A precisely formed high performance cerium magnet and a method of making the same

Abstract

This invention relates to a precision-formed high-performance cerium magnet and its preparation method, belonging to the field of rare-earth permanent magnet materials technology. It addresses at least one of the problems in existing cerium magnets with large aspect ratios: low dimensional accuracy, poor uniformity of shrinkage deformation, low magnetic properties, and high cost. The method of this invention improves the uniformity and flowability of the magnetic powder by controlling the particle size of the cerium magnet alloy powder and using additives, combined with the control of vibration pressure sieving and a low-oxygen atmosphere under heating conditions. Furthermore, it utilizes high-magnetic-field pre-orientation pressing and assisted support sintering processes to achieve the pressing of uniform, high-density green blanks with large aspect ratios and the preparation of magnets with small deformation, balancing high magnetic uniformity and low impurity content. The cerium magnet prepared by this invention has good magnetic performance and structural dimensional consistency, making it suitable for low-cost production of high-quality cerium magnets.

Description

Technical Field

[0001] This invention relates to the field of rare earth permanent magnet materials technology, and in particular to a precision-formed high-performance cerium magnet and its preparation method. Background Technology

[0002] Sintered rare earth permanent magnet materials possess excellent performance and are key functional materials supporting the development of emerging industries such as new energy, intelligent manufacturing, and energy conservation and environmental protection. Traditional praseodymium-neodymium magnets suffer from high manufacturing costs due to the imbalance between rare earth resource reserves and consumption, which also hinders the balanced utilization of rare earth resources. Cerium, as a light rare earth element, has abundant reserves, ample market supply, and low price. Therefore, the development and production of cerium magnets can significantly reduce the cost of permanent magnet materials and optimize the comprehensive utilization of rare earth resources.

[0003] Because cerium-containing magnets are more prone to oxidation during preparation, have lower intrinsic magnetic properties, and exhibit poor sintering stability, existing processes struggle to simultaneously control the performance and structural consistency of cerium magnets. Problems arise during preparation, including low green body orientation, uneven density, and high sintering shrinkage deformation, leading to significant dimensional deformation in the prepared magnets, difficulty in ensuring performance consistency, increased consumption of rare earth materials, and insufficient magnetic properties. In particular, with the increasing demands for miniaturization, high consistency, and low cost in permanent magnet applications, existing sintered rare earth permanent magnet preparation technologies are insufficient to meet the requirements for precise sintering dimensional control and high overall performance. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a precision-formed high-performance cerium magnet and its preparation method, so as to solve at least one of the problems of low dimensional accuracy, poor uniformity of shrinkage deformation, low magnetic properties and high cost of cerium magnets with large aspect ratio in the prior art.

[0005] In a first aspect, the present invention provides a method for preparing a precision-formed high-performance cerium magnet, the method comprising the following steps: S1: Prepare raw materials according to the composition of cerium magnet alloy, melt the raw materials in vacuum to form rapid solidification castings, and crush the castings into fine magnetic powder with a particle size of 1.5~3.0μm; S2: Add 0.4~0.8% of additives to the fine magnetic powder, mix the powder under inert gas protection, and perform vibration pressure sieving under heated gas protection. The treated magnetic powder is then oriented and pressed into a green blank by magnetic field. S3: The green blank is loaded into a material box and then subjected to sintering and tempering to obtain the high-performance cerium magnet.

[0006] Furthermore, in S1, the mass percentage of cerium in the cerium magnet alloy is 10-20%.

[0007] Furthermore, in S2, the oxygen content in the inert gas is ≤10ppm, and the mixing time is ≥3h.

[0008] Furthermore, in S2, the pressing process includes first pre-orienting the powder, and then further pressing it into a green compact; And / or, in S2, the heating temperature is 50~80℃ and the pressure is 0.15~0.4MPa.

