A magnet material, a method for manufacturing the same, and a samarium-cobalt magnet material

Abstract

The application discloses a magnet material, a preparation method thereof and a samarium-cobalt magnet material. The preparation method of the magnet material comprises the following steps: hydrogen absorption, airflow grinding, press forming, hydrogen blowing, dehydrogenation and decarburization reaction and sintering of an alloy sheet; a compact is obtained after the press forming; hydrogen is contained in an atmosphere for the airflow grinding treatment; when the hydrogen blowing treatment is performed, the mass ratio of the compact to hydrogen is 10:(0.5-1), and the hydrogen flow is 0.05-0.2 kg / h; the dehydrogenation and decarburization reaction is performed under the condition that the temperature is continuously raised to T, and T is 580-720 DEG C; the continuous temperature rising comprises a first stage and a second stage; the first stage is that the temperature is raised from T0 to T1, and T1 is 400-500 DEG C; the second stage is that the temperature is raised from T1 to T. The carbon content of the magnet material prepared by the application is 50-300 ppm, and the magnet material can further improve the coercive force while maintaining a high remanence.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of magnet materials and its preparation method and samarium-cobalt magnet material. BACKGROUND

[0002] At present, Sm2Co 17 The carbon content of permanent magnet material is generally above 700 ppm, and the carbon element mainly exists in the form of ZrC and FeC3 in the matrix phase. Since the introduction of carbon element consumes Fe element providing remanence and Zr element improving coercivity, too high carbon content will lead to the decrease of remanence and coercivity of the magnet. It is found that the high Fe content samarium-cobalt magnet is more sensitive to carbon content, and the preparation of high magnetic energy product samarium-cobalt magnet above 32 MGOe must increase the Fe content, so reducing the carbon content in the magnet is a very effective means for preparing high magnetic energy product samarium-cobalt material.

[0003] However, the existing technology has limited degree of reducing carbon content, and there is a lack of a method capable of greatly reducing carbon content. SUMMARY

[0004] The present application mainly aims to overcome the defects that the residual carbon element in the magnet material cannot be effectively removed in the prior art, and provides a magnet material and its preparation method and samarium-cobalt magnet material. The carbon content of the product obtained by the present application is 50-300 ppm, compared with the magnet prepared by the conventional process with carbon content above 700 ppm, the remanence is increased by 0.05-0.15 kGs, the coercivity is increased by 3-6 kOe, and the higher the Fe content of the formula, the greater the performance improvement.

[0005] The main sources of carbon content of sintered magnet are two, i.e. micro amount of plastic particles and carbon residue of organic additives introduced due to high speed friction of powder and pipeline in the airflow milling process. It is found in the experiment that these carbon-containing substances are difficult to completely volatilize in the sintering process, and will decompose to produce carbon black when the temperature exceeds 400℃. The free carbon has high activity and will have carburizing reaction with Fe and Zr elements to form carbide, which cannot be volatilized under the conventional sintering conditions and finally remains in the magnet and reduces the magnetic performance.

[0006] The inventor found through repeated experiments that after hydrogen absorption treatment, hydrogen is introduced in the airflow milling process, combined with the hydrogen blowing treatment of specific hydrogen flow and hydrogen mass, and the dehydrogenation and decarburization reaction, the carbon content in the magnet material can be reduced to below 300 ppm, which is much lower than the level of the prior art. For example, if the hydrogen flow or the mass content of hydrogen is too low during the hydrogen blowing treatment, the carbon content in the final magnet material cannot be significantly reduced.

[0007] The present application mainly solves the above technical problems through the following technical solutions.

[0008] The application provides a preparation method of a magnet material, which comprises the following steps:

[0009] The alloy sheet is sequentially subjected to hydrogen absorption treatment, airflow mill treatment, press forming, hydrogen blowing treatment, dehydrogenation decarburization reaction and sintering treatment; the press forming obtains a compact;

[0010] The airflow mill treatment is carried out in a hydrogen-containing atmosphere;

[0011] During the hydrogen blowing treatment, the mass ratio of the compact to hydrogen gas used in the hydrogen blowing treatment is 10:(0.5-1); during the hydrogen blowing treatment, the flow rate of hydrogen gas is 0.05-0.2 kg / h;

[0012] The dehydrogenation decarburization reaction is carried out under the condition of continuously heating to T ℃, wherein T ℃ is 580-720 ℃;

[0013] The continuous heating comprises a first stage and a second stage;

[0014] The first stage is heating from T0 to T1 ℃, wherein T0 is less than T1, and T1 ℃ is 400-500 ℃;

[0015] The second stage is heating from T1 ℃ to T ℃;

[0016] The atmosphere in the first stage is vacuum and / or inert atmosphere;

[0017] The atmosphere in the second stage contains hydrogen gas, and the volume ratio of the hydrogen gas to all the gases in the atmosphere in the second stage is 5-10%.

[0018] In the application, the preparation method of the alloy sheet can be conventional in the art, and the alloy sheet is preferably prepared by one or more of the following methods: melt spinning, centrifugal casting and ingot casting. If the alloy sheet is a magnet material obtained after sintering, the magnet material is easy to break during the hydrogen absorption operation.

[0019] In the application, the alloy sheet can be a samarium-cobalt alloy sheet and / or a neodymium-iron-boron alloy sheet, and is preferably a samarium-cobalt alloy sheet.

[0020] When the alloy sheet contains the samarium-cobalt alloy sheet, the samarium-cobalt alloy sheet preferably comprises the following components: Sm 23.0-26 wt.%, Cu 4.0-6 wt.%, Fe 17-20 wt.%, Zr 2.0-3.5 wt.% and Co 45-49 wt.%, wherein wt.% is the mass percentage of each component in the total mass of the samarium-cobalt alloy sheet.

[0021] In a preferred embodiment of the application, the alloy sheet consists of: Sm 26 wt.%, Fe 17 wt.%, Cu 5.5 wt.%, Zr: 3.5 wt.%, the balance being Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet.

[0022] In a preferred embodiment of the application, the alloy sheet consists of: Sm 24 wt.%, Fe 18 wt.%, Cu 4 wt.%, Zr 3 wt.%, the balance being Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet.

[0023] In a preferred embodiment of the application, the alloy sheet consists of: Sm 24 wt.%, Fe 19 wt.%, Cu 5.5 wt.%, Zr: 2 wt.%, the balance being Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet.

