High-density, low-loss rare-earth permanent magnet powder, bonded magnet, and method for manufacturing the same.

Abstract

The present invention provides a high density, low loss rare earth permanent magnet powder, a bonded magnet, and a method for producing the same. The molecular formula of the high density rare earth permanent magnet powder is Sm x Fe 100-x-y-z M y I z (wherein 6.0≦x≦9.5, 0≦y≦13, 1≦z≦15.2, M is a 3d transition metal and / or a 4d transition metal, and I is an interstitial atom, including N or a combination of N and H.) The high density rare earth permanent magnet powder has a maximum magnetic energy product of 36.299 MGOe or more and a compressed density of 5.5 g / cm. 3 The rare earth permanent magnet powder in the embodiment of the present invention has better overall properties than conventional rare earth permanent magnet powder, and can further improve the magnetic properties, increase the density of the magnetic powder, and make the particle size distribution of the magnetic powder more uniform.

Description

[Technical Field]

[0001] This application claims priority to two Chinese patent applications filed with the China National Intellectual Property Office on April 14, 2022: Application No. 202210392476.9, Title of Invention: "High-Density Rare Earth Permanent Magnet Powder and Method for Manufacturing the Same," and Application No. 202210386759.2, Title of Invention: "High-Density, Low-Loss Rare Earth Permanent Magnet Material and Method for Manufacturing the Same." All of the contents of these applications are incorporated into this application by reference.

[0002] The present invention relates to magnetic materials, particularly high-density, low-loss rare-earth permanent magnet powder, a method for producing high-density, low-loss rare-earth permanent magnet powder, high-density, low-loss rare-earth bonded magnets, and a method for producing high-density, low-loss rare-earth bonded magnets. [Background technology]

[0003] Since the 1970s and 1980s, rare-earth permanent magnet materials have been considered by the industry as key materials in high-tech application fields related to the interconversion of magnetic, electrical, and mechanical energy, and exhibit magnetic energy densities several times higher than conventional magnetic materials that do not contain rare-earth components. Rare-earth permanent magnet materials are a general term for a family of intermetallic compounds typically formed by rare-earth transition metals and other metals or nonmetals, and depending on the combination of components, they can form permanent magnetic materials with various phase structures and potential application value.

[0004] To date, commercially available rare-earth permanent magnet materials are mainly neodymium iron boron manufactured by sintering and bonding processes. However, with the trend towards miniaturization, weight reduction, higher frequency, and higher speed in downstream motor products, neodymium iron boron materials have gradually become unable to keep up with the sophistication and development of downstream industries due to factors such as reaching the theoretical limit of their magnetic properties, large eddy current losses, and complex molding processes. Furthermore, neodymium iron boron is typically expensive due to the addition of heavy rare-earth elements during manufacturing, and its cost fluctuates significantly due to market factors, resulting in a lack of cost-effectiveness.

[0005] Generally, rare earth permanent magnet materials are used primarily in high-end motor fields such as high-frequency and high-speed motors, as well as in fields such as high-performance micromotors, special-shaped motors, and sensors, covering strategic emerging fields such as new energy vehicles, energy-saving and environmentally friendly frequency conversion home appliances, and intelligent manufacturing industries. For example, in the automotive sector, rare earth permanent magnet materials are tested in car wipers, electronic throttles, blowers, batteries, cooling fans, sunroofs, power steering, electric air conditioners, fuel tank cap opening and closing, electric windows, doors, seat adjustments, pre-collision systems, electric brake systems, and other automotive parts.

[0006] The rapid development of permanent magnet drive motors for new energy vehicles is driving increasingly higher peak speeds. This requires motors that can achieve higher energy efficiency, smaller size, and lower cost in this high-speed environment. Rare-earth bonded magnets need to have superior overall properties. However, existing rare-earth bonded magnets often possess only excellent magnetic properties, lacking significant advantages in other areas, and as a result, they are not well-suited to existing commercial applications. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The technical problem that this application aims to solve is to provide high-density, low-loss rare-earth permanent magnet powder, a method for producing high-density, low-loss rare-earth permanent magnet powder, a high-density, low-loss rare-earth bonded magnet, and a method for producing high-density, low-loss rare-earth bonded magnet, which improve the overall properties of rare-earth bonded magnets and enable them to be successfully applied in conventional commercial environments. [Means for solving the problem]

[0008] To solve the above problem, the present invention relates to a molecular formula Sm x Fe 100-x-y-z My I z (Here, 6.0 ≦ x ≦ 9.5, 0 ≦ y ≦ 13, 1 ≦ z ≦ 15.2, M is a 3d transition metal and / or a 4d transition metal, I is an interstitially located atom, and includes N, or a combination of N and H.) and has a maximum magnetic energy product of 36.299 MGOe or more and a compression density of 5.5 g / cm 3 or more, to provide a high-density rare earth permanent magnet powder.

[0009] Optionally, the 3d transition metal and / or 4d transition metal includes one or more of Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, Mo.

[0010] Optionally, the high-density rare earth permanent magnet powder has a particle size of 0.6 μm ≦ x10 ≦ 0.92 μm, 2 μm ≦ x50 ≦ 2.55 μm, 5.93 μm ≦ x99 ≦ 8.1 μm.

[0011] Optionally, the high-density rare earth permanent magnet powder has a residual magnetic induction strength of 14.289 kGs or more and an intrinsic coercive force of 10.255 kOe or more.

[0012] Optionally, in thermogravimetric analysis in an air atmosphere at 400 °C, the high-density rare earth permanent magnet powder has a weight gain rate of less than 3.2%.

[0013] The present invention also provides a step of obtaining raw materials, where the raw materials include an Sm element, an Fe element, and a 3d transition metal and / or a 4d transition metal, and the ratios of the Sm element, Fe element, and 3d transition metal and / or 4d transition metal in the raw materials are the same as the ratios of each element in the high-density rare earth permanent magnet powder, a step of manufacturing a samarium-iron master alloy using the raw materials, Samarium- Iron master alloy is subjected to a gas-solid reaction with nitrogen or a mixed gas of nitrogen and hydrogen to form a samarium-iron-nitrogen alloy Sm x Fe 100-x-y-z M y I z forming step, A method for manufacturing high-density rare earth permanent magnet powder is disclosed, including the step of polishing the samarium-iron-nitrogen alloy to obtain the high-density rare earth permanent magnet powder.

