A samarium iron nitride / samarium aluminum copper composite material and a preparation method thereof

Abstract

The application relates to the technical field of magnetic materials, in particular to a samarium iron nitrogen / samarium aluminum copper composite material and a preparation method thereof. The samarium iron nitrogen / samarium aluminum copper composite material comprises samarium iron nitrogen, samarium aluminum copper, a surfactant and a binder; wherein the chemical formula of the samarium iron nitrogen is Sm2Fe 17 N3; the samarium iron nitrogen / samarium aluminum copper composite material reduces the oxidation of a samarium iron nitrogen phase, improves the coercive force of the samarium iron nitrogen / samarium aluminum copper composite material, and has the antioxidant and anticorrosion abilities and better magnetic properties through the addition of the surfactant.

Description

Technical Field

[0001] This invention relates to the field of magnetic materials technology, specifically to a samarium iron nitrogen / samarium aluminum copper composite material and its preparation method. Background Technology

[0002] Samarium iron nitrogen (Sm2Fe) 17 N x Samarium iron nitride (SmFeNi) has seen rapid development in recent years as a permanent magnet material. Its superior properties, such as high saturation magnetization (1.54-1.57T), a large anisotropic field (21-26T), and a high Curie temperature (743K) comparable to NdFeB, have garnered significant attention. It holds immense application potential in electric vehicles and motors and is likely to surpass NdFeB in the near future, becoming the next generation of rare-earth permanent magnet materials. Furthermore, SmFeNi is cheaper than NdFeB, offering a greater advantage in raw material costs. However, current SmFeNi nitriding processes involve N atoms entering the SmFe alloy, but above 600℃, N atoms will detach from SmFe. 17 When N3 is extracted from the compound, it decomposes to form α-Fe and SmN phases. Traditional methods for preparing samarium iron nitride magnets suffer from problems such as easy oxidation and unstable magnetic properties. Therefore, developing an efficient and stable method for preparing samarium iron nitride magnets is of great practical significance. Summary of the Invention

[0003] The purpose of this invention is to solve the problem that traditional methods of preparing samarium iron nitrogen magnets produce a large amount of α-Fe phase and have low coercivity. Therefore, this invention provides a samarium iron nitrogen / samarium aluminum copper composite material and its preparation method. This samarium iron nitrogen / samarium aluminum copper composite material reduces the oxidation of the samarium iron nitrogen phase and improves the coercivity of the samarium iron nitrogen / samarium aluminum copper composite material. Furthermore, the samarium iron nitrogen / samarium aluminum copper composite material obtained by this method has oxidation and corrosion resistance and better magnetic properties.

[0004] To achieve the above objectives, in a first aspect, the present invention provides a samarium iron nitrogen / samarium aluminum copper composite material, characterized in that the samarium iron nitrogen / samarium aluminum copper composite material comprises: samarium iron nitrogen, samarium aluminum copper, a surfactant, and a binder; wherein,

[0005] The chemical formula of the samarium iron nitrogen is Sm2Fe. 17 N3.

[0006] Preferably, the weight ratio of samarium aluminum copper to samarium iron nitrogen is 2-15:100.

[0007] Preferably, the surfactant has a mass concentration of 5wt%-10wt% in the samarium iron nitrogen / samarium aluminum copper composite material.

[0008] Preferably, the mass concentration of the binder in the samarium iron nitrogen / samarium aluminum copper composite material is 3wt%-6wt%.

[0009] Preferably, the surfactant is selected from one or more of oleic acid, oleylamine, AEO-3, and dodecanoic acid.

[0010] Preferably, the adhesive is selected from one or more of epoxy resin E51, epoxy resin E44, epoxy resin K51, silicone resin and polyphenylene sulfide.

[0011] Secondly, the present invention provides a method for preparing samarium iron nitrogen / samarium aluminum copper composite material, characterized in that the method includes: mixing and ball milling samarium iron nitrogen and samarium iron copper, adding a surfactant to obtain samarium iron nitrogen / samarium aluminum copper composite material powder, adding a binder, and pressing into shape.

[0012] Preferably, the method for preparing the samarium iron nitrogen includes:

[0013] 1) Vacuum melting of samarium source and iron source, melting 3-5 times to obtain samarium-iron alloy ingot, and spinning the samarium-iron alloy ingot into samarium-iron alloy sheet in a rapid quenching furnace;

[0014] 2) The samarium-iron alloy sheet is annealed, mechanically crushed, and then jet milled in a nitrogen atmosphere to obtain samarium-iron alloy powder;

[0015] 3) The samarium iron alloy powder is nitrided under a nitrogen atmosphere to obtain samarium iron nitrogen powder.