[0024] In a preferred embodiment of the application, the alloy sheet consists of: Sm 25.8 wt.%, Fe 19.5 wt.%, Cu 5.5 wt.%, Zr: 3.5 wt.%, the balance being Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet.

[0025] In a preferred embodiment of the application, the alloy sheet consists of: Sm 26 wt.%, Fe 20 wt.%, Cu 5.5 wt.%, Zr: 3.5 wt.%, the balance being Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet.

[0026] When the alloy sheet comprises a neodymium iron boron alloy sheet, the alloy sheet can be conventional in the art, for example comprising: Nd 28-30 wt.%, Cu 0.1-0.2 wt.%, Co 1-2 wt.%, Zr 0.1-0.3 wt.%, B 0.9-1 wt.% and the balance Fe, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet.

[0027] The neodymium iron boron alloy sheet, for example, consists of: Pr 1 wt.%, Nd 29 wt.%, Dy 0.9 wt.%, Al 0.1 wt.%, B 0.9 wt.%, Cu 0.16 wt.%, Co 1.5 wt.%, Zr 0.18 wt.%, Ga 0.2 wt.%, the balance being Fe, wt.% being the percentage of the mass of each component to the total mass of the neodymium iron boron alloy sheet.

[0028] In the present application, the hydrogen gas used in the preparation method of the magnet material can be the meaning commonly understood in the art, generally refers to pure hydrogen, can be hydrogen with a purity of more than 98% or more than 99%, for example 99.9%. The density of the hydrogen gas can be conventional in the art, generally 0.0899 kg / m 3 .

[0029] In the present application, the process of hydrogen absorption treatment can be conventional in the art.

[0030] Preferably, the temperature of the hydrogen absorption treatment is 100-250℃, for example 150℃ or 200℃.

[0031] Preferably, the pressure of the hydrogen absorption treatment is 0.1-0.5 MPa, for example 0.3 MPa or 0.4 MPa.

[0032] Preferably, the time of the hydrogen absorption treatment is 2-5h, for example 3h.

[0033] In the present application, preferably, no dehydrogenation treatment is performed after the hydrogen absorption treatment and before the jet mill treatment. The dehydrogenation treatment can be the meaning commonly understood in the art, generally refers to removing hydrogen elements in the main phase hydride by heating.

[0034] In the present application, the process of jet mill treatment can be conventional in the art, generally crushing the material to a powder with a D50 of 4-6um.

[0035] In the present application, preferably, nitrogen is used as the grinding gas during the jet mill treatment. The nitrogen generally refers to nitrogen with a purity of more than 99.9%.

[0036] In the present application, generally, coarse crushing and medium crushing are also performed in the art after the hydrogen absorption treatment and before the jet mill treatment.

[0037] In the present application, during the jet mill treatment, the hydrogen gas contained in the atmosphere of the jet mill treatment can be introduced during the jet mill treatment, and the concentration of the introduced hydrogen gas is preferably 50-200ppm, for example 100ppm or 150ppm, ppm being the volume concentration. The volume concentration refers to the ratio of the volume of the introduced hydrogen gas to the total volume of the grinding gas and the hydrogen gas during the jet mill treatment. If the concentration of the introduced hydrogen gas is too high during the jet mill treatment, the powder compression performance will decrease, it is difficult to achieve qualified green density during the compression process, and finally the density of the magnet material will be low and the remanence will be low.

[0038] In the present application, the compression molding can be conventional in the art, generally compression molding in a magnetic field.

[0039] The press forming is preferably oriented press forming in a constant magnetic field of 1.5-2T.

[0040] In the application, the hydrogen blowing treatment adopts a specific flow rate and a specific hydrogen mass, so that the flow of hydrogen blows away part of the volatile organic additives in the green compact, and the green compact adsorbs a specific content of H2.

[0041] In the application, the content of hydrogen in the magnet obtained after the hydrogen blowing treatment is preferably less than 3500ppm, and if the content of hydrogen in the magnet after the hydrogen blowing treatment is too high, the magnet after the sintering treatment will have a risk of cracks.

[0042] In the application, the mass of the green compact to the mass of hydrogen used in the hydrogen blowing treatment is preferably 10:(0.6-1), for example 10:0.8.

[0043] The hydrogen blowing treatment of the application is, for example, continuously supplying hydrogen into a closed container in which the green compact is placed, and when the mass of the green compact is 10kg and the flow rate of hydrogen is 0.1kg / h, the aeration time is 5-10h.

[0044] In the application, the flow rate of hydrogen in the hydrogen blowing treatment is preferably 0.08-0.12kg / h, for example 0.1kg / h.

[0045] In the application, the hydrogen used in the hydrogen blowing treatment can be recycled under the condition of being equipped with a purification device, so as to save cost.

[0046] In the application, the time of the hydrogen blowing treatment is preferably 5-10h, for example 6h or 8h.

[0047] In the application, the dehydrogenation and decarburization reaction is preferably carried out under the condition of continuously heating to 600-700℃.

[0048] In the application, T0 is preferably 150-200℃.

[0049] In the application, the heating rate of the first stage is preferably greater than the heating rate of the second stage.

[0050] In the application, the heating rate of the first stage is preferably 0.5-1℃ / min, for example 0.6℃ / min or 0.7℃ / min. It is found in experiments that when the heating rate of the first stage is in this range, the impurities such as organic additives can be completely removed, the amount of carbide generated is small, and thus the best removal effect is achieved.

[0051] In the present application, the temperature increasing rate of the second stage is preferably 0.1-0.5℃ / min, for example 0.2℃ / min or 0.3℃ / min. It has been found in experiments that the temperature increasing rate of the second stage in this range can make the decarburization reaction proceed thoroughly, and achieve the best carbon removal effect.

[0052] In the present application, the atmosphere of the first stage is preferably vacuum. The vacuum atmosphere of the first stage is more conducive to the removal of impurities such as organic additives. The second stage is a slow dehydrogenation decarburization stage, which mainly removes carbon-containing organic solvents. The vacuum is generally achieved by vacuum pumping. It has been found in experiments that if the atmosphere of the first stage contains hydrogen, the removal efficiency of impurities such as organic additives will be reduced, the generation of carbides will be increased, and thus the decarburization efficiency will be affected.

[0053] In the present application, the inert atmosphere in the first stage can be the commonly understood meaning in the art, for example argon.

