Rare earth permanent magnet material with added yttrium and manufacturing process for it

Abstract

Rare-earth permanent magnet material with added yttrium, the chemical formula of which is expressed in mass percent as follows: (YxRe1-x)aFe100-ab-cMbBc, where 0.05 ≤ x ≤ 0.5, 20 ≤ a ≤ 28, 0.5 ≤ b ≤ 2, 0.5 ≤ c ≤ 1.5, where Re is Nd and / or Pr, and where M is Al and / or Nb, where Re is partially replaced by Ce in the material, and the mass content of Ce in Re is 0 to 20%, excluding the value 0.

Description

TECHNICAL AREA

[0001] The present invention relates to the field of rare-earth permanent magnet materials, in particular a rare-earth permanent magnet material with added yttrium and a manufacturing process therefor. STATE OF THE ART

[0002] A rare-earth permanent magnet material is an alloy consisting of a rare-earth metal mixed with samarium and neodymium and a transition metal (such as cobalt, iron, etc.). It is pressed and sintered using a powder metallurgy process and magnetically charged by a magnetic field, thus producing a magnetic material. Since the discovery of NdFeB rare-earth permanent magnet material, it has been used in many fields, such as electronic products, medical devices, the automotive industry, and energy transportation, due to its comprehensive magnetic properties. With continuous technological innovation, the demands on the heat resistance of magnets are constantly increasing. A single NdFeB permanent magnet material can no longer meet these market requirements.With the year-on-year increase in the production and consumption of NdFeB, the raw material neodymium and the commonly used metal dysprosium are also being depleted more rapidly, leading to increased material costs. Therefore, it is necessary to find other rare earth metals that can replace these scarce resources and improve the heat resistance performance of NdFeB, while simultaneously reducing the production costs of permanent magnet materials. This would allow for meeting market demand and achieving a comprehensive and balanced utilization of rare earth resources.

[0003] On the other hand, the extraction of yttrium-bearing or yttrium-rich rare earth ore in southern China means that the elements with high occurrences and reserves in rare earth mines are only being exploited to a limited extent, thus hindering the comprehensive utilization of rare earth resources. Therefore, it is necessary to exploit these abundant rare earth resources to develop new magnetic materials. This involves producing cost-effective permanent magnet materials based on optimizing the magnet composition and the manufacturing process to reduce raw material costs.

[0004] Since the anisotropy field of Y2Fe 14 B is much lower than that of Nd2Fe 14 B, is, the Y2Fe produced according to the conventional manufacturing process can 14 B-magnets do not meet the performance requirements. It is therefore necessary to develop a new type of permanent magnet alloy. However, the tests also show that Y2Fe14 B exhibits a positive coercive force temperature coefficient in a certain temperature range, and at room temperature the Curie temperature is slightly higher than that of NdFeB, indicating that the heat resistance of NdFeB can be improved by using a suitable method with yttrium as an additive.

[0005] Currently, much research is being conducted in this area. CN 1898757A discloses a method for producing a rare-earth permanent magnet material, comprising the following steps: applying a powder comprising one or more components selected from group R 2 -Oxide, R 3 -Fluoride and R 4 -Fluoride on a sintered magnet with R 1 -Fe-B component, where R 1 one or more components selected from the group of Y and Sc, R 2 , R 3 and R 4One or more components selected from the group consisting of Y and Sc are used, wherein a magnetic powder body is heat-treated in a vacuum or in an inert gas at or below a sintering temperature of the magnet. While this invention may contain the rare-earth permanent magnet material yttrium, it does not mention a similar effect of yttrium with other rare-earth metals, such as neodymium or neptunium, which could partially replace the rare-earth metals lacking in NdFeB magnetic materials. CN 103545079A discloses a yttrium-containing double-phase permanent magnet having a formula in weight percent: (Y η re 1-η ) α Fe 100-α-β-γ B β TM γ, where 0.05≤η≤0.6, 29≤α≤33, 0.8≤β≤1.4, 0.5≤γ≤3.6, where Re is one or more elements of Nd, Pr, Dy, Tb, Ho, where TM is one or more elements of Ga, Co, Cu, Nb, Al, where the yttrium-containing double-primary-phase permanent magnet is a double-primary-phase structure with a primary phase (Y, Re)-Fe-B and a primary phase (Nd, Pr)-Fe-B. It is an application of Y in a rare-earth permanent magnet material, but the sintering process is used in its manufacture, which can lead to increased grain size and limits its production.