[0009] Furthermore, the magnetic field strength of the powder loading is ≥3.0T, and the powder density is 1.5~2.5 g / cm³. 3 The magnetic field strength for further suppression is 1.8~2T, and the suppression time is 10~20s.

[0010] Furthermore, in S2, the density of the green body is ≥4.1 g / cm³. 3 .

[0011] Furthermore, in S3, the material box is provided with a support partition for fixing and supporting the green blank. The support partition limits the orientation direction of the green blank to 60~75° with the horizontal bottom surface of the material box, and multiple green blanks are stacked and aligned along the same center line.

[0012] Furthermore, in S3, the sintering is carried out in a vacuum furnace, and the sintering process involves first stabilizing the furnace at 150~250℃ for 2~4 hours, then raising the temperature to 1000~1040℃ and holding it for 2~5 hours, and finally cooling it to below 200℃.

[0013] Furthermore, in S3, the aspect ratio of the high-performance cerium magnet is ≥4, the maximum length of the magnet is ≤100mm, and the maximum deformation is ≤0.3mm.

[0014] Secondly, the present invention provides a high-performance cerium magnet prepared by the above method, wherein the remanence of the high-performance cerium magnet is ≥11.5kGs and the magnet density uniformity is ≤0.5%.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. The method of the present invention improves the uniformity and fluidity of magnetic powder mixing by controlling the particle size of cerium magnet alloy powder and using additives, combined with the control of vibrating pressure sieving and low oxygen content atmosphere under heating conditions. This lays the foundation for pressing and orientation forming of high-density, highly oriented green bodies, while balancing the improvement of magnetic powder fluidity with low impurity content.

[0016] 2. The method of the present invention further regulates the matrix orientation and density consistency of the pressed green body through the pre-oriented pressing process, thereby obtaining a controlled preparation of a high-uniformity, high-density green body formed in one step. This ensures the control of the pressing dimensional accuracy and uniformity of the formed magnet, reduces the impact of the non-uniformity of the formed structure size and poor density distribution on the deformation and performance of the sintered magnet, and provides the maximum guarantee for the stable control of the shrinkage deformation consistency of the sintered magnet.

[0017] 3. This invention utilizes the support partition inside the material box to a certain extent to limit the deformation and dimensional consistency of the magnet during the sintering shrinkage process. The stability treatment in the low-temperature section suppresses the stability of the magnet sintering process and further reduces the impurity content of the magnet, thereby improving the comprehensive performance of the high-cerium magnet with a length-to-diameter ratio. The first-stage tempering heat treatment shortens the heat treatment process. Combined with the addition of high cerium content, the production process cost is reduced while obtaining excellent cerium magnet magnetic properties.

[0018] 4. This invention effectively controls the dimensional accuracy of the cerium magnet manufacturing process through the above-mentioned processes and parameters. This improves the overall performance of cerium magnets while achieving stable production of high aspect ratio cerium magnets. It reduces the loss of matrix material and the decline in performance and consistency caused by differences in magnet deformation and density, thus achieving low-cost production of high-performance cerium magnets. The remanence of the high-performance cerium magnet is ≥11.5 kGs, and the magnet density consistency is ≤0.5%. The cerium magnets prepared by this invention have good magnetic performance and structural dimensional consistency, making them suitable for low-cost production of high-quality cerium magnets.

[0019] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0020] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0021] Figure 1 The curve shows the typical density uniformity variation of the high-performance cerium magnet prepared in Example 1 of this invention. Detailed Implementation

[0022] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0023] A specific embodiment of the present invention discloses a method for preparing a precision-formed high-performance cerium magnet, the method comprising the following steps: S1: Prepare raw materials according to the composition of cerium magnet alloy, melt the raw materials under vacuum to form rapid solidification castings, and crush the castings into powder with a particle size of 1.5~3.0μm (e.g., 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2.0μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3.0μm). S2: Add 0.4~0.8% (e.g., 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%) of additives to the fine magnetic powder, mix the powder under inert gas protection, and perform vibration pressure sieving under heated gas protection. The treated magnetic powder is then oriented and pressed into a green body by magnetic field orientation. S3: The green blank is loaded into a material box and then subjected to sintering and tempering to obtain the high-performance cerium magnet.