[0054] In the present application, the second stage is a hydrogenation decarburization stage. The atmosphere of the second stage is preferably a mixed gas, which generally also contains an inert gas, and the inert gas is preferably argon. The atmosphere of the second stage (i.e. hydrogen and inert gas) is preferably introduced at the beginning of the second stage (the beginning of the introduction in the present application is preferably hydrogen introduced at 400-500℃), and the atmosphere is preferably replaced every 20-30min to make the reaction C+2H2→CH4 proceed to the right. If hydrogen is introduced at a temperature greater than 500℃ in the second stage, the generation of carbides will be increased, and thus the decarburization effect will be affected, and the carbon content cannot be effectively reduced to below 300ppm.

[0055] In the present application, the volume concentration of hydrogen in the atmosphere of the second stage is preferably 6-10%. For example, 7% or 9%, the volume concentration refers to the ratio of the volume of hydrogen in the atmosphere of the second stage to the total volume of the atmosphere.

[0056] In the present application, the ratio of hydrogen in the atmosphere of the second stage to the mass of the green compact is preferably (0.5-1):10, for example 0.6:10, 0.7:10, 0.8:10 or 0.9:10.

[0057] In the present application, the inflation pressure of the second stage is preferably 0.05-0.2MPa, for example 0.1MPa. The inflation pressure is generally the gas pressure of the mixed gas (hydrogen and inert atmosphere) in the sintering furnace, which is given by the sintering furnace pressure gauge reading.

[0058] In the process, the H2 adsorbed by the blank itself in the first few processes, especially in the hydrogen absorption treatment, also begins to be removed. The H2 removed from the interior of the material is more likely to have a decarburization reaction with the carbon decomposed from the carbon-containing substance, thereby removing almost all the residual carbon, reducing the carbon content of the magnet, and the decarburization reaction is C+2H2→CH4. The purpose of the process is to slowly release the hydrogen adsorbed in the interior of the magnet, prevent the sample from cracking or even breaking due to a large amount of dehydrogenation in a short time, and further help the decarburization process to be more thorough. In the dehydrogenation and decarburization reaction, the decarburization reaction and the dehydrogenation reaction are carried out at the same time, but after the temperature reaches T1 ℃, the hydrogen adsorbed in the interior of the magnet has been mostly released, so a small amount of hydrogen needs to be filled to further continue the decarburization reaction, so that the carbon content is further reduced.

[0059] In the present application, the first stage further includes a pretreatment stage, which is preferably heating from T0' to T0, wherein T0' is 0-40℃, for example 25-30℃.

[0060] Preferably, the heating rate of the pretreatment stage is 4-6℃ / min, for example 5℃ / min.

[0061] Preferably, the pretreatment stage is carried out in a vacuum state.

[0062] In the present application, the dehydrogenation and decarburization reaction and the sintering treatment are carried out in the same reactor, for example a sintering furnace.

[0063] In the present application, in order to directly carry out the sintering treatment after the dehydrogenation and decarburization reaction, after the dehydrogenation and decarburization reaction is completed, the temperature is preferably continued to be raised to the temperature of the sintering treatment. The temperature of the sintering treatment can be conventional in the art, generally 4-6℃ / min, for example 5℃ / min.

[0064] In the present application, after the decarburization reaction and before the sintering treatment, a vacuum extraction operation is preferably carried out until the temperature in the reaction container is raised to the temperature of the sintering treatment.

[0065] In the present application, the process of the sintering treatment can be conventional in the art.

[0066] Preferably, the gas atmosphere of the sintering treatment is an inert gas, for example argon. The argon is generally argon with a purity of more than 99.9%.

[0067] Preferably, the temperature of the sintering treatment is 1200-1220℃, for example 1210℃ or 1215℃.

[0068] Preferably, the time of the sintering treatment is 2-5h, for example 3h.

[0069] In the present application, the sintering treatment is preferably followed by a solid solution treatment and an aging treatment in sequence.

[0070] The temperature of the solid solution treatment is preferably 1140-1190℃, for example 1160℃ or 1170℃.

[0071] The time of the solid solution treatment is preferably 1-40h, for example 10h, 20h or 30h.

[0072] The temperature of the aging treatment is preferably 800-900℃, for example 830℃, 850℃ or 860℃.

[0073] The time of the aging treatment is preferably 5-40h, for example 20h.

[0074] The aging treatment is generally followed by a cooling operation.

[0075] The temperature of the cooling operation can be 350-450℃, for example 400℃.

[0076] The rate of the cooling operation to the temperature of the cooling operation can be 0.5-1℃ / min, for example 0.7℃ / min.

[0077] The holding time of the cooling operation can be 2-6h, for example 3h or 4h.

[0078] The present application also provides a magnet material prepared by the above method.

[0079] The present application also provides a samarium-cobalt magnet material comprising the following components:

[0080] Sm: 23.0-26wt.%;

[0081] Cu: 4.0-6wt.%;

[0082] Fe: 17-20wt.%;

[0083] Zr: 2.0-3.5wt.%;

[0084] Co: 45-49wt.%; wt.% is the percentage of the mass of each component to the total mass of the samarium-cobalt magnet material;

[0085] The carbon content in the samarium-cobalt magnet material is below 300ppm.

[0086] In the present application, the content of Sm can be 24-26wt.%, for example 25.8wt.%.

[0087] In the present application, the content of Cu can be 4-5wt.%.

[0088] In the present application, the content of Fe can be 18-20 wt.%, for example 19 wt.% or 19.5 wt.%.

[0089] In the present application, the content of Zr can be 2.5-3.5 wt.%, for example 3 wt.%.

[0090] In a preferred embodiment of the present application, the Sm-Co magnet material is composed of the following components: Sm 26 wt.%, Fe 17 wt.%, Cu 5.5 wt.%, Zr 3.5 wt.%, and the balance being Co; the carbon content in the Sm-Co magnet material is 300 ppm.

[0091] In a preferred embodiment of the present application, the Sm-Co magnet material is composed of the following components: Sm 24 wt.%, Fe 18 wt.%, Cu 4 wt.%, Zr 3 wt.%, and the balance being Co; the carbon content in the Sm-Co magnet material is 225 ppm.

[0092] In a preferred embodiment of the present application, the Sm-Co magnet material is composed of the following components: Sm 24 wt.%, Fe 19 wt.%, Cu 5.5 wt.%, Zr 2 wt.%, and the balance being Co; the carbon content in the Sm-Co magnet material is 158 ppm.

