Ti-CONTAINING NEODYMIUM IRON BORON MAGNET AND PREPARATION METHOD AND APPLICATION THEREOF

Abstract

SOLUTION: A Ti-containing neodymium iron boron magnet includes main phase crystal grains, thin-layer grain boundary phases, and triangular region grain boundary phases. TiB2 crystals are contained in the Ti-containing neodymium iron boron magnet. A total number N of TiB2 crystals in the Ti-containing neodymium iron boron magnet, a number N1 of TiB2 crystals distributed in the main phase crystal grains, and a number N2 of TiB2 crystals in the triangular region grain boundary phases satisfy 0≤N1 / N≤0.05 and 0≤N2 / N≤0.3.EFFECT: In thin-layer grain boundary phases of a Ti-containing neodymium iron boron magnet manufactured by the method, nanoscale needle-shaped TiB2 crystals are evenly distributed and the number of TiB2 crystals distributed inside main phase crystal grains and in triangular region grain boundary phases is small, thereby, a magnet manufactured by this invention has high coercivity and high squareness.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of neodymium-iron-boron magnets, and more particularly to Ti-containing neodymium-iron-boron magnets and their manufacturing methods and uses. [Background technology]

[0002] Due to their excellent magnetic properties, neodymium iron boron sintered magnets are widely used in motors, information technology, medical equipment, and other fields. The high-efficiency motors used in new energy vehicles, in particular, place high demands on magnet performance. However, conventional neodymium iron boron sintered magnets have a low coercive force H at high temperatures. CJ In recent years, in order to improve coercivity and heat resistance, grain boundary diffusion methods have been used to diffuse heavy rare earth elements (Dy, Tb, etc.) from the surface of the magnet into its interior so that the heavy rare earth elements are concentrated in the outer periphery of the main phase crystal grains, thereby improving the magnet's coercivity and suppressing a decrease in remanence Br.

[0003] However, due to the rapidly increasing demand in the magnet market for low-cost, high-performance neodymium-iron-boron sintered magnets, there is a need to improve the coercivity of magnets while minimizing the amount of heavy rare earth elements used. Titanium-containing neodymium-iron-boron magnets can be produced by mixing neodymium-iron-boron alloy powder with titanium hydride powder or by adding titanium to the neodymium-iron-boron alloy during melting. The resulting neodymium-iron-boron magnets can achieve a certain level of coercivity while minimizing the amount of heavy rare earth elements used, but it is relatively difficult to further improve the coercivity using conventional technology. Summary of the Invention

[0004] The present invention provides a Ti-containing NdFeB magnet, as well as a method for producing and using the same. The Ti-containing NdFeB magnet produced by the method of the present invention has nanoscale, needle-like TiB2 crystals uniformly distributed in the thin grain boundary phase, and only a small number of TiB2 crystals distributed inside the main phase crystal grains, resulting in a magnet with high coercivity and high squareness.

[0005] To achieve the above object, a first aspect of the present invention provides a Ti-containing NdFeB magnet, which includes a main phase crystal grain, a thin grain boundary phase, and a triangular region grain boundary phase, and the Ti-containing NdFeB magnet includes TiB2 crystals, The distribution of TiB2 crystals in Ti-containing neodymium iron boron magnets satisfies the following formulas (1) and (2): 0≦N1 / N≦0.05 Formula (1) 0≦N2 / N≦0.3 Equation (2) where N1 / N represents the ratio of the number N1 of TiB2 crystals distributed inside the main phase crystal grains to the total number N of TiB2 crystals distributed in the main phase crystal grains, triangular region grain boundaries, and thin layer grain boundaries in the Ti-containing neodymium iron boron magnet, and N2 / N represents the ratio of N2 to the number N2 of TiB2 crystals in the triangular region grain boundary phase.

[0006] Optionally, 0≦N2 / N≦0.2.

[0007] Optionally, the TiB2 crystals have a length of 100-500 nm and a width of 1-20 nm.

[0008] Optionally, the distribution of TiB2 crystals in the thin grain boundary phase satisfies the following equation (3): 0.3≦L T / L≦0.8 Equation (3) In equation (3), L T / L is the total length of the TiB2 crystal in the thin grain boundary phase, L T represents the ratio of the total length L of the thin grain boundary phase to the total length L of the thin grain boundary phase.

[0009] Optionally, the Ti-containing neodymium iron boron magnet comprises R, Ti, M, B, and Fe, wherein the element R is one or more selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce, and M is one or more selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf, and W; The Ti-containing neodymium-iron-boron magnet contains 28.5 to 31.5 wt% R, 0.05 to 0.75 wt% Ti, 1.2 to 2.5 wt% M, 0.9 to 0.97 wt% B, and the remainder Fe.

[0010] A second aspect of the present invention provides a method for producing a Ti-containing NdFeB magnet, comprising the steps of compacting an R-Ti-MB-Fe alloy powder to obtain a compact, sintering the compact, and aging the compact to obtain a magnet, The sintering process includes a first sintering process and a second sintering process, The temperature for the first sintering treatment is 480 to 850°C, and the temperature-retention time is 5 to 12 hours, while the temperature for the second sintering treatment is 900 to 1100°C, and the temperature-retention time is 1 to 10 hours.

[0011] Optionally, the temperature of the first sintering treatment is 500 to 850°C, and the temperature-keeping time is 5 to 10 hours, and the temperature of the second sintering treatment is 900 to 1080°C, and the temperature-keeping time is 1 to 6 hours.

[0012] optionally, in the R-Ti-MB-Fe alloy powder, the element R is one or more selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce; and M is one or more selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf, and W; The R-Ti-MB-Fe alloy powder contains 28.5 to 31.5 wt% of R, 0.05 to 0.75 wt% of Ti, 1.2 to 2.5 wt% of M, 0.9 to 0.97 wt% of B, and the remainder is Fe.

[0013] Optionally, the method further includes preparing R-Ti-MB-Fe alloy flakes by a rapid solidification method, and subjecting the R-Ti-MB-Fe alloy flakes to a hydrogen pulverization and jet mill pulverization process to obtain R-Ti-MB-Fe alloy powder, wherein the R-Ti-MB-Fe alloy powder has an average particle size D50 of 2-5 μm.

[0014] Optionally, the method further comprises mixing the R1-Fe-B-M1 main alloy powder and the R2-Ti-M2 auxiliary alloy powder to obtain an R-Ti-MB-Fe alloy powder, wherein the mass ratio of the R1-Fe-B-M1 main alloy powder to the R2-Ti-M2 auxiliary alloy powder is (10-150):1; R1 is one or more elements selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce, M1 is one or more elements selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf, and W, and the R1-Fe-B-M1 main alloy powder contains 28 to 31 wt% of R1, 0.5 to 3 wt% of M1, 0.85 to 0.97 wt% of B, and the remainder is Fe; R2 is selected from Pr and / or Nd, M2 is one or more selected from Co, Cu, Al and Ga, and the content of R2 in the R2-Ti-M2 auxiliary alloy powder is 50-95 wt%, the content of Ti is 5-30 wt%, and the content of M2 is 0-20 wt%.