[0006] CN 102956336A discloses that relatively abundant and inexpensive gadolinium, holmium, and yttrium can partially replace rare earth elements such as neodymium, praseodymium, and dysprosium, resulting in sintered NdFeB with a higher Curie temperature and higher coercivity, improved corrosion resistance, and enhanced operating temperature, toughness, and processability. CN 105788794 discloses a manufacturing process for a permanent magnet with enriched yttrium, in which the ratio of the Y, Fe, and B content is adjusted and Nd and Mn are added, increasing the saturation magnetization and coercivity of the permanent magnet material and thus improving the overall magnetic properties of the permanent magnet material.In CN 102360655A, the addition of yen and ganite (Gd) ensures the coercivity of the magnet by replacing as much expensive neodymium as possible, thereby reducing manufacturing costs. Specifically, the addition of yen and ganite reduces the density of the magnet and improves the processing properties of NdFeB. In CN 104064303A, the introduction of yen and ganite effectively solves a segregation problem in the alloy ingot after melting, a problem caused by different melting points and handling in the conventional melting process. The addition of ganite enhances the thermal stability of the alloy ingot while maintaining the magnetic properties of the permanent magnet material. The addition of yen allows for the partial replacement of ganite and ganite (Pr), enabling the use of a conventional electrolytic furnace and thus reducing production costs.Furthermore, the influence of the permanent magnetic material properties of α-Fe can be avoided. CN 101834045A discloses a sintered NdFeB and a manufacturing process for it, wherein a sintered yttrium-containing NdFeB permanent magnet material is produced using a melting, casting, pulverizing, molding, and sintering process, whereby Nd and Pr can be replaced by a relatively excess Y component, thereby reducing the use of Nd and Pr by 3 to 30%. CN 102982937A discloses a heat-resistant magnetic material and a manufacturing process for it, wherein the NdFeB matrix is ​​neodymium, cobalt, silicon, manganese, boron, and the remainder being iron. Dysprosium iron alloy, samarium iron alloy, and yttrium iron alloy are added to the NdFeB permanent magnet material.

[0007] In the prior art, which encompasses the technology described above, NdFeB permanent magnet material undergoes yttrium doping in its composition and manufacturing process to produce a low-cost rare-earth permanent magnet with good heat resistance. Although yttrium is used as an additive in the prior art, the heat resistance of NdFeB is improved and production costs are reduced. However, many processes inevitably involve the use of large quantities of heavy rare-earth and precious metals, and the process selection often utilizes a sintering process, which does not allow for good control of the grain size and potential α-Fe content during the magnet manufacturing process. PRESENTATION OF THE INVENTION

[0008] Therefore, the present invention is based on the objective of providing a rare-earth permanent magnet material based on yttrium in which the main phase crystal grains are finer and the heat resistance of the magnet is improved.

[0009] To solve the above problem, the following technical solutions are used in the present invention:

[0010] A rare-earth permanent magnet material with added yttrium is provided, the amount of which is expressed in mass percent according to the chemical formula of the material as follows: (Y x re 1-x ) a Fe 100-a-b-c M b B c, where 0.05 ≤ x ≤ 0.5, 20 ≤ a ≤ 28, 0.5 ≤ b ≤ 2, 0.5 ≤ c ≤ 1.5, where Re is Nd and / or Pr, and where M is Al and / or Nb, where x is, for example, 0.07, 0.09, 0.12, 0.15, 0.2, 0.23, 0.27, 0.31, 0.35, 0.4, 0.44, 0.48, etc., where a is, for example, 21, 23, 25, 27, etc., and where b is, for example, 0.8, 1.2, 1.4, 1.6, 1.9, etc., and where c is, for example, 0.8, 1.0, 1.2, 1.4 and the like.

[0011] In practice, x is measured by the atomic percentage of added yttrium in the total rare earth content, i.e., the yttrium content is 5% to 50% of the total rare earth content (the combined amount of Y and Re). The present invention avoids the use of heavy rare earths, thus further reducing costs. Numerous studies have shown that M leads to rapid grain refinement and promotes the formation of an amorphous band. However, the grain size can be further reduced by the addition of Y. The final grain size is thereby significantly reduced, and the presence of yttrium couples the magnetic properties, contributing to improved performance.

[0012] The rare-earth permanent magnet material provided by the invention can offer good magnetic properties, a lower temperature coefficient, and improved temperature resistance. Due to the use of a relatively abundant, light rare-earth element Y instead of Nd and / or Pr, manufacturing costs are also significantly reduced.

[0013] Preferably, the material has a single 2:14:1 phase structure, wherein yttrium constitutes 100% of the main phase.

[0014] Preferably, the material has an average grain size of 30 nm to 45 nm and preferably a standard deviation of 4 to 9. Compared to an average grain size of the initial NdFeB crystal phase of 80-120 nm and a standard deviation of 14-20, the grain size is significantly refined and the shape distribution is more uniform.

[0015] In the invention, the formation of a single main phase structure can be promoted by adding a suitable amount of yttrium. Furthermore, the average grain size of the permanent magnet material is much finer and more uniform than the initial average NdFeB grain size of 80-120 nm. The addition of yttrium also promotes the mutual coupling of phase exchangers, leading to an increase in the magnet's remanence and magnetic energy product.

[0016] Preferably, Re is partially replaced by Ce in the material. The use of Ce with 4f electrons contributes to the anisotropy field and compensates for the decrease in magnetic properties due to the addition of the Y element, thus improving the overall magnetic properties of the magnetic powder. Preferably, the mass content of Ce in Re is 0 to 20%, excluding 0%, which enhances the overall magnetic properties of the magnetic powder.

[0017] Preferably, the mass ratio of Y:Ce is 1-2, for example 1.1, 1.3, 1.5, 1.7, 1.9, etc. By adding Ce and controlling the range of the addition ratio of Y and Ce, the decrease in magnetic properties due to the addition of the Y element can be compensated for and can be achieved for the overall magnetic properties of the magnetic powders.