[0016] Preferably, in step 1), the molar ratio of the samarium source to the iron source is 2.4-2.7:17, wherein the samarium source is measured in samarium atoms and the iron source is measured in iron atoms.

[0017] More preferably, in step 1), the conditions for vacuum melting include: placing the samarium source above the iron source, and before melting, the vacuum degree is 1.5 × 10⁻⁶. -2 Pa; during melting, argon gas of 250mbar-300mbar is introduced; the melting temperature is 1540℃-1600℃.

[0018] More preferably, in step 1), the conditions for the belt spinning include: the rotational speed of the copper roller is controlled at 15m / s-20m / s.

[0019] More preferably, in step 1), the samarium source is elemental samarium, and the iron source is elemental iron.

[0020] More preferably, in step 2), the annealing includes: under an argon atmosphere, at a temperature of 950℃-1100℃, for a time of 10-15h.

[0021] More preferably, in step 2), the conditions for the air jet mill include: the rotational speed is 3000 r / min-5000 r / min.

[0022] More preferably, in step 3), the nitriding conditions include: a temperature of 430℃-500℃ and a time of 10-16h.

[0023] Preferably, the preparation method of the samarium-iron-copper alloy powder includes: vacuum melting of samarium source, aluminum source and copper source, spinning into samarium-aluminum-copper alloy strip in a rapid quenching furnace, mechanically crushing the samarium-aluminum-copper alloy strip and pulverizing it in an air jet mill under nitrogen atmosphere to obtain samarium-aluminum-copper alloy powder.

[0024] Preferably, the molar ratio of the samarium source, aluminum source, and copper source is 3:4:3, wherein the samarium source is calculated in terms of samarium atoms, the aluminum source in terms of aluminum atoms, and the copper source in terms of copper atoms.

[0025] More preferably, the conditions for vacuum melting include a temperature of 1100℃-1200℃.

[0026] More preferably, the conditions for the air jet mill include: a rotational speed of 3000 r / min to 5000 r / min.

[0027] Preferably, the weight ratio of samarium aluminum copper to samarium iron nitrogen is 2-15:100.

[0028] Preferably, the surfactant has a mass concentration of 5wt%-10wt% in the samarium iron nitrogen / samarium aluminum copper composite material.

[0029] More preferably, the binder has a mass concentration of 3wt%-6wt% in the samarium iron nitrogen / samarium aluminum copper composite material.

[0030] Preferably, the surfactant is selected from one or more of oleic acid, oleylamine, AEO-3, and dodecanoic acid.

[0031] Preferably, the adhesive is selected from one or more of epoxy resin E51, epoxy resin E44, epoxy resin K51, silicone resin and polyphenylene sulfide.

[0032] Preferably, the ball milling conditions include: a ball-to-material ratio of 10-30:1, a rotation speed of 150 r / min-350 r / min, and the ball milling media being alcohol and / or 2-methylpentane.

[0033] Preferably, the conditions for compression molding include a pressure of 1500MPa-2000MPa.

[0034] In the above technical solution, the samarium iron nitrogen / samarium aluminum copper composite material of the present invention adds samarium aluminum copper phase (Sm-Al-Cu) and adds surfactant to assist ball milling during the ball milling process. Because Sm-Al-Cu is oxidized, the samarium iron nitrogen phase (Sm2Fe) is formed. 17 The decomposition process of N3 is inhibited, and Sm-Al-Cu can effectively prevent the formation of the α-Fe phase, thereby improving the anisotropy of Sm2Fe. 17 The coercivity of the N3 magnet and the addition of surfactants form a mesh-like protective film on the surface of the samarium iron nitrogen / samarium aluminum copper composite material, which is uniformly coated on the surface of the samarium iron nitrogen / samarium aluminum copper composite material, further improving its oxidation and corrosion resistance, and ultimately enabling the samarium iron nitrogen / samarium aluminum copper composite material to exhibit good magnetic properties.