[0015] Optionally, the method includes the steps of preparing R1-Fe-B-M1 main alloy flakes by rapid solidification, and subjecting the R1-Fe-B-M1 main alloy flakes to hydrogen pulverization and jet mill pulverization to obtain R1-Fe-B-M1 main alloy powder, wherein the R1-Fe-B-M1 main alloy powder has an average particle size D50 of 2-5 μm; The method further includes the steps of preparing R2-Ti-M2 auxiliary alloy flakes by a rapid solidification method, and subjecting the R2-Ti-M2 auxiliary alloy flakes to a hydrogen pulverization treatment and a jet mill pulverization treatment to obtain R2-Ti-M2 auxiliary alloy powder, and the R2-Ti-M2 auxiliary alloy powder has an average particle size D50 of 0.5 to 2 μm.

[0016] Optionally, the molding process is an orientation molding process, and the orientation molding process is performed under a condition of a magnetic induction strength of 1.8 to 2.5 T; The aging treatment includes a first aging treatment and a second aging treatment. The treatment temperature for the first aging treatment is 850 to 950°C and the heat-holding time is 3 to 5 hours, and the treatment temperature for the second aging treatment is 450 to 600°C and the heat-holding time is 0.5 to 5 hours.

[0017] A third aspect of the present invention provides a Ti-containing neodymium iron boron magnet produced by the method according to the second aspect of the present invention.

[0018] According to the above technical solution, the present invention sinters a compact using a multi-temperature step-by-step sintering method. The compact is sintered at a temperature between 480 and 850°C for 5 to 10 hours in the first sintering step. This allows Ti to be distributed more abundantly in the lamellar grain boundary phase. Then, in the second sintering step (900 to 1080°C), Ti combines with B, resulting in the in-situ growth of fine, uniformly distributed nanoscale needle-shaped TiB2 crystals in the lamellar grain boundary phase. During the subsequent aging treatment, TiB2 crystals have a high melting point (3225°C) and do not migrate with the liquid phase formed within the magnet. Therefore, the TiB2 crystals distributed abundantly in the lamellar grain boundary phase remain in the lamellar grain boundary phase between adjacent main-phase grains, providing a "pinning" effect on the grain boundary migration of the main-phase grains and effectively inhibiting the growth of the main-phase grains. The method of the present invention effectively reduces the number of TiB2 crystals inside the main phase crystal grains and in the triangular grain boundary phase. The large amount of TiB2 crystals present in the thin grain boundary phase provides excellent magnetic isolation between adjacent main phase crystal grains. Therefore, even when using a small amount of heavy rare earth or no heavy rare earth, the resulting Ti-containing neodymium iron boron magnet exhibits improved coercivity and squareness, resulting in excellent magnetic performance.

[0019] Other features and advantages of the present invention are described in detail in the following specific embodiments.

[0020] The drawings are used to provide a further understanding of the present invention, constitute a part of the specification, and are used to explain the present invention in conjunction with the following specific embodiments, but are not intended to limit the present invention. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is an SEM photograph of a Ti-containing neodymium-iron-boron magnet produced in Example 1 of the present invention. [Figure 2] 1 is a TEM photograph of TiB2 crystals in a Ti-containing neodymium iron boron magnet produced in Example 1 of the present invention. [Figure 3] FIG. 2 is a diagram showing the total length L of the thin-layer grain boundary phase of the Ti-containing neodymium-iron-boron magnet produced in Example 1 of the present invention. [Figure 4] FIG. 2 is a diagram showing the total length LT of TiB2 crystals in the thin grain boundary phase of the Ti-containing neodymium-iron-boron magnet produced in Example 1 of the present invention. [Figure 5] 1 is an electron diffraction pattern of TiB2 crystals in a Ti-containing neodymium-iron-boron magnet produced in Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. Note that the specific embodiments described here are used only to explain and interpret the present invention, and are not intended to limit the present invention.

[0023] A first aspect of the present invention provides a Ti-containing NdFeB magnet, which includes main phase crystal grains, a thin grain boundary phase, and a triangular region grain boundary phase, and the Ti-containing NdFeB magnet contains TiB2 crystals, which are in the form of needle-like particles. The distribution of TiB2 crystals in Ti-containing NdFeB magnets satisfies the following formulas (1) and (2): 0≦N1 / N≦0.05 Formula (1) 0≦N2 / N≦0.3 Equation (2) where N1 / N represents the ratio of the number N1 of TiB2 crystals distributed inside the main phase crystal grains to the total number N of TiB2 crystals distributed in the main phase crystal grains, triangular region grain boundaries, and thin layer grain boundaries in the Ti-containing neodymium iron boron magnet, and N2 / N represents the ratio of N2 to the number N2 of TiB2 crystals in the triangular region grain boundary phase.

[0024] In the present invention, the distribution of TiB2 crystals in a Ti-containing NdFeB magnet can be represented by averaging the distribution of TiB2 crystals across multiple cross sections of the magnet. That is, multiple different cross sections of the magnet can be randomly selected to measure the N1 / N and N2 / N values, respectively, and the average N1 / N and N2 / N values ​​of the multiple different cross sections represent the N1 / N and N2 / N values ​​of the magnet, respectively.

[0025] For example, the N1 / N and N2 / N values ​​of a Ti-containing neodymium iron boron magnet can be measured using the following method: Five or more arbitrary cross sections of the magnet are observed with a scanning electron microscope, and the number of TiB2 crystals in the main phase crystal grains, triangular region grain boundaries, and lamella grain boundaries of the entire or partial region of each cross section is counted. The N1 / N and N2 / N values ​​for each cross section are then calculated. The average N1 / N and N2 / N values ​​of all cross sections are then calculated and used as the N1 / N and N2 / N values ​​of the Ti-containing neodymium iron boron magnet. In a further embodiment, when calculating the N1 / N and N2 / N values ​​of each cross section, three or more observation regions can be randomly selected from the cross section, and the N1 / N and N2 / N values ​​of each observation region can be calculated and averaged to use the N1 / N and N2 / N values ​​of the cross section. The size of the observation regions can be, for example, 30 μm × 20 μm.

