An Fe-Ni co-doped SmCo4B-based permanent magnet thin strip and its preparation method

Abstract

The present invention relates to an Fe-Ni co-doped SmCo<subgt;4< / subgt;B-based permanent magnet thin strip and a preparation method thereof. The elemental composition formula of the material is SmCo<subgt;x< / subgt>Fe<subgt;y< / subgt>Ni<subgt;z< / subgt>B, where the subscripts x, y, and z in the formula represent the molar ratio numbers of the defined elements among the elements, and the symbols for defining the element composition range satisfy: x + y + z = 4, x = 1 to 3.5, y = 0.2 to 2.0, z = 0.12 to 1.2. The stable SmCo<subgt;4< / subgt>B-based permanent magnet thin strip prepared by the method of the present invention has an intrinsic coercivity of 39.6 kOe to 88.8 kOe, a remanence of 18.4 emu / g to 63.8 emu / g, and a maximum magnetization intensity of 20.2 emu / g to 83.7 emu / g at room temperature under an applied magnetic field of 90 kOe, far exceeding the room temperature coercivity and magnetization intensity of the SmCo<subgt;4< / subgt>B-based permanent magnet thin strip prepared by the prior art.

Description

Technical Field

[0001] The technical solution of the present invention relates to magnets of hard magnetic materials containing rare earth metals and magnetic transition metals, and specifically relates to an iron-nickel co-doped SmCo4B-based permanent magnet thin strip and a preparation method thereof. Background Art

[0002] Rare earth permanent magnet materials refer to permanent magnet materials based on intermetallic compounds formed by rare earth elements such as Pr, Nd, Sm, etc. and transition metal elements such as Fe, Co, etc. They are currently the type of permanent magnet materials with the highest coercivity and the largest magnetic energy product, and have been widely used in various industries. Rare earth permanent magnet materials have gone through three generations of development: SmCo5, Sm2Co 17 , Nd2Fe 14 B. Among them, Nd-Fe-B permanent magnets have the largest magnetic energy product, while Sm-Co magnets are rare earth permanent magnets with the highest operating temperature. Their magnetic energy products have approached the theoretical limit, and the development space has been greatly restricted. Therefore, it is imperative to develop a new type of Sm-Co permanent magnet material with higher coercivity, higher magnetic energy product, and excellent temperature stability.

[0003] Research has found that the Sm-Co-B alloy obtained by adding B element to the SmCo5 alloy has a large magnetocrystalline anisotropy energy. Research shows that (Oesterreicher H, Spada F, Abache C. Anisotropic and highmagnetization rare earth transition metal compounds containing metalloids[J]. Materials Research Bulletin, 1984, 19(8): 1069-1076; Ido H, Sugiyama K, Hachino H, et al. Magnetic study of Sm n+1 Co 3n+5 B 2n (n = 0, 1, 2, 3) in a pulsed high field[J]. Physica B: Condensed Matter, 1992, 177(1-4): 265-269), in every second layer of the SmCo5 structure, a CeCo4B-type hexagonal structure SmCo4B phase with a P6 / mmm space group is obtained through the ordered substitution of Co by B. It has an anisotropy field as high as 120 T at 4.2 K, far higher than 71 T of SmCo5, which makes it a very promising candidate permanent magnet material with great research value and application prospects.

[0004] Ido et al. (Ido H, Nashima O, Takahashi T, et al. New magnetic material based on SmCo4B[J]. Journal of Applied Physics, 1994, 76(10): 6165 - 6167.) replaced Co with Fe in the SmCo4B alloy and prepared a single-phase SmCo 1.7 Fe 2.3 B compound by arc melting combined with a heat treatment process, and obtained a saturation magnetization of 81.4 emu / g at 300 K. Jiang et al. (Jiang X, Devaraj A, Balamurugan B, et al. Microstructure of multistage annealed nanocrystalline SmCo2Fe2B alloy with enhanced magnetic properties[J]. Journal of Applied Physics, 2014, 115(6): 063902; Jiang X, Balamurugan B, Shield J E. Effect of Fe content on structural and magnetic properties of SmCo 4-x Fe x B alloys[J]. Journal of Alloys and Compounds, 2014, 617: 479 - 484.) prepared a series of annealed SmCo 4-x Fe x B ribbons by melt spinning combined with heat treatment, and found that when x < 1, the ribbons were composed only of a single-phase Sm(Co,Fe)4B, and when x ≥ 1, the alloy consisted of Sm(Co,Fe)4B and Sm2(Co,Fe) 17 B y two phases, and the coercivity increased with increasing Fe content until x = 1, reaching a maximum of 41 kOe. The saturation magnetization of the ribbon with x = 2 was increased by about 24% compared to x = 0. Chi et al. (Chi X, Li Y, Han X H, et al. A comparative study on structures and magnetic properties of SmCo4B and SmCo 3.1 Fe 0.9B ribbons [J]. Physica B: Condensed Matter, 2018, 545: 176 - 181.) found that replacing Co with 22.5 at% Fe increased the disorder degree of rapidly quenched SmCo4B ribbons, resulting in a decrease in coercivity. By analyzing the atomic structure, it was found that the atomic mismatch effect was the main mechanism. Satio et al. (Saito T, Nishio - Hamane D. Synthesis of Sm(Co,Fe)4B compounds by rapid quenching and subsequent heat treatment [J]. Intermetallics, 2019, 107: 6 - 9.) melt - quenched SmCo 4-x Fe x B ribbons at a speed of 50 m / s and then annealed them in an argon atmosphere at 700 °C for 1 h. It was found that the x = 0 alloy was composed of a single - phase SmCo4B, the 0 < x ≤ 1.5 alloys were composed of a single - phase Sm(Co,Fe)4B, and the x = 1.5 alloy had a maximum coercivity of 25 kOe and a remanent magnetization of 34 emu / g. Chi et al. (Chi X, Li Y, Han X H, et al. A new Sm(Co,Fe,Cu)4B / Sm2(Co,Fe,Cu)7 cell structure with the coercivity of up to 5.01 T [J]. Journal of Magnetism and Magnetic Materials, 2018, 458: 66 - 74.) found that when studying Fe, Cu co - doped SmCo4B - type ribbons, the ribbons were all composed of CeCo4B - type Sm(Co,Fe,Cu)4B and Nd5Co 19 B6 - type Sm5(Co,Fe,Cu) 19 B6 phases, and a coercivity of 50 kOe and a saturation magnetization of 27.8 emu / g were obtained at room temperature.

[0005] Literature ( P, Landa A, Locht I, et al. Prediction of the new efficient permanent magnet SmCoNiFe3[J]. Physical Review B, 2017, 96(10):100404.) pointed out that by substituting Co with Fe in SmCo5 magnets and using Ni as a thermodynamic stabilizer, Sm-Co magnets with excellent magnetic properties can be obtained. Mikhov et al. (Mikhov M, Gong W, Hadjipanayis G. Magnetic properties of melt-spun and as-cast SmCo 5-x Ni x alloys[J]. Journal of Applied Physics, 1987, 61(8):3460 - 3462.) studied the magnetic properties of as-cast, ribbon, and powder of SmCo 5-x Ni x alloys at temperatures from 4.2 K to 900 K and in magnetic fields up to 75 kOe. It was found that all samples had a CaCu5-type structure. At 4.2 K, the highest coercivity of SmCo4Ni ribbons was 30 kOe, and that of SmCo3Ni2 powders was 51 kOe. Landa et al. (Landa A, Soderlind P, Parker D, et al. Thermodynamics of the SmCo5 compound doped with Fe and Ni: an ab initio study[J]. Journal of Alloys and Compounds, 2018, 765:659 - 663.) showed that the SmCoNiFe3 magnet has a large magnetic energy product (about 70.5% of Nd2Fe 14 B), which is 56% larger than that of the SmCo5 magnet. Gavrikov et al. (Gavrikov I S, Karpenkov D Y, Zheleznyi M V, et al. Effect of Ni doping on stabilization of Sm(Co 1-x Fe x )5 compound: thermodynamic calculation and experiment[J]. Journal of Physics: Condensed Matter, 2020, 32(42):425803.) found that under the same preparation conditions, SmCo5 ribbons and SmCo0.8 Fe 0.15 Ni 0.05 The thin strip, and the latter exhibits a higher coercivity value of 13 kOe and a remanence value of 45 emu / g.