[0024] Compared with existing technologies, the method of this invention improves the uniformity and flowability of magnetic powder mixing by controlling the particle size of cerium magnet alloy powder and using additives, combined with the control of vibratory pressure sieving and low-oxygen atmosphere under heating conditions. This lays the foundation for the pressing and orientation forming of high-density, highly oriented green blanks, balancing improved magnetic powder flowability with low impurity content. It should be noted that the control of vibratory pressure sieving and low-oxygen atmosphere under heating conditions, combined with additives, improves the uniformity of powder mixing, reduces agglomeration and frictional resistance, and improves compaction flowability and density consistency; simultaneously, it reduces the internal stress of the formed green blank and improves process stability. The additives used in this invention are all commonly used additives in existing technologies, such as lubricants and / or antioxidants. Specifically, in S1, the mass percentage of cerium in the cerium magnet alloy is 10-20%, for example, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%.

[0025] It should be noted that the method of the present invention is applicable to cerium-containing rare earth permanent magnet materials with a cerium content of 10-20% by mass in the prior art.

[0026] Specifically, in S2, the oxygen content in the inert gas is ≤10ppm, for example, 9ppm, 8ppm, 7ppm, 6ppm, 5ppm, and the mixing time is ≥3h, for example, 3h, 3.2h, 3.4h, 3.6h, 3.8h, 4h, etc.

[0027] Preferably, the inert gas is Ar or other inert gas.

[0028] Specifically, in S2, the heating temperature is 50~80℃, for example, 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, 72℃, 74℃, 76℃, 78℃, 80℃, and the pressure in the pressure screening process is 0.15~0.4MPa, for example, 0.15MPa, 0.17MPa, 0.19MPa, 0.20MPa, 0.22MPa, 0.24MPa, 0.26MPa, 0.28MPa, 0.3MPa, 0.32MPa, 0.34MPa, 0.36MPa, 0.38MPa, 0.4MPa.

[0029] Specifically, in S2, the pressing process includes first pre-orienting the powder, and then further pressing it into a green blank.

[0030] Preferably, the magnetic field strength of the powder loading is ≥3.0T, for example, 3.0T, 3.2T, 3.4T, 3.6T, 3.8T, 4.0T, etc., and the powder loading density is 1.5~2.5 g / cm³. 3 For example, 1.5g / cm 3 1.6g / cm 3 1.7g / cm 3 1.8g / cm 3 1.9g / cm 3 2.0g / cm 3 2.2g / cm 3 2.3g / cm 3 2.4g / cm 3 2.5g / cm 3 The magnetic field strength for further suppression is 1.8~2T, for example, 1.8T, 1.82T, 1.84T, 1.86T, 1.88T, 1.9T, 1.92T, 1.94T, 1.96T, 1.98T, 2T, and the suppression time is 10~20s, for example, 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s, 20s.

[0031] It should be noted that the method of the present invention further regulates the matrix orientation and density consistency of the pressed green body through the pre-oriented pressing process, thereby obtaining a controlled preparation of a high-uniformity, high-density green body formed in one step. This ensures the control of the pressing dimensional accuracy and uniformity of the formed magnet, reduces the impact of the non-uniformity of the formed structure size and poor density distribution on the deformation and performance of the sintered magnet, and provides the maximum guarantee for the stable control of the shrinkage deformation consistency of the sintered magnet.

[0032] More preferably, in S2, the density of the green body is ≥4.1 g / cm³.3 For example, 4.1 g / cm³ 3 4.2g / cm 3 4.3g / cm 3 4.4 g / cm 3 4.5g / cm 3 4.6g / cm 3 4.7g / cm 3 4.8g / cm 3 .