[0014] Optionally, the step of manufacturing a samarium-iron master alloy using the raw materials is including the step of manufacturing a samarium-iron master alloy by a rapid solidification flake technique using the raw materials.

[0015] Optionally, in the step of manufacturing a samarium-iron master alloy by a rapid solidification flake technique using the raw materials, the rotational speed of the rapid solidification roll is 50-80 m / s, and the thickness of the manufactured samarium-iron master alloy is less than 1 mm.

[0016] Optionally, in the gas-solid reaction process, the reaction temperature is 400-800 °C, the time is 1-200 hours, and the air pressure is 0.1-2.0 MPa.

[0017] Optionally, in the polishing process, the total energy output is 60-80 KJ.

[0018] The present invention also provides a high-density and low-loss rare earth bonded magnet including high-density rare earth permanent magnet powder, an adhesive, and a processing aid.

[0019] Optionally, the adhesive contains at least one of chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyether imide, polyformaldehyde, chlorosulfonated polyethylene, and / or at least one of a copolymer, blend, and polymer alloy formed of chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyether imide, polyformaldehyde, chlorosulfonated polyethylene.

[0020] Optionally, the adhesive contains a thermoplastic elastomer.

[0021] Optionally, the processing aid contains at least one of a coupling agent, plasticizer, lubricant, and flame retardant.

[0022] Optionally, the coupling agent contains a titanate-based coupling agent and / or a silane-based coupling agent.

[0023] Optionally, the plasticizer contains at least one of dioctyl phthalate DOP, stearate, fatty acid, phosphate ester, benzene polycarboxylic acid ester, and alkyl sulfonic acid ester.

[0024] Optionally, the lubricant contains at least one of silicone oil, wax, fatty acid, oleic acid, polyester, synthetic ester, carboxylic acid, alumina, silica, and titanium dioxide.

[0025] The present invention also includes mixing high-density rare earth permanent magnet powder, an adhesive, and a processing aid to obtain a mixture, A method for producing a high-density, low-loss rare-earth bonded magnet is provided, comprising the step of processing the mixture by an extrusion molding or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet.

[0026] The step of optionally processing the mixture by an extrusion or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet is as follows: When using an extrusion molding process, the steps include kneading the mixture in a kneader, heating and melting the mixture, then injecting it into a single-screw extruder with a magnetic field orientation exceeding 8 kOe, extruding it with the single-screw extruder, and then cooling and molding it to obtain a high-density, low-loss rare-earth bonded magnet.

[0027] The step of optionally processing the mixture by an extrusion or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet is as follows: When using an injection molding process, the steps include producing the mixture as mixed pellets using a twin-screw extruder, The process includes the steps of heating and melting the mixed pellets, then injection molding them in an injection molding machine with a magnetic field orientation exceeding 8 kOe to obtain a high-density, low-loss rare-earth bonded magnet. [Effects of the Invention]

[0028] Compared to the prior art, this invention offers the following advantages.

[0029] The rare earth permanent magnet powder in the embodiments of the present invention has superior overall properties compared to conventional rare earth permanent magnet powders, further improving magnetic properties, increasing the density of the magnetic particles, and making the particle size distribution of the magnetic particles more uniform. By applying this rare earth permanent magnet powder to a rare earth permanent magnet material, the overall properties of the rare earth permanent magnet material are effectively improved, enabling rare earth bonded magnets to be successfully applied in conventional commercial environments.

[0030] In the embodiment of the present invention, high-density, low-loss rare-earth bonded magnets, high-density rare-earth permanent magnet powder is used in the manufacture of the high-density, low-loss rare-earth bonded magnets. The high-density rare-earth permanent magnet powder further improves the magnetic properties, increases the density of the magnetic particles, and makes the particle size distribution of the magnetic particles more uniform. Applying this rare-earth permanent magnet powder to rare-earth bonded magnets effectively improves the overall properties of the rare-earth bonded magnets and reduces the magnetic field strength requirements in the manufacturing process of the rare-earth bonded magnets, thereby reducing the manufacturing cost of the rare-earth bonded magnets to some extent and enabling the rare-earth bonded magnets to be successfully applied in conventional commercial environments.

[0031] The above description is merely an outline of the technical solution of this application. In order to understand the technical solution of this application more clearly, and in order to make it easier to understand the above and other objectives, features, and advantages of this application, which can be implemented in accordance with the contents of the specification, specific embodiments of this application are given below. [Modes for carrying out the invention]

[0032] To further clarify the purpose, technical solutions, and advantages of the embodiments of this application, the technical solutions of the embodiments of this application will be described clearly and completely below with reference to the drawings of the embodiments of this application, although it is clear that the embodiments described are only a part of the embodiments of this application and not all of them. All other embodiments obtained by a person skilled in the art without creative work based on the embodiments of this application are within the scope of protection of this application.

[0033] This invention relates to a molecular formula Sm x Fe 100-x-y-z M y I z (where 6.0 ≤ x ≤ 9.5, 0 ≤ y ≤ 13, 1 ≤ z ≤ 15.2, M is a 3d transition metal and / or a 4d transition metal, I is an interstitial atom, including N or a combination of N and H.) The maximum magnetic energy product is 36.299 MGOe or greater, and the compressive density is 5.5 g / cm³. 3 The above describes a high-density rare-earth permanent magnet powder.

[0034] Specifically, in the high-density rare-earth permanent magnet powder manufactured according to the present invention, the composition of the high-density rare-earth permanent magnet powder is rationally controlled without using heavy rare-earth metals, and the final high-density rare-earth permanent magnet powder produced by a specific synthesis method has a maximum magnetic energy product of 36.299 MGOe or higher and a compressed density of 5.5 g / cm³. 3 This concludes the explanation. The goal is to maintain high magnetic properties while effectively improving compressive density, thereby enhancing the overall properties of the high-density rare-earth permanent magnet powder.

