cj =1.12 T; the temperature coefficients of remanence and coercivity in the range of 27 ℃ to 127 ℃ are -0.12% / ℃ and -0.33% / ℃, respectively.

[0057] A comprehensive analysis of Examples 1–6 and Comparative Examples 1–8 shows that the nanocrystalline materials prepared using the process of this invention still exhibit excellent room temperature coercivity and high temperature stability even at relatively low roller speeds.

[0058] Further analysis combining phase and microstructure, Figure 1The X-ray diffraction (XRD) results showed that in Comparative Example 3, the diffraction peak intensity corresponding to the Laves-type RE(Fe, Co)2 phase was relatively high, indicating a higher content of this phase, which led to deterioration of magnetic properties. In contrast, the diffraction peaks of the RE(Fe, Co)2 phase in Example 3 almost disappeared, indicating that this phase was effectively suppressed, which is beneficial to improving the magnetic properties of the material. In addition, the overall intensity of the diffraction peaks in Comparative Example 5 decreased significantly, and typical amorphous "bun peaks" appeared, indicating that a large number of amorphous phases were generated in the microstructure.

[0059] pass Figure 2 and Figure 3 As can be seen from the scanning electron microscope (SEM) morphology comparison, the grain size of Example 3 is significantly smaller than that of Comparative Example 3, which helps to improve the magnetic properties. Figures 4 to 6 Transmission electron microscopy (TEM) analysis further confirmed that Example 3 was mainly composed of a tetragonal 2:14:1 main phase; while Comparative Example 3 contained more cubic RE(Fe, Co)2 phase. The experimental results show that the presence of a large amount of RE(Fe, Co)2 phase in the material has a serious negative impact on the magnetic properties. Example 6 demonstrates the nanostructure characteristics of a boron-rich phase as a grain boundary phase surrounding the 2:14:1 main phase.

[0060] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A high-boron Y–Ce–Co co-substituted nanocrystalline material, characterized in that, Its main phase is Nd2Fe 14 Type B tetragonal structure, its general chemical formula expressed as a mass percentage is: [RE x (Y y Ce 1-y ) 1-x ] z Fe 100-z-u-v-w Co u M v B w RE is one or more of the rare earth elements La, Pr, Nd, Gd, Tb, Dy, Ho, and Er; M is one or more of the elements Al, Cr, Cu, Ga, Mn, Mo, N, Nb, P, Pb, Sb, Sn, Si, Ta, Ti, V, W, Zn, and Zr; x, y, z, u, v, and w are expressed as mass percentages and satisfy the following relationships: 0 ≤ x ≤ 0.9, 0.05 ≤ y ≤ 0.9, 25 ≤ z ≤ 35, 5 ≤ u ≤ 50, 0 ≤ v ≤ 3, and 1.7 ≤ w ≤ 3; B accounts for 1.7% to 3% of the total mass of the material. The nanocrystalline material is prepared by a melt rapid quenching process; the melt rapid quenching process involves spraying melt onto a rotating roller with a surface linear velocity of 12 m / s to 18 m / s, and the melt directly solidifies into a material with a uniform nanocrystalline structure.

2. The high-boron Y–Ce–Co co-substituted nanocrystalline material according to claim 1, characterized in that, The microstructure of the material is a uniform nanocrystalline structure obtained directly by a rapid quenching process, with an average size of 10~100nm for the main phase grains.

3. The high-boron Y–Ce–Co co-substituted nanocrystalline material according to claim 1, characterized in that, The nanocrystalline material is directly condensed into a ribbon through the melt quenching process without crystallization annealing.

4. A method for preparing a high-boron Y–Ce–Co co-substituted nanocrystalline material as described in any one of claims 1 to 3, characterized in that, Includes the following steps: 1) Ingredients: Weigh out the elemental metals RE, Y, Ce, Fe, Co, M and Fe-B master alloy raw materials with a purity of not less than 99.5% according to the mass percentage ratio of the general chemical formula. Among them, RE is one or more of the rare earth elements La, Pr, Nd, Gd, Tb, Dy, Ho and Er, and M is one or more of the elements Al, Cr, Cu, Ga, Mn, Mo, N, Nb, P, Pb, Sb, Sn, Si, Ta, Ti, V, W, Zn and Zr. 2) Smelting: The prepared raw materials are placed in a smelting furnace and smelted under the protection of inert gas to obtain alloy ingots with uniform composition; 3) Rapid quenching of melt: After the alloy ingot is crushed, it is placed in a melting container with nozzles. After melting, the spraying pressure is controlled at 0.05~0.2 MPa, and the melt is sprayed onto a rotating roller with a surface linear velocity of 12~18 m / s. The melt is directly solidified into a material with a nanocrystalline structure.

5. The method for preparing the high-boron Y–Ce–Co co-substituted nanocrystalline material according to claim 4, characterized in that, Step 3) The melting is achieved by high-frequency induction heating at a heating rate of 10~300 ℃ / s. The alloy ingot is heated to 1100~1550 ℃ and held for 1~10 min to make the melt composition uniform.

6. The method for preparing the high-boron Y–Ce–Co co-substituted nanocrystalline material according to claim 4, characterized in that, Step 3) The rotating roller is a metal roller, and its material is selected from pure copper, chromium zirconium copper alloy or beryllium copper alloy.

7. The method for preparing the high-boron Y–Ce–Co co-substituted nanocrystalline material according to claim 4, characterized in that, In step 3), the surface linear velocity of the rotating roller is 14~16 m / s.

8. The method for preparing the high-boron Y–Ce–Co co-substituted nanocrystalline material according to claim 4, characterized in that, During the spraying process in step 3), the distance between the spray nozzle and the surface of the rotating roller is controlled to be 0.3~2.0 mm.

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