[0033] Specifically, in S3, the material box is provided with a support partition for fixing and supporting the green blank. The support partition limits the orientation of the green blank to be placed at an angle of 60~75° with the horizontal bottom surface of the material box, for example, 60°, 62°, 64°, 66°, 68°, 70°, 72°, 74°, 75°, and multiple green blanks are stacked and aligned along the same center line.

[0034] Specifically, in S3, the sintering is carried out in a vacuum furnace. The sintering process involves first stabilizing the temperature at 150~250℃ (e.g., 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃) for 2~4 hours (e.g., 2h, 2.2h, 2.4h, 2.6h, 2.8h, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h, 4h) and then raising the temperature to... Hold at 1000~1040℃ (e.g., 1000℃, 1005℃, 1010℃, 1015℃, 1020℃, 1025℃, 1030℃, 1035℃, 1040℃) for 2~5 hours (e.g., 2h, 2.2h, 2.4h, 2.6h, 2.8h, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h, 4h, 4.2h, 4.4h, 4.6h, 4.8h, 5h) and then cool to below 200℃.

[0035] It should be noted that the present invention utilizes the support partition inside the material box to a certain extent to limit the deformation and dimensional consistency of the magnet during the sintering shrinkage process. The stability of the magnet sintering process is suppressed by the stabilization treatment in the low temperature section, and the impurity content of the magnet is further reduced, thereby improving the comprehensive performance of the high cerium magnet with a length-to-diameter ratio. The heat treatment process is shortened by using a first-stage tempering heat treatment. Combined with the addition of high cerium content, the production process cost is reduced while obtaining excellent magnetic properties of cerium magnets.

[0036] Specifically, in S3, the tempering temperature is 550~630℃, for example, 550℃, 560℃, 570℃, 580℃, 590℃, 600℃, 610℃, 620℃, 630℃, and the temperature is maintained for 3~6 hours, for example, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h, 4h, 4.2h, 4.4h, 4.6h, 4.8h, 5h, 5.2h, 5.4h, 5.6h, 5.8h, 6h, and then cooled to room temperature.

[0037] Specifically, in S3, the aspect ratio of the high-performance cerium magnet is ≥4, for example, 4, 5, 6, 7, 8, 9, 10; the maximum length of the magnet is ≤100mm, for example, 100mm, 90mm, 80mm, 70mm, 60mm, 50mm, 40mm; and the maximum deformation is ≤0.3mm, for example, 0.3mm, 0.28mm, 0.26mm, 0.24mm, 0.22mm, 0.20mm, 0.18mm, 0.16mm, 0.14mm, 0.12mm, 0.1mm.

[0038] Another specific embodiment of the present invention discloses a high-performance cerium magnet prepared by the above method.

[0039] Specifically, the remanence of the high-performance cerium magnet is ≥11.5kGs, and the magnet density uniformity is ≤0.5%.

[0040] This invention achieves stable production of high aspect ratio cerium magnets by effectively controlling the dimensional accuracy of the above-mentioned processes and parameters during the cerium magnet manufacturing process. This improves the overall performance of cerium magnets and reduces the loss of matrix material and the decline in performance and consistency caused by differences in magnet deformation and density. This results in the low-cost preparation of high-magnetic-performance cerium magnets.

[0041] The technical solution of the present invention will be further explained and illustrated below with reference to specific embodiments. The following embodiments use lubricants and antioxidants as examples for explanation and illustration, but are not limited to these.