[0035] Meanwhile, the method for preparing samarium iron nitrogen / samarium aluminum copper composite material of the present invention introduces a surfactant during the ball milling process. The surfactant can form a mesh-like protective film on the surface of the samarium iron nitrogen / samarium aluminum copper composite material, which improves the dispersion uniformity of the material during the ball milling process. The coated samarium iron nitrogen / samarium aluminum copper composite material has excellent anti-oxidation and anti-corrosion capabilities, and also improves the magnetic properties of the samarium iron nitrogen / samarium aluminum copper composite material.

[0036] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 The image shows the XRD pattern of the samarium iron nitrogen / samarium aluminum copper composite magnet of Embodiment 1 of the present invention.

[0039] Figure 2 The image shows the XRD pattern of the samarium iron nitrogen magnet of Comparative Example 1 of this invention.

[0040] Figure 3 Hysteresis loop diagrams of the samarium iron nitrogen / samarium aluminum copper composite magnet of Example 1, the samarium iron nitrogen magnet of Comparative Example 1, and the samarium iron nitrogen / samarium aluminum copper magnet of Comparative Example 2.

[0041] Figure 4 The graph shows the change in magnetic property loss over time for the samarium iron nitrogen / samarium aluminum copper composite magnet of Example 1 and the samarium iron nitrogen / samarium aluminum copper magnet of Comparative Example 2.

[0042] Figure 5 A diagram of the samarium-iron alloy strip thin sheet prepared in step (1) of Example 1 of this invention;

[0043] Figure 6 A diagram of the samarium aluminum copper alloy strip obtained in step (1) of Example 2 of this invention;

[0044] Figure 7 The image shows the SEM image of the samarium iron nitrogen / samarium aluminum copper powder after ball milling with surfactant added in step (1) of Example 1.

[0045] Figure 8 SEM image of samarium iron nitrogen powder after ball milling in step (1) of Comparative Example 1;

[0046] Figure 9 SEM image of samarium iron nitrogen / samarium aluminum copper powder after ball milling in step (1) of Comparative Example 2 without the addition of surfactant;

[0047] Figure 10 A cross-sectional view of the material placement position during the smelting process of samarium-iron alloy in step (1) of Example 1. Detailed Implementation

[0048] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0049] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0050] In a first aspect, the present invention provides a samarium iron nitrogen / samarium aluminum copper composite material, characterized in that the samarium iron nitrogen / samarium aluminum copper composite material comprises: samarium iron nitrogen, samarium aluminum copper, surfactant and binder;

[0051] in,

[0052] The chemical formula of the samarium iron nitrogen is Sm2Fe. 17 N3.

[0053] The samarium iron nitrogen / samarium aluminum copper composite material of the present invention, by adding samarium aluminum copper phase (Sm-Al-Cu) and adding surfactant to assist ball milling, results in the oxidation of Sm-Al-Cu, which in turn leads to the formation of samarium iron nitrogen phase (Sm2Fe). 17 The decomposition process of N3 is inhibited, and Sm-Al-Cu can effectively prevent the formation of the α-Fe phase, thereby improving the anisotropy of Sm2Fe. 17The coercivity of the N3 magnet and the addition of surfactants form a mesh-like protective film on the surface of the samarium iron nitrogen / samarium aluminum copper composite material, which is uniformly coated on the surface of the samarium iron nitrogen / samarium aluminum copper composite material, further improving its oxidation and corrosion resistance, and ultimately enabling the samarium iron nitrogen / samarium aluminum copper composite material to exhibit good magnetic properties.

[0054] In a preferred embodiment of the present invention, in order to suppress the precipitation of the α-Fe phase, the weight ratio of the samarium aluminum copper alloy to the samarium iron nitrogen alloy is 2-15:100, for example, it can be 2:100, 3:100, 4:100 or 5:100. If there is too little samarium aluminum copper, the suppression effect may not be good, and if there is too much samarium aluminum copper alloy, it will affect the magnetic properties of samarium iron nitrogen.

[0055] In a preferred embodiment of the present invention, in order to avoid agglomeration of magnetic powder and improve its resistance to oxidation and corrosion, the surfactant in the samarium iron nitrogen / samarium aluminum copper composite material has a mass concentration of 5wt%-10wt%.

[0056] In a preferred embodiment of the present invention, if the amount of adhesive used is small, the finished product is prone to cracking; if the amount used is large, it is difficult to form and affects the magnetic properties. The weight percentage of the adhesive in the samarium iron nitrogen / samarium aluminum copper composite material is 3wt%-6wt%.

[0057] In a preferred embodiment of the present invention, the surfactant is selected from one or more of oleic acid, oleylamine, AEO-3 and dodecanoic acid.