[0035] Optionally, the 3d transition metal and / or 4d transition metal includes one or more of the following: Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, and Mo.

[0036] Optionally, the high-density rare-earth permanent magnet powder has particle sizes of 0.6 μm ≤ x10 ≤ 0.92 μm, 2 μm ≤ x50 ≤ 2.55 μm, and 5.93 μm ≤ x99 ≤ 8.1 μm.

[0037] Specifically, the present invention improves the compression density while ensuring a wide particle size distribution through a particular synthesis method, thereby reducing losses after magnetic powder molding and improving the overall properties of the rare earth permanent magnet material produced afterward.

[0038] Optionally, the high-density rare-earth permanent magnet powder has a residual magnetic induction intensity of 14.289 kGs or higher and an intrinsic coercivity of 10.255 kOe or higher.

[0039] Specifically, the high-density rare-earth permanent magnet powder of the present invention has a high magnetic energy product, resulting in a greater amount of energy that can be converted. Furthermore, it exhibits high residual magnetic induction strength and intrinsic coercivity. High residual magnetic induction strength and intrinsic coercivity result in a magnet with high demagnetization resistance and high magnetic field strength. Therefore, high-density rare-earth permanent magnet powder can be widely used in fields such as household appliances, new energy vehicles, wind turbines, and industrial motors.

[0040] Optionally, the high-density rare-earth permanent magnet powder exhibits a weight increase rate of less than 3.2% in thermogravimetric analysis at 400°C in an air atmosphere.

[0041] Specifically, in thermogravimetric analysis of high-density rare-earth permanent magnet powder, a low weight increase rate indicates high thermal stability, allowing the powder to retain its inherent properties as much as possible even in high-temperature environments, making it suitable for a variety of application environments.

[0042] The present invention also, A step of obtaining raw materials, wherein the raw materials comprise Sm element, Fe element, and 3d transition metal and / or 4d transition metal, and the proportions of Sm element, Fe element, and 3d transition metal and / or 4d transition metal in the raw materials are the same as the proportions of each element in the high-density rare-earth permanent magnet powder. A step of producing a samarium-iron matrix alloy using the aforementioned raw materials, samarium- Iron master alloy This is subjected to a gas-solid reaction with nitrogen or a mixture of nitrogen and hydrogen to produce a samarium-iron-nitrogen alloy Sm x Fe 100-x-y-z M y I z The steps of forming, A method for producing high-density rare-earth permanent magnet powder is disclosed, comprising the step of polishing the samarium-iron-nitrogen alloy to obtain the high-density rare-earth permanent magnet powder.

[0043] Specifically, jet milling and / or ball milling may be used for polishing samarium-iron-nitrogen alloys. Of these, jet milling crushes coarse particles by repeatedly colliding and rubbing through the intersection of multiple high-pressure airflows, and the desired powder particle size can be obtained by controlling the polishing pressure and the speed of the sorter.

[0044] The step of producing a samarium-iron matrix alloy using the raw materials, optionally, The process includes the step of producing a samarium-iron matrix alloy using the aforementioned raw materials by rapid solidification flake technology.

[0045] Specifically, samarium- Iron master alloy Rapid solidification technology is used in its manufacture. Compared to conventional smelting techniques such as arc melting and ingot casting, the cooling rate of the molten metal is faster, and the distribution of the crystalline phase becomes more uniform. The average grain size of the crystal grain distribution of the rapidly solidified thin strip produced by this method is 8 μm or less, which is advantageous for controlling the diffusion of nitrogen atoms and the grain size distribution in subsequent steps.

[0046] In the optional step of producing a samarium-iron matrix alloy using the aforementioned raw materials by rapid solidification flake technology, the rotation speed of the rapid solidification roll is 50-80 m / s, and the thickness of the produced samarium-iron matrix alloy is less than 1 mm. By rationally controlling the rotation speed of the rapid solidification roll, the precipitation of the crystalline phase can be effectively suppressed during the manufacturing process, and the occurrence of crystal aggregates can be avoided. The width of the main phase columnar crystals decreases as the sheet thickness decreases. When the sheet thickness is small, when the sheet is powdered, a large amount of polycrystalline particles and ultrafine powder are likely to be generated, thereby making it easier to obtain a high-density permanent magnet powder with good overall properties.

[0047] Optionally, in the gas-solid reaction process, the reaction temperature is 400-800°C, the duration is 1-200 hours, and the atmospheric pressure is 0.1-2.0 MPa. By rationally controlling the reaction conditions in the above gas-solid reaction process, it is possible to facilitate the formation of a good crystalline phase and to obtain high-density permanent magnet powder with a good particle size distribution in subsequent processing processes.

[0048] Optionally, the total energy output in the polishing process is 60-80 kJ. By rationally controlling the energy output in the polishing process, the manufactured high-density permanent magnet powder is given a better particle size distribution and higher intrinsic coercivity.

[0049] The demagnetization process of single-crystal samarium-iron-nitrogen magnetic powder is characterized by a nucleation mechanism, where the residual magnetic induction intensity and coercivity of the magnetic powder change in response to changes in particle size. Previous processes have often prioritized magnetic properties while neglecting the actual needs and effects in applied processes. By controlling the powdering parameters and energy range, high-density permanent magnet powder with high magnetic properties and suitable for downstream magnet manufacturing can be obtained. This high-density permanent magnet powder does not focus solely on the level of a single magnetic property, but rather improves the overall properties of the magnetic powder based on the saturation magnetization intensity and crystalline magnetic anisotropy field from the previous process, ensuring a wide particle size distribution while increasing compressive density and coercivity, and reducing losses of the magnetic powder after molding. The manufactured high-density permanent magnet powder has a maximum magnetic energy product of 40 MGOe or more, a residual magnetism of 14.7 kGs or more, an intrinsic coercivity of 11 kOe or more, and a TG weight increase (@400°C, air atmosphere) of ≤3.2%.