[0093] In a preferred embodiment of the present application, the Sm-Co magnet material is composed of the following components: Sm 25.8 wt.%, Fe 19.5 wt.%, Cu 5.5 wt.%, Zr 3.5 wt.%, and the balance being Co; the carbon content in the Sm-Co magnet material is 108 ppm.

[0094] In a preferred embodiment of the present application, the Sm-Co magnet material is composed of the following components: Sm 26 wt.%, Fe 20 wt.%, Cu 5.5 wt.%, Zr 3.5 wt.%, and the balance being Co; the carbon content in the Sm-Co magnet material is 50 ppm.

[0095] On the basis of common knowledge in the art, the above-mentioned preferred conditions can be combined arbitrarily, thereby obtaining preferred examples of the present application.

[0096] The reagents and raw materials used in the present application are commercially available.

[0097] The positive progress effect of the present application is that the preparation method of the magnet material of the present application can effectively remove the residual carbon elements in the magnet material, and the carbon content in the finally prepared magnet material is below 300 ppm. Compared with the magnet prepared by the conventional process, the carbon content of which is above 700 ppm, the remanence can be increased by 0.05-0.15 kGs, the coercive force can be increased by 3-6 kOe, and the performance improvement range is larger for the formula with higher Fe content. BRIEF DESCRIPTION OF DRAWINGS

[0098] Figure 1 Figure 1 shows the temperature rising curve of the dehydrogenation and decarburization reaction to the sintering process in Example 1. DETAILED DESCRIPTION

[0099] The present application will be further described by way of examples, but the present application is not limited to the examples described. The experimental methods in the following examples, for which no specific conditions are mentioned, are selected according to the conventional methods and conditions, or according to the instructions of the commercial products.

[0100] The purity of the hydrogen used in the following Examples 1 to 6 and Comparative Examples 1 to 8 is 99.9%, and the density is 0.0899 kg / m3. 3 The temperature at room temperature is 25 to 30°C.

[0101] Example 1

[0102] 1. The raw materials were prepared according to the alloy sheet composition in Table 1, and the cast ingot or ribbon was prepared by melt preparation using the strip casting method, centrifugal casting or ingot casting.

[0103] 2. Hydrogen absorption treatment

[0104] The obtained cast ingot or ribbon was subjected to hydrogen absorption treatment at a temperature of 100°C, a hydrogen pressure of 0.2 MPa and for a time of 2 h, and was directly cooled to room temperature after the hydrogen absorption was completed, without dehydrogenation treatment.

[0105] 3. Jet mill treatment

[0106] The hydrogen-absorbed samarium-cobalt cast ingot or ribbon was subjected to jet mill treatment after coarse crushing and medium crushing to obtain a powder having an average particle size of 4 to 6 μm, wherein high-purity N2was used as the grinding gas during the jet mill treatment, and 50 ppm of H2was simultaneously added to the gas circuit.

[0107] 4. Press forming and hydrogen blowing treatment

[0108] The obtained powder was oriented and press formed in a constant magnetic field having a magnetic field strength of 1.5 ≦ B ≦ 2 T, and the 10 kg press compact after the forming was placed in a sealed container and continuously supplied with flowing H2at a flow rate of 0.1 kg / h for a time of 5 h.

[0109] 5. Dehydrogenation and decarburization reaction and sintering treatment

[0110] The press compact after the hydrogen blowing treatment was subjected to dehydrogenation and decarburization reaction in a vacuum sintering furnace, and the process parameters were as follows:

[0111] Pretreatment stage: room temperature to 150°C, temperature rising rate 5°C / min, vacuum pumping;

[0112] First stage: 150-400℃, temperature increasing rate is 1℃ / min, vacuumizing;

[0113] Second stage: 400-600℃, temperature increasing rate is 0.5℃ / min; stop vacuumizing when reaching 400℃, and fill in 5% volume concentration of H2 / Ar mixed gas, filling pressure is 0.1MPa; as Figure 1 The figure shows the temperature increasing curve during the dehydrogenation and decarburization reaction and sintering process in this embodiment, Figure 1 T1 is 150℃, T2 is 400℃, and T3 is 600℃.

[0114] After the dehydrogenation and decarburization reaction, continue vacuumizing, and start temperature increasing to sintering stage, sintering temperature is 1200℃, after reaching the temperature, pass in high purity inert atmosphere to sinter, sintering time is 2h; solid solution temperature is 1140℃, and solid solution time is 1h.

[0115] 6, aging treatment

[0116] After sintering the blank, vacuum aging treatment is carried out, aging treatment is 800℃ for 5h, and then decrease to 400℃ at a rate of 0.7℃ / min for 2h.

[0117] Example 2

[0118] 1, according to the alloy sheet component allocation in Table 1, cast ingot or ribbon sheet is prepared by using strip casting, centrifugal casting or ingot casting.

[0119] 2, hydrogen absorption treatment

[0120] The obtained cast ingot or ribbon sheet is subjected to hydrogen absorption treatment, hydrogen absorption temperature is 100℃, hydrogen pressure is 0.2MPa, and time is 3h, after the hydrogen absorption is finished, it is directly cooled to room temperature, and no dehydrogenation treatment is carried out;

[0121] 3, jet mill treatment

[0122] After the hydrogen absorption, the samarium-cobalt cast ingot or ribbon sheet is subjected to coarse crushing and medium crushing, and then the powder with an average particle size of 4-6um is prepared by using jet mill, wherein high purity N2 is used as grinding gas during the jet mill process, and 100ppm of hydrogen is supplemented in the gas circuit at the same time;

[0123] 4, pressing forming and hydrogen blowing treatment

[0124] The obtained powder is oriented and pressed in a constant magnetic field with a magnetic field strength satisfying 1.5≦B≦2T, and the 10kg pressed blank after forming is placed in a sealed container, and flowing hydrogen is continuously passed in, the flow rate is 0.1kg / h, and the time is 6h.

[0125] 5, dehydrogenation and decarburization reaction and sintering treatment

[0126] The green compact after hydrogen blowing treatment is first subjected to dehydrogenation and decarburization reaction in a vacuum sintering furnace, and the process parameters are as follows:

[0127] Pretreatment stage: room temperature ~ 150℃, heating rate 5℃ / min, vacuum pumping;

[0128] First stage: 150~400℃, heating rate 1℃ / min, vacuum pumping;

[0129] Second stage: 400~600℃, heating rate 0.5℃ / min; stop vacuum pumping when reaching 400℃, and fill in 5% volume concentration of H2 / Ar mixed gas, with a filling pressure of 0.1MPa;

[0130] After the dehydrogenation and decarburization reaction, continue vacuum pumping and start heating to the sintering stage, with a sintering temperature of 1200℃, and after reaching the temperature, introduce high-purity inert atmosphere sintering, with a sintering time of 3h; solid solution temperature is 1160℃, and solid solution time is 10h.