[0006] In summary, one of the most effective methods for preparing Sm-Co compounds is to perform melt spinning on the as-cast master alloy and then heat-treat it. Currently, the hard magnetic properties of SmCo4B-based permanent magnet thin strips are mainly improved by adding Fe and Cu elements to replace part of Co. The anisotropy field of SmCo4B as the main phase is as high as 1200 kOe. The SmCo4B-based permanent magnet thin strips prepared should theoretically have extremely high coercivity. However, so far, there has been no report on SmCo4B-based thin strip alloy materials with a high coercivity exceeding 50 kOe and a high magnetization intensity at room temperature, and the magnetic properties of the thin strips still need to be further improved. Summary of the Invention

[0007] The object of the present invention is to provide an Fe-Ni co-doped SmCo4B-based permanent magnet thin strip and a preparation method thereof in view of the deficiencies in the current technology. The element composition formula of the SmCo4B-based permanent magnet thin strip is SmCo x Fe y Ni z B. By simultaneously adding Fe and Ni elements and regulating the ratio of Fe:Co:Ni, a new phase composition and microstructure are formed with SmCo4B, Sm3Co 11 B4, Sm5Co 19 B6-type phases as the main phases and Sm2Co7B3, Sm2Co 14 B, Sm 1.1 Fe4B4-type phases as trace phases. The main phases have a high nucleation field, and the trace phases mainly act as grain boundary phases to pin the main phases. The hard magnetization mechanism of the thin strip is that the nucleation and pinning mechanisms coexist, and at the same time, there is a strong exchange coupling effect; in the preparation method, the SmCo4B-based permanent magnet thin strip prepared by the melt centrifugal spinning technology has an extremely high room temperature coercivity and a high magnetization intensity.

[0008] The technical solution adopted by the present invention to solve this technical problem is:

[0009] An Fe-Ni co-doped SmCo4B-based permanent magnet thin strip, the element composition formula of which is SmCo x Fe y Ni z B, where the subscript symbols x, y, and z in the formula represent the molar ratio numbers of the defined elements among the elements, and the symbols for defining the element composition range satisfy: x + y + z = 4, x = 1 to 3.5, y = 0.2 to 2.0, z = 0.12 to 1.2;

[0010] The thickness of the thin strip is 25 μm to 60 μm, its intrinsic coercivity at room temperature is 39.6 kOe to 88.8 kOe, the remanence is 18.4 emu / g to 63.8 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field is 20.2 emu / g to 83.7 emu / g.

[0011] The preparation method of the iron-nickel co-doped SmCo4B-based permanent magnet thin strip adopts the melt centrifugal rapid quenching technology, and includes the following steps:

[0012] The first step, raw material preparation:

[0013] According to the atomic ratio in the general formula SmCo x Fe y Ni z B, calculate the mass percentage of each element, and then weigh the required amounts of component raw materials: pure Sm, pure Co, pure Fe, pure Ni and boron source materials according to this mass percentage, thus completing the raw material preparation. In the above general formula, it is limited that the element composition satisfies: x + y + z = 4, x = 1 to 3.5, y = 0.2 to 2.0, z = 0.12 to 1.2;

[0014] The boron source material described is B-Fe, B-Co alloy or pure B powder;

[0015] The second step, melting the raw materials to prepare the master alloy ingot, which is one of the following two methods:

[0016] Method 1: Put the raw materials prepared in the first step into the crucible of a vacuum arc melting furnace or a vacuum induction melting furnace at the same time. When melting, first evacuate the furnace body to a vacuum degree of 10 -2 Pa to 10 -3 Pa, raise the furnace temperature to 50 °C to 185 °C higher than the melting point of pure Co until all pure Sm, pure Co, pure Fe, pure Ni and boron source materials are melted, then keep for 5 to 50 minutes, and then naturally cool in the mold to obtain the SmCo x Fe y Ni z B master alloy ingot;

[0017] Or method 2, put the boron source material into the bunker alone. When melting, first evacuate the furnace body to a vacuum degree of 10 -2 Pa to 10 - 3 Pa, raise the furnace temperature to 50 °C to 185 °C higher than the melting point of pure Co until all pure Sm, pure Co, pure Fe and pure Ni raw materials are melted, add the boron source material, then keep for 10 to 50 minutes, and then naturally cool in the mold to obtain the SmCo x Fe y Ni z B master alloy ingot;

[0018] Step 3, Preparation of SmCo4B-based rapidly quenched thin strip:

[0019] Load the SmCo x Fe y Ni z B master alloy ingot into a melt spinning furnace, remelt it, and perform melt spinning on a cooling copper roller or molybdenum roller rotating at a circumferential speed of 20 m / s to 60 m / s, thus obtaining the SmCo4B-based rapidly quenched thin strip;

[0020] Step 4, Preparation of SmCo4B-based permanent magnet thin strip:

[0021] Anneal the SmCo4B-based rapidly quenched thin strip prepared in Step 3 at 600 °C to 900 °C for a holding time of 10 min to 60 min, thereby obtaining an Fe-Ni co-doped SmCo4B-based permanent magnet thin strip, the elemental composition formula of which is SmCo x Fe y Ni z B, the thickness of the thin strip is 25 μm to 60 μm, its coercivity at room temperature is 39.6 kOe to 88.8 kOe, the remanence is 18.4 emu / g to 63.8 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field is 20.2 emu / g to 83.7 emu / g.

[0022] The melting temperature in Method 1 or Method 2 described above is 1500 °C - 1680 °C.

[0023] In the preparation of the raw materials in the first step, calculate the mass percentages of each element according to the atomic ratio in the general formula SmCo x Fe y Ni z B, and on the basis of weighing the required amount of pure Sm according to this mass percentage, additionally add 3% - 10% (mass percentage) of pure Sm, thereby completing the preparation of the raw materials.

[0024] All the raw materials used are obtained through commercial purchase, all the equipment used is well-known chemical engineering equipment, and all the process operation methods used are well-known methods to those skilled in the art of this technology.

[0025] The substantial features of the present invention are:

[0026] In the current technology, for the patent "A SmCo4B-based permanent magnet thin strip ZL201710189336.0", the composition is: SmCo x Fe y Cu zB; The magnetization intensity of the ribbon is increased by adding Fe to SmCo4B, and the coercivity of the ribbon is maintained by adding Cu. The co-addition of Fe and Cu microscopically forms a nearly single-phase microstructure of SmCo x Fe y Cu z B, and high coercivity is achieved by means of the high anisotropy field of the SmCo4B-type phase. However, due to the nearly single-phase structure, the coupling and pinning effects between multiple phases are lacking, and Cu is a non-magnetic element, resulting in limitations such as not very high coercivity, remanence, and saturation magnetization intensity.