[0058] In a preferred embodiment of the present invention, the adhesive is selected from one or more of epoxy resin E51, epoxy resin E44, epoxy resin K51, silicone resin and polyphenylene sulfide.

[0059] Secondly, the present invention provides a method for preparing samarium iron nitrogen / samarium aluminum copper composite material, characterized in that the method includes: mixing and ball milling samarium iron nitrogen powder and samarium aluminum copper alloy powder, adding a surfactant to obtain samarium iron nitrogen / samarium aluminum copper composite material powder, adding a binder, and pressing into shape.

[0060] The method for preparing samarium iron nitrogen / samarium aluminum copper composite material of the present invention introduces a surfactant during the ball milling process. The surfactant can form a mesh-like protective film on the surface of the samarium iron nitrogen / samarium aluminum copper composite material, which improves the dispersion uniformity of the material during the ball milling process. The coated samarium iron nitrogen / samarium aluminum copper composite material has excellent anti-oxidation and anti-corrosion ability, and also improves the magnetic properties of the samarium iron nitrogen / samarium aluminum copper composite material.

[0061] In a preferred embodiment of the present invention, the method for preparing the samarium-iron-nitrogen alloy includes:

[0062] 1) Vacuum melting of samarium source and iron source, melting 3-5 times to obtain samarium-iron alloy ingot, and spinning the samarium-iron alloy ingot into samarium-iron alloy sheet in a rapid quenching furnace;

[0063] 2) The samarium-iron alloy sheet is annealed, mechanically crushed, and then jet milled in a nitrogen atmosphere to obtain samarium-iron alloy powder;

[0064] 3) The samarium iron alloy powder is nitrided under a nitrogen atmosphere to obtain samarium iron nitrogen.

[0065] In a preferred embodiment of the present invention, in order to prevent excessive samarium volatilization, an excess of 20%-35% samarium is added. In step 1), the molar ratio of the samarium source to the iron source is 2.4-2.7:17, for example, it can be 2.4:17, 2.5:17, 2.6:17 or 2.7:17, wherein the samarium source is calculated in terms of samarium atoms and the iron source is calculated in terms of iron atoms.

[0066] In a preferred embodiment of the present invention, to prevent excessive samarium volatilization, the vacuum melting conditions in step 1) include: placing the samarium source above the iron source, and before melting, the vacuum degree is 1.5 × 10⁻⁶. -2 Pa; During smelting, argon gas of 250mbar-300mbar is introduced, for example, 250mbar, 260mbar, 270mbar, 280mbar, 290mbar or 300mbar; The smelting temperature is 1540℃-1600℃, for example, 1540℃, 1550℃, 1560℃, 1570℃, 1580℃, 1590℃ or 1600℃. The smelting process of iron block at the bottom and samarium at the top is adopted. The temperature at the bottom of the crucible is higher than the temperature at the top of the crucible, which can effectively reduce the volatilization of samarium.

[0067] In a preferred embodiment of the present invention, in step 1), the conditions for the belt spinning include: the rotational speed of the copper roller is controlled at 15m / s-20m / s, for example, it can be 15m / s, 16m / s, 17m / s, 18m / s, 19m / s or 20m / s.

[0068] In a preferred embodiment of the present invention, in step 1), the samarium source is elemental samarium and the iron source is elemental iron.

[0069] In a preferred embodiment of the present invention, the mechanical crushing time of the samarium-iron alloy sheet is controlled between 30s and 180s, for example, it can be 30s, 60s, 90s, 120s, 150s or 180s.

[0070] In a preferred embodiment of the present invention, in order to eliminate impurities and make the obtained samarium-iron phase purer, in step 2), the annealing includes: under an argon atmosphere, at a temperature of 950℃-1100℃ for 10-15 hours, for example, the temperature can be 950℃, 1000℃, 1050℃ or 1100℃, and the time can be 10 hours, 11 hours, 12 hours, 13 hours, 14 hours or 15 hours.

[0071] In a preferred embodiment of the present invention, the higher the rotation speed, the finer the powder produced. In step 2), the conditions of the air jet mill include: the rotation speed is 3000 r / min-5000 r / min, for example, it can be 3000 r / min, 3500 r / min, 4000 r / min, 4500 r / min or 5000 r / min.

[0072] In a preferred embodiment of the present invention, the samarium iron nitrogen coarse powder after air jet milling is placed in a glove box and further sieved using a grading sieve. The mesh size of the grading sieve can be 100 mesh, 200 mesh, 300 mesh, 400 mesh, or 500 mesh.