[0131] 6. Aging treatment

[0132] The sintered blank is subjected to vacuum aging treatment, with an aging process of 830℃ for 10h, and then cooled to 400℃ at a cooling rate of 0.7℃ / min for 3h.

[0133] Example 3

[0134] 1. Prepare raw materials according to the alloy sheet component allocation in Table 1, and prepare cast ingots or ribbon sheets by melt casting or ingot casting.

[0135] 2. Hydrogen absorption treatment

[0136] The obtained cast ingot or ribbon sheet is subjected to hydrogen absorption treatment, with a hydrogen absorption temperature of 150℃, a hydrogen pressure of 0.5MPa, and a time of 5h, and after the hydrogen absorption is completed, it is directly cooled to room temperature without dehydrogenation treatment.

[0137] 3. Jet mill treatment

[0138] After the hydrogen absorption of the samarium-cobalt cast ingot or ribbon sheet, coarse crushing and medium crushing are performed, and then a jet mill is used to obtain a powder with an average particle size of 4-6um, wherein high-purity N2 is used as the grinding gas during the jet mill process, and 100ppm of hydrogen is supplemented in the gas circuit.

[0139] 4. Pressing, hydrogen blowing treatment

[0140] The obtained powder is oriented and pressed in a constant magnetic field with a magnetic field strength meeting 1.5≦B≦2T, and the 10kg green compact after forming is placed in a sealed container and continuously introduced with flowing hydrogen, with a flow rate of 0.1kg / h and a time of 8h.

[0141] 5. Dehydrogenation and decarburization, sintering treatment

[0142] The green compact after hydrogen blowing treatment is first treated by dehydrogenation and decarburization heat treatment process in a vacuum sintering furnace, and the specific process parameters are as follows:

[0143] Pretreatment stage: room temperature ~ 200°C, heating rate 5°C / min, vacuum pumping;

[0144] First stage: 200~500°C, heating rate 0.7°C / min, vacuum pumping;

[0145] Second stage: 500~700°C, heating rate 0.3°C / min; stop vacuum pumping when reaching 400°C, and fill in 7% volume concentration of H2 / Ar mixed gas, with a filling pressure of 0.1 MPa;

[0146] After the dehydrogenation and decarburization reaction is completed, vacuum pumping is continued, and heating to the sintering stage is started, with a sintering temperature of 1210°C, and after reaching the temperature, high-purity inert atmosphere sintering is carried out, with a sintering time of 3h; the solid solution temperature is 1170°C, and the solid solution time is 20h.

[0147] 6. Aging treatment

[0148] The sintered blank is subjected to vacuum aging treatment, with an aging process of 850°C for 20h, and then cooled to 400°C at a cooling rate of 0.7°C / min for 3h.

[0149] Example 4

[0150] 1. Raw materials are prepared according to the alloy sheet composition in Table 1, and cast ingots or ribbon sheets are prepared by melt spinning, centrifugal casting or ingot casting.

[0151] 2. Hydrogen absorption treatment

[0152] The obtained cast ingot or ribbon sheet is subjected to hydrogen absorption treatment, with a hydrogen absorption temperature of 200°C, a hydrogen pressure of 0.5 MPa, and a time of 5h, and after the hydrogen absorption is completed, it is directly cooled to room temperature without dehydrogenation treatment.

[0153] 3. Jet mill treatment

[0154] After the hydrogen-absorbed samarium-cobalt cast ingot or ribbon sheet is coarsely and mediumly broken, a powder with an average particle size of 4-6um is prepared by jet milling, wherein high-purity N2 is used as the grinding gas during the jet milling process, and 150ppm of hydrogen is simultaneously added in the gas circuit.

[0155] 4. Pressing, hydrogen blowing treatment

[0156] The obtained powder was oriented and pressed into shape in a constant magnetic field with a magnetic field strength of 1.5≦B≦2T. The 10kg pressed blank was placed in a sealed container and continuously circulated with flowing hydrogen gas at a flow rate of 0.1kg / h for 10h.

[0157] 5. Dehydrogenation and decarburization reaction, sintering treatment

[0158] The pressed compact after hydrogen blowing treatment is first subjected to a dehydrogenation and decarburization heat treatment process in a vacuum sintering furnace. The specific process parameters are as follows:

[0159] Pretreatment stage: room temperature to 200℃, heating rate of 5℃ / min, vacuuming;

[0160] First stage: 200~500℃, heating rate is 0.5℃ / min, vacuuming;

[0161] Second stage: 500~700℃, heating rate is 0.2℃ / min; when the temperature reaches 400℃, stop the vacuuming and fill with 9% volume concentration of H2 / Ar mixed gas at a filling pressure of 0.1MPa.

[0162] After the dehydrogenation and decarbonization reaction is completed, vacuum is continued and the temperature is raised to the sintering stage. The sintering temperature is 1215℃. After reaching the temperature, a high-purity inert atmosphere is introduced for sintering, and the sintering time is 4 hours. The solution temperature is 1180℃ and the solution time is 30 hours.

[0163] 6. Timeliness processing

[0164] The sintered blank was subjected to vacuum aging treatment. The aging process involved holding at 860℃ for 40 hours, followed by cooling to 400℃ at a rate of 0.7℃ / min and holding for 4 hours.

[0165] Example 5

[0166] 1. Prepare raw materials according to the alloy sheet composition in Table 1, and prepare ingots or strip sheets by melting using the strip casting method, centrifugal casting or ingot casting method.

[0167] 2. Hydrogen absorption treatment

[0168] The resulting ingots or strips were subjected to hydrogen absorption treatment at a temperature of 250°C and a hydrogen pressure of 0.5 MPa for 5 hours. After the hydrogen absorption was completed, the ingots were directly cooled to room temperature without any dehydrogenation treatment.

[0169] 3. Air jet milling treatment

[0170] After hydrogen absorption, samarium cobalt ingots or strips are coarsely and mediumly crushed, and then milled into powder with an average particle size of 4-6 μm using air jet milling. High-purity N2 is used as the grinding gas during the air jet milling process, and 200 ppm of hydrogen is added to the gas path at the same time.