[0042] Example 1 This embodiment of a method for preparing a precision-molded high-performance cerium magnet includes the following steps: S1: According to the cerium magnet alloy composition Ce 10 Nd 20.9 B 0.97 Ga 0.1 Co 0.7 Zr 0.15 Ti 0.2 Fe balThe raw materials were prepared, wherein cerium accounted for 10% by mass. The raw materials were then vacuum melted into rapidly solidified castings, and the alloy was crushed and finely ground into fine magnetic powder with a particle size of 2.9μm by an air jet mill. S2: Add an additive accounting for 0.4% of the mass of the fine magnetic powder to the fine magnetic powder, and mix the powder for 3 hours under an inert gas Ar protection environment. The oxygen content of the inert gas is ≤10ppm. Perform vibration pressure sieving treatment under a gas protection environment of 70℃ and a pressure of 0.35MPa. The treated magnetic powder is loaded into the molding cavity, and the powder density is adjusted to 2.5 g / cm³ under a pre-orientation magnetic field of 3T. 3 Then, an automatic forming press is used to apply a 2T orientation magnetic field and slowly press the material to a density of 4.3 g / cm³. 3 The green blank is pressed in 15 seconds. S3: Multiple green blanks are sequentially loaded into a material box. The material box is provided with a support partition for fixing and supporting the green blanks. The support partition limits the orientation of the green blanks to 75° with the horizontal bottom surface of the material box. Multiple green blanks are stacked and aligned along the same center line. They are then placed in a vacuum sintering furnace, held at 200°C for 3 hours, then heated to 1037°C and held for 4.5 hours. After cooling to below 100°C, they are tempered at 590°C for 5 hours and then cooled to room temperature to obtain the high-performance cerium magnet.

[0043] Samples were taken from multiple different locations of the high-performance cerium magnet prepared in this embodiment. The density uniformity variation curves at different locations are shown in the figure. Figure 1 As shown in the figure, the density consistency is good at different locations.

[0044] Example 2 The method for preparing a precision-molded high-performance cerium magnet in this embodiment is similar to that in Example 1, except that in S1, the particle size of the fine magnetic powder is 2.1 μm. In S2, the additive's mass percentage is 0.6%, the vibration pressure sieve pressure is 0.4 MPa, the pre-orientation magnetic field strength is 5 T, and the powder density is 1.7 g / cm³. 3 The density of the green body is 4.2 g / cm³. 3 .

[0045] In S3, the temperature is raised to 1025℃ during sintering and held for 3 hours.

[0046] Example 3 This embodiment of a method for preparing a precision-molded high-performance cerium magnet includes the following steps: S1: According to the cerium magnet alloy composition Ce 18 Nd 7.8 Pr 5.5 B 0.99 Ga 0.1 Al0.1 Zr 0.1 Cu 0.15 Fe bal The raw materials were prepared, wherein cerium accounted for 18% by mass. The raw materials were then vacuum melted into rapidly solidified castings, and the alloy was crushed and finely ground into fine magnetic powder with a particle size of 2.7μm by an air jet mill. S2: Add an additive accounting for 0.5% of the mass of the fine magnetic powder to the fine magnetic powder, and mix the powder for 4 hours under an inert gas Ar protection environment. The oxygen content of the inert gas is ≤5ppm. Perform vibration pressure sieving treatment under a gas protection environment of 50℃ and a pressure of 0.25MPa. The treated magnetic powder is loaded into the molding cavity, and the powder density is adjusted to 2.0 g / cm³ under a pre-orientation magnetic field of 6T. 3 Then, an automatic forming press is used to apply a 1.8T orientation magnetic field and slowly press the material to a density of 4.4 g / cm³. 3 The green blank is pressed in 12 seconds. S3: Multiple green blanks are sequentially loaded into a material box. The material box is provided with a support partition for fixing and supporting the green blanks. The support partition limits the orientation of the green blanks to 60° with the horizontal bottom surface of the material box. Multiple green blanks are stacked and aligned along the same center line. They are then placed in a vacuum sintering furnace, held at 180°C for 3 hours, then heated to 1032°C and held for 4 hours. After cooling to below 200°C, they are tempered at 605°C for 4 hours to obtain the high-performance cerium magnet.