[0073] In a preferred embodiment of the present invention, in step 3), the nitriding conditions include: a temperature of 430℃-500℃, for example, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃ or 500℃; and a time of 10-16h, for example, 10h, 11h, 12h, 13h, 14h, 15h or 16h.

[0074] In a preferred embodiment of the present invention, the method for preparing the samarium-aluminum-copper alloy powder includes: vacuum melting a samarium source, an aluminum source, and a copper source; spinning the samarium-aluminum-copper alloy strip in a rapid quenching furnace to form a samarium-aluminum-copper alloy strip; mechanically crushing the samarium-aluminum-copper alloy strip and pulverizing it in an air jet mill under nitrogen atmosphere to obtain samarium-aluminum-copper alloy powder.

[0075] In a preferred embodiment of the present invention, the mechanical crushing time of the samarium aluminum copper strip is controlled between 30s and 180s, for example, it can be 30s, 60s, 90s, 120s, 150s or 180s.

[0076] In a preferred embodiment of the present invention, the molar ratio of the samarium source, the aluminum source and the copper source is 3:4:3, wherein the samarium source is measured in samarium atoms, the aluminum source is measured in aluminum atoms, and the copper source is measured in copper atoms.

[0077] In a preferred embodiment of the present invention, the conditions for vacuum melting include a temperature of 1100℃-1200℃, for example, 1100℃, 1150℃ or 1200℃.

[0078] In a preferred embodiment of the present invention, the conditions for the air jet mill include: a rotational speed of 3000 r / min to 5000 r / min, for example, 3000 r / min, 3500 r / min, 4000 r / min, 4500 r / min or 5000 r / min.

[0079] In a preferred embodiment of the present invention, in order to suppress the precipitation of the α-Fe phase, the weight ratio of samarium aluminum copper to samarium iron nitrogen is 2-15:100, for example, it can be 2:100, 3:100, 4:100 or 5:100.

[0080] In a preferred embodiment of the present invention, in order to avoid agglomeration of magnetic powder and improve its resistance to oxidation and corrosion, the surfactant in the samarium iron nitrogen / samarium aluminum copper composite material has a mass concentration of 5wt%-10wt%.

[0081] In a preferred embodiment of the present invention, if the amount of adhesive used is small, the finished product is prone to cracking; if the amount used is large, it is difficult to form and affects the magnetic properties. The weight percentage of the adhesive in the samarium iron nitrogen / samarium aluminum copper composite material is 3wt%-6wt%.

[0082] In a preferred embodiment of the present invention, the surfactant is selected from one or more of oleic acid, oleylamine, AEO-3 and dodecanoic acid.

[0083] In a preferred embodiment of the present invention, the adhesive is selected from one or more of epoxy resin E51, epoxy resin E44, epoxy resin K51, silicone resin and polyphenylene sulfide.

[0084] In a preferred embodiment of the present invention, the ball milling conditions include: a ball-to-material ratio of 10-30:1, for example, 10:1, 15:1, 20:1, 25:1 or 30:1; a rotational speed of 150 r / min-350 r / min, for example, 150 r / min, 200 r / min, 250 r / min, 300 r / min or 350 r / min; and the ball milling medium being alcohol and / or 2-methylpentane.

[0085] In a preferred embodiment of the present invention, the conditions for compression molding include: a pressure of 1500MPa-2000MPa, for example, 1500MPa, 1600MPa, 1700MPa, 1800MPa, 1900MPa or 2000MPa.

[0086] In a preferred embodiment of the present invention, in order to prevent oxidation of the samarium-iron alloy sheet and the samarium-aluminum-copper strip, the alloy sheet that has been spun out is placed in a sealed container filled with nitrogen for protection to isolate it from oxygen.

[0087] The present invention will be described in detail below through examples. In the following examples, the drugs and pharmaceuticals are all conventional commercially available products.

[0088] Preparation Example 1

[0089] (1) Place an iron ingot (Fe) with a purity of 99.9% at the bottom of the crucible, place a samarium block (Sm) with a purity of 99.9% on top of the iron ingot, and evacuate to a vacuum of 1.5 × 10⁻⁶. -2 Pa, first melted at low power for 10 minutes, then argon gas at 280 mbar was introduced and the melting power was increased. The alloy was repeatedly melted three times to obtain a samarium-iron alloy ingot with uniform composition. The melting temperature was controlled at 1540℃. Then, it was spun into sheets in a rapid quenching furnace to obtain samarium-iron (Sm2Fe). 17 The alloy sheets were placed in a sealed container filled with nitrogen for storage.

