阅读说明：本技术 烧结钐钴磁体的制备方法 (Preparation method of sintered samarium cobalt magnet ) 是由 宋奎奎 于 2019-09-27 设计创作，主要内容包括：本发明公开了一种烧结钐钴磁体的制备方法,包括：1)合金粉末a的制备,2)辅料b的制备,3)混粉,4)氢破制备粉末,5)磁粉钝化处理,6)磁场成型、等静压,7)烧结固溶、时效处理。本发明在中压吸氢,在氧气气氛下进行混粉,无需经过气流磨工艺直接制备磁性能好、力学性能好的烧结钐钴磁体。(The invention discloses a preparation method of a sintered samarium cobalt magnet, which comprises the following steps: 1) preparing alloy powder a, 2) preparing auxiliary material b, 3) mixing powder, 4) preparing powder by hydrogen crushing, 5) passivating magnetic powder, 6) forming in a magnetic field, isostatic pressing, and 7) sintering, solid dissolving and aging treatment. According to the invention, hydrogen is absorbed at medium pressure, powder mixing is carried out in an oxygen atmosphere, and the sintered samarium-cobalt magnet with good magnetic property and good mechanical property is directly prepared without a jet milling process.)

1. A method of making a sintered samarium cobalt magnet, comprising:

1) samarium cobalt alloy raw materials are prepared according to the following weight percentages: (Sm)_1-xR_x): 25-27%, Fe: 8-25%, Zr: 2-4%, Cu: 3-8% of Co, and the balance of Co, wherein x is more than or equal to 0 and less than or equal to 0.9; wherein R is one or more of Ce, Pr, Nd, Gd, Tb, Dy, Ho and Er;

smelting and casting a prepared samarium cobalt alloy raw material in an inert atmosphere, and then mechanically crushing and crushing in the middle under the protection of nitrogen to prepare alloy powder a with the size of 0.05-1 mm;

2) cleaning and drying the waste material with the components consistent with the alloy powder a, and then mechanically crushing the waste material under the protection of nitrogen to obtain an auxiliary material b with the size of 0.05-1 mm;

3) mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1: 0.2-0.5 for 0.5-3 h to obtain alloy powder c;

4) introducing hydrogen into the alloy powder c at normal temperature, keeping the pressure at 0.5-5 MPa and the pressure maintaining time at 6-24 h to allow the alloy powder c to absorb hydrogen to be saturated, then heating to 100-250 ℃, keeping the temperature and the pressure for 6-48 h to further absorb hydrogen, finally keeping the temperature and the pressure at 300-500 ℃ for 3-5 h, and dehydrogenating to prepare alloy powder d;

5) adding lubricant with the total weight of 0.1-0.5 per mill into the alloy powder d, and simultaneously supplementing 3000-20000 ppm of oxygen, and mixing for 0.5-3 h to obtain alloy magnetic powder e;

6) directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the orientation molding magnetic field intensity is 1.2-2T, and then carrying out cold isostatic pressing, wherein the cold isostatic pressing pressure is 200-300 MPa, so as to prepare a green body;

7) pre-sintering the green body at 1160-1190 ℃ for 0.5-2 h, heating to 1190-1220 ℃, sintering for 1-5 h for densification, cooling to 1130-1180 ℃ for 2-10 h for solid solution treatment, and quickly cooling to room temperature by air; and then heating to 800-900 ℃, keeping the temperature for 5-40 h, then cooling to 400 ℃ by controlling the temperature, keeping the temperature for 1-20 h, and carrying out air cooling to the room temperature to obtain the sintered samarium-cobalt magnet.

2. The method of making a sintered samarium cobalt magnet of claim 1 wherein in step 1) the samarium cobalt alloy starting