[0171] 4. Press forming, hydrogen blowing treatment

[0172] The obtained powder is oriented and press formed in a constant magnetic field with a magnetic field strength of 1.5 ≦ B ≦ 2T, and the 10kg green compact after forming is placed in a sealed container and continuously supplied with flowing hydrogen at a flow rate of 0.1kg / h for 10h.

[0173] 5. Dehydrogenation and decarburization reaction, sintering treatment

[0174] The green compact after hydrogen blowing treatment is first subjected to dehydrogenation and decarburization heat treatment in a vacuum sintering furnace, and the specific process parameters are as follows:

[0175] Pretreatment stage: room temperature ~ 200℃, heating rate 5℃ / min, vacuum pumping;

[0176] First stage: 200~500℃, heating rate 0.5℃ / min, vacuum pumping;

[0177] Second stage: 500~700℃, heating rate 0.1℃ / min; vacuum pumping is stopped when reaching 400℃, and 10% volume concentration of H2 / Ar mixed gas is filled, with a filling pressure of 0.1MPa;

[0178] After the dehydrogenation and decarburization reaction is completed, vacuum pumping is continued, and heating to the sintering stage is started, with a sintering temperature of 1220℃, and after reaching the temperature, high-purity inert atmosphere sintering is carried out, with a sintering time of 5h; the solid solution temperature is 1190℃, and the solid solution time is 40h.

[0179] 6. Aging treatment

[0180] The sintered blank is subjected to vacuum aging treatment, with an aging process of 900℃ for 5h, and then cooled to 400℃ at a cooling rate of 0.7℃ / min for 6h.

[0181] Example 6

[0182] 1. Raw materials are prepared according to the alloy sheet composition in Table 1, and neodymium-iron-boron ribbon is prepared by melt spinning.

[0183] 2. Hydrogen absorption treatment

[0184] The obtained ribbon is subjected to hydrogen absorption treatment, with a hydrogen absorption temperature of 300℃, a hydrogen pressure of 0.1MPa, and a time of 5h, and after the hydrogen absorption is completed, it is directly cooled to room temperature without dehydrogenation treatment.

[0185] 3. Airflow mill treatment

[0186] The hydrogen-absorbed neodymium-iron-boron ribbon is coarsely and medium broken, and then a powder with an average particle size of 4-5 um is prepared by using an air flow mill, wherein high-purity N2 is used as a grinding gas in the air flow mill process, and 100 ppm of hydrogen is supplemented in the gas circuit.

[0187] 4. Press forming and hydrogen blowing treatment

[0188] The obtained powder is oriented and press formed in a constant magnetic field with a magnetic field strength of 1.5 ≦ B ≦ 2T, and the 10 kg green compact after forming is placed in a sealed container, and flowing hydrogen is continuously introduced with a flow rate of 0.1 kg / h for 10 h.

[0189] 5. Dehydrogenation and decarburization reaction and sintering treatment

[0190] The green compact after the hydrogen blowing treatment is first subjected to a dehydrogenation and decarburization heat treatment process in a vacuum sintering furnace, and the specific process parameters are as follows:

[0191] Pretreatment stage: room temperature ~ 200°C, heating rate 5°C / min, vacuum pumping;

[0192] First stage: 200-500°C, heating rate 0.5°C / min, vacuum pumping;

[0193] Second stage: 500-700°C, heating rate 0.1°C / min; stop vacuum pumping when reaching 400°C, and fill in 10% volume concentration of H2 / Ar mixed gas, with a filling pressure of 0.1 MPa;

[0194] After the dehydrogenation and decarburization reaction is completed, vacuum pumping is continued, and the temperature is raised to the sintering stage, with a sintering temperature of 1060°C, and after reaching the temperature, high-purity inert atmosphere is introduced for sintering, with a sintering time of 5 h; after sintering is completed, the temperature is cooled to room temperature.

[0195] 6. Aging treatment

[0196] The sintered blank is subjected to vacuum aging treatment, and the aging process is 900°C for 5 h, and then rapidly cooled to room temperature, and then heated to 500°C for 3 h, and then rapidly cooled to room temperature after completion.

[0197] Comparative Example 1

[0198] 1. The raw materials are prepared according to the alloy sheet component allocation in Table 1, and cast ingots or ribbon strips are prepared by using a ribbon casting method, centrifugal casting or ingot casting.

[0199] 2. The obtained samarium-cobalt cast ingot or ribbon strip is directly coarsely and medium broken, and then a powder with an average particle size of 4-6 um is prepared by using an air flow mill, wherein high-purity N2 is used as a grinding gas in the air flow mill process.

[0200] 4. The obtained powder is oriented and compacted in a constant magnetic field with a magnetic field strength of 1.5 ≦ B ≦ 2T.

[0201] 5. The green compact is first treated by a normal dewaxing heat treatment process in a vacuum sintering furnace, and the specific process parameters are as follows: heating at a rate of 5°C / min to 500°C and maintaining for 1h, then heating at a rate of 5°C / min to the sintering stage, and the subsequent sintering, solid solution, aging and other treatment processes are consistent with those of Example 1.

[0202] Comparative Example 2

[0203] Except that 1% volume concentration of H2 / Ar mixed gas is filled in the second stage of the dehydrogenation and decarburization reaction, the rest is consistent with Example 2.

[0204] Comparative Example 3

[0205] Except that the cast ingot or the spun ribbon is not subjected to hydrogen absorption treatment, the rest of the steps is consistent with Example 3.

[0206] Comparative Example 4

[0207] Except that the green compact is not subjected to hydrogen blowing treatment and is directly sintered, the rest of the steps is consistent with Example 4.

[0208] Comparative Example 5

[0209] Except that the dehydrogenation and decarburization process is not used, but a conventional dewaxing process is used, the rest of the steps is consistent with Example 5. The conventional dewaxing process is the same as that of Comparative Examples 1 and 2.

[0210] Comparative Example 6

[0211] Except that hydrogen is not supplemented during the jet milling process, the rest of the steps is consistent with Example 5.

[0212] Comparative Example 7

[0213] Except that 30% volume concentration of H2 / Ar mixed gas is filled in the second stage of the dehydrogenation and decarburization reaction, the rest of the steps is consistent with Example 5. 2 / Ar mixed gas, the rest of the steps is consistent with Example 5.