[0090] (2) Step (1) Sm2Fe 17 The alloy sheet was annealed at 1050℃ for 12 hours in an argon atmosphere, then placed in a crushing chamber and coarsely crushed for 60 seconds under nitrogen atmosphere, followed by further crushing of Sm2Fe. 17 The alloy coarse powder was subjected to air jet milling at a speed of 4000 r / min, and the Sm2Fe after air jet milling was... 17 The alloy powder was placed in a glove box and further sieved using a 300-mesh grading sieve;

[0091] (3) The samarium iron alloy powder after screening in step (2) was subjected to nitriding treatment in a tube furnace at a temperature of 460℃ for 12 hours to obtain samarium iron nitride (Sm2Fe). 17 N3) coarse powder.

[0092] Preparation Example 2

[0093] (1) Samarium (Sm), aluminum (Al), and copper (Cu), all with a purity of 99.9%, were vacuum-melted. Before melting, the vacuum was first evacuated to 1.5 × 10⁻⁶. -2 Pa, first melt at low power for 10 minutes, then fill with 280 mbar argon gas and melt at increased power, and repeatedly melt the alloy 3 times to obtain a samarium aluminum copper alloy ingot with uniform composition. The temperature is controlled at 1150℃ during melting. Then, the strip is spun into sheets in a fast quenching furnace to obtain samarium aluminum copper alloy sheets, which are then stored in a sealed container filled with nitrogen.

[0094] (2) The samarium-aluminum-copper alloy sheet from step (1) was placed in a crushing tank and filled with nitrogen for coarse crushing for 60 seconds. Then, the samarium-aluminum-copper alloy coarse powder was subjected to air jet milling again at a speed of 4000 r / min. The samarium-aluminum-copper alloy powder after air jet milling was placed in a glove box and further screened with a 300-mesh grading sieve to obtain samarium-aluminum-copper (Sm-Al-Cu) alloy powder.

[0095] Example 1

[0096] (1) The Sm2Fe prepared in Preparation Example 1 17 N3 coarse powder was mixed with Sm-Al-Cu alloy powder prepared in Preparation Example 2. The mass of Sm-Al-Cu alloy powder was Sm2Fe. 17 5% of the mass of N3 coarse powder was milled using 2-methylpentane as the medium and AEO-3 as the surfactant. The amount of surfactant was 6% of the weight of the samarium iron nitrogen / samarium aluminum copper alloy mixed powder. The ball-to-powder ratio was 10:1, the ball milling time was 9 hours, and the ball milling speed was 200 r / min to obtain refined samarium iron nitrogen / samarium aluminum copper mixed powder.

[0097] (2) Add 4% of E51 epoxy resin based on the mass of the refined samarium iron nitrogen / samarium aluminum copper mixed powder in step (1), and press it into a cylindrical samarium iron nitrogen / samarium aluminum copper composite magnet with a diameter of 15.07 mm and a height of 7.51 mm, denoted as B1.

[0098] Comparative Example 1

[0099] (1) The Sm2Fe prepared in Preparation Example 1 17 N3 coarse powder was ball-milled with alcohol as the medium at a ball-to-material ratio of 10:1 for 9 hours at a milling speed of 200 r / min to obtain refined Sm2Fe. 17 N3 powder;

[0100] (2) Add 4% by mass of Sm2Fe from step (1) 17 E51 epoxy resin of N3 powder quality was pressed into a cylindrical samarium iron nitride magnet with a diameter of 15.03 mm and a height of 7.54 mm, denoted as D1.

[0101] Comparative Example 2

[0102] (1) The Sm2Fe prepared in Preparation Example 1 17 N3 coarse powder was mixed with Sm-Al-Cu alloy powder prepared in Preparation Example 2. The mass of Sm-Al-Cu alloy powder was Sm2Fe. 17 5% of the mass of N3 coarse powder was ball-milled with alcohol as the medium at a ball-to-powder ratio of 10:1 for 9 hours at a ball milling speed of 200 r / min to obtain refined samarium iron nitrogen / samarium aluminum copper mixed powder.