[0026] In a preferred embodiment, 0≦N2 / N≦0.2. In a specific embodiment, N1 / N may be 0, 0.01, 0.02, 0.03, 0.04, 0.05, or any value between these. N2 / N may be 0, 0.01, 0.03, 0.05, 0.08, 0.1, 0.12, 0.15, 0.18, 0.2, or any value between these.

[0027] The Ti-containing neodymium-iron-boron magnet of the present invention has very few TiB2 crystals distributed within the main phase grains and in the triangular grain boundary phase. Most TiB2 crystals are uniformly present in the thin grain boundary phase between adjacent main phase grains, providing better isolation between adjacent main phase grains within the magnet. The TiB2 crystals have a "pinning" effect on the grain boundary migration of the main phase grains, effectively preventing the growth of the main phase grains and reducing the grain size, thereby improving the magnet's remanence and coercivity. The Ti-containing neodymium-iron-boron magnet of the present invention has high coercivity and high squareness, resulting in excellent magnetic performance.

[0028] In the present invention, the thin grain boundary phase refers to a grain boundary phase formed between two adjacent main phase crystal grains, and the triangular region grain boundary phase refers to a grain boundary phase surrounded by three or more main phase crystal grains.

[0029] In a specific embodiment, the length of the TiB2 crystals is 100 to 500 nm, and the width is 1 to 20 nm. Specifically, the length of the TiB2 crystals can be 100 nm, 120 nm, 150 nm, 180 nm, 200 nm, 220 nm, 250 nm, 270 nm, 300 nm, 320 nm, 350 nm, 380 nm, 400 nm, 410 nm, 420 nm, 450 nm, 480 nm, 500 nm, or any value between these, and the width can be 1, 5, 8, 10, 12, 15, 18, 20 nm, or any value between these. In the present invention, by controlling the length and width of the TiB2 crystals within the above ranges, the formed TiB2 crystals are advantageously uniformly distributed in the thin grain boundary phase between adjacent main phase crystal grains, and the isolating effect of the TiB2 crystals on the main phase crystal grains is fully exerted, providing a "pinning" effect on the grain boundary migration of the main phase crystal grains, effectively preventing the growth of the main phase crystal grains, and further enhancing their magnetic isolation role, making it possible to produce high-performance magnets with high coercivity and high squareness.

[0030] In a specific embodiment, the distribution of TiB2 crystals in the thin grain boundary phase satisfies the following formula (3): 0.3≦L T / L≦0.8 Equation (3) In equation (3), L T / L is the total length of the TiB2 crystal in the thin grain boundary phase, L T This represents the ratio of the total length L of the thin grain boundary phase to the total length L of the thin grain boundary phase. T / L may be 0.3, 0.35, 0.4, 0.43, 0.5, 0.55, 0.58, 0.6, 0.65, 0.7, 0.75, 0.8, or a value between any two of these. In the above embodiment, the TiB2 crystals present in large quantities in the thin grain boundary phase between adjacent main phase crystal grains better isolate the main phase crystal grains of the magnet, have a "pinning" effect on the grain boundary migration of the main phase crystal grains, effectively block the growth of the main phase crystal grains, and refine the crystal grains, thereby significantly improving the coercive force, squareness, and remanence of the magnet and resulting in excellent performance.

[0031] In the present invention, the total length L of TiB2 crystals in the thin grain boundary phase of the magnet T The ratio of the length of the TiB2 crystals in the lamellar grain boundary phase to the total length L of the lamellar grain boundary phase can be shown by averaging the ratio of the length of the TiB2 crystals in the lamellar grain boundary phase to the length of the lamellar grain boundary phase in multiple cross sections of the magnet. That is, multiple different cross sections of the magnet are selected and L is calculated. T The L / L values ​​can be measured at multiple different cross sections. T The average value of / L is the L of the magnet. T / L value.

[0032] For example, the L of Ti-containing neodymium iron boron magnets can be calculated using the following method: T The / L value can be measured by observing five or more arbitrary cross sections of a magnet with a scanning electron microscope and measuring the L value of the entire or partial area of ​​each cross section. T The / L values ​​are calculated and the L T After calculating the / L value, the average value was calculated and the L value of the Ti-containing neodymium-iron-boron magnet was calculated. T In a further embodiment, the L T When calculating the / L value, three or more observation areas are randomly selected from the cross section, and the L value of each observation area is calculated. T Calculate the / L values ​​for each section and calculate the average value. T The size of the observation area is, for example, 30 μm×20 μm.

[0033] In a specific embodiment, the average grain size of the main phase grains is 5 μm or less.

[0034] The Ti-containing neodymium-iron-boron magnet of the present invention has significantly improved magnetic performance because the TiB2 crystals present in large quantities in the thin grain boundary phase can effectively control the grain size of the main phase crystal grains.

[0035] In a specific embodiment, the Ti-containing neodymium iron boron magnet comprises R, Ti, M, B, and Fe, wherein the element R is one or more selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce, and M is one or more selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf, and W; The Ti-containing neodymium-iron-boron magnet contains 28.5 to 31.5 wt% R, 0.05 to 0.75 wt% Ti, 1.2 to 2.5 wt% M, 0.9 to 0.97 wt% B, and the remainder Fe.

[0036] A second aspect of the present invention provides a method for producing a Ti-containing NdFeB magnet, comprising the steps of compacting an R-Ti-MB-Fe alloy powder to obtain a compact, sintering the compact, and aging the compact to obtain a magnet, The sintering process includes a first sintering process and a second sintering process, The temperature for the first sintering treatment is 480 to 850°C, and the temperature-retention time is 5 to 12 hours, while the temperature for the second sintering treatment is 900 to 1100°C, and the temperature-retention time is 1 to 10 hours.

[0037] In specific embodiments, the temperature of the first sintering step can be 480, 500, 550, 580, 600, 620, 650, 700, 720, 750, 765, 800, or any value between two of these, and the incubation time can be 5, 5.5, 6, 6.5, 7, 8, 9, 9.5, 10, 10.5, 11, 12, or any value between two of these.

[0038] The inventors' research has revealed that the TiB2 crystals formed in conventional Ti-containing NdFeB magnets are concentrated in the triangular grain boundary phase, which has a relatively low isolating effect on the main phase grains and limits further improvement in coercivity. Therefore, the present application adjusts the manufacturing process to control the distribution of TiB2 crystals within the magnet so that more TiB2 crystals are distributed in the thin grain boundary phase, which sufficiently isolates the main phase grains and has a "pinning" effect on the grain boundary migration of the main phase grains, thereby further improving the coercivity of the magnet.