[0214] The alloy sheet composition and part of the process settings in Examples 1-6 and Comparative Examples 1-8 are shown in Table 1.

[0215] Table 1

[0216]

[0217]

[0218] Note: The hydrogen content in the magnet after hydrogen blowing treatment in Examples 1-6 is less than 3500ppm.

[0219] 2. Measurement of magnetic properties and carbon content

[0220] The magnetic properties of the magnet materials prepared in Examples 1-6 and Comparative Examples 1-8 were measured at 20°C using a pulse field magnetometer (PFM), and the samples had the following dimensions: cylinder, and the carbon content was measured using a carbon analyzer. The results are shown in Table 2 below.

[0221] Table 2

[0222]

[0223] Comparing the magnetic properties and carbon content of Example 1 and Comparative Example 1, it can be seen that the remanence and coercivity of the magnet prepared using the carbon reduction process of the present application are significantly improved, and the carbon content is reduced from more than 700 ppm to less than 300 ppm. Comparing Examples 2 and 5 with Comparative Examples 2 and 7, it can be seen that too low a concentration of H2 in the H2 / Ar mixture supplied in the second stage of the dehydrogenation and decarburization reaction will reduce the decarburization efficiency, and too high a concentration will easily cause the sample to absorb hydrogen and crack, and will also have an adverse effect on the furnace fittings. Comparing Example 5 with Comparative Example 5, it can be seen that when the blank contains a large amount of hydrogen and the removal atmosphere contains hydrogen, not using the dehydrogenation and decarburization process of the present application will reduce the carbon content to some extent, but will easily cause a large amount of hydrogen to be released and will eventually cause the sample to crack. It was also found in the experiment that when the hydrogen flow or the mass content of hydrogen is higher than in the present application, the compact will crack after the sintering treatment, and a qualified magnet material cannot be obtained. Comparing the other examples and comparative examples, it can be seen that the hydrogen absorption treatment, the additional hydrogen in the air jet milling treatment, and the hydrogen blowing treatment of the compact all make a significant contribution to reducing the carbon content, and the ingot hydrogen absorption treatment is the most important. This is because the ingot hydrogen absorption is the main measure for increasing the hydrogen content in the blank.

Claims

1. A method of producing a magnet material, characterized by, It comprises the following steps: The alloy sheet is sequentially subjected to hydrogen absorption treatment, airflow milling treatment, press forming, hydrogen blowing treatment, dehydrogenation decarburization reaction and sintering treatment; the press forming obtains a compact; The alloy sheet is a samarium-cobalt alloy sheet or a neodymium-iron-boron alloy sheet; wherein the samarium-cobalt alloy sheet comprises the following components: Sm 23-26 wt.%, Cu 4.0-6 wt.%, Fe 17-20 wt.%, Zr 2.0-3.5 wt.% and Co 45~49 wt.%, wt.% being the percentage of the mass of each component to the total mass of the samarium-cobalt alloy sheet; wherein the neodymium-iron-boron alloy sheet comprises the following components: Nd 28~30 wt.%, Cu 0.1~0.2 wt.%, Co 1~2 wt.%, Zr 0.1~0.3 wt.%, B 0.9~1 wt.% and the balance of Fe, wt.% being the percentage of the mass of each component to the total mass of the neodymium-iron-boron alloy sheet; No dehydrogenation treatment is performed after the hydrogen absorption treatment and before the airflow milling treatment; The atmosphere of the airflow milling treatment contains hydrogen; During the hydrogen blowing treatment, the mass ratio of the compact to the hydrogen gas used in the hydrogen blowing treatment is 10:(0.5~1); during the hydrogen blowing treatment, the flow rate of the hydrogen gas is 0.05~0.2 kg / h; The dehydrogenation decarburization reaction is performed under the condition of continuously heating to T ℃, wherein T ℃ is 580~720 ℃; The continuous heating comprises a first stage and a second stage; The first stage is heating from T0 to T1 ℃, wherein T0 is less than T1, and T1 ℃ is 400~500 ℃; The second stage is heating from T1 ℃ to T ℃; The atmosphere of the first stage is vacuum and / or inert atmosphere; The atmosphere of the second stage contains hydrogen, and the volume ratio of the hydrogen to the total volume of all gases in the atmosphere of the second stage is 5~10%.

2. The method of producing a magnet material according to claim 1, wherein The alloy sheet is prepared by one or more of the following processes: tape casting, centrifugal casting and ingot casting.

3. The method of producing a magnet material according to claim 1, wherein The alloy sheet is composed of the following components: Sm 26 wt.%, Fe 17 wt.%, Cu 5.5 wt.%, Zr: 3.5 wt.%, and the balance of Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet; Alternatively, the alloy sheet is composed of the following components: Sm 24 wt.%, Fe 18 wt.%, Cu 4 wt.%, Zr 3 wt.%, and the balance of Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet; Alternatively, the alloy sheet is composed of the following components: Sm 24 wt.%, Fe 19 wt.%, Cu 5.5 wt.%, Zr: 2 wt.%, and the balance of Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet; Alternatively, the alloy sheet is composed of the following components: Sm 25.8 wt.%, Fe 19.5 wt.%, Cu 5.5 wt.%, Zr: 3.5 wt.%, and the balance of Co, wt.% being the percentage of the mass of each component to the total mass of the alloy sheet; Alternatively, the alloy piece is composed of the following components: Sm 26wt.%, Fe 20wt.%, Cu 5.5wt.%, Zr: 3.5wt.%, and the balance being Co, wt.% being the percentage of the mass of each component to the total mass of the alloy piece; Alternatively, the alloy piece is composed of the following components: Pr 1wt.%, Nd 29wt.%, Dy 0.9wt.%, Al 0.1wt.%, B 0.9wt.%, Cu 0.16wt.%, Co 1.5wt.%, Zr 0.18wt.%, Ga 0.2wt.%, and the balance being Fe, wt.% being the percentage of the mass of each component to the total mass of the alloy piece.

4. The method of producing a magnet material according to claim 1, wherein The temperature of the hydrogen absorption treatment is 100-250℃; And / or, the pressure of the hydrogen absorption treatment is 0.1-0.5MPa; And / or, the time of the hydrogen absorption treatment is 2-5h; And / or, the hydrogen gas contained in the atmosphere of the jet mill treatment is introduced during the jet mill treatment; And / or, the press forming is performed in a magnetic field.