[0050] As one possible embodiment of the present invention, after manufacturing high-density permanent magnet powder, the magnet may be surface-treated to further improve the oxidation resistance of the magnetic powder and the rotational effect of the magnetic powder in the magnetic field formation process, thereby laying the foundation for manufacturing high-density, low-loss magnets.

[0051] Specifically, the surface treatment agent and the high-density permanent magnet powder may be dissolved in a mixed solvent containing alcohols and ketones, and the surface treatment agent may be coated onto the surface of the high-density permanent magnet powder.

[0052] Here, the surface treatment agent may be a coupling agent such as titanate or silanes, which can prevent oxidation of the magnetic powder in subsequent processes, improve dispersibility and tackiness, and is advantageous for producing a permanent magnet material with excellent properties.

[0053] The present invention provides a high-density, low-loss rare-earth bonded magnet comprising high-density rare-earth permanent magnet powder, an adhesive, and a processing aid.

[0054] Specifically, the high-density rare-earth permanent magnet powder of the present invention ensures a wide particle size distribution while improving compression density, reducing loss of magnetic powder after molding, and improving the overall properties of the rare-earth bonded magnets manufactured later.

[0055] Furthermore, high-density rare-earth permanent magnet powder has a high magnetic energy product, allowing it to store more energy, and also possesses high residual magnetic induction strength and intrinsic coercivity. High residual magnetic induction strength and intrinsic coercivity result in magnets with high demagnetization resistance and high magnetic field strength. Therefore, high-density rare-earth permanent magnet powder can be widely used in fields such as household appliances, new energy vehicles, wind turbines, and industrial motors.

[0056] In thermogravimetric analysis of high-density rare-earth permanent magnet powder, a low weight increase rate indicates high thermal stability, allowing the powder to retain its inherent properties as much as possible even in high-temperature environments, making it suitable for a variety of application environments.

[0057] As one possible embodiment of the present invention, after manufacturing high-density permanent magnet powder, the magnet may be surface-treated to further improve the oxidation resistance of the magnetic powder and the rotational effect of the magnetic powder in the magnetic field formation process, thereby laying the foundation for manufacturing high-density, low-loss magnets.

[0058] Specifically, the surface treatment agent and the high-density permanent magnet powder may be dissolved in a mixed solvent containing alcohols and ketones, and the surface treatment agent may be coated onto the surface of the high-density permanent magnet powder.

[0059] Here, the surface treatment agent may be a coupling agent such as titanate or silanes, which can prevent oxidation of the magnetic powder in subsequent processes, improve dispersibility and tackiness, and is advantageous for producing bonded magnets with superior properties.

[0060] Optionally, the adhesive comprises at least one of chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyetherimide, polyformaldehyde, and chlorosulfonated polyethylene, and / or comprises at least one copolymer, blend, or polymer alloy formed from at least one of chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyetherimide, polyformaldehyde, and chlorosulfonated polyethylene.

[0061] Among these, the polyamide resin may include, for example, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66, etc. The liquid crystal polymer may be aromatic polyester, etc. The polyolefin may be polyethylene, polypropylene, etc.

[0062] Optionally, the adhesive includes at least one thermoplastic elastomer, such as styrenes (SBS, SIS, SEBS, SEPS), alkenes (TP0, TPV), dienes (TPB, TPI), vinyl chlorides (TPVC, TCPE), urethanes (TPU), esters (TPEE), amides (TPAE), organofluorines (TPF), silicones, and ethylenes.

[0063] Specifically, the adhesive plays a role in improving the fluidity of the magnetic powder particles and the bonding strength between them, thereby imparting mechanical properties and corrosion resistance to the magnet. Depending on the molding process and the needs of use, the type of adhesive used may be a material that exhibits high bonding strength, high adhesive strength, low water absorption, and excellent dimensional stability.

[0064] For example, if the high-density, low-loss rare-earth bonded magnet to be manufactured is a bonded magnet, the adhesive may be at least one of the following: chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyetherimide, polyformaldehyde, chlorosulfonated polyethylene, and / or at least one copolymer, blend, or polymer alloy formed from at least one of the following: chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyetherimide, polyformaldehyde, chlorosulfonated polyethylene.

[0065] If the high-density, low-loss rare-earth bonded magnet to be manufactured is a magnetic elastomer, a thermoplastic elastomer may be used as the adhesive, but depending on the actual needs, at least one of the following may be used: chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyetherimide, polyformaldehyde, chlorosulfonated polyethylene, and / or at least one copolymer, blend, or polymer alloy formed from at least one of the following: chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyetherimide, polyformaldehyde, chlorosulfonated polyethylene.

[0066] Optionally, the processing aid may include at least one of a coupling agent, plasticizer, lubricant, or flame retardant, thereby further improving the overall properties of the high-density, low-loss rare-earth bonded magnet.

[0067] Optionally, the coupling agent includes a titanate-based coupling agent and / or a silane-based coupling agent. The coupling agent can effectively improve the bonding between the magnetic powder and the adhesive, and also effectively promotes an improvement in the orientation factor of the powder particles in a magnetic field.

[0068] Optionally, the plasticizer includes at least one of dioctyl phthalate DOP, stearate, fatty acid, phosphate ester, benzene polycarboxylic acid ester, and alkyl sulfonic acid ester.

[0069] Optionally, the lubricant includes at least one of the following: silicone oil, wax, fatty acid, oleic acid, polyester, synthetic ester, carboxylic acid, alumina, silica, and titanium dioxide. Plasticizers and lubricants can improve the properties of high-density, low-loss rare-earth bonded magnets, simplify processing conditions to some extent, and increase processing efficiency.

[0070] Optionally, the flame retardants include organic flame retardants, inorganic flame retardants, halogenated flame retardants (organic chlorides and organic bromides), and non-halogenated flame retardants. Organic flame retardants include bromine-based, phosphorus-nitrogen-based, nitrogen-based, and red phosphorus-based or compound-based flame retardants, while inorganic flame retardants include antimony trioxide, magnesium hydroxide, aluminum hydroxide, and silicon-based flame retardants.

[0071] The present invention also, The steps include: mixing high-density rare-earth permanent magnet powder, an adhesive, and a processing aid to obtain a mixture; A method for producing a high-density, low-loss rare-earth bonded magnet is provided, comprising the step of processing the mixture by an extrusion molding or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet.