[0018] Preferably, the yttrum element is incorporated into a neodymium-iron-boron magnet using a manufacturing process for nanocrystalline bonded permanent magnet material, thereby significantly improving the magnet's corrosion resistance and thermal stability, thus increasing the heat resistance of the existing magnetic material. The permanent magnet material of the present invention undergoes a magnet manufacturing process. After thermal demagnetization at 120 °C for 100 h, the irreversible magnetic flux loss is less than 2%, preferably less than 1%.

[0019] Another object of the present invention is to provide a method for producing a rare-earth permanent magnet material with added yttrium, comprising the following steps:

[0020] (1) According to the present invention, the permanent magnet material is composed as follows: it is melted into a block, which is melted at high temperature and then cast into a rotating roll and subjected to rotational quenching to obtain a quenched thin strip.

[0021] (2) Heat treatment and quenching of the product in the step ( 1 ) obtained thin band, which is then pulverized into alloy powder.

[0022] (3) Bonding of the in the step ( 2 ) obtained alloy powder with a binder to obtain a permanent magnet material.

[0023] The known patent CN 103545079A describes a sintering process for producing a double main phase alloy, in which the property after the addition of yttrium is mainly described, wherein the addition of yttrium is carried out by the doping process and a magnetic bonding manufacturing process is carried out so that all yttrium elements enter the main phase, whereby the modification of the crystal grains (refinement of the crystal grains) is carried out, whereby it is found that the material produced by this process increases the coupling between the soft and the hard magnetic phase and generates an increased effect of residual magnetization.

[0024] The rare earth required for the production of the raw material is a single rare earth metal or a rare earth metal mixed in a specific ratio.

[0025] Preferably, the melting is carried out in a step ( 1) Vacuum melting.

[0026] Preferably, the melting temperature is 100 to 300°C above the melting point of the raw material used to produce the quenched strip, for example, 105°C, 115°C, 130°C, 150°C, 180°C, 210°C, 250°C, 270°C, 290°C, and so on. The raw material here refers to rare earth elements, with iron elements and NbFe / BFe alloys being melted at their maximum melting point by checking their melting point 100 to 300°C above the melting point.

[0027] Preferably, the casting process is carried out by means of a high-vacuum single-roll rotary quenching process.

[0028] Preferably the speed of the rotary quenching roller is 15 to 45 m / s, for example 17 m / s, 20 m / s, 24 m / s, 28 m / s, 33 m / s, 36 m / s, 40 m / s, 44 m / s, etc.

[0029] Preferably, the cooling rate of the rotary quenching cooling is 10 5 up to 10 6 °C / s, for example 3*10 5 , 5*10 5 , 7*10 5, 9*10 5 etc. and the alloy exhibits solidification at a high growth rate with a high degree of subcooling (from 1 to 100 cm / s or more).

[0030] With varying wheel speeds in the quenching process, the cooling rate also varies, and consequently, so do the microstructure, thermodynamics, and kinetics of the solidification system. At low wheel speeds, α-Fe precipitates. If the wheel speed is too high, the atomic spatial arrangement of the amorphous ribbon changes significantly with increasing cooling wheel speed, resulting in a decrease in Bs and Hc, respectively. In practice, the alloy melt is rapidly cooled by the preferred wheel speed (cooling rate 10⁻⁶). 5 up to 10 6K / s), or the heterogeneous nucleation phenomenon during the cooling process is suppressed, so that the alloy has a solidification of a high growth rate at a high degree of undercooling (from 1 to 100 cm / s or more) and thus an amorphous or nanocrystalline metastable quenched ribbon is obtained by rapid solidification.

[0031] In one embodiment, high-temperature melting involves melting the raw material at a temperature of 100 to 300 °C above the melting point of the raw material of the quenched thin strip, wherein the roller speed is 15 to 45 m / s, and wherein, in the step of rotary quenching and cooling, the cooling rate is 10 5 up to 10 6 °C / s.

[0032] Preferably the temperature of the heat treatment in step ( 2) 600 to 800 °C, for example 630 °C, 660 °C, 700 °C, 730 °C, 760 °C, 790 °C etc., wherein the heat treatment time is 5 to 15 min, for example 7 min, 9 min, 11 min, 13 min etc.

[0033] The quenched thin ribbon is a disordered material, containing a large number of amorphous structures with numerous defects, such as dislocations and vacancies. Therefore, effective heat treatment of the quenched sample is necessary to improve the material's magnetic properties. Obtaining a nanocrystalline material of uniform size requires a large amount of nucleation of the alloy from a disordered amorphous state within a short time. Thermodynamic experiments show that the crystallization time is short, generally 5 to 15 minutes, with a heat treatment temperature of 600 to 800 °C, which is advantageous for achieving a large number of nucleations within a short time.

[0034] Preferably, quenching is carried out by water-cooled quenching, whereby the heat-treated alloy is immersed in cold water.

[0035] Preferably the quenching time is 30 to 60 min, for example 35 min, 40 min, 45 min, 50 min, 54 min, 58 min etc.

[0036] Quenching is a crucial step in the crystallization process, directly impacting the organization and properties of the sample after crystallization. During cooling, the rate should exceed the critical cooling rate to ensure a stable alloy microstructure, while the quenching time should be sufficient to cool the alloy sample adequately, thus preventing grain growth and potential surface oxidation.