[0103] (2) Add 4% of E51 epoxy resin of the mass of the refined samarium iron nitrogen / samarium aluminum copper mixed powder in step (1), and press it into a cylindrical samarium iron nitrogen / samarium aluminum copper magnet with a diameter of 15.07 mm and a height of 7.51 mm, denoted as D2.

[0104] Detection Example 1

[0105] The samarium iron nitrogen / samarium aluminum copper composite magnet of Example 1 and the samarium iron nitrogen magnet of Comparative Example 1 were analyzed by X-ray diffraction (XRD). The results are shown in the figure. Figure 1-2 .

[0106] Depend on Figure 1 XRD pattern of the samarium iron nitrogen / samarium aluminum copper composite magnet in Example 1 and Figure 2 As can be seen from the XRD pattern of the samarium iron nitrogen magnet in Comparative Example 1, the samarium iron nitrogen / samarium aluminum copper composite magnet of Example 1, after the addition of the samarium aluminum copper (Sm-Al-Cu) phase, has a samarium iron nitrogen (Sm2Fe) content. 17 The N3) XRD pattern still retains Th2Zn 17 The phase structure shows sharp diffraction peaks without any impurity peaks. ， By comparing with the standard PDF card, no diffraction peaks of the Sm-Al-Cu phase were detected, indicating that its crystal structure has not changed. Compared with the samarium iron nitrogen magnet without the addition of samarium aluminum copper in Comparative Example 1, the α-Fe phase was significantly reduced.

[0107] Detection Example 2

[0108] The magnetic properties of Examples 1-3 described above were tested, and the specific test results are shown in Table 1 and 2. Figure 3 As shown:

[0109] Table 1

[0110] Group Innate coercivity / kOe Remanence / kGS Maximum magnetic energy product / MGOe Example 1 12.5 13.1 12.4 Comparative Example 1 9.1 11.1 10.4 Comparative Example 2 11.1 12.2 11.8

[0111] From Table 1 and Figure 3 The hysteresis loop diagrams of the Sm-Fe-Ni / Sm-Al-Cu composite magnets of Example 1, Comparative Example 1, and Comparative Example 2 show that the magnetic properties of the Sm-Fe-Ni / Sm-Al-Cu composite magnets of Example 1 and Comparative Example 2, which have added the Sm-Al-Cu (Sm-Al-Cu) phase, are significantly improved compared to the Sm-Fe magnet of Comparative Example 1 without the Sm-Al-Cu (Sm-Al-Cu) phase. This is because the addition of Sm-Al-Cu reduces the generation of the α-Fe phase, greatly improving the coercivity. At the same time, the addition of surfactants to the Sm-Fe-Ni / Sm-Al-Cu composite magnets of Example 1 improves the oxidation resistance, reduces the generation of non-magnetic samarium oxide and iron oxide, and increases the remanence and maximum energy product.

[0112] Detection Example 3

[0113] The data on the change of magnetic performance loss over time of the samarium iron nitrogen / samarium aluminum copper composite magnet of Example 1 and the samarium iron nitrogen / samarium aluminum copper magnet of Comparative Example 2 exposed to air were fitted, and the results are shown in [the figure]. Figure 4 .

[0114] Depend on Figure 4It can be seen that the samarium iron nitrogen / samarium aluminum copper composite magnet prepared by ball milling with surfactant in Example 1 has less magnetic property loss compared with the samarium iron nitrogen / samarium aluminum copper magnet prepared without surfactant in Comparative Example 2.

[0115] As can be seen from the above data, the performance of the Sm-Al-Cu phase and surfactant-assisted ball milling combined in Example 1 was improved compared with the conventional Sm-Al-Cu magnet in Comparative Example 1 and the Sm-Al-Cu magnet in Comparative Example 2 which only added the Sm-Al-Cu phase. This is because the addition of the Sm-Al-Cu phase inhibited the precipitation of the α-Fe phase and greatly improved the coercivity, while the addition of the surfactant greatly improved the oxidation and corrosion resistance of the magnetic powder and increased the remanence and energy product.

[0116] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0117] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0118] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A samarium iron nitrogen / samarium aluminum copper composite material, characterized in that, The samarium iron nitrogen / samarium aluminum copper composite material comprises: samarium iron nitrogen, samarium aluminum copper, surfactant, and binder; wherein, The chemical formula of the samarium iron nitrogen is Sm2Fe. 17 N3; The weight ratio of samarium aluminum copper to samarium iron nitrogen is 2-15:100; The surfactant has a mass concentration of 5wt%-10wt% in the samarium iron nitrogen / samarium aluminum copper composite material; The binder has a mass concentration of 3wt%-6wt% in the samarium iron nitrogen / samarium aluminum copper composite material.