[0072] Specifically, because the particle size distribution of the high-density rare-earth permanent magnet powder is good, the magnetic field strength in the manufacturing process of high-density, low-loss rare-earth bonded magnets can be lower than the generally required 13 kOe. This reduces the manufacturing cost of rare-earth bonded magnets to some extent, enabling them to be successfully applied to conventional commercial environments and giving them good overall properties.

[0073] The optional step of processing the mixture by an extrusion or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet is: When using an extrusion molding process, the steps include kneading the mixture in a kneader, heating and melting the mixture, then injecting it into a single-screw extruder with a magnetic field orientation exceeding 8 kOe, extruding it with the single-screw extruder, and then cooling and molding it to obtain a high-density, low-loss rare-earth bonded magnet.

[0074] When implementing this specifically, if an extrusion molding process is used, the addition ratio of adhesive and processing aid may be 4% to 30%.

[0075] The optional step of processing the mixture by an extrusion or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet is: When using an injection molding process, the steps include producing the mixture as mixed pellets using a twin-screw extruder, The method includes the steps of heating and melting the mixed pellets, and then injection molding them in an injection molding machine with a magnetic field orientation exceeding 8 kOe to obtain a high-density, low-loss rare-earth bonded magnet.

[0076] In specific implementations, when using an injection molding process, the addition ratio of adhesive and processing aids may be 5% to 30%. In processes for producing mixed pellets using a twin-screw extruder, the temperature may be controlled to 130°C to 350°C. In processes for injection molding in addition to an injection molding machine with a magnetic field orientation exceeding 8 kOe, the temperature may be controlled to between 190°C and 350°C.

[0077] The shape of the magnet can be manufactured in various three-dimensional shapes such as tile, cylindrical, ring, square, and flat shapes by selecting various molds according to the actual needs, but the present invention is not limited thereto.

[0078] To help those skilled in the art better understand the present invention, the method for producing the high-density, low-loss rare-earth bonded magnet of the present invention will be described below with reference to several specific examples.

[0079] Manufacturing of high-density rare-earth permanent magnet powder

[0080] Example 1 Other raw material components besides nitrogen were mixed in. These included rare earth elements Sm, as well as Fe, Co, and Nb, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, Co 8%, and Nb 5%.

[0081] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 10 hours to cool to room temperature, resulting in a sheet with a thickness of 0.5 mm and an average grain size of 7.5 μm. Annealing treatment was not required.

[0082] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction in a nitrogen atmosphere of 0.1 to 2.0 MPa at a reaction temperature of 400°C for 1 hour.

[0083] The material processed in the above steps was ground in a ball mill for 5 hours, and the energy required for this grinding was 60 kJ.

[0084] Example 2 Other raw material components besides nitrogen were mixed in. These included rare earth elements Sm, as well as Fe, Co, and Nb, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, Co 8%, and Nb 5%.

[0085] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 8 hours to cool to room temperature, resulting in a sheet with a thickness of 0.5 mm and an average grain size of 7.3 μm. Annealing treatment was not required.

[0086] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 400°C for 150 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0087] The material processed in the above steps was ground in a ball mill for 5 hours. The energy required for this grinding was 60 kJ.

[0088] Example 3 Other raw material components besides nitrogen were mixed in. These included rare earth elements Sm, as well as Fe, Co, and Nb, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, Co 8%, and Nb 5%.

[0089] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roller rotated at 80 m / s, and it took 10 hours to cool to room temperature, resulting in a sheet with a thickness of 0.4 mm and an average grain size of 6.9 μm. Annealing treatment was not required.

[0090] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 400°C for 200 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0091] The material processed in the above steps was ground in a ball mill for 5 hours. The energy required for this grinding was 60 kJ.

[0092] Example 4 Other raw material components besides nitrogen were mixed in. These included rare earth elements Sm, as well as Fe, Co, and Nb, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, Co 8%, and Nb 5%.

[0093] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 10 hours to cool to room temperature, resulting in a sheet with a thickness of 0.4 mm and an average grain size of 7.3 μm. Annealing treatment was not required.

[0094] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 600°C for 150 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0095] The material processed in the above steps was ground in a ball mill for 5 hours. The energy required for this grinding was 60 kJ.

[0096] Example 5 Other raw material components besides nitrogen were mixed in. These included rare earth elements Sm, as well as Fe, Co, and Nb, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, Co 8%, and Nb 5%.

[0097] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 8 hours to cool to room temperature, resulting in a sheet with a thickness of 0.4 mm and an average grain size of 7.3 μm. Annealing treatment was not required.

[0098] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 800°C for 150 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0099] The material processed in the above steps was ground in a ball mill for 6 hours. The energy required for this grinding was 65 kJ.

[0100] Example 6 Other raw material components besides nitrogen were mixed in. These included rare earth elements Sm, as well as Fe, Co, and Nb, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, Co 8%, and Nb 5%.

[0101] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 8 hours to cool to 40°C, resulting in a sheet with a thickness of 0.4 mm and an average grain size of 7.3 μm. Annealing was not required.

[0102] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 600°C for 60 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0103] The material processed in the above steps was ground in a ball mill for 6 hours. The energy required for this grinding was 70 kJ.

[0104] Example 7 Other raw material components besides nitrogen were mixed in. These included the rare earth element Sm, as well as Fe, Ti, and Cr. The atomic percentages of the mixture were Sm 6%, Fe 72.8%, Ti 3%, and Cr 3%.

[0105] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 8 hours to cool to 40°C, resulting in a sheet with a thickness of 0.4 mm and an average grain size of 7.3 μm. Annealing was not required.

[0106] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 600°C for 60 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0107] The material processed in the above steps was ground in a ball mill for 4 hours. The energy required for this grinding was 80 kJ.

[0108] Example 8 Other raw material components besides nitrogen were mixed in. These included rare earth elements Sm, as well as Fe, V, and Mn, with the atomic percentages of the mixture being Sm 6%, Fe 72.8%, V 3%, and Mn 3%.