[0027] The elemental composition formula of the SmCo4B-based permanent magnet ribbon of the present invention is SmCo x Fe y Ni z B. Both Fe and Ni are ferromagnetic elements. The addition of Ni will improve the stability of the SmCo4B phase, thereby inhibiting the phase decomposition of SmCo4B, forming a new phase composition and microstructure with SmCo4B, Sm3Co 11 B4, Sm5Co 19 B6-type phases as the main phases and Sm2Co7B3, Sm2Co 14 B, Sm 1.1 Fe4B4-type phases as trace phases, so that the highest coercivity is increased from the previous highest of 54 kOe to 88 kOe, and the performance is greatly improved.

[0028] The beneficial effects of the present invention are as follows:

[0029] (1) The elemental composition formula designed in the present invention is SmCo x Fe y Ni z B. The innovation mechanism of a Fe-Ni co-doped SmCo4B-based permanent magnet ribbon is as follows:

[0030] 1) It is found that Sm 1+n Co 5+3n B 2nThe Sm-Co-B ternary alloy has a very high anisotropy field. The anisotropy field of SmCo4B can reach 120 T at 4.2 K, while that of SmCo5 is only 71 T under the same conditions. However, the Curie temperature and magnetization of SmCo4B are relatively low. In the Sm-Co-B ternary alloy, the anisotropy constant K1 of the alloy is mainly provided by the Sm sublattice. The anisotropy of the Sm sublattice can be improved by doping with Fe and Ni. Since Fe, Co, and Ni all belong to transition metal elements, from the formation enthalpies of SmCo4B, SmCo2Fe2B, and SmCo3NiFeB, the ΔH values of SmCo4B, SmCo2Fe2B, and SmCo3NiB are -0.252, -0.241, and -0.286 eV respectively. It can be seen that the addition of Fe will reduce the stability of the SmCo4B phase, while the addition of Ni will increase the stability of the SmCo4B phase, thus inhibiting the phase decomposition of SmCo4B. In addition, the magnetic moment of Fe (2.2μ B ) is higher than that of Co (1.72μ B ). Therefore, substituting Fe and Ni for Co can increase the magnetic moment of the Co site in SmCo4B and the phase stability, and further increase the magnetization of the alloy. Therefore, co-doping with appropriate amounts of Fe and Ni can increase the coercivity and magnetization of SmCo4B-based permanent magnet thin strips. Practice has proved that in the SmCo4B-based alloy thin strips of the present invention, by adjusting the proportions of Fe, Co, and Ni alloying elements and using the melt-spinning technology combined with heat treatment, fine-grained SmCo4B-based hard magnetic thin strips with equiaxed or rod-like and plate-like microstructures and ultra-high coercivity are obtained, forming a new phase composition and microstructure with SmCo4B, Sm3Co 11 B4, Sm5Co 19 B6-type phases as the main phases and Sm2Co7B3, Sm2Co 14 B, Sm 1.1 Fe4B4-type phases as trace phases. The main phases have a high nucleation field, and the trace phases mainly act as grain boundary phases to pin the main phases. The hard magnetization mechanism of the thin strips is: the coexistence of nucleation and pinning mechanisms, and at the same time, there is a strong exchange coupling effect; an ultra-high coercivity of 39.6 kOe - 88.8 kOe is stably obtained, and the high magnetization comes from a multi-step magnetization mechanism.

[0031] 2) There is currently no report on the co-doping of Fe and Ni in SmCo4B alloys. Therefore, the characteristics of the magnetic properties of SmCo 4-x Fe x B alloys with the addition of Ni are not clearly understood. Since the magnetic moment of Ni is lower than that of Fe and Co, the addition of Ni may reduce the magnetization of SmCo4B. However, in the present invention, by co-doping SmCo4B alloys with Fe and Ni elements, the coercivity and magnetization of the alloy are further increased, and SmCo with better comprehensive magnetic properties is obtained.4-x-y Fe x Ni y The B alloy, that is, the element composition formula of the present invention is SmCo x Fe y Ni z B alloy.

[0032] (2) The present invention co-dopes the SmCo4B alloy with Fe and Ni elements to form SmCo 4-x-y Fe x Ni y B phase. By optimizing the Fe and Ni elements, the coercivity and magnetization intensity of the SmCo4B phase can be improved, and a permanent magnet alloy with better comprehensive magnetic properties is obtained. Compared with the prior art, the significant progress of the present invention is that the magnetic properties of the magnet are measured by a comprehensive physical property measurement system, and the SmCo4B-based permanent magnet thin strip prepared by the method of the present invention has an intrinsic coercivity of 39.6 kOe to 88.8 kOe, a remanence of 18.4 emu / g to 63.8 emu / g, and a maximum magnetization intensity of 20.2 emu / g to 83.7 emu / g at room temperature under an applied magnetic field of 90 kOe, far exceeding the room temperature coercivity and magnetization intensity of the SmCo4B-based permanent magnet thin strip prepared by the prior art. Brief Description of the Drawings

[0033] The present invention will be further described below with reference to the drawings and embodiments.

[0034] Figure 1 X-ray diffraction pattern of the SmCo 3.5 Fe 0.38 Ni 0.12 B permanent magnet thin strip for Example 1;

[0035] Figure 2 Magnetic hysteresis loop of the SmCo 3.5 Fe 0.38 Ni 0.12 B permanent magnet thin strip for Example 1;

[0036] Figure 3 Transmission electron microscope image of the SmCo 3.5 Fe 0.38 Ni 0.12 B permanent magnet thin strip for Example 1;

[0037] Figure 4 X-ray diffraction pattern of the SmCo 3.0 Fe 0.8 Ni 0.2 B permanent magnet thin strip for Example 2;

[0038] Figure 5 For Example 2 of SmCo3.0 Fe 0.8 Ni 0.2 Hysteresis loop of the permanent magnet thin strip of B;

[0039] Figure 6 For SmCo of Example 3 2.2 Fe 1.2 Ni 0.6 X-ray diffraction pattern of the permanent magnet thin strip of B;

[0040] Figure 7 For SmCo of Example 3 2.2 Fe 1.2 Ni 0.6 Hysteresis loop of the permanent magnet thin strip of B;

[0041] Figure 8 For SmCo of Example 3 2.2 Fe 1.2 Ni 0.6 Transmission electron microscope image of the permanent magnet thin strip of B. Among them, Figure 8 a is the morphology of typical equiaxed grains, Figure 8 b is the morphology of large grains;

[0042] Figure 9 For SmCo of Example 4 2.4 Fe 1.2 Ni 0.4 X-ray diffraction pattern of the permanent magnet thin strip of B;

[0043] Figure 10 For SmCo of Example 4 2.4 Fe 1.2 Ni 0.4 Hysteresis loop of the permanent magnet thin strip of B;

[0044] Figure 11 For SmCo of Example 4 2.4 Fe 1.2 Ni 0.4 Transmission electron microscope image of the permanent magnet thin strip of B;

[0045] Figure 12 For SmCo2Fe of Example 5 1.2 Ni 0.8 X-ray diffraction pattern of the permanent magnet thin strip of B;

[0046] Figure 13 For SmCo2Fe of Example 5 1.2 Ni 0.8 Hysteresis loop of the permanent magnet thin strip of B;

[0047] Figure 14 For SmCo2Fe of Example 5 1.2 Ni 0.8Transmission electron microscope image of the permanent magnet thin strip of B