[0039] This invention uses a multi-temperature sintering method to sinter the compact. The first sintering step (480-850°C) is held for 5-10 hours, allowing Ti to be distributed more abundantly in the lamellar grain boundary phase. The second sintering step (900-1080°C) then combines Ti with B, ultimately resulting in the in-situ growth of fine, uniformly distributed needle-shaped TiB2 crystals in the lamellar grain boundary phase. During the subsequent aging treatment, TiB2 crystals have a high melting point (3225°C) and do not migrate with the liquid phase formed within the magnet. Therefore, the TiB2 crystals abundant in the lamellar grain boundary phase of the magnet remain in the lamellar grain boundary phase between adjacent main-phase grains, providing a "pinning" effect on the grain boundary migration of the main-phase grains and effectively preventing the growth of the main-phase grains. The method of the present invention effectively reduces the number of TiB2 crystals inside the main phase crystal grains and in the triangular grain boundary phase. The TiB2 crystals are present in large quantities in the thin grain boundary phase, allowing the TiB2 crystals in the thin grain boundary phase to play an excellent role in magnetic isolation. Therefore, even when using a small amount of heavy rare earth or no heavy rare earth, the Ti-containing neodymium iron boron magnet produced has improved coercivity and squareness, and exhibits excellent magnetic performance.

[0040] In the present invention, conventional equipment in the art can be used for the compacting, sintering and aging treatments.

[0041] In a preferred embodiment, the first sintering step is performed at a temperature of 500 to 850°C with an incubation time of 5 to 10 hours, while the second sintering step is performed at a temperature of 900 to 1080°C with an incubation time of 1 to 6 hours. In this embodiment, by controlling the temperature of each sintering step within a preferred range, Ti element can be more fully and uniformly diffused into the thin grain boundary phase, further reducing the number of TiB2 crystals inside the main phase crystal grains and at the triangular grain boundaries. The presence and uniform distribution of acicular TiB2 crystals in the thin grain boundary phase further enhances the magnetic isolation role of the thin grain boundary phase, resulting in a magnet with high coercivity and high squareness.

[0042] In a specific embodiment, in the R-Ti-MB-Fe alloy powder, the element R is one or more selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce, and M is one or more selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf, and W.

[0043] In a specific embodiment, the R-Ti-MB-Fe alloy powder contains 28.5 to 31.5 wt% of R, 0.05 to 0.75 wt% of Ti, 1.2 to 2.5 wt% of M, 0.9 to 0.97 wt% of B, and the remainder is Fe.

[0044] In specific embodiments, the Ti content can be 0.05, 0.1, 0.15, 0.2, 0.28, 0.3, 0.35, 0.4, 0.42, 0.45, 0.5, 0.55, 0.58, 0.6, 0.65, 0.7, 0.72, 0.75, or any value between these; and the B content can be 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, or any value between these.

[0045] In a specific embodiment, a one-alloy method is used, which further includes the steps of preparing R-Ti-MB-Fe alloy flakes by rapid solidification, and subjecting the R-Ti-MB-Fe alloy flakes to hydrogen pulverization and jet mill pulverization to obtain R-Ti-MB-Fe alloy powder, wherein the R-Ti-MB-Fe alloy powder has an average particle size D50 of 2-5 μm.

[0046] In a specific embodiment, a two-alloy method is used to manufacture a magnet, further reducing the number of TiB2 crystals in the interior of the main phase grains and in the triangular region grain boundary phase and further increasing the number of TiB2 crystals in the thin layer grain boundary phase, thereby further improving the coercivity and squareness of the manufactured magnet. Specifically, the method further includes mixing an R1-Fe-B-M1 main alloy powder with an R2-Ti-M2 auxiliary alloy powder to obtain an R-Ti-MB-Fe alloy powder.

[0047] In a specific embodiment, the mass ratio of the R1-Fe-B-M1 main alloy powder to the R2-Ti-M2 auxiliary alloy powder is (10-150):1, preferably (20-135):1. Specifically, the mass ratio of the R1-Fe-B-M1 main alloy material to the R2-Ti-M2 auxiliary alloy material may be 20:1, 30:1, 50:1, 75:1, 90:1, 100:1, 110:1, 120:1, 130:1, 135:1, or any value between two of these. In the above embodiment, controlling the mass ratio of the main alloy powder to the auxiliary alloy powder to a preferred value prevents a decrease in the remanence of the magnet due to excessive addition of rare earth elements.

[0048] In a specific embodiment, R1 is one or more selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce, M1 is one or more selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf, and W, and the R1-Fe-B-M1 main alloy powder contains 28-31 wt% R1, 0.5-3 wt% M1, 0.85-0.97 wt% B, and the remainder Fe.

[0049] In a specific embodiment, R2 is selected from Pr and / or Nd, M2 is one or more selected from Co, Cu, Al, and Ga, and the R2-Ti-M2 auxiliary alloy powder contains 50-95 wt% R2, 5-30 wt% Ti, and 0-20 wt% M2. Specifically, the Ti content may be 5, 10, 12, 15, 20, 22, 25, 28, 30, or any value between these, and the M2 content may be 0, 1, 2, 5, 8, 10, 15, 18, 20, or any value between these.

[0050] In a specific embodiment, the method includes the steps of preparing R1-Fe-B-M1 main alloy flakes by rapid solidification, and then subjecting the R1-Fe-B-M1 main alloy flakes to hydrogen pulverization and jet mill pulverization to obtain R1-Fe-B-M1 main alloy powder, the R1-Fe-B-M1 main alloy powder having an average particle size D50 of 2-5 μm; The method further includes the steps of preparing R2-Ti-M2 auxiliary alloy flakes by a rapid solidification method, and subjecting the R2-Ti-M2 auxiliary alloy flakes to a hydrogen pulverization treatment and a jet mill pulverization treatment to obtain R2-Ti-M2 auxiliary alloy powder, and the R2-Ti-M2 auxiliary alloy powder has an average particle size D50 of 0.5 to 2 μm.

[0051] In the above embodiment, when the average particle size D50 of the main alloy powder is controlled to 2 to 5 μm and the average particle size D50 of the auxiliary alloy powder is controlled to 0.5 to 2 μm, the dispersion uniformity of the powders after mixing is improved, and therefore the diffusion uniformity of the Ti element during sintering is further improved.

[0052] In a specific embodiment, the molding process is an orientation molding process, and the orientation molding process is carried out under the condition of a magnetic induction strength of 1.8 to 2.5T.

[0053] In a specific embodiment, the aging treatment includes a first aging treatment and a second aging treatment, the treatment temperature of the first aging treatment is 850 to 950°C and the heat-holding time is 3 to 5 hours, and the treatment temperature of the second aging treatment is 450 to 600°C and the heat-holding time is 0.5 to 5 hours.