[0109] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 10 hours to cool to room temperature, resulting in a sheet with a thickness of 0.5 mm and an average grain size of 7.5 μm. Annealing treatment was not required.

[0110] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 400°C for 1 hour in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0111] The material processed in the above steps was ground in a ball mill for 5 hours. The energy required for this grinding was 60 kJ.

[0112] Example 9 Other raw material components besides nitrogen were mixed in. These included the rare earth elements Sm and Fe, and the atomic percentages of the mixture were Sm 9.5% and Fe 89.5%.

[0113] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 8 hours to cool to room temperature, resulting in a sheet with a thickness of 0.5 mm and an average grain size of 7.3 μm. Annealing treatment was not required.

[0114] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 400°C for 150 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0115] The material processed in the above steps was ground in a ball mill for 5 hours. The energy required for this grinding was 60 kJ.

[0116] Example 10 Other raw material components besides nitrogen were mixed in. These included the rare earth elements Sm, as well as Fe, Ni, and Mo, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, Ni 8%, and Mo 5%.

[0117] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roller rotated at 80 m / s, and it took 10 hours to cool to room temperature, resulting in a sheet with a thickness of 0.4 mm and an average grain size of 6.9 μm. Annealing treatment was not required.

[0118] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 400°C for 200 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0119] The material processed in the above steps was ground in a ball mill for 5 hours. The energy required for this grinding was 60 kJ.

[0120] Example 11 Other raw material components besides nitrogen were mixed in. These included the rare earth element Sm, as well as Fe, Cu, and Zn, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, Cu 8%, and Zn 5%.

[0121] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 8 hours to cool to room temperature, resulting in a sheet with a thickness of 0.4 mm and an average grain size of 7.3 μm. Annealing treatment was not required.

[0122] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 800°C for 150 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0123] The material processed in the above steps was ground in a ball mill for 6 hours. The energy required for this grinding was 65 kJ.

[0124] Example 12 Other raw material components besides nitrogen were mixed in. These included rare earth elements Sm, as well as Fe and Zr, with the atomic percentages of the mixture being Sm 8.5%, Fe 76%, and Zr 13%.

[0125] Using the above raw materials, samarium- Iron master alloy The following was manufactured: The rapid solidification roll rotated at 50 m / s, and it took 8 hours to cool to 40°C, resulting in a sheet with a thickness of 0.4 mm and an average grain size of 7.3 μm. Annealing was not required.

[0126] The above rapidly cooled and solidified flakes were subjected to a gas-solid reaction at 600°C for 60 hours in a nitrogen atmosphere of 0.1 to 2.0 MPa.

[0127] The material processed in the above steps was ground in a ball mill for 6 hours. The energy required for this grinding was 70 kJ.

[0128] The rare-earth permanent magnet powder in the embodiments of the present invention exhibits better overall properties compared to conventional rare-earth permanent magnet powders, further improving magnetic properties, increasing the density of the magnetic particles, and making the particle size distribution of the magnetic particles more uniform. Some of the advantages of the embodiments of the present invention compared to the prior art will be explained below with specific experimental data.

[0129] Table 1: Properties of magnetic powder JPEG0007872435000001.jpg83145

[0130] From the above, it is clear that the rare earth permanent magnet powder in the embodiments of the present invention obtains magnetic properties such as high maximum magnetic energy product, remanent magnetism, and intrinsic coercivity, while also exhibiting a more uniform particle size distribution and compressive density. Furthermore, in the thermogravimetric analysis process, the weight increase was less than 3.2% at 400°C in an air atmosphere, demonstrating that the rare earth permanent magnet powder can maintain good stability even in high-temperature environments. For this reason, the rare earth permanent magnet powder exhibits superior overall properties. The overall properties (magnetic energy product) of the magnetic powder are improved, a wide particle size distribution is ensured, and the compressive density and coercivity are improved, reducing the loss of magnetic powder after molding. Manufacturing of high-density, low-loss rare-earth bonded magnets

[0131] Example 13 In Example 6, high-density rare-earth permanent magnet powder, polyamide resin (nylon 12), titanate coupling agent, diethylhexyl phthalate (DOP), silica, and butylhydroxyanisole (BHA) were mixed to obtain a mixture. Here, the ratio of polyamide resin (nylon 12), titanate coupling agent, diethylhexyl phthalate (DOP), silica, and butylhydroxyanisole was 90:2:2:4:2. The masses of polyamide resin (nylon 12), titanate, diethylhexyl phthalate (DOP), silica, and butylhydroxyanisole, and their proportions in the mixture, are shown in Table 2.

[0132] The mixed pellets were heated to 200°C to melt them, and then injected into an injection molding machine with a magnetic field orientation of 8 kOe to obtain a high-density, low-loss rare-earth bonded magnet.

[0133] Subsequently, an irreversible loss test (GB / T 40794-2021) was performed on high-density, low-loss rare-earth bonded magnets under the condition of being kept at 120°C for 192 hours.

[0134] Table 2. Properties of high-density, low-loss rare-earth bonded magnets JPEG0007872435000002.jpg48145

[0135] Example 14 In Example 7, high-density rare-earth permanent magnet powder, polyamide resin (nylon 12), titanate coupling agent, diethylhexyl phthalate (DOP), silica, and butylhydroxyanisole (BHA) were mixed to obtain a mixture. Here, the ratio of polyamide resin (nylon 12), titanate coupling agent, diethylhexyl phthalate (DOP), silica, and butylhydroxyanisole was 90:2:2:4:2. The masses of polyamide resin (nylon 12), titanate coupling agent, diethylhexyl phthalate (DOP), silica, and butylhydroxyanisole, and their proportions in the mixture, are shown in Table 3.

[0136] The mixed pellets were heated to 200°C to melt them, and then injected into an injection molding machine with a magnetic field orientation of 8 kOe to obtain a high-density, low-loss rare-earth bonded magnet.

[0137] Subsequently, an irreversible loss test (GB / T 40794-2021) was performed on high-density, low-loss rare-earth bonded magnets under the condition of being kept at 120°C for 192 hours.