[0048] Figure 15 For SmCo of Example 6 1.6 Fe 1.6 Ni 0.8 X-ray diffraction pattern of the permanent magnet thin strip of SmCoFeNiB

[0049] Figure 16 For SmCo of Example 6 1.6 Fe 1.6 Ni 0.8 Demagnetization curve of the permanent magnet thin strip of SmCoFeNiB

[0050] Figure 17 X-ray diffraction pattern of the permanent magnet thin strip of SmCoFe₂NiB of Example 7

[0051] Figure 18 Demagnetization curve of the permanent magnet thin strip of SmCoFe₂NiB of Example 7

[0052] Figure 19 Transmission electron microscope image of the permanent magnet thin strip of SmCoFe₂NiB of Example 7. Among them, Figure 19 a is the spherical grain morphology, Figure 19 b is the equiaxed and elongated grain morphology;

[0053] Figure 20 X-ray diffraction pattern of the permanent magnet thin strip of SmCo₂FeNiB of Example 8

[0054] Figure 21 Demagnetization curve of the permanent magnet thin strip of SmCo₂FeNiB of Example 8

[0055] Figure 22 Transmission electron microscope image of the permanent magnet thin strip of SmCo₂FeNiB of Example 8

[0056] Figure 23 For SmCo of Example 9 2.6 Fe 0.2 Ni 1.2 X-ray diffraction pattern of the permanent magnet thin strip of SmCoFeNiB

[0057] Figure 24 For SmCo of Example 9 2.6 Fe 0.2 Ni 1.2 Demagnetization curve of the permanent magnet thin strip of SmCoFeNiB Detailed implementation mode

[0058] Example 1

[0059] SmCo in the SmCo₄B-based permanent magnet thin strip 3.5 Fe 0.38 Ni0.12 Preparation method of B thin strip.

[0060] First step, raw material preparation:

[0061] Calculate the elemental composition formula SmCo according to the atomic ratio (i.e., the molar ratio between elements) 3.5 Fe 0.38 Ni 0.12 The mass percentages of the constituent elements in B, weigh the required amounts of component raw materials according to this mass percentage: pure Sm, pure Co, pure Fe, pure Ni and B-Co alloy. When preparing the ingredients, additionally add pure Sm with a mass percentage of 3% of the pure Sm calculated according to the above raw material ratio, thus completing the raw material preparation;

[0062] Second step, melting raw materials to prepare master alloy ingot:

[0063] Put the raw materials prepared in the first step into the crucible of the vacuum arc melting furnace at the same time. When melting, first evacuate the furnace body to a vacuum degree of 3×10 -3 Pa, raise the furnace temperature to 50°C higher than the melting point of pure Co until all pure Sm, pure Co, pure Fe, pure Ni and B-Co alloy are melted, then keep it for 20 minutes and then cool naturally in the mold to obtain SmCo 3.5 Fe 0.38 Ni 0.12 B master alloy ingot;

[0064] Third step, preparation of SmCo4B-based rapidly quenched thin strip:

[0065] Put the SmCo 3.5 Fe 0.38 Ni 0.12 B master alloy prepared in the second step into the melt spinning furnace, remelt it and perform melt spinning on the rotating cooling molybdenum roller wheel with a circumferential speed of 20 m / s, then the SmCo4B-based rapidly quenched thin strip is obtained;

[0066] Fourth step, preparation of SmCo4B-based permanent magnet thin strip:

[0067] Put the thin strip prepared by melt spinning in the third step into the vacuum annealing furnace, with a vacuum degree of 3×10 -3 Pa, perform annealing treatment at 850°C, and the holding time is 20 min, then the SmCo4B-based permanent magnet thin strip product is obtained, and its elemental composition formula is SmCo 3.5 Fe 0.38 Ni 0.12 B. The thickness of this thin strip is 60 μm, the length is 2 mm to 8 mm, the width is 1 mm to 2 mm, the intrinsic coercivity at room temperature is 39.6 kOe, the remanence is 63.8 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field is 83.7 emu / g.

[0068] Figure 1 The X-ray diffraction pattern of the SmCo4B-based permanent magnet thin strip prepared in this example, with the elemental composition formula of SmCo 3.5 Fe 0.38 Ni 0.12 B. The thin strip is composed of Sm(Co,Fe,Ni)4B, Sm3(Co,Fe,Ni) 11 B4 and a small amount of Sm2(Co,Fe,Ni) 14 B phase.

[0069] Figure 2 The initial magnetization curve and hysteresis loop of the SmCo4B-based permanent magnet thin strip with the elemental composition formula of SmCo 3.5 Fe 0.38 Ni 0.12 B prepared in this example. The magnetic properties were measured on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. Its intrinsic coercivity is 39.6 kOe, the remanence is 63.8 emu / g, and the maximum magnetization intensity (saturation magnetization intensity) at 90 kOe magnetic field is 83.7 emu / g. The thickness of the thin strip was measured using a micrometer to be 60 μm.

[0070] Figure 3 The transmission electron microscope image of the SmCo4B-based permanent magnet thin strip with the elemental composition formula of SmCo 3.5 Fe 0.38 Ni 0.12 B prepared in this example. As can be seen from the figure, the thin strip is composed of equiaxed grains, and the average grain size is 86 nm. Among them, the bright-colored grains are Sm3(Co,Fe,Ni) 11 B4 phase, the gray grains are Sm(Co,Fe,Ni)4B phase, and the grains with stripes are Sm2(Co,Fe,Ni) 14 B phase.

[0071] Example 2

[0072] Preparation method of the SmCo4B-based permanent magnet thin strip of SmCo 3.0 Fe 0.8 Ni 0.2 B thin strip.

[0073] The first step, raw material preparation:

[0074] Calculated according to the atomic ratio, the elemental composition formula SmCo 3.0 Fe 0.8 Ni 0.2The mass percentages of the constituent elements in B. Weigh the required amounts of the component raw materials according to these mass percentages: pure Sm, pure Co, pure Fe, pure Ni, and pure B powder. When formulating the ingredients, an additional amount of pure Sm is added, which is 5% of the mass of pure Sm weighed according to the above raw material ratio, thus completing the preparation of the raw materials.

[0075] The second step is to melt the raw materials to prepare a master alloy ingot:

[0076] Put the B powder prepared in the first step into a separate bin, and put the other raw materials into the crucible of a vacuum induction melting furnace at the same time. When melting, first evacuate the furnace body to a vacuum degree of 10 -2 Pa to 10 -3 Pa, and raise the furnace temperature to 185°C above the melting point of pure Co until all the pure Sm, pure Co, pure Fe, and pure Ni raw materials are melted. Then add the B powder, and after maintaining for 15 minutes, let it cool naturally in a mold to obtain a SmCo 3.0 Fe 0.8 Ni 0.2 B master alloy ingot;

[0077] The third step is the preparation of SmCo4B-based rapidly quenched thin strips:

[0078] Put the SmCo 3.0 Fe 0.8 Ni 0.2 B master alloy prepared in the second step into a melt spinning furnace. After remelting, perform melt spinning on a cooling copper roller rotating at a circumferential speed of 40 m / s, and then SmCo4B-based rapidly quenched thin strips are obtained;

[0079] The fourth step is the preparation of SmCo4B-based permanent magnet thin strips:

[0080] Put the thin strips prepared by melt spinning in the third step into a vacuum annealing furnace with a vacuum degree of 1×10 -3 Pa, and perform annealing treatment at 850°C for a holding time of 30 min. Thus, SmCo4B-based permanent magnet thin strips are obtained, and their elemental composition formula is SmCo 3.0 Fe 0.8 Ni 0.2 B. The thickness of this thin strip is 53 μm, the intrinsic coercivity at room temperature is 45.1 kOe, the remanence is 37.3 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field is 50.4 emu / g.