[0054] In a specific embodiment, the hydrogen absorption pressure in the hydrogen pulverization treatment is 0.2 to 0.4 MPa, the dehydrogenation temperature is 550 to 600°C, and the pulverization pressure in the jet mill pulverization is 0.5 to 0.9 MPa.

[0055] A third aspect of the present invention provides a Ti-containing neodymium iron boron magnet produced by the method according to the second aspect of the present invention.

[0056] In a specific embodiment, a diffusion source containing a heavy rare earth element (for example, Dy, Tb) can be used to perform grain boundary diffusion treatment on the Ti-containing neodymium iron boron magnet produced by the present invention.

[0057] The Ti-containing neodymium iron boron magnet of the present invention has higher remanence, higher coercive force, and higher squareness.

[0058] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. All raw materials used in the examples are commercially available.

[0059] Example 1 S1: R1-Fe-B-M1 main alloy powder and R2-Ti auxiliary alloy powder were prepared by the following steps. (1) R1-Fe-B-M1 main alloy raw materials were blended in mass percentages (wt%), where R1 was PrNd and M1 contained Ga, Cu, Co, and Al, with PrNd at 30.5 wt%, Ga at 0.15 wt%, Cu at 0.25 wt%, Co at 0.91 wt%, Al at 0.25 wt%, B at 0.91 wt%, and the remainder Fe. The blended main alloy raw materials were cast by a rapid solidification method to produce R1-Fe-B-M1 main alloy flakes, where the roll surface linear velocity during the rapid solidification method was 0.85 m / s and the casting temperature was 1460°C. The R1-Fe-B-M1 main alloy flakes were subjected to hydrogen pulverization and jet mill fine pulverization, respectively, to obtain R1-Fe-B-M1 main alloy powder. The hydrogen absorption pressure during hydrogen pulverization was 0.3 MPa, the dehydrogenation temperature was 550°C, the jet mill pulverization pressure was 0.55 MPa, and the average particle size D50 of the R1-Fe-B-M1 main alloy powder was 3.8 μm.

[0060] (2) The R2-Ti auxiliary alloy raw materials were blended in mass percentages (wt%), where R2 was PrNd, with PrNd at 85 wt% and Ti at 15 wt%. The blended auxiliary alloy raw materials were cast using a rapid solidification method to produce R2-Ti auxiliary alloy flakes. The R2-Ti auxiliary alloy flakes were then subjected to hydrogen pulverization and jet mill fine pulverization to obtain R2-Ti auxiliary alloy powder. The hydrogen absorption pressure during hydrogen pulverization was 0.3 MPa, the dehydrogenation temperature was 550°C, the jet mill pulverization pressure was 0.5 MPa, and the average particle size D50 of the R2-Ti auxiliary alloy powder was 1 μm.

[0061] S2: Ti-containing neodymium-iron-boron magnets were manufactured using the prepared R1-Fe-B-M1 main alloy powder and R2-Ti auxiliary alloy powder. The R1-Fe-B-M1 main alloy powder and the R2-Ti auxiliary alloy powder were uniformly mixed in a 99:1 weight ratio to obtain the R-Ti-MB-Fe alloy powder. The R-Ti-MB-Fe alloy powder contained 31 wt% PrNd, 0.15 wt% Ga, 0.25 wt% Cu, 0.9 wt% Co, 0.25 wt% Al, 0.9 wt% B, 0.15 wt% Ti, and the remainder Fe. The resulting R-Ti-MB-Fe alloy powder was compacted, sintered, and aged, and then machined to produce a Ti-containing neodymium-iron-boron magnet 1 measuring 15 mm thick (orientation direction), 20 mm long, and 40 mm wide, designated CT-1. The compaction was an orientation compaction process, performed in a N2 gas atmosphere with a magnetic induction strength of 2 T. The sintering process consisted of two steps: the first at 550°C and for 8 hours, the second at 1060°C and for 6 hours, followed by quenching to room temperature. The aging process consisted of two steps: the first at 850°C and for 3.5 hours, and the second at 460°C and for 1 hour.

[0062] Observation and analysis of the microstructure of the manufactured Ti-containing neodymium iron boron magnet 1 revealed that the Ti-containing neodymium iron boron magnet CT-1 comprises main phase crystal grains and a grain boundary phase, and the grain boundary phase comprises a thin grain boundary phase and a triangular region grain boundary phase, with the thin grain boundary phase referring to the grain boundary phase formed between two adjacent main phase crystal grains and the triangular region grain boundary phase referring to the grain boundary phase surrounded by three or more main phase crystal grains.

[0063] The distribution of TiB2 crystals in the Ti-containing neodymium-iron-boron magnet produced in Example 1 and the distribution of TiB2 crystals in the thin grain boundary phase are measured and shown in Figures 1 and 2. It was observed that the magnet contained a large amount of needle-shaped black crystals, i.e., TiB2 crystals, and that the TiB2 crystals were distributed mainly in the thin grain boundary phase between adjacent main phase crystal grains. T The ratios of / L and N1 / N were 0.45, 0.02, and 0.09, respectively, indicating that only a small amount of TiB2 crystals existed inside the main phase grains and in the triangular grain boundary phase, while most of the needle-shaped TiB2 crystals were present in the thin grain boundary phase between adjacent main phase grains. This resulted in better isolation of the main phase grains and resulted in the magnet having excellent overall magnetic properties.

[0064] Example 2 In step S2, the temperature of the first sintering treatment was 490°C, the temperature was maintained for 8 hours, and the manufacturing method was the same as in Example 1, except that the resulting Ti-containing neodymium-iron-boron magnet 2 was designated CT-2.

[0065] Example 3 S1: R1-Fe-B-M1 main alloy powder and R2-Ti-M2 auxiliary alloy powder were prepared by the following steps. (1) R1-Fe-B-M1 main alloy raw materials were blended in mass percentages (wt%), where R1 was PrNd and M1 contained Ga, Co, and Al, with PrNd at 29.5 wt%, Ga at 0.21 wt%, Co at 1.33 wt%, Al at 0.26 wt%, B at 0.96 wt%, and the remainder Fe. The blended main alloy raw materials were cast by a rapid solidification method to produce R1-Fe-B-M1 main alloy flakes, where the roll surface linear velocity during the rapid solidification method was 0.85 m / s and the casting temperature was 1460°C. The R1-Fe-B-M1 main alloy flakes were subjected to hydrogen pulverization and jet mill fine pulverization, respectively, to obtain R1-Fe-B-M1 main alloy powder. The hydrogen absorption pressure during hydrogen pulverization was 0.3 MPa, the dehydrogenation temperature was 550°C, the jet mill pulverization pressure was 0.55 MPa, and the average particle size D50 of the R1-Fe-B-M1 main alloy powder was 3.8 μm.