5. The method of producing a magnet material according to claim 4, wherein The temperature of the hydrogen absorption treatment is 150℃ or 200℃; And / or, the pressure of the hydrogen absorption treatment is 0.3MPa or 0.4MPa; And / or, the time of the hydrogen absorption treatment is 3h; And / or, the concentration of the introduced hydrogen gas in the jet mill treatment is 50~200ppm; And / or, the magnetic field strength of the magnetic field is 1.5~2T; And / or, the magnetic field is a constant magnetic field.

6. The method of producing a magnet material according to claim 5, wherein The concentration of the introduced hydrogen gas in the jet mill treatment is 100ppm or 150ppm.

7. The method of producing a magnet material according to claim 1, wherein The mass ratio of the green compact to the hydrogen gas used in the hydrogen blowing treatment is 10:(0.6~1); And / or, the flow rate of the hydrogen gas in the hydrogen blowing treatment is 0.08~0.12kg / h; And / or, the hydrogen content in the magnet obtained after the hydrogen blowing treatment is below 3500ppm.

8. The method of producing a magnet material according to claim 7, wherein The mass ratio of the green compact to the hydrogen gas used in the hydrogen blowing treatment is 10:0.8; And / or, the flow rate of the hydrogen gas in the hydrogen blowing treatment is 0.1kg / h.

9. The method of producing a magnet material according to any one of claims 1 to 8, wherein The dehydrogenation and decarburization reaction is performed under the condition of continuously increasing the temperature to 600~700℃; And / or, the T0 is 150~200℃; And / or, the temperature increasing rate of the first stage is greater than that of the second stage; And / or, the first stage further includes a pretreatment stage, and the pretreatment stage increases the temperature from T0’ to the T0, and the T0’ is 0~40℃; And / or, the atmosphere in the second stage is introduced at the beginning of the second stage; And / or, the atmosphere in the second stage is a mixed gas containing hydrogen, and the mixed gas further includes an inert gas; And / or, the mass ratio of the hydrogen in the atmosphere of the second stage to the green compact is (0.5~1):

10.

10. The method of producing a magnet material according to claim 9, wherein The temperature increasing rate of the first stage is 0.5-1℃ / min; And / or, the temperature increasing rate of the second stage is 0.1-0.5℃ / min; And / or, the T0’ is 25~30℃; And / or, the temperature rising rate of the pre-treatment stage is 4-6 ℃ / min; And / or, in the second stage, the volume concentration of hydrogen in the mixed gas is 6-10%, the volume concentration refers to the proportion of the volume of the hydrogen and the total volume of the mixed gas; And / or, the mass ratio of hydrogen in the atmosphere of the second stage to the green compact is 0.6:10, 0.7:10, 0.8:10 or 0.9:

10.

11. The method of producing a magnet material according to claim 10, wherein The temperature rising rate of the first stage is 0.6 ℃ / min or 0.7 ℃ / min; And / or, the temperature rising rate of the second stage is 0.2 ℃ / min or 0.3 ℃ / min; And / or, the temperature rising rate of the pre-treatment stage is 5 ℃ / min; And / or, in the second stage, the volume concentration of hydrogen in the mixed gas is 7% or 9%, the volume concentration refers to the proportion of the volume of the hydrogen and the total volume of the mixed gas.

12. The method of producing a magnet material according to any one of claims 1 to 8, wherein The temperature of the sintering treatment is 1200-1220 ℃; And / or, the time of the sintering treatment is 2-5 h; And / or, after the sintering treatment, solid solution treatment and aging treatment are sequentially performed.

13. The method of producing a magnet material according to claim 12, wherein The temperature of the sintering treatment is 1210 ℃ or 1215 ℃; And / or, the time of the sintering treatment is 3 h; And / or, the temperature of the solid solution treatment is 1140-1190 ℃; And / or, the time of the solid solution treatment is 1-40 h; And / or, the temperature of the aging treatment is 800-900 ℃; And / or, the time of the aging treatment is 5-40 h.

14. The method of producing a magnet material according to claim 13, wherein The temperature of the solid solution treatment is 1160 ℃ or 1170 ℃; And / or, the time of the solid solution treatment is 10 h, 20 h or 30 h; And / or, the temperature of the aging treatment is 830 ℃, 850 ℃ or 860 ℃; And / or, the time of the aging treatment is 20 h.

15. A magnet material, characterized by, It is prepared by the method for preparing a magnet material according to any one of claims 1-14.

16. The magnet material of claim 15, wherein, It is composed of: Sm: 23.0-26 wt.%; Cu: 4.0-6 wt.%; Fe: 17-20 wt.%; Zr: 2.0-3.5 wt.%; Co: 45-49 wt.%; wt.% is the percentage of the mass of each component to the total mass of the magnet material; The carbon content in the magnet material is below 300 ppm.

17. The magnet material of claim 16, wherein, The content of Sm is 24-26 wt.%; And / or, the content of Cu is 4-5 wt.%; And / or, the content of Fe is 18-20 wt.%; And / or, the content of Zr is 2.5-3.5 wt.%.

18. The magnet material of claim 17, wherein, The content of Sm is 25.8 wt.%; And / or, the content of Fe is 19 wt.% or 19.5 wt.%; And / or, the content of Zr is 3 wt.%.

19. The magnet material of claim 16, wherein, The magnet material is composed of Sm 26 wt.%, Fe 17 wt.%, Cu 5.5 wt.%, Zr 3.5 wt.% and the balance of Co; the carbon content in the magnet material is 300 ppm; Alternatively, the magnet material consists of the following components: Sm 24 wt.%, Fe 18 wt.%, Cu 4 wt.%, Zr 3 wt.%, the balance being Co; the carbon content in the magnet material is 225 ppm; Alternatively, the magnet material consists of the following components: Sm 24 wt.%, Fe 18 wt.%, Cu 4 wt.%, Zr 3 wt.%, the balance being Co; the carbon content in the magnet material is 225 ppm; Alternatively, the magnet material consists of the following components: Sm 24 wt.%, Fe 18 wt.%, Cu 4 wt.%, Zr 3 wt.%, the balance being Co; the carbon content in the magnet material is 225 ppm; Alternatively, the magnet material consists of the following components: Sm 24 wt.%, Fe 18 wt.%, Cu 4 wt.%, Zr 3 wt.%, the balance being Co; the carbon content in the magnet material is 225 ppm.

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