[0037] Preferably, the alloy powder has an average grain size of 100 nm to 200 nm, for example 110 nm, 125 nm, 140 nm, 150 nm, 160 nm, 173 nm, 180 nm, 190 nm, etc. The quenched thin strip can be reduced in size to alloy powder with an average grain size of 100 nm to 200 nm by coarse crushing and grinding.

[0038] Preferably the binder is in the step ( 3 ) an epoxy resin.

[0039] Preferably, the binder is used in an amount of 0.5 to 2 wt.%, for example 0.7 wt.%, 0.9 wt.%, 1.2 wt.%, 1.5 wt.%, 1.8 wt.% etc. of the alloy powder.

[0040] Preferably, the bonding process is as follows: mixing the alloy powders with the solution in which the binder is dissolved, and evaporating the solvent to obtain a permanent magnet material. After evaporation of the solvent, the product can be further ground to obtain a permanent magnet powder.

[0041] In the bonding process described above, epoxy resin is used as a binder to coat the surface of the alloy powders (rapidly quenched magnetic powders). This coating not only isolates oxygen but also prevents oxidation of the magnet, thereby reducing the loss of irreversible magnetic flux to some extent. It also partially improves heat resistance.

[0042] Preferably, the organic solvent is one or a combination of two or more of ethanol, toluene, xylene, and acetone. The purpose of the organic solvent is to improve the volatility of the epoxy resin binder, preferably acetone, and to ensure safety and environmental friendliness.

[0043] The adhesive can be a different type of epoxy resin adhesive, such as one or a combination of two or more of E51, E44, and E12, and other low-melting-point alloys, such as MnBi adhesive, which is used to modify the magnet's properties. The metallic element is a zinc binder.

[0044] In one embodiment, the bonding process is as follows: using an epoxy resin as a binder, dissolving it in acetone, preparing an epoxy resin-acetone solution, slowly pouring the alloy powders into this epoxy resin-acetone solution, and then stirring until the acetone has completely evaporated. The permanent magnet material is obtained by grinding.

[0045] Advantageously, the procedure includes the following steps:

[0046] (1) Components: The raw materials with the composition (Y x re 1-x ) a Fe 100-a-b-c M b B c are produced, wherein 0.05 ≤ x ≤ 0.5, 20 ≤ a ≤ 28, 0.5 ≤ b ≤ 2, 0.5 ≤ c ≤ 1.5, where Re is one or more of Nd and Pr, and where M is one or more of Al and / or Nb, where the content of each of the above elements is a weight content.

[0047] (2) Rapid quenching strip: Vacuum melting of the prepared raw materials into a block and using the high vacuum single twisting process to melt the obtained mother alloy block at high temperature and then cast into a rotating roll and subject to rotational quenching to obtain a quenched thin strip.

[0048] High-temperature melting of the raw material at a temperature of 100 to 300 °C above the melting point of the raw material of the quenched strip, wherein the roller speed is 15 to 45 m / s, and wherein in the step of rotary quenching and cooling the cooling rate is 10 5 up to 10 6 The temperature is °C / s. The alloy exhibits solidification at a high growth rate with a high degree of subcooling (from 1 to 100 cm / s or more).

[0049] With varying quenching speeds, the cooling rate also varies, influencing the microstructure, thermodynamics, and kinetics of the solidification system. At low wheel speeds, α-Fe is precipitated. If the wheel speed is too high, the atomic spatial arrangement of the amorphous ribbon changes significantly with increasing cooling roll speed, resulting in a decrease in Bs and Hc. In practice, the alloy melt is rapidly cooled by the preferred wheel speed (cooling rate 10⁻⁶). 5 up to 10 6 K / s), or the heterogeneous nucleation phenomenon during the cooling process is suppressed, so that the alloy has a solidification of a high growth rate at a high degree of undercooling (from 1 to 100 cm / s or more) and thus an amorphous or nanocrystalline metastable quenched ribbon is obtained by rapid solidification.

[0050] (3) Heat treatment: The heat treatment temperature is 600 to 800 °C and the heat treatment time is 5 to 15 minutes.

[0051] The quenched thin ribbon is a disordered material containing a large number of amorphous structures with numerous defects, such as dislocations and vacancies. Therefore, effective heat treatment of the quenched sample is necessary to improve the material's magnetic properties. Obtaining a nanocrystalline material of uniform size requires a large amount of nucleation of the alloy from a disordered amorphous state within a short time. Thermodynamic experiments show that the crystallization time is short, generally 5 to 15 minutes.

[0052] (4) Water-cooled quenching: In quenching, the alloy is immersed in cold water after heat treatment, with a quenching time of 30 to 60 minutes.

[0053] Cooling is a crucial step in the crystallization process, directly impacting the organization and properties of the sample after crystallization. During cooling, the rate should exceed the critical cooling rate to ensure a stable alloy microstructure, while the quenching time should be sufficient to cool the alloy sample adequately, thus preventing grain growth and potential surface oxidation.

[0054] The quenched thin strip is reduced in size to alloy powder with an average grain size of 100 nm to 200 nm by coarse crushing and grinding.

[0055] (5) Preparation of the powders mixed with binder: Using an epoxy resin as a binder, dissolving it in acetone, preparing an epoxy resin-acetone solution, slowly pouring the alloy powders into the epoxy resin-acetone solution and then stirring until the acetone has completely evaporated. The permanent magnet material is obtained by grinding.