[0066] (2) R2-Ti-M2 auxiliary alloy raw materials were blended in mass percentages (wt%), where R2 was PrNd and M2 contained Cu and Ti, with PrNd at 82 wt%, Ti at 10 wt%, and Cu at 8 wt%. The blended auxiliary alloy raw materials were cast using a rapid solidification method to produce R2-Ti-M2 auxiliary alloy flakes. The R2-Ti-M2 auxiliary alloy flakes were then subjected to hydrogen pulverization and jet mill fine grinding to obtain R2-Ti-M2 auxiliary alloy powder. The hydrogen absorption pressure during hydrogen pulverization was 0.3 MPa, the dehydrogenation temperature was 550°C, and the jet mill grinding pressure was 0.5 MPa. The average particle size D50 of the R2-Ti-M2 auxiliary alloy powder was 1 μm.

[0067] S2: Ti-containing neodymium-iron-boron magnets were manufactured using the prepared R1-Fe-B-M1 main alloy powder and R2-Ti-M2 auxiliary alloy powder. The R-Ti-MB-Fe alloy powder was obtained by uniformly mixing the R1-Fe-B-M1 main alloy powder and the R2-Ti-M2 auxiliary alloy powder in a 39:1 weight ratio. The R-Ti-MB-Fe alloy powder contained 30.8 wt% PrNd, 0.2 wt% Ga, 0.2 wt% Cu, 1.3 wt% Co, 0.25 wt% Al, 0.94 wt% B, 0.25 wt% Ti, and the remainder Fe. The resulting R-Ti-MB-Fe alloy powder was compacted, sintered, and aged, and then machined to produce a Ti-containing neodymium-iron-boron magnet 3 measuring 15 mm thick (orientation direction), 20 mm long, and 40 mm wide. This magnet was designated CT-3. The compaction was an orientation compaction process, performed in a N2 gas atmosphere with a magnetic induction strength of 2 T. The sintering process consisted of two steps: the first at 650°C and a holding time of 7 hours, the second at 1060°C and a holding time of 5 hours, and then quenched to room temperature. The aging process consisted of two steps: the first at 850°C and a holding time of 3.5 hours, and the second at 460°C and a holding time of 1 hour.

[0068] Example 4 In step S1, (2) The manufacturing method was the same as in Example 3, except that the R2-Ti-M2 auxiliary alloy raw materials were blended in a mass percentage (wt%), where R2 was PrNd, M2 contained Cu and Ti, with PrNd being 57 wt%, Ti being 35 wt%, and Cu being 8 wt%, and the resulting Ti-containing neodymium iron boron magnet 4 was designated CT-4.

[0069] Example 5 S1: R-Ti-MB-Fe alloy powder was prepared by the following steps. (1) R-Ti-MB-Fe alloy raw materials were blended in mass percentages (wt%), where R is PrNd, and M contains Ga, Cu, Co, and Al, with PrNd 30.5 wt%, Ga 0.2 wt%, Cu 0.2 wt%, Co 0.8 wt%, Al 0.25 wt%, Ti 0.1 wt%, B 0.9 wt%, and the remainder Fe. The blended R-Ti-MB-Fe alloy raw materials were cast by a rapid solidification method to produce R-Ti-MB-Fe alloy flakes. The roll surface linear velocity in the rapid solidification method was 0.85 m / s, and the casting temperature was 1460°C. The R-Ti-MB-Fe alloy pieces were subjected to hydrogen pulverization and jet mill fine pulverization, respectively, to obtain R-Ti-MB-Fe alloy powder. The hydrogen absorption pressure during hydrogen pulverization was 0.3 MPa, the dehydrogenation temperature was 550°C, the jet mill pulverization pressure was 0.5 MPa, and the average particle size D50 of the R-Ti-MB-Fe alloy powder was 3.8 μm.

[0070] S2: The prepared R-Ti-MB-Fe alloy powder was used to manufacture a Ti-containing neodymium-iron-boron magnet. The R-Ti-MB-Fe alloy powder was compacted, sintered, and aged, then machined to produce Ti-containing neodymium-iron-boron magnets 5 (CT-5) measuring 15 mm thick (orientation direction), 20 mm long, and 40 mm wide. The compaction was performed under a N2 gas atmosphere with a magnetic induction strength of 2 T. The sintering process consisted of two steps: the first at 550°C and a holding time of 8 hours; the second at 1050°C and a quenching time of 6 hours after sintering; and the magnets were quenched to room temperature after 6 hours of sintering. The aging process consisted of two steps: the first at 850°C and a holding time of 3.5 hours; and the second at 460°C and a holding time of 1 hour.

[0071] Comparative Example 1 The manufacturing method was the same as in Example 1, except that in step S2, no step-wise sintering was used, the sintering temperature was 1060°C, and the temperature retention time was 6 hours. The resulting Ti-containing neodymium-iron-boron magnet was designated DCT-1.

[0072] Comparative Example 2 In step S2, the temperature of the first sintering treatment was 870°C, the temperature was maintained for 4 hours, and the manufacturing method was the same as in Example 1, except that the resulting Ti-containing neodymium-iron-boron magnet was named DCT-2.

[0073] Comparative Example 3 In step S2, the temperature of the first sintering treatment was 465°C, the temperature was maintained for 8 hours, and the manufacturing method was the same as in Example 1, except that the resulting Ti-containing neodymium-iron-boron magnet was named DCT-3.

[0074] Measurement example The components and contents of the R1-Fe-B-M1 main alloy powder, R2-Ti-M2 auxiliary alloy powder, and R-Ti-MB-Fe alloy powder in Examples 1 to 4 and Comparative Examples 1 to 3, as well as the components and contents of the produced Ti-containing magnets, and the components and contents of the R-Ti-MB-Fe alloy powder in Example 5, as well as the components and contents of the produced Ti-containing magnets, were measured using an ICP component analyzer, and the results are shown in Tables 1 and 2.

[0075] The average particle sizes of the main alloy powder and the auxiliary alloy powder were measured using a particle size analyzer.

[0076] The magnet of Example 1 was subjected to mirror polishing, and then a cross-sectional image was taken with a scanning electron microscope. The resulting SEM photograph is shown in FIG.

[0077] The position A9 in Figure 1 was selected and observed under a transmission electron microscope, and the results are shown in Figure 2. Here, the length of the TiB2 crystal was 409 nm and the width was 20 nm.