2. The samarium iron nitrogen / samarium aluminum copper composite material according to claim 1, characterized in that, The surfactant is selected from one or more of oleic acid, oleylamine, AEO-3, and dodecanoic acid.

3. The samarium iron nitrogen / samarium aluminum copper composite material according to claim 1 or 2, characterized in that, The adhesive is selected from one or more of epoxy resin E51, epoxy resin E44, epoxy resin K51, silicone resin and polyphenylene sulfide.

4. A method for preparing samarium iron nitrogen / samarium aluminum copper composite materials, characterized in that, The method includes: mixing and ball milling samarium iron nitrogen and samarium aluminum copper, adding a surfactant to obtain a powder of samarium iron nitrogen / samarium aluminum copper composite material, adding a binder, and pressing it into shape; The weight ratio of samarium aluminum copper to samarium iron nitrogen is 2-15:100; The surfactant has a mass concentration of 5wt%-10wt% in the samarium iron nitrogen / samarium aluminum copper composite material; The binder has a mass concentration of 3wt%-6wt% in the samarium iron nitrogen / samarium aluminum copper composite material.

5. The method according to claim 4, characterized in that, The method for preparing the samarium iron nitrogen includes: 1) Vacuum melting of samarium source and iron source, melting 3-5 times to obtain samarium-iron alloy ingot, and spinning the samarium-iron alloy ingot into samarium-iron alloy sheets in a rapid quenching furnace; 2) The samarium-iron alloy sheet is annealed, mechanically crushed, and then gas-milled in a nitrogen atmosphere to obtain samarium-iron alloy powder; 3) The samarium iron alloy powder is nitrided under a nitrogen atmosphere to obtain samarium iron nitrogen powder.

6. The method according to claim 5, characterized in that, In step 1), the molar ratio of the samarium source to the iron source is 2.4-2.7:17, wherein the samarium source is calculated in terms of samarium atoms and the iron source is calculated in terms of iron atoms; In step 1), the conditions for vacuum melting include: placing the samarium source above the iron source, and before melting, the vacuum degree is 1.5 × 10⁻⁶. -2 Pa; During melting, argon gas of 250mbar-300mbar is introduced; the melting temperature is 1540℃-1600℃; In step 1), the conditions for the belt spinning include: the rotational speed of the copper roller is controlled at 15m / s-20m / s; In step 1), the samarium source is elemental samarium, and the iron source is elemental iron; In step 2), the annealing includes: under an argon atmosphere, at a temperature of 950℃-1100℃ for 10-15 hours; In step 2), the conditions for the air jet mill include: the rotational speed is 3000 r / min-5000 r / min; In step 3), the nitriding conditions include a temperature of 430℃-500℃ and a time of 10-16 h.

7. The method according to any one of claims 4-6, characterized in that, The preparation method of the samarium aluminum copper alloy powder includes: vacuum melting of samarium source, aluminum source and copper source, spinning into samarium aluminum copper alloy thin strip in a rapid quenching furnace, mechanically crushing the samarium aluminum copper alloy thin strip and grinding it into powder by air jet milling under nitrogen atmosphere to obtain samarium aluminum copper alloy powder. The molar ratio of the samarium source, aluminum source and copper source is 3:4:3, wherein the samarium source is calculated in terms of samarium atoms, the aluminum source is calculated in terms of aluminum atoms, and the copper source is calculated in terms of copper atoms. The conditions for vacuum melting include: a temperature of 1100℃-1200℃; The conditions for the air jet mill include: a rotational speed of 3000 r / min to 5000 r / min.

8. The method according to claim 4, characterized in that, The surfactant is selected from one or more of oleic acid, oleylamine, AEO-3, and dodecanoic acid.

9. The method according to claim 4, characterized in that, The adhesive is selected from one or more of epoxy resin E51, epoxy resin E44, epoxy resin K51, silicone resin and polyphenylene sulfide.

10. The method according to claim 4, characterized in that, The ball milling conditions include: a ball-to-material ratio of 10-30:1, a rotation speed of 150 r / min-350 r / min, and the ball milling media being alcohol and / or 2-methylpentane.

11. The method according to claim 4, characterized in that, The conditions for compression molding include a pressure of 1500MPa-2000MPa.

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