[0056] The amount of epoxy resin in the step ( 5 The binder content is 0.5 to 2 wt% of the quenched magnetic powders. The powders, mixed with the binder, are coated with the epoxy resin as a coating layer to cover the surface of the quenched magnetic powders. This coating not only isolates oxygen but also prevents oxidation of the magnet, thereby reducing the loss of irreversible magnetic flux to some extent. Heat resistance is also improved.

[0057] The invention provides a Y-cerium nanocrystal-bonded magnetic powder and a manufacturing process therefor, wherein the alloy is melted by a high-vacuum single-roll quenching process and sprayed onto a rotating high-speed roller to rapidly cool the alloy melt (cooling rate 10 5 up to 10 6to suppress the heterogeneous nucleation phenomenon during the cooling process (K / s), resulting in a solidification of the alloy with a high growth rate at a high degree of undercooling (from 1 to 100 cm / s or more) and yielding a thin ribbon with fine grains or even an amorphous structure. The ribbon is then crushed and heat-treated, and subsequently produced into an isotropic composite magnet. The grain size can be effectively refined in the experimental preparation process.The manufactured magnet has a single 2:14:1 main phase structure, and the resulting permanent magnet, after thermal demagnetization at 120 °C for 100 h, has a non-reversible magnetic flux loss of less than 2%, with the average grain size of the Y-Cer nanocrystal bonded magnetic powder being 30 nm to 45 nm and a standard deviation of 4 to 9, thus effectively preventing grain growth during the bonding process and achieving a high-performance permanent magnet material with a nanocrystalline structure.

[0058] In the invention, relatively surplus and inexpensive rare-earth yttrium and cerium are used instead of Nd and Pr in NdFeB, whereby the main phase crystal is refined and good magnetic properties are maintained by controlling the ratio of rare-earth elements such as yttrium, cerium and neodymium and by adding a suitable amount of Nb and Al elements, so that the rare-earth elements are integrated and balanced and the manufacturing costs of the magnet are greatly reduced. List of characters Fig. Figure 1 is a TEM image of a permanent magnet material with an alloy composition (Nd (Pr)) 25 Fe bal M 1,2 B 0,8 (wt%). Fig. Figure 2 is a TEM image of a yttrium-containing permanent magnet material with an alloy composition (Y 0,2 Nd (Pr) 0,8 ) 25 Fe bal M 1,2 B 0,8 (wt%). DETAILED DESCRIPTION

[0059] To better understand the contents of the present invention, the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments of the invention. These show: Example 1

[0060] The permanent magnet material produced in this embodiment has the following alloy composition: Permanent magnet (Y 0,1 (Nd, Pr, Ce) 0,9 ) 27 Fe bal M 1,45 B1 (where M is Al and Nb) (wt%), the specific steps are as follows: (1) Production of a parent alloy with the above alloy composition, wherein the mass percentage of Nd, Pr and Ce in the raw material is 70:20:10 and the phase forms of M and B are, respectively, an iron alloy with an iron content of 35% and 80%. Y is added in the form of a pure metal and the remaining amount is mixed with pure iron metal. The NdFeB rare-earth permanent magnet material is then produced using the following process steps. (2) The prepared raw materials are placed in a vacuum arc furnace to be melted uniformly. The current is switched off until the alloying liquid has cooled to obtain a mother alloy block. The produced block is placed in a high-vacuum single-twist quenching device and melted at high temperature, then cast into a rotating roll and subjected to rotational quenching and cooling at a rate of 3*10 5 The steel is cooled in K / s. The quenching process is carried out under a protective atmosphere, and the molten steel is sprayed onto a roller rotating at a wheel speed of 20 m / s to obtain a quenched thin strip. (3) Heat treatment of the above-mentioned quenched strip, wherein the heat treatment temperature is 750 °C and the heat treatment time is 15 minutes. (4) Hydrating the quenching zone obtained after the above heat treatment for 30 min, crushing and grinding it into alloy powder with an average particle size of 100 nm. (5) Weighing epoxy resin in an amount of 1 wt% of the selected magnetic powders, dissolving it in acetone to prepare an epoxy resin-acetone solution. The preferred quenched magnetic powder mentioned above is slowly poured into an epoxy resin-acetone solution and stirred until the acetone has completely evaporated, the mixture being crushed to obtain the powder mixed with binder. Zinc stearate (surface lubricant, which facilitates demolding) is added in an amount of 0.05 wt% of the powder mixed with binder, the mixture being blended uniformly to form a block which is mechanically pressed into a pellet in a specified shape. The pellet is placed in an oven for curing, the heat treatment being carried out at 150°C for 1 h to obtain a yttrium-containing NdFeB-bonded permanent magnet material.