[0078] The distribution of TiB2 crystals in a magnet can be analyzed using commercially available image analysis software (ImageProPlus). Five or more randomly selected cross sections of the magnet were analyzed, and three or more 30 μm × 20 μm regions were randomly selected from each cross section. The number of TiB2 crystals in the main phase crystal grains (N1), the number of TiB2 crystals in the triangular grain boundary phase (N2), and the number of TiB2 crystals in the thin grain boundary phase were calculated in each region of each cross section. The sum of N1, N2, and the number of TiB2 crystals in the thin grain boundary phase was defined as N. The N1 / N and N2 / N values ​​for each region were calculated and averaged to obtain the N1 / N and N2 / N values ​​for the cross section. The average N1 / N and N2 / N values ​​for all cross sections were calculated to obtain the N1 / N and N2 / N values ​​for the magnet. The results are shown in Table 3. The distribution parts of TiB2 crystals in the thin grain boundary phase overlap, and when counting the number, the overlapping parts are counted as one. For example, the number of TiB2 crystals at position A8 in Figure 1 was 1.

[0079] The distribution of TiB2 crystals in the lamellar grain boundary phase of the magnet was analyzed using the following method. Five or more arbitrary cross sections of the magnet were randomly selected and analyzed, and three or more 30 μm × 20 μm regions were randomly selected for each cross section. Image analysis software (ImageProPlus) was used to calculate the total length L of the lamellar grain boundary phase (the total length of the black line in Figure 3) and the total length L of the lamellar grain boundary phase TiB2 crystals in each region of each cross section. T (the total length of the black line in Figure 4) and calculate the L T Calculate the L / L value and calculate the L T Calculate the average value of / L and calculate the L T / L value, and L of all cross sections T Calculate the average value of the / L value and calculate the L value of the magnet. T The results are shown in Table 3.

[0080] Electron diffraction measurements were carried out on the TiB2 crystals of the magnet of Example 1, and the results are shown in Figure 5. Analysis of the crystal structure confirmed that the acicular TiB2 crystals were of a hexagonal system.

[0081] The magnetic properties of the Ti-containing neodymium-iron-boron magnets of Examples 1 to 5 and Comparative Examples 1 to 3 were measured using a BH analyzer, and the results are shown in Table 3.

[0082] TIFF2025133704000002.tif205170

[0083] TIFF2025133704000003.tif86170

[0084] TIFF2025133704000004.tif74170

[0085] As can be seen from Table 3, the present invention uses a multi-temperature sintering method to sinter the compact. The first sintering step (480-850°C) is held for 5-10 hours, allowing Ti to be more fully distributed in the lamellar grain boundary phase. The second sintering step (900-1080°C) then combines Ti with B, ultimately resulting in the in-situ growth of fine, uniformly distributed nanoscale acicular TiB2 crystals in the lamellar grain boundary phase of the magnet. This effectively reduces the number of TiB2 crystals within the main-phase grains and at the triangular grain boundaries. The acicular TiB2 crystals, abundant in the lamellar grain boundary phase of the magnet, are always present in the lamellar grain boundary phase between adjacent main-phase grains, providing better isolation for the main-phase grains. The TiB2 crystals provide a "pinning" effect on the grain boundary migration of the main-phase grains, effectively blocking their growth. The present invention enables the production of Ti-containing neodymium iron boron magnets with significantly improved coercivity and squareness, achieving excellent magnetic performance, even when using small amounts of heavy rare earth elements or no heavy rare earth elements at all.

[0086] Comparing Example 2 with Example 1, it is found that by controlling the temperature of the first sintering treatment within the preferred range of 500 to 850°C, it is possible to distribute more Ti element in the thin layer grain boundary phase. Subsequent sintering at 900 to 1080°C further promotes bonding between Ti element and B element, further reducing the amount of TiB2 crystals inside the main phase crystal grains and in the triangular region grain boundary phase, and further increasing the number of fine and uniformly distributed acicular TiB2 crystals grown in situ in the thin layer grain boundary phase, thereby further improving the coercive force and squareness of the manufactured magnet.

[0087] Comparing Example 4 with Example 1, it is clear that by controlling the content of Ti element in the auxiliary alloy within the preferred range of the present application and further controlling the content of Ti element in the magnet within the range specified in the present application, the Ti element and the B element are better bonded together, making it possible to further improve the coercive force and squareness of the manufactured magnetic material.

[0088] Comparing Example 5 with Example 1, it can be seen that by using the two-alloy method to produce a Ti-containing NdFeB magnet, the number of fine, uniformly distributed acicular TiB2 crystals grown in situ in the thin grain boundary phase can be further increased, while the number of TiB2 crystals inside the main phase crystal grains can be further reduced. The TiB2 crystals located in the thin grain boundary phase provide excellent magnetic isolation, effectively blocking the growth of the main phase crystal grains, thereby improving the coercivity and squareness of the magnet.

[0089] Comparing Comparative Example 1 with Example 1, it is found that when the mixed alloy raw material is directly sintered at a high temperature of 1,060°C without performing step-by-step sintering, the Ti element is unable to diffuse sufficiently into the thin grain boundary phase, and most of the TiB2 crystals are present inside the main phase crystal grains and in the triangular region grain boundary phase. As a result, the number of TiB2 crystals grown in situ in the thin grain boundary phase of the magnet is small and they are difficult to distribute uniformly in the thin grain boundary phase, and they are unable to fulfill their role of magnetic isolation between adjacent main phase crystal grains. This makes it difficult to sufficiently isolate the main phase crystal grains, and the main phase crystal grains tend to become larger in size, resulting in a significant decrease in the remanence of the magnet and decreases in coercivity and squareness.

[0090] Comparing Comparative Examples 2 and 3 with Example 1, it is found that the temperature of the first sintering treatment was outside the range specified in the present application, so the Ti element was unable to diffuse sufficiently into the thin grain boundary phase. It was therefore difficult for the Ti element to effectively bond with the B element in the subsequent second sintering treatment. Ultimately, the amount of acicular TiB2 crystals grown in situ in the thin grain boundary phase of the magnet was small, and the thin grain boundary phase was not easily distributed uniformly, preventing it from fulfilling its role of magnetic isolation between adjacent main phase crystal grains. This made it difficult for the main phase crystal grains to be sufficiently isolated, and the size of the main phase crystal grains was likely to increase, resulting in a significant decrease in the remanence of the magnet as well as reduced coercivity and squareness.

[0091] Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the specific contents of the above embodiments. Various simple modifications can be made to the technical means of the present invention within the scope of the technical idea of ​​the present invention, and all of these simple modifications fall within the scope of protection of the present invention.

[0092] It should be noted that each of the specific technical features described in the above specific embodiments can be combined in any suitable manner unless there is a contradiction, and in order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0093] Furthermore, various embodiments of the present invention can be arbitrarily combined, and as long as they are not contrary to the spirit of the present invention, they should also be considered as part of the disclosure of the present invention. [Explanation of symbols]

[0094] In FIG. 1, A1 to A9 are TiB2 crystals at the thin layer grain boundaries, B is a TiB2 crystal at the triangular region grain boundary, and C is a TiB2 crystal inside the main phase crystal grain. However, A1 to A9 are used only to indicate the TiB2 crystals at the thin layer grain boundaries, and do not mean that there are only nine TiB2 crystals.