[0138] Table 3. Properties of high-density, low-loss rare-earth bonded magnets. JPEG0007872435000003.jpg48144

[0139] Example 15 In Example 6, high-density rare-earth permanent magnet powder, thermoplastic elastomer (TPE), oleic acid, butylhydroxyanisole (BHA), and magnesium hydroxide were mixed to obtain a mixture. Here, the ratio of thermoplastic elastomer (TPE), oleic acid, butylhydroxyanisole (BHA), and magnesium hydroxide was 88:6:4:2, and the mass of thermoplastic elastomer (TPE), oleic acid, butylhydroxyanisole (BHA), and magnesium hydroxide, and their proportions in the mixture are shown in Table 4.

[0140] The mixed pellets were heated to 180°C to melt them, and then injected into an injection molding machine with a magnetic field orientation of 8 kOe to obtain a high-density, low-loss rare-earth bonded magnet.

[0141] Subsequently, flame retardancy and hardness tests were conducted on high-density, low-loss rare-earth bonded magnets.

[0142] Table 4. Properties of high-density, low-loss rare-earth bonded magnets. JPEG0007872435000004.jpg48149

[0143] Example 16 The high-density rare-earth permanent magnet powder produced in Example 6, nitrile rubber, titanate coupling agent, benzene polycarboxylic acid ester, and oleic acid were mixed to obtain a mixture. Here, the ratio of nitrile rubber, titanate coupling agent, benzene polycarboxylic acid ester, and oleic acid was 88:2:4:6, and the mass of nitrile rubber, titanate coupling agent, benzene polycarboxylic acid ester, and oleic acid, and their proportions in the mixture are shown in Table 5.

[0144] The aforementioned mixture was manufactured as mixed pellets using a twin-screw extruder.

[0145] The mixed pellets were heated to 80°C to melt them, and then injected into an injection molding machine with a magnetic field orientation of 8 kOe to obtain a high-density, low-loss rare-earth bonded magnet.

[0146] Subsequently, an irreversible loss test (GB / T 40794-2021) was performed on high-density, low-loss rare-earth bonded magnets under the condition of being kept at 120°C for 192 hours.

[0147] Table 5 Properties of high-density, low-loss rare-earth bonded magnets JPEG0007872435000005.jpg48144

[0148] Example 17 The high-density rare-earth permanent magnet powder produced in Example 7, nitrile rubber, titanate coupling agent, benzene polycarboxylic acid ester, and oleic acid were mixed to obtain a mixture. Here, the ratio of nitrile rubber, titanate coupling agent, benzene polycarboxylic acid ester, and oleic acid was 88:2:4:6, and the mass of nitrile rubber, titanate coupling agent, benzene polycarboxylic acid ester, and oleic acid, and their proportions in the mixture are shown in Table 6.

[0149] The aforementioned mixture was manufactured as mixed pellets using a twin-screw extruder.

[0150] The mixed pellets were heated to 80°C to melt them, and then injected into an injection molding machine with a magnetic field orientation of 8 kOe to obtain a high-density, low-loss rare-earth bonded magnet.

[0151] Subsequently, an irreversible loss test (GB / T 40794-2021) was performed on high-density, low-loss rare-earth bonded magnets under the condition of being kept at 120°C for 192 hours.

[0152] Table 6. Properties of high-density, low-loss rare-earth bonded magnets. JPEG0007872435000006.jpg48145

[0153] Example 18 The high-density rare-earth permanent magnet powder produced in Example 7, thermoplastic elastomer (TPE 50% + TPU 50%), oleic acid, butylhydroxyanisole (BHA), and magnesium hydroxide were mixed to obtain a mixture. Here, the ratio of thermoplastic elastomer (TPE 50% + TPU 50%), oleic acid, butylhydroxyanisole (BHA), and magnesium hydroxide was 70:5:20:5, and the mass of thermoplastic elastomer (TPE 50% + TPU 50%), oleic acid, butylhydroxyanisole (BHA), and magnesium hydroxide, and their proportions in the mixture are shown in Table 7.

[0154] The aforementioned mixture was manufactured as mixed pellets using a twin-screw extruder.

[0155] The mixed pellets were heated to 150°C to melt them, and then injected into an injection molding machine with a magnetic field orientation of 8 kOe to obtain a high-density, low-loss rare-earth bonded magnet.

[0156] Subsequently, flame retardancy and hardness tests were conducted on high-density, low-loss rare-earth bonded magnets.

[0157] Table 7 Properties of high-density rare-earth permanent magnet powder JPEG0007872435000007.jpg48145

[0158] From the above, it has been found that the manufactured high-density, low-loss rare-earth bonded magnets possess good overall properties even when the magnetic field strength is reduced. This effectively improves the overall properties of rare-earth bonded magnets, reduces the magnetic field strength requirements in the manufacturing process of rare-earth bonded magnets, thereby lowering the manufacturing cost of rare-earth bonded magnets to some extent and enabling them to be successfully applied in conventional commercial environments.

[0159] In this specification, “an embodiment,” “an embodiment,” or “one or more embodiments” means that a particular feature, structure, or property described in relation to an embodiment is included in at least one embodiment of the present application. However, the example phrase “in an embodiment” does not necessarily refer to the same embodiment.

[0160] The specification provided herein describes many specific details. However, it is understood that the embodiments of this application can be implemented without these specific details. In some examples, known methods, structures, and techniques are not described in detail so as not to obscure the understanding of this specification.

[0161] In the claims, no reference numerals between parentheses limit the scope of the claims. The word “including” does not preclude the existence of elements or steps not described in the claims. The word “one” or “one” preceding an element does not preclude the existence of multiple such elements. The present application can be realized by hardware comprising several different elements and a appropriately programmed computer. In claims listing several devices, some of these devices may be embodied by the same hardware. The use of words such as “first,” “second,” and “third” does not indicate any order. These words can be interpreted as names.

[0162] The above embodiments are used solely to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may be modified or some of their technical features may be replaced with equivalents. However, these modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present application.