[0061] The magnetic properties of the test magnet are measured and shown in Table 1. Table 1 shows the magnetic properties of the yttrium-containing NdFeB-bonded permanent magnet material of example 1. Nominal composition (wt%) Br Hcj (BH) max Average grain size of the crystal Deviation of grain size Magnetic flux loss at 120°C for 100h (Yo,i(Nd, Pr, Ce) 0,9 ) 27 Fe bal M 1,45 B1 6.64 kg 12.05KOe 9.08MGOe 34.65nm 8,73 1,4% Example 2

[0062] The permanent magnet material produced in this embodiment has the following alloy composition: Permanent magnet (Y 0,2 (Nd, Pr, Ce)0.8) 25 Fe bal M 1,2 B 0,8 (where M is Nb) (wt%), the specific steps are as follows: (1) Production of a parent alloy with the above alloy composition, wherein the mass percentage of Nd, Pr and Ce in the raw material is 70:20:10 and the phase forms of M and B are each an iron alloy with an iron content of 35% and 80%, respectively. Y is added in the form of a pure metal and the remaining amount is mixed with pure ferrous metal. (2) The prepared raw materials are placed in a vacuum arc furnace to be melted uniformly. The current is switched off until the alloying liquid has cooled to obtain a mother alloy ingot. The produced ingot is placed in a high-vacuum single-twist quenching device and melted at high temperature, then cast into a rotating roll and subjected to rotational quenching and cooling at a rate of 8*10 5 The steel is cooled in kJ / s. The quenching process is carried out under a protective atmosphere, and the molten steel is sprayed onto a roller rotating at a wheel speed of 30 m / s to obtain a quenched thin strip. (3) Heat treatment of the above-mentioned quenched strip, wherein the heat treatment temperature is 700 °C and the heat treatment time is 12 minutes. (4) Hydrating the quenching zone obtained after the above heat treatment for 40 min, crushing and grinding it into alloy powder with an average particle size of 150 nm. (5) Weighing epoxy resin in an amount of 0.8 wt% of the selected magnetic powders, dissolving it in acetone to prepare an epoxy resin-acetone solution. The preferred quenched magnetic powder mentioned above is slowly poured into an epoxy resin-acetone solution and stirred until the acetone has completely evaporated, the mixture being crushed to obtain the powder mixed with binder. Zinc stearate is added in an amount of 0.05 wt% of the powder mixed with binder, the mixture being blended uniformly to form a block which is mechanically pressed into a pellet in a specified shape. The pellet is placed in an oven for curing, the heat treatment being carried out at 150°C for 1 h to obtain a yttrium-containing NdFeB-bonded permanent magnet material.

[0063] The magnetic properties of the test magnet are measured and shown in Table 2. Table 2 shows the magnetic properties of the yttrium-containing NdFeB-bonded permanent magnet material of embodiment 2. Nominal composition (wt%) Br Hcj (BH) max Average grain size of the crystal Deviation of grain size Magnetic flux loss at 120°C for 100h (Y 0,2 (Nd, Pr, Ce) 0,8 ) 25 Fe bal M 1,2 B 0,8 6.74 kg 9.85KOe 8.76MGOe 38.44nm 4,62 1,3%

[0064] Fig. Figure 1 represents the TEM without yttrium at the beginning. According to a statistical calculation of the grain size, an average grain size of 85.57 nm and a standard deviation of 15.74 nm are obtained. Fig. Figure 2 shows the TEM image of the magnet after the addition of yttrium in this embodiment. For the statistical calculation of the grain size, an average grain size of 38.44 nm and a standard deviation of 4.62 nm are obtained.

[0065] By comparing the grain size of two TEM images, it can be seen that the addition of yttrium leads to grain refinement of the bound magnet, with the grain size being significantly refined after the addition of yttrium and the standard deviation being reduced, indicating that the morphology distribution becomes more uniform. Example 3

[0066] The permanent magnet material produced in this embodiment has the following alloy composition: Permanent magnet (Y 0,5 (Nd, Pr, Ce) 0,5 ) 28 Fe bal M 1,4 B 1,5 (where M is Nb) (wt%), the specific steps are as follows: (1) Production of a parent alloy with the above alloy composition, wherein the mass percentage of Nd, Pr and Ce in the raw material is 70:20:10 and the phase forms of M and B are each an iron alloy with an iron content of 35% and 80%, respectively. Y is added in the form of a pure metal and the remaining amount is mixed with pure ferrous metal. (2) The prepared raw materials are placed in a vacuum arc furnace to be melted uniformly. The current is switched off until the alloying liquid has cooled to obtain a mother alloy block. The produced block is placed in a high-vacuum single-twist quenching device and melted at high temperature, then cast into a rotating roll and subjected to rotational quenching and cooling at a rate of 4*10 5The steel is cooled in kJ / s. The quenching process is carried out under a protective atmosphere, and the molten steel is sprayed onto a roller rotating at a wheel speed of 25 m / s to obtain a quenched thin strip. (3) Heat treatment of the above-mentioned quenched strip, wherein the heat treatment temperature is 730 °C and the heat treatment time is 13 minutes. (4) Hydrating the quenching zone obtained after the above heat treatment for 50 min, reducing it to alloy powder with an average particle size of 200 nm by coarse crushing and grinding. (5) Weighing epoxy resin in an amount of 1.2 wt% of the selected magnetic powders, dissolving it in acetone to prepare an epoxy resin-acetone solution. The preferred quenched magnetic powder mentioned above is slowly poured into an epoxy resin-acetone solution and stirred until the acetone has completely evaporated, the mixture being crushed to obtain the powder mixed with binder. Zinc stearate is added in an amount of 0.05 wt% of the powder mixed with binder, the mixture being blended uniformly to form a block which is mechanically pressed into a pellet in a specified shape. The pellet is placed in an oven for curing, the heat treatment being carried out at 150°C for 1 h to obtain a yttrium-containing NdFeB-bonded permanent magnet material.