[0047] Example 4 This embodiment of a method for preparing a precision-molded high-performance cerium magnet includes the following steps: S1: According to the cerium magnet alloy composition Ce 14 Nd 16.3 Gd 1.1 B 0.97 Ga 0.15 Zr 0.2 Cu 0.2 Al 0.15 Fe bal The raw materials were prepared, wherein cerium accounted for 14% by mass. The raw materials were then vacuum melted into rapidly solidified castings, and the alloy was crushed and finely ground into fine magnetic powder with a particle size of 1.7μm by an air jet mill. S2: Add an additive accounting for 0.75% of the mass of the fine magnetic powder to the fine magnetic powder, and mix the powder for 5 hours under an inert gas Ar protection environment. The oxygen content of the inert gas is ≤5ppm. Perform vibration pressure sieving treatment under gas protection at 80℃ and a pressure of 0.2MPa. The treated magnetic powder is loaded into the molding cavity, and the powder density is adjusted to 2.2 g / cm³ under a 5T pre-orientation magnetic field. 3 Then, an automatic forming press is used to apply a 2T orientation magnetic field and slowly press the material to a density of 4.1 g / cm³.3 The green blank is pressed in 20 seconds; S3: Multiple green blanks are sequentially loaded into a material box. The material box is provided with a support partition for fixing and supporting the green blanks. The support partition limits the orientation of the green blanks to 70° with the horizontal bottom surface of the material box. Multiple green blanks are stacked and aligned along the same center line. They are then placed in a vacuum sintering furnace and held at 250°C for 4 hours. The temperature is then raised to 1006°C and held for 2.5 hours. The temperature is then cooled to below 100°C and tempered at 620°C for 3 hours to obtain the high-performance cerium magnet.

[0048] Comparative Example 1 The preparation method of a precision-molded high-performance cerium magnet in this comparative example is similar to that in Example 1, except that in S2, the mass ratio of the additive is 0.6%, the oxygen content of the inert gas is ≤30ppm, and after mixing, the magnetic powder is directly loaded into the mold cavity for orientation and pressing. Vibration pressure sieving is not used, nor is pre-orientation to control the powder density, and it is pressed into a green blank. In S3, multiple green blanks are placed directly into the sintering box and arranged in parallel.

[0049] Comparative Example 2 The preparation method of this comparative example of a precision-molded high-performance cerium magnet is similar to that of Example 3, except that in S2, the mass ratio of the additive is 0.9%, and the magnet is subjected to vibration pressure sieving under gas protection at 100°C at a pressure of 0.1 MPa. The treated magnetic powder is then loaded into the molding cavity, and the powder density is adjusted to 2.7 g / cm³ under a pre-orientation magnetic field of 3T. 3 This yields the green body; S3: Place multiple pressed green blanks vertically into the sintering box in sequence, then put them into the vacuum sintering furnace, then heat them to 1045℃ for 4 hours, and then temper them for heat treatment.

[0050] Comparative Example 3 The preparation method of a precision-formed high-performance cerium magnet in this comparative example is similar to that in Example 4, except that the fine magnetic powder particle size is 3.6 μm in S1. In S2, the additive accounts for 0.3% of the total mass, and the oxygen content of the inert gas is ≤50ppm. After mixing, the powder is vibrated and sieved at room temperature, then loaded into the molding cavity and pressed to a density of 3.9g / cm³ using an automatic molding press with a 2T orientation magnetic field applied directly. 3 The green blank has a pressing cycle of 5 seconds; In S3, the green billet is loaded into a vacuum sintering furnace, then heated to 1050℃ for 2 hours, and then tempered at 500℃ for 3 hours.

[0051] The magnets prepared in the above embodiments and comparative examples were sampled and tested at at least two different locations. The maximum deformation and density consistency of the magnets at different locations were tested (expressed as the maximum deviation, the same as the method in Embodiment 1). The maximum length, aspect ratio and remanence of the magnets are shown in Table 1.