Claims

1. A method for producing high-density rare-earth permanent magnet powder, The molecular formula of the aforementioned magnetic powder is Sm ｘ Fe １００－ｘ－ｙ－ｚ M ｙ I ｚ (Here, x = 8.5, y = 13, 1 ≤ z ≤ 15.2, M is a 3d transition metal and / or a 4d transition metal, and I is an interstitial atom, including N or a combination of N and H.) The aforementioned method, A step of obtaining raw materials, wherein the raw materials comprise Sm element, Fe element, and 3d transition metal and / or 4d transition metal, and the proportions of Sm element, Fe element, and 3d transition metal and / or 4d transition metal in the raw materials are the same as the proportions of each element in the high-density rare-earth permanent magnet powder. A step of producing a samarium-iron matrix alloy using the aforementioned raw materials, The steps include: reacting a samarium-iron matrix alloy with nitrogen or a mixture of nitrogen and hydrogen in a gas-solid reaction to form a samarium-iron-nitrogen alloy Sm x Fe 100-x-y-z My I z; The step of polishing the samarium-iron-nitrogen alloy to obtain the high-density rare-earth permanent magnet powder is included. In the gas-solid reaction process, the reaction temperature is 600°C, the duration is 60 hours, and the atmospheric pressure is 0.1–2.0 MPa. A method for producing high-density rare-earth permanent magnet powder, characterized by the following features.

2. The method for producing high-density rare-earth permanent magnet powder according to claim 1, characterized in that the 3d transition metal and / or 4d transition metal includes multiple types selected from Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, and Mo.

3. A method for producing high-density rare-earth permanent magnet powder according to claim 1, characterized in that the particle size is 0.6 μm ≤ x 10 ≤ 0.92 μm, 2 μm ≤ x 50 ≤ 2.55 μm, and 5.93 μm ≤ x 99 ≤ 8.1 μm.

4. A method for producing high-density rare-earth permanent magnet powder according to claim 1, characterized in that the residual magnetic induction intensity is 14.289 kGs or more and the intrinsic coercivity is 10.255 kOe or more.

5. A method for producing high-density rare-earth permanent magnet powder according to claim 1, characterized in that the weight increase rate is less than 3.2% in thermogravimetric analysis at 400°C in an air atmosphere.

6. The step of producing a samarium-iron matrix alloy using the aforementioned raw materials is: A method for producing high-density rare-earth permanent magnet powder according to claim 1, characterized by comprising the step of producing a samarium-iron matrix alloy using the aforementioned raw materials by rapid solidification flake technology.

7. The method for producing high-density rare-earth permanent magnet powder according to claim 6, characterized in that, in the step of producing a samarium-iron matrix alloy by rapid solidification flake technology using the raw materials, the rotation speed of the rapid solidification roll is 50 to 80 m / s, and the thickness of the produced samarium-iron matrix alloy is less than 1 mm.

8. The method for producing high-density rare-earth permanent magnet powder according to Claim 1, characterized in that the total energy output in the polishing process is 60 to 80 kJ.

9. A method for producing a high-density, low-loss rare-earth bonded magnet using high-density rare-earth permanent magnet powder, an adhesive, and a processing aid produced by any one of claims 1 to 8, The steps include: mixing high-density rare-earth permanent magnet powder, an adhesive, and a processing aid to obtain a mixture; The process includes the step of processing the mixture by an extrusion or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet. A method for manufacturing high-density, low-loss rare-earth bonded magnets, characterized by the following:

10. The method for producing a high-density, low-loss rare-earth bonded magnet according to claim 9, characterized in that the adhesive comprises at least one of chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyetherimide, polyformaldehyde, and chlorosulfonated polyethylene, and / or comprises at least one copolymer, blend, or polymer alloy formed from at least one of chlorinated polyethylene, polyamide resin, thermoplastic polyimide, liquid crystal polymer, polyphenylene sulfide, polyphenylene ether, polyolefin, modified polyolefin, polycarbonate, polymethyl methacrylate, polyether, polyether ketone, polyetherimide, polyformaldehyde, and chlorosulfonated polyethylene.

11. The method for producing a high-density, low-loss rare-earth bonded magnet according to claim 9, characterized in that the adhesive comprises a thermoplastic elastomer.

12. The method for producing a high-density, low-loss rare-earth bonded magnet according to claim 9, characterized in that the processing aid includes at least one of a coupling agent, a plasticizer, a lubricant, and a flame retardant.

13. The method for producing a high-density, low-loss rare-earth bonded magnet according to claim 12, characterized in that the coupling agent includes a titanate-based coupling agent and / or a silane-based coupling agent.

14. The method for producing a high-density, low-loss rare-earth bonded magnet according to claim 12, characterized in that the plasticizer comprises at least one of dioctyl phthalate DOP, stearate, fatty acid, phosphate ester, benzene polycarboxylic acid ester, and alkyl sulfonic acid ester.

15. The method for producing a high-density, low-loss rare-earth bonded magnet according to claim 12, characterized in that the lubricant comprises at least one of the following: silicone oil, wax, fatty acid, oleic acid, polyester, synthetic ester, carboxylic acid, alumina, silica, and titanium dioxide.

16. The step of processing the mixture by an extrusion or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet is as follows: A method for producing a high-density, low-loss rare-earth bonded magnet according to claim 9, characterized in that, when using an extrusion molding process, the method includes the steps of kneading the mixture in a kneader, heating and melting the mixture, then injecting it into a single-screw extruder with a magnetic field orientation exceeding 8 kOe, extruding it with the single-screw extruder, and then cooling and molding it to obtain a high-density, low-loss rare-earth bonded magnet.

17. The step of processing the mixture by an extrusion or injection molding process in an environment where the magnetic field orientation exceeds 8 kOe to produce a high-density, low-loss rare-earth bonded magnet is as follows: When using an injection molding process, the steps include producing the mixture as mixed pellets using a twin-screw extruder, A method for producing a high-density, low-loss rare-earth bonded magnet according to claim 9, comprising the steps of heating and melting the mixed pellets, then adding them to an injection molding machine with a magnetic field orientation exceeding 8 kOe and injection molding them to obtain a high-density, low-loss rare-earth bonded magnet.

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