[0067] The magnetic properties of the test magnet are measured and shown in Table 3. Table 3 shows the magnetic properties of the yttrium-containing NdFeB-bonded permanent magnet material of embodiment 3. Nominal composition (wt%) Br Hcj (BH) max Average grain size of the crystal Deviation of grain size Magnetic flux loss at 120°C for 100h (Y 0,5 (Nd, Pr, Ce) 0,5 ) 28 Fe bal M 1,4 B 1,5 6.55 kg 10.84KOe 8.30MGOe 43.40nm 6,45 1,2% Examples 4-6

[0068] The procedures are carried out according to the method of embodiment 1, except that the composition and operating conditions are as shown in Table 4, with the results of the magnetic properties obtained by testing the product being shown in Table 5. Table 4 shows the composition and manufacturing conditions of the permanent magnet materials of embodiments 4-6. Nominal composition (wt%) Mass ratio of Nd, Pr, Ce Example 4 (Y 0,05 (Nd, Pr, Ce) 0,95 ) 20 Fe bal Al 0,5 B 0,5 60:20:20 Example 5 (Y 0,3 (Nd, Pr, Ce) 0,7 ) 26 Fe bal Al2B 1,5 75:20:5 Example 6 (Y 0,3 (Nd, Pr, Ce) 0,7 ) 23 Fe bal Nb 1,2 B 0,8 65:20:15 Continuation of Table 4 Cooling rate of rotational quenching (°C / s) Rolling rate of the rotary quenching (m / s) Heat treatment conditions (°C, min) Deterrence time (min) Average grain size of the alloy powder (nm) Amount of added epoxy resin (wt%) Example 4 2*10 5 15 800, 5 60 150 0,5 Example 5 10 6 30 600, 10 50 100 1 Example 6 5*10 5 45 700, 15 35 200 2 Table 5 shows the magnetic properties of the NdFeB-bonded permanent magnet materials of embodiments 4 to 6. Br / KGs Hcj / KOe (BH)max / MGOe Average grain size of the crystal / nm Deviation of grain size Magnetic flux loss at 120°C for 100h Example 4 6,98 10,65 8,73 44,78 4,56 1,5% Example 5 6,54 10,76 8,21 36,64 12,67 1,9% Example 6 6,62 11,40 8,39 40,36 7,44 1,8%

[0069] As can be seen from the exemplary embodiments above, the examples described above of the present invention achieve the following technical effects: In the present invention, the amount of Nd(Pr, Ce), Fe, and B is modified, whereby the rare-earth permanent magnet material Nd(Pr)FeB is produced by combining the elements Y and Ce with the conventional rare-earth permanent magnet material, exhibiting an average grain size of 30 to 45 nm and a standard deviation of 4.62. In contrast, the average grain size of the initial NdFeB crystal phase is 80 to 120 nm and the standard deviation is 14 to 20. This results in a significantly refined grain and a more uniform morphology distribution. With good magnetic properties, the temperature coefficient is lower and the temperature resistance is improved.Due to the replacement of Nd, Pr by the relatively common light rare earth elements Y, Ce, production costs are also greatly reduced. Comparative example 1

[0070] Same as in embodiment 1, except that the mass ratio of Nd, Pr, Ce is 60:10:30, with the Ce mass percentage exceeding 20%. Comparative example 2

[0071] Same as in embodiment 1, except that the composition (Y 0,1 (Nd, Pr, Ce) 0,9 ) 32 Fe bal M 1,45 B1 is. Comparative example 3

[0072] Same as in embodiment 1, except that the composition (Y 0,1 (Nd, Pr, Ce) 0,9 ) 20 FC bal M 1,45 B1 is. Comparative example 4

[0073] Same as in embodiment 1, except that the cooling rate of the rotary quenching is 10 4 °C / s. Comparative example 5

[0074] Same as in embodiment 1, except that the cooling rate of the rotary quenching is 10 7 °C / s. Comparative example 6

[0075] Same as in embodiment 1, except that the rotational quenching roller speed is 10m / s. Comparative example 7

[0076] Same as in embodiment 1, except that the rotational quenching roller speed is 55m / s. Comparative example 8

[0077] Same as in embodiment 1, except that the heat treatment conditions are 500°C for 25 minutes. Comparative example 9

[0078] Same as in embodiment 1, except that the heat treatment conditions are 900 °C for 3 min. Comparative example 10

[0079] Same as in embodiment 1, except that the quenching time is 20 minutes. Comparative example 11

[0080] Same as in embodiment 1, except that the quenching time is 80 minutes. Comparative example 12

[0081] Same as in embodiment 1, except that the average grain size of the alloy powder is 50nm. Comparative example 14

[0082] Same as in embodiment 1, except that the average grain size of the alloy powder is 300nm. Comparative example 15

[0083] Same as in embodiment 1, except that the amount of epoxy resin added is 0.3 wt. %. Comparative example 16

[0084] Same as in embodiment 1, except that the amount of epoxy resin added is 3 wt. %,.