[0081] Figure 4 The X-ray diffraction pattern of the SmCo4B-based permanent magnet thin strip with the elemental composition formula SmCo 3.0 Fe 0.8 Ni 0.2 B prepared in this example. The thin strip consists of Sm(Co,Fe,Ni)4B, Sm3(Co,Fe,Ni) 11B4 and a small amount of Sm5(Co,Fe,Ni) 19 composed of B6 phase

[0082] Figure 5 The initial magnetization curve and hysteresis loop of the SmCo4B-based permanent magnet thin strip with the element composition formula of SmCo 3.0 Fe 0.8 Ni 0.2 B prepared in this example were measured for magnetic properties on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. Its intrinsic coercivity was 45.1 kOe, the remanence was 37.3 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field was 50.4 emu / g. The thickness of the thin strip was measured using a micrometer to be 53 μm.

[0083] Example 3

[0084] Preparation method of SmCo4B-based permanent magnet thin strip of SmCo 2.2 Fe 1.2 Ni 0.6 B thin strip

[0085] The first step, raw material preparation:

[0086] Calculate the mass percentages of the constituent elements in the element composition formula SmCo 2.2 Fe 1.2 Ni 0.6 B, and weigh the required amounts of component raw materials according to these mass percentages: pure Sm, pure Co, pure Fe, pure Ni, and B-Co alloy. When formulating the ingredients, an additional 6% of pure Sm by mass percentage of the pure Sm weighed according to the above raw material ratio is added, thus completing the raw material preparation;

[0087] The second step, melting raw materials to prepare master alloy ingots:

[0088] Put the raw materials prepared in the first step into the crucible of a vacuum induction melting furnace at the same time. During melting, first evacuate the furnace body to a vacuum degree of 4×10 -2 Pa, raise the furnace temperature to 180℃ higher than the melting point of pure Co until all pure Sm, pure Co, pure Fe, pure Ni, and B-Co alloy are melted, then keep it for 5 minutes and then naturally cool in the mold to obtain SmCo 2.2 Fe 1.2 Ni 0.6 B master alloy ingots;

[0089] The third step, preparation of SmCo4B-based rapidly quenched thin strips:

[0090] The SmCo 2.2 Fe 1.2 Ni 0.6The B master alloy is loaded into a melt spinning quenching furnace, remelted, and then melt spun on a cooling molybdenum roller rotating at a circumferential speed of 40 m / s to obtain a SmCo4B-based rapidly quenched thin strip.

[0091] Step 4: Preparation of the SmCo4B-based permanent magnet thin strip:

[0092] The thin strip prepared by melt spinning quenching in the third step is loaded into a vacuum annealing furnace with a vacuum degree of 4×10 -2 Pa, annealed at 900 °C for 10 min to obtain a SmCo4B-based permanent magnet thin strip product with an elemental composition formula of SmCo 2.2 Fe 1.2 Ni 0.6 B. The thickness of the thin strip is 50 μm, the intrinsic coercivity at room temperature is 49.1 kOe, the remanence is 30.8 emu / g, and the maximum magnetization intensity under a magnetic field of 90 kOe is 34.9 emu / g.

[0093] Figure 6 The X-ray diffraction pattern of the SmCo4B-based permanent magnet thin strip with an elemental composition formula of SmCo 2.2 Fe 1.2 Ni 0.6 B prepared in this example. The thin strip is composed of Sm(Co,Fe,Ni)4B, Sm3(Co,Fe,Ni) 11 B4 and a small amount of Sm2(Co,Fe,Ni)7B3 phases.

[0094] Figure 7 The hysteresis loop of the SmCo4B-based permanent magnet thin strip with an elemental composition formula of SmCo 2.2 Fe 1.2 Ni 0.6 B prepared in this example. The magnetic properties are measured on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. The intrinsic coercivity is 49.1 kOe, the remanence is 30.8 emu / g, and the maximum magnetization intensity under a magnetic field of 90 kOe is 34.9 emu / g. The thickness of the thin strip is measured to be 50 μm using a micrometer.

[0095] Figure 8 The transmission electron microscope image of the SmCo4B-based permanent magnet thin strip with an elemental composition formula of SmCo 2.2 Fe 1.2 Ni 0.6 B prepared in this example. The thin strip is composed of equiaxed grains with an average grain size of 120 nm. The bright-colored grains are Sm3(Co,Fe,Ni) 11 B4 phase, the gray-colored grains are Sm(Co,Fe,Ni)4B and Sm2(Co,Fe,Ni)7B3 phases, and the larger grains are Sm3(Co,Fe,Ni)11 B4。

[0096] Example 4

[0097] SmCo in SmCo4B-based permanent magnet thin strip 2.4 Fe 1.2 Ni 0.4 Preparation method of Fe-B thin strip

[0098] The first step, raw material preparation:

[0099] Calculate the elemental composition formula of SmCo 2.4 Fe 1.2 Ni 0.4 The mass percentages of the constituent elements in B, and weigh the required amounts of the component raw materials according to this mass percentage: pure Sm, pure Co, pure Fe, pure Ni and B-Co alloy. When mixing, additionally add pure Sm with a mass percentage of 7% of the pure Sm weighed according to the above raw material ratio, thus completing the raw material preparation;

[0100] The second step, melting raw materials to prepare master alloy ingot:

[0101] Put the raw materials prepared in the first step into the crucible of the vacuum arc melting furnace at the same time. When melting, first evacuate the furnace body to a vacuum degree of 1×10 -2 Pa, raise the furnace temperature to 80°C higher than the melting point of pure Co until all pure Sm, pure Co, pure Fe, pure Ni and B-Co alloy are melted, then keep it for 50 minutes and then cool naturally in the mold to obtain SmCo 2.4 Fe 1.2 Ni 0.4 B master alloy ingot;

[0102] The third step, preparation of SmCo4B-based rapidly quenched thin strip:

[0103] Put the SmCo 2.4 Fe 1.2 Ni 0.4 B master alloy into the melt spinning furnace, remelt it and perform melt spinning on the rotating cooling copper roller with a circumferential speed of 40 m / s, thus obtaining the SmCo4B-based rapidly quenched thin strip;

[0104] The fourth step, preparation of SmCo4B-based permanent magnet thin strip:

[0105] Put the thin strip prepared by melt spinning in the third step into the vacuum annealing furnace, with a vacuum degree of 1×10 -2 Pa, perform annealing treatment at 850°C, and the holding time is 40 min, thus obtaining the SmCo4B-based permanent magnet thin strip product, and its elemental composition formula is SmCo 2.4 Fe 1.2 Ni 0.4B. The thickness of the thin strip is 52 μm, the intrinsic coercivity at room temperature is 40.4 kOe, the remanence is 48.3 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field is 55.3 emu / g.

[0106] Figure 9 The X-ray diffraction pattern of the SmCo4B-based permanent magnet thin strip product with the elemental composition formula SmCo 2.4 Fe 1.2 Ni 0.4 B prepared in this example. The thin strip consists of the main phase Sm3(Co,Fe,Ni) 11 B4, the secondary phase Sm(Co,Fe,Ni)4B, and a small amount of Sm5(Co,Fe,Ni) 19 B6 phase.