Claims

1. A Ti-containing neodymium-iron-boron magnet, The Ti-containing neodymium-iron-boron magnet includes main phase crystal grains, a thin grain boundary phase, and a triangular region grain boundary phase, The Ti-containing neodymium-iron-boron magnet contains TiB ２ It contains crystals, TiB of the Ti-containing neodymium-iron-boron magnet ２ A Ti-containing neodymium-iron-boron magnet whose crystal distribution satisfies the following formulas (1) and (2): 0≦N １ / N≦0.05 Formula (1) 0≦N ２ / N≦0.3 Formula (2) However, N １ / N is TiB distributed inside the main phase crystal grains. ２ Number of crystals N １ and TiB distributed in the main phase crystal grains, triangular region grain boundaries, and thin layer grain boundaries in the Ti-containing neodymium-iron-boron magnet. ２ represents the ratio to the total number of crystals N, and N ２ / N is the TiB in the triangular region grain boundary phase. ２ Number of crystals N ２ represents the ratio of N to N.

2. 0≦N ２ 2. The Ti-containing neodymium iron boron magnet according to claim 1, wherein / N≦0.

2.

3. The TiB ２ 2. The Ti-containing neodymium iron boron magnet according to claim 1, wherein the crystal length is 100 to 500 nm and the width is 1 to 20 nm.

4. TiB in the thin grain boundary phase ２ The Ti-containing neodymium iron boron magnet according to claim 1, wherein the crystal distribution satisfies the following formula (3): 0.3≦L Ｔ / L≦0.8 Formula (3) In formula (3), L Ｔ / L is the TiB in the thin grain boundary phase ２ Total length of crystal L Ｔ and the total length L of the thin grain boundary phase.

5. The Ti-containing neodymium-iron-boron magnet contains R, Ti, M, B, and Fe, where the element R is one or more selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce, and the element M is one or more selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf, and W, 2. The Ti-containing neodymium iron boron magnet according to claim 1, wherein the R content in the Ti-containing neodymium iron boron magnet is 28.5 to 31.5 wt%, the Ti content is 0.05 to 0.75 wt%, the M content is 1.2 to 2.5 wt%, the B content is 0.9 to 0.97 wt%, and the balance is Fe.

6. A method for producing a Ti-containing neodymium-iron-boron magnet, comprising the steps of: The method includes a step of molding the R-Ti-M-B-Fe alloy powder to obtain a compact, sintering the compact, and aging the compact to obtain a magnet; the sintering process includes a first sintering process and a second sintering process, The temperature of the first sintering treatment is 480 to 850°C, and the temperature-keeping time is 5 to 12 hours, and the temperature of the second sintering treatment is 900 to 1100°C, and the temperature-keeping time is 1 to 10 hours.

7. 7. The method according to claim 6, wherein the temperature of the first sintering treatment is 500 to 850°C, and the temperature-keeping time is 5 to 10 hours, and the temperature of the second sintering treatment is 900 to 1080°C, and the temperature-keeping time is 1 to 6 hours.

8. In the R-Ti-M-B-Fe alloy powder, the element R is one or more selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce, and M is one or more selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf, and W; 7. The method according to claim 6, wherein the R-Ti-M-B-Fe alloy powder has an R content of 28.5 to 31.5 wt %, a Ti content of 0.05 to 0.75 wt %, an M content of 1.2 to 2.5 wt %, a B content of 0.9 to 0.97 wt %, and the remainder being Fe.

9. 7. The method of claim 6, further comprising the steps of preparing R-Ti-M-B-Fe alloy flakes by a rapid solidification method, and subjecting the R-Ti-M-B-Fe alloy flakes to a hydrogen pulverization treatment and a jet mill pulverization treatment to obtain the R-Ti-M-B-Fe alloy powder, wherein the R-Ti-M-B-Fe alloy powder has an average particle size D50 of 2 to 5 μm.

10. R １ -Fe-B-M １ Main alloy powder and R ２ -Ti-M ２ The method further comprises the step of mixing an auxiliary alloy powder to obtain the R-Ti-MB-Fe alloy powder, １ -Fe-B-M １ The main alloy powder and the R ２ -Ti-M ２ The mass ratio of the auxiliary alloy powder is (10-150):1; The R １ is one or more elements selected from Nd, Pr, Dy, Tb, Ho, La, Y, and Ce, and the M １ is one or more selected from Cr, Co, Ni, Ga, Cu, Al, Zr, Nb, Mo, Sn, Hf and W, and the R １ -Fe-B-M １ R in the main alloy powder １ The content of is 28 to 31 wt%, M １ The content of is 0.5 to 3 wt%, the content of B is 0.85 to 0.97 wt%, and the balance is Fe, The R ２ is selected from Pr and / or Nd, and said M ２ is one or more selected from Co, Cu, Al and Ga, ２ -Ti-M ２ R in the auxiliary alloy powder ２ The content of is 50 to 95 wt%, the content of Ti is 5 to 30 wt%, ２ The method according to claim 6, wherein the content of is 0 to 20 wt %.

11. Rapid solidification method １ -Fe-B-M １ A main alloy piece is prepared, and the R １ -Fe-B-M １ The main alloy flakes were subjected to hydrogen pulverization and jet mill pulverization, and the R １ -Fe-B-M １ The main alloy powder is obtained, and １ -Fe-B-M １ the main alloy powder has an average particle size D50 of 2 to 5 μm; Rapid solidification method ２ -Ti-M ２ Auxiliary alloy pieces are prepared, and the R ２ -Ti-M ２ The auxiliary alloy flakes are subjected to hydrogen pulverization and jet mill fine pulverization, ２ -Ti-M ２ Auxiliary alloy powder is obtained, and the R ２ -Ti-M ２ the auxiliary alloy powder has an average particle size D50 of 0.5 to 2 μm; The method of claim 10 further comprising:

12. the molding process is an orientation molding process, and the orientation molding process is carried out under the condition of a magnetic induction strength of 1.8 to 2.5 T; 7. The method according to claim 6, wherein the aging treatment includes a first aging treatment and a second aging treatment, the first aging treatment is performed at a temperature of 850 to 950°C for a holding time of 3 to 5 hours, and the second aging treatment is performed at a temperature of 450 to 600°C for a holding time of 0.5 to 5 hours.

13. A Ti-containing neodymium-iron-boron magnet produced by the method according to any one of claims 6 to 12.

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