[0052] Table 1

[0053] As shown in Table 1, the magnets prepared by this invention have a maximum deformation ≤0.3 mm, density uniformity ≤0.29%, maximum length ≤100 mm, aspect ratio ≥4, and remanence ≥11.7 kGs. Therefore, the cerium magnets prepared by the method of this invention have high shrinkage deformation and density uniformity, and their magnetic properties are also significantly better than those of the comparative examples, demonstrating the technical effectiveness of this invention.

[0054] In summary, this invention achieves precise control over the shrinkage deformation and density distribution of high-performance cerium magnets by controlling the uniformity and flowability of magnet alloy powder, combined with comprehensive optimization of orientation pressing and sintering processes. It also effectively improves magnetic properties while reducing the impurity content of the magnets. By utilizing systematic optimization and synergistic control throughout the entire process, it successfully solves the industry challenges of deformation, high consistency, and performance regulation in the preparation of high aspect ratio cerium magnets, providing a reliable guarantee for the low-cost preparation of high-performance cerium magnets.

[0055] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of making a precision formed high performance cerium magnet, characterized by, The method includes the following steps: S1: Prepare raw materials according to the composition of cerium magnet alloy, melt the raw materials in vacuum to form rapid solidification castings, and crush the castings into fine magnetic powder with a particle size of 1.5~3.0μm; S2: Add 0.4~0.8% of additives to the fine magnetic powder, mix the powder under inert gas protection, and perform vibration pressure sieving under heated gas protection. The treated magnetic powder is then oriented and pressed into a green blank by magnetic field. S3: The green blank is loaded into a material box and then subjected to sintering and tempering to obtain the high-performance cerium magnet.

2. The method of claim 1, wherein the high performance ceramer magnet is precision formed. In S1, the mass percentage of cerium in the cerium magnet alloy is 10-20%.

3. The method for preparing a precision-formed high-performance cerium magnet according to claim 1, characterized in that, In S2, the oxygen content in the inert gas is ≤10ppm, and the mixing time is ≥3h.

4. The method for preparing a precision-formed high-performance cerium magnet according to any one of claims 1-3, characterized in that, In S2, the pressing process includes first pre-orienting powder loading, and then further pressing into a green compact; And / or, in S2, the heating temperature is 50~80℃ and the pressure is 0.15~0.4MPa.

5. The method of claim 4, wherein the high performance ceramer magnet is precision formed. The magnetic field strength of the powder loading is ≥3.0T, and the powder density is 1.5~2.5 g / cm³. 3 The magnetic field strength for further suppression is 1.8~2T, and the suppression time is 10~20s.

6. The method of claim 1, wherein the high performance ceramer magnet is precision formed. S2, the density of the green body is ≥ 4.1 g / cm3 3 .

7. The method of claim 1-3, wherein the method of making a precision formed high performance cerium magnet is characterized by, In S3, the material box is provided with a support partition for fixing and supporting the green blank. The support partition limits the orientation of the green blank to 60~75° with the horizontal bottom surface of the material box, and multiple green blanks are stacked and aligned along the same center line.

8. The method of claim 1-3, wherein the method of making a precision formed high performance cerium magnet is characterized by, In S3, the sintering is carried out in a vacuum furnace. The sintering process involves first stabilizing the furnace at 150-250°C for 2-4 hours, then raising the temperature to 1000-1040°C and holding it for 2-5 hours, and finally cooling it to below 200°C.

9. The method of claim 1-3, wherein the method of making a precision formed high performance cerium magnet is characterized by, In S3, the aspect ratio of the high-performance cerium magnet is ≥4, the maximum length of the magnet is ≤100mm, and the maximum deformation is ≤0.3mm.

10. A high performance cermet magnet produced by the method of any one of claims 1 to 9, characterized by The remanence of the high-performance cerium magnet is ≥11.5kGs, and the magnet density uniformity is ≤0.5%.

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