[0107] Figure 10 The initial magnetization curve and hysteresis loop of the SmCo4B-based permanent magnet thin strip with the elemental composition formula SmCo 2.4 Fe 1.2 Ni 0.4 B prepared in this example. The magnetic properties were measured on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. Its intrinsic coercivity is 40.4 kOe, the remanence is 48.3 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field is 55.3 emu / g. The thickness of the thin strip was measured using a micrometer to be 52 μm.

[0108] Figure 11 The transmission electron microscope image of the SmCo4B-based permanent magnet thin strip with the elemental composition formula SmCo 2.4 Fe 1.2 Ni 0.4 B prepared in this example. The grains are equiaxed, and the average grain size is 96 nm. The bright grains are Sm3(Co,Fe,Ni) 11 B4 phase, and the gray grains are Sm(Co,Fe,Ni)4B and Sm5(Co,Fe,Ni) 19 B6 phase.

[0109] Example 5

[0110] Preparation method of SmCo4B-based permanent magnet thin strip of SmCo2Fe 1.2 Ni 0.8 B thin strip.

[0111] First step, raw material preparation:

[0112] Calculate the elemental composition formula SmCo2Fe according to the atomic ratio 1.2 Ni 0.8The mass percentages of the constituent elements in B, weigh the required amounts of the component raw materials according to these mass percentages: pure Sm, pure Co, pure Fe, pure Ni, and B-Co alloy. When formulating the ingredients, additionally add pure Sm in an amount equal to 8% of the mass percentage of pure Sm weighed according to the above raw material ratio, thereby completing the preparation of the raw materials;

[0113] The second step, melting the raw materials to prepare the master alloy ingot:

[0114] Put the raw materials prepared in the first step into the crucible of the vacuum arc melting furnace at the same time. When melting, first evacuate the furnace body to a vacuum degree of 6×10 -3 Pa, raise the furnace temperature to 120°C higher than the melting point of pure Co until all of the pure Sm, pure Co, pure Fe, pure Ni, and B-Co alloy are melted. Then, keep it for 30 minutes and then cool it naturally in the mold to obtain the SmCo2Fe 1.2 Ni 0.8 B master alloy ingot;

[0115] The third step, preparation of the SmCo4B-based rapidly quenched thin strip:

[0116] Put the SmCo2Fe 1.2 Ni 0.8 B master alloy prepared in the second step into the melt spinning furnace. After remelting, perform melt spinning on the rotating cooling molybdenum roller wheel with a circumferential speed of 40 m / s, thereby obtaining the SmCo4B-based rapidly quenched thin strip;

[0117] The fourth step, preparation of the SmCo4B-based permanent magnet thin strip:

[0118] Put the thin strip prepared by melt spinning in the third step into the vacuum annealing furnace, with a vacuum degree of 6×10 -3 Pa, perform annealing treatment at 600°C, and the holding time is 60 min, thereby obtaining the SmCo4B-based permanent magnet thin strip. Its elemental composition formula is SmCo2Fe 1.2 Ni 0.8 B. The thickness of this thin strip is 57 μm, the intrinsic coercivity at room temperature is 62.4 kOe, the remanence is 24.2 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field is 28.4 emu / g.

[0119] Figure 12 The X-ray diffraction pattern of the SmCo4B-based permanent magnet thin strip with the elemental composition formula SmCo2Fe 1.2 Ni 0.8 B prepared in this example. The thin strip consists of the main phase Sm3(Co,Fe,Ni) 11 B4, the secondary phases Sm(Co,Fe,Ni)4 and Sm5(Co,Fe,Ni) 19 B6 phases.

[0120] Figure 13 The initial magnetization curve and hysteresis loop of the SmCo4B-based permanent magnet thin strip with the elemental composition formula of SmCo2Fe 1.2 Ni 0.8 B prepared in this example were measured for magnetic properties on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. Its intrinsic coercivity was 62.4 kOe, the remanence was 24.2 emu / g, and the maximum magnetization intensity was 28.4 emu / g under a 90 kOe magnetic field. The thickness of the thin strip was measured to be 57 μm using a micrometer.

[0121] Figure 14 The transmission electron microscope image of the SmCo4B-based permanent magnet thin strip with the elemental composition formula of SmCo2Fe 1.2 Ni 0.8 B prepared in this example. The thin strip was composed of Sm3(Co,Fe,Ni) 11 B4 and Sm(Co,Fe,Ni)4B grains. There was a grain boundary phase between the grains, which was the Sm5(Co,Fe,Ni) 19 B6 phase. The average grain size was 160 nm.

[0122] Example 6

[0123] Preparation method of the SmCo4B-based permanent magnet thin strip of SmCo 1.6 Fe 1.6 Ni 0.8 B thin strip.

[0124] The first step, raw material preparation:

[0125] Calculate the mass percentages of the constituent elements in the elemental composition formula SmCo 1.6 Fe 1.6 Ni 0.8 B. Weigh the required amounts of the component raw materials according to this mass percentage: pure Sm, pure Co, pure Fe, pure Ni, and B-Fe alloy. When preparing the ingredients, an additional 8% of the mass of pure Sm weighed according to the above raw material ratio is added. Thus, the raw material preparation is completed;

[0126] The second step, melting the raw materials to prepare the master alloy ingot:

[0127] Put the raw materials prepared in the first step into the crucible of the vacuum arc melting furnace at the same time. During melting, first evacuate the furnace body to a vacuum degree of 4×10 -3 Pa, raise the furnace temperature to 130℃ higher than the melting point of pure Co until all the pure Sm, pure Co, pure Fe, pure Ni, and B-Fe alloy are melted, then keep it for 20 minutes and then cool naturally in the mold to obtain the SmCo 1.6 Fe 1.6 Ni 0.8 B master alloy ingot;

[0128] Step 3, Preparation of SmCo4B-based rapidly quenched ribbon:

[0129] Load the SmCo 1.6 Fe 1.6 Ni 0.8 master alloy prepared in Step 2 into a melt spinning furnace. After remelting, perform melt spinning on a cooling molybdenum roller rotating at a circumferential speed of 40 m / s to obtain the SmCo4B-based rapidly quenched ribbon;

[0130] Step 4, Preparation of SmCo4B-based permanent magnet ribbon:

[0131] Load the ribbon prepared by melt spinning in Step 3 into a vacuum annealing furnace with a vacuum degree of 4×10 -3 Pa, perform annealing treatment at 700 °C for a holding time of 40 min to obtain the SmCo4B-based permanent magnet ribbon product. Its elemental composition formula is SmCo 1.6 Fe 1.6 Ni 0.8 B. The thickness of the ribbon is 48 μm, the intrinsic coercivity at room temperature is 66.1 kOe, the remanence is 26.5 emu / g, and the maximum magnetization intensity under a magnetic field of 90 kOe is 30.2 emu / g.

[0132] Figure 15 The X-ray diffraction pattern of the SmCo4B-based permanent magnet ribbon with the elemental composition formula of SmCo 1.6 Fe 1.6 Ni 0.8 B prepared in this example. The ribbon consists of the main phase Sm(Co,Fe,Ni)4B, the secondary phase Sm5(Co,Fe,Ni) 19 B6 and a small amount of Sm3(Co,Fe,Ni) 11 B4, Sm2(Co,Fe,Ni)7B3 phases.