[0085] The test results of the magnetic properties of the permanent magnet materials produced in comparison examples 1 to 16 are shown in the following Table 6. Table 6 Magnetic properties of NdFeB-bonded permanent magnet materials of comparison examples 1 to 16 Br / KGs Hcj / KOe (BH)max / MGOe Average grain size of the crystal / nm Deviation of grain size Magnetic flux loss at 120 ℃ for 100h Comparative example 1 5,78 7,84 6,10 52,07 50,09 2,1% Comparative example 2 5,82 7,96 6,45 62,88 48,16 2,3% Comparative example 3 4,37 7,22 6,62 54,68 50,31 2,5% Comparative example 4 4,68 7,84 6,76 48,89 51,37 2,5% Comparative example 5 4,73 7,96 6,58 52,24 51,16 2,3% Comparative example 6 4,67 7,22 6,23 54,71 50,40 2,5% Comparative example 7 4,73 7,84 6,47 52,15 56,12 2,8% Comparative example 8 4,95 7,96 6,40 55,27 53,17 2,4% Comparative example 9 5,16 7,22 6,23 69,87 48,23 2,2% Comparative example 10 4,63 7,84 6,40 50,42 50,30 2,7% Comparative example 11 4,80 7,96 6,45 74,12 50,31 2,5% Comparative example 12 4,96 7,2 6,59 60,25 50,23 2,6% Comparative example 13 5,08 7,84 6,24 57,23 48,12 2,4% Comparison example 14 4,98 7,96 6,44 67,25 51,15 2,6% Comparative example 15 5,42 7,22 6,32 54,68 49,30 2,4% Comparative example 16 5,29 7,22 6,68 49,23 48,78 2,3%

[0086] From a comparison of the product properties in Table 6 with the properties of the exemplary embodiments, it is evident that the comprehensive magnetic properties of the manufactured permanent magnet material are significantly reduced if the raw material composition or content, grain size and the like, and the manufacturing process parameters are not within the scope of the present invention.

[0087] It is obvious that the embodiments described above are merely illustrative examples and do not limit the present invention. People skilled in the art in this field can conceive of various modifications and alterations based on the foregoing description. A complete listing of all embodiments is neither necessary nor possible. Any obvious modifications or alterations derived therefrom are covered by the scope of protection of the present invention. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 1898757 A

[0005] CN 103545079 A [0005, 0023] CN 102956336 A

[0006] CN 105788794

[0006] CN 102360655 A

[0006] CN 104064303 A

[0006] CN 101834045 A

[0006] CN 102982937 A

[0006]

Claims

[1] Rare-earth permanent magnet material with added yttrium, the chemical formula of which is expressed in mass percent as follows: (Y x re 1-x ) a Fe 100-a-b-c M b B c , where 0.05 ≤ x ≤ 0.5, 20 ≤ a ≤ 28, 0.5 ≤ b ≤ 2, 0.5 ≤ c ≤ 1.5, where Re is Nd and / or Pr, and where M is Al and / or Nb. [2] Material according to claim 1, characterized by , that the material has a single phase structure of 2:14:1, with yttrium comprising 100% of the main phase. [3] Material according to claim 1 or 2, characterized by that the material has an average grain size of 30 nm to 45 nm and preferably a standard deviation of 4 to 9. [4] Material according to any one of claims 1 to 3, characterized by, that Re is partially replaced by Ce in the material, wherein preferably the mass content of Ce in Re is 0 to 20%, excluding the value 0. [5] Material according to any one of claims 1 to 4, characterized by , that the mass ratio of Y:Ce is 1 to 2. [6] Material according to any one of claims 1 to 5, characterized by , that the yttrum element is incorporated into a neodymium-iron-boron magnet using a manufacturing process for nanocrystalline bonded permanent magnet material. [7] Method for producing a rare-earth permanent magnet material with added yttrium according to any one of claims 1 to 6, comprising the following steps: (1) Preparation of the raw materials according to the composition of the permanent magnet material according to any one of claims 1 to 6; melting into a block; then the block is melted at high temperature and then cast into a rotating roll and then cooled by rotational quenching to obtain a quenched thin strip; (2) Heat treatment of the strip obtained in step (1) followed by quenching, and then pulverizing to alloy powder; (3) Bonding the alloy powders obtained in step (2) with a binder to obtain a permanent magnet material. [8] Method according to claim 7, characterized by , that the melting in step (1) is vacuum melting; wherein preferably the melting temperature is 100 to 300°C above the melting point of the raw material for the production of the quenched thin strip; wherein preferably the casting is carried out by a high-vacuum single-roll rotary quenching process; wherein preferably the speed of the rotary quenching roller is 15 to 45 m / s; wherein preferably the cooling rate of the rotary quenching cooling 10 5 up to 10 6 ℃ / s. [9] Method according to claim 7 or 8, characterized by , that the temperature of the heat treatment in step (2) is 600 to 800 °C, with the heat treatment time being 5 to 15 min; wherein quenching is preferably carried out by water cooling quenching; where preferably the quenching time is 30 to 60 minutes; wherein preferably the alloy powder has an average grain size of 100 nm to 200 nm. [10] Method according to any one of claims 7 to 9, characterized by , that the binder in step (3) is an epoxy resin; wherein the binder is used in an amount of 0.5 to 2 wt.% of the alloy powder; wherein preferably the bonding process proceeds as follows: mixing the alloy powders with the solution in which the binder is dissolved, and evaporating the solvent to obtain a permanent magnet material; wherein preferably the organic solvent is one or a combination of two or more from ethanol, toluene, xylene and acetone, and preferably is acetone.