[0133] Figure 16 The demagnetization curve of the SmCo4B-based permanent magnet ribbon with the elemental composition formula of SmCo 1.6 Fe 1.6 Ni 0.8 B prepared in this example. Measure the magnetic properties on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. Its intrinsic coercivity is 66.1 kOe, the remanence is 26.5 emu / g. The maximum magnetization intensity M 9T is 30.2 emu / g. Measure the thickness of the ribbon to be 48 μm using a micrometer.

[0134] Example 7

[0135] The invention discloses a preparation method of SmCoFe2NiB thin strip of SmCo4B-based permanent magnetic thin strip.

[0136] The first step is raw material preparation:

[0137] The mass percentages of the constituent elements in the elemental composition formula SmCoFe2NiB are calculated according to the atomic ratios, and the required amounts of component raw materials are weighed according to the mass percentages: pure Sm, pure Co, pure Fe, pure Ni, and B-Fe alloy. During the mixing process, 8% of the mass percentage of the pure Sm weighed according to the above raw material ratio is additionally added to complete the raw material preparation;

[0138] The second step is to melt the raw materials to prepare the master alloy ingot:

[0139] The raw materials prepared in the first step are placed into the crucible of the vacuum arc melting furnace at the same time. When melting, the furnace body is vacuumed to 3×10 -3 Pa, the furnace temperature is raised to 150 ° C, which is higher than the melting point of pure Co, until all pure Sm, pure Co, pure Fe, pure Ni and B-Fe alloy are melted, and then kept for 20 minutes, and then naturally cooled in the mold to obtain a SmCoFe2NiB master alloy ingot;

[0140] The third step is the preparation of SmCo4B-based rapid quenching thin ribbon:

[0141] The SmCoFe2NiB master alloy prepared in the second step was placed in a melt quenching furnace, remelted, and then quenched on a cooled molybdenum roller rotating at a peripheral speed of 50 m / s to obtain a SmCo4B-based quenched thin strip;

[0142] Step 4: Preparation of SmCo4B-based permanent magnetic ribbons:

[0143] The thin strip prepared by the third step of melt rapid quenching is placed in a vacuum annealing furnace with a vacuum degree of 3×10 -3 Pa, annealing treatment was carried out at 850 ° C, and the holding time was 20 minutes, thereby obtaining a SmCo4B-based permanent magnetic thin strip product with an elemental composition of SmCoFe2NiB. The thickness of the thin strip was 41 μm, the intrinsic coercivity was 67.3 kOe at room temperature, the remanence was 20.5 emu / g, and the maximum magnetization intensity was 24.2 emu / g under a magnetic field of 90 kOe.

[0144] Figure 17 The X-ray diffraction pattern of the SmCo4B-based permanent magnetic ribbon with the elemental composition formula SmCoFe2NiB prepared in this embodiment is shown in FIG. The ribbon is composed of the main phase Sm(Co, Fe, Ni)4, the secondary phase Sm2(Co, Fe, Ni) 14 B and trace phase Sm 1.1 Fe4B4 phase.

[0145] Figure 18 The demagnetization curve of the SmCo4B-based permanent magnet thin strip with the element composition formula SmCoFe2NiB prepared in this example. The magnetic properties were measured on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. Its intrinsic coercivity was 67.3 kOe, and the remanence was 20.5 emu / g. The maximum magnetization intensity at a magnetic field of 90 kOe was 24.2 emu / g. The thickness of the thin strip was measured to be 41 μm using a micrometer.

[0146] Figure 19 The transmission electron microscope image of the SmCo4B-based permanent magnet thin strip with the element composition formula SmCoFe2NiB prepared in this example. The thin strip presents two tissue morphologies. One is the microstructure of bright Sm2(Co,Fe,Ni) 14 B grains coating spherical Sm with a size of 5-10 nm 1.1 Fe4B4 grains, and the other is the microstructure composed of equiaxed Sm(Co,Fe,Ni)4B grains and strip-shaped Sm2(Co,Fe,Ni) 14 B grains with random orientations, and there are many dislocations in the strip-shaped grains. The average size in the length direction of the measured strip-shaped grains is 250 nm, and the size in the width direction is 110 nm.

[0147] Example 8

[0148] Preparation method of SmCo2FeNiB thin strip of SmCo4B-based permanent magnet thin strip.

[0149] The first step, raw material preparation:

[0150] Calculate the mass percentages of the constituent elements in the element composition formula SmCo2FeNiB according to the atomic ratio, and weigh the required amounts of component raw materials according to this mass percentage: pure Sm, pure Co, pure Fe, pure Ni, and B-Co alloy. When preparing the ingredients, an additional 10% of pure Sm by mass percentage of the pure Sm weighed according to the above raw material ratio is added, thus completing the raw material preparation;

[0151] The second step, melting the raw materials to prepare the master alloy ingot:

[0152] Put the raw materials prepared in the first step into the crucible of a vacuum induction melting furnace at the same time. During melting, first evacuate the furnace body to a vacuum degree of 4×10 -3 Pa, raise the furnace temperature to 100 °C higher than the melting point of pure Co until all pure Sm, pure Co, pure Fe, pure Ni, and B-Co alloy are melted, and then keep it for 40 minutes and then naturally cool in the mold to obtain the SmCo2FeNiB master alloy ingot;

[0153] The third step, preparation of SmCo4B-based rapidly quenched thin strip:

[0154] The SmCo2FeNiB master alloy prepared in the second step is loaded into a melt spinning furnace. After remelting, it is subjected to melt spinning on a cooling copper roller rotating at a circumferential speed of 60 m / s, thereby obtaining a rapidly quenched SmCo4B-based thin strip.

[0155] Step 4: Preparation of SmCo4B-based permanent magnet thin strip:

[0156] The thin strip prepared by melt spinning in the third step is loaded into a vacuum annealing furnace with a vacuum degree of 4×10 -3 Pa. Annealing treatment is carried out at 750 °C for a holding time of 40 min, thereby obtaining a SmCo4B-based permanent magnet thin strip product with an elemental composition formula of SmCo2FeNiB. The thickness of the thin strip is 25 μm, the intrinsic coercivity at room temperature is 75.2 kOe, the remanence is 22.3 emu / g, and the maximum magnetization intensity under a magnetic field of 90 kOe is 26.5 emu / g.

[0157] Figure 20 This is the X-ray diffraction pattern of the SmCo4B-based permanent magnet thin strip with an elemental composition formula of SmCo2FeNiB prepared in this example. The thin strip consists of the main phase Sm(Co,Fe,Ni)4, the secondary phase Sm2(Co,Fe,Ni) 14 B and the trace phase Sm 1.1 Fe4B4 phases.

[0158] Figure 21 This is the demagnetization curve of the SmCo4B-based permanent magnet thin strip with an elemental composition formula of SmCo2FeNiB prepared in this example. The magnetic properties are measured on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. The intrinsic coercivity is 75.2 kOe, the remanence is 22.3 emu / g, and the maximum magnetization intensity under a magnetic field of 90 kOe is 26.5 emu / g. The thickness of the thin strip is measured to be 25 μm using a micrometer.

[0159] Figure 22 This is the transmission electron microscope image of the SmCo4B-based permanent magnet thin strip with an elemental composition formula of SmCo2FeNiB prepared in this example. The thin strip consists of randomly oriented striped long-grain crystals. These polyphase mixed grains are composed of Sm(Co,Fe,Ni)4B, Sm2(Co,Fe,Ni) 14 B and Sm 1.1 Fe4B4 phases, with obvious grain boundaries. The grain boundary phase is Sm 1.1 Fe4B4. The length of the long-grain crystals is 140 - 500 nm, and the width is 60 - 160 nm.

[0160] Example 9

[0161] SmCo4B-based permanent magnet thin strip of SmCo 2.6 Fe0.2 Ni 1.2 Preparation method of Ni-B thin strip.

[0162] First step, raw material preparation:

[0163] Calculate the elemental composition formula SmCo 2.6 Fe 0.2 Ni 1.2 The mass percentages of the constituent elements in B. Weigh the required amounts of the component raw materials according to this mass percentage: pure Sm, pure Co, pure Fe, pure Ni and B-Co alloy. When preparing the ingredients, add an additional 10% of the mass of pure Sm weighed according to the above raw material ratio. Thus, the raw material preparation is completed;

[0164] Second step, melting the raw materials to prepare the master alloy ingot:

[0165] Put the raw materials prepared in the first step into the crucible of the vacuum induction melting furnace at the same time. When melting, first evacuate the furnace body to a vacuum degree of 3×10 -3 Pa, raise the furnace temperature to 100°C higher than the melting point of pure Co until all pure Sm, pure Co, pure Fe, pure Ni and B-Co alloy are melted. Then, keep it for 10 minutes and then cool it naturally in the mold to obtain the SmCo 2.6 Fe 0.2 Ni 1.2 B master alloy ingot;

[0166] Third step, preparation of SmCo4B-based rapidly quenched thin strip:

[0167] Put the SmCo 2.6 Fe 0.2 Ni[[ID=?]] 1.2 B master alloy prepared in the second step into the melt spinning quenching furnace. After remelting, perform melt spinning quenching on the rotating cooling copper roller with a circumferential speed of 55 m / s to obtain the SmCo4B-based rapidly quenched thin strip;

[0168] Fourth step, preparation of SmCo4B-based permanent magnet thin strip:

[0169] Put the thin strip prepared by melt spinning quenching in the third step into the vacuum annealing furnace. The vacuum degree is 3×10 -3 Pa, perform annealing treatment at 850°C, and the holding time is 45 min. Thus, the SmCo4B-based permanent magnet thin strip product is obtained. The elemental composition formula of the SmCo4B-based permanent magnet thin strip product is SmCo 2.6 Fe 0.2 Ni 1.2 B. Use a micrometer to measure the thickness of the thin strip as 32 μm, the intrinsic coercivity at room temperature is 88.8 kOe, the remanence is 18.4 emu / g, and the maximum magnetization intensity under a magnetic field of 90 kOe is 20.2 emu / g. It should be noted that there seems to be an error in the original text where the "339" tag is used without a clear corresponding element name. I have translated it as "?" in the above translation for the sake of consistency, but it may need to be corrected according to the actual situation.

[0170] Figure 23 The element composition formula of the SmCo 2.6 Fe 0.2 Ni 1.2 B-based permanent magnet thin strip prepared in this embodiment, the thin strip consists of the main phase Sm(Co,Fe,Ni)4, the secondary phase Sm2(Co,Fe,Ni) 14 B and the trace phase Sm 1.1 Fe4B4 phase.

[0171] Figure 24 The element composition formula of the SmCo 2.6 Fe 0.2 Ni 1.2 B-based permanent magnet thin strip's demagnetization curve. The magnetic properties are measured on a comprehensive physical property measurement system with an external magnetic field of 90 kOe. Its intrinsic coercivity is 88.8 kOe, and the remanence is 18.4 emu / g. The maximum magnetization intensity at a magnetic field of 90 kOe is 20.2 emu / g.

[0172] Matters not covered by this invention are well-known technologies.

Claims

1. A Fe-Ni co-doped SmCo4B-based permanent magnet thin strip, characterized in that The thin strip element has a composition formula of SmCo x Fe y Ni z B, where the subscript symbols x, y, and z in the formula represent the molar ratio numbers of the defined elements among the elements, and the symbols for defining the element composition range satisfy: x + y + z = 4, x = 1 to 3.5, y = 0.2 to 2.0, z = 0.12 to 1.2; The preparation method of the iron-nickel co-doped SmCo4B-based permanent magnet thin strip, which uses the melt centrifugal rapid quenching technology, includes the following steps: The first step, raw material preparation: According to the atomic ratio in the general formula SmCo x Fe y Ni z B, calculate the mass percentages of each element, and then weigh the required amounts of component raw materials according to the mass percentages: pure Sm, pure Co, pure Fe, pure Ni, and boron source materials, thus completing the preparation of raw materials. In the above general formula, it is limited that the element composition satisfies: x + y + z = 4, x = 1 to 3.5, y = 0.2 to 2.0, z = 0.12 to 1.2; The boron source material is B-Fe, B-Co alloy or pure B powder; The second step, melting the raw materials to prepare the master alloy ingot, which is one of the following two methods: Method 1: Put the raw materials prepared in the first step into the crucible of a vacuum arc melting furnace or a vacuum induction melting furnace at the same time. When melting, first evacuate the furnace body to a vacuum degree of 10 -2 Pa to 10 -3 Pa, raise the furnace temperature to 50°C to 185°C higher than the melting point of pure Co until all the pure Sm, pure Co, pure Fe, pure Ni and boron source materials are melted. Then, keep it for 5 to 50 minutes and then cool it naturally in the mold to obtain the SmCo x Fe y Ni z B master alloy ingot; Or Method 2: Put the boron source material into the bin alone. When smelting, first evacuate the furnace body to a vacuum degree of 10 -2 Pa to 10 -3 Pa. Raise the furnace temperature to 50°C to 185°C higher than the melting point of pure Co until all the pure Sm, pure Co, pure Fe, and pure Ni raw materials are melted. Add the boron source material, and then keep it for 10 to 50 minutes and then cool it naturally in the mold to obtain the SmCo x Fe y Ni z FeNiB master alloy ingot; The third step, preparation of the SmCo4B-based rapid quenching thin strip: Put the SmCo x Fe y Ni z master alloy ingot into a melt spinning furnace, remelt it, and perform melt spinning on a cooling copper roller or molybdenum roller rotating at a circumferential speed of 20 m / s to 60 m / s, thus obtaining the SmCo4B-based rapidly quenched thin strip; The fourth step, preparation of the SmCo4B-based permanent magnet thin strip: Anneal the SmCo4B-based rapid quenching thin strip prepared in the third step at 600°C to 900°C for a holding time of 10 min to 60 min, thereby obtaining the iron-nickel co-doped SmCo4B-based permanent magnet thin strip.

2. The Fe-Ni co-doped SmCo4B-based permanent magnet thin strip according to claim 1, characterized in that, The thickness of the thin strip is 25 μm to 60 μm, its intrinsic coercivity at room temperature is 39.6 kOe to 88.8 kOe, the remanence is 18.4 emu / g to 63.8 emu / g, and the maximum magnetization intensity under a 90 kOe magnetic field is 20.2 emu / g to 83.7 emu / g.

3. The Fe-Ni co-doped SmCo4B-based permanent magnet thin strip according to claim 1, characterized in that, In the preparation method, in the first-step raw material preparation, according to the atomic ratio in the general formula SmCo x Fe y Ni z B, the mass percentages of each element are calculated, and on the basis of weighing the required amount of pure Sm according to this mass percentage, an additional 3% - 10% (mass percentage) of pure Sm is added, thereby completing the raw material preparation.

4. The Fe-Ni co-doped SmCo4B-based permanent magnet thin strip according to claim 1, characterized in that, In the preparation method, the melting temperature in the first method or the second method is 1500°C - 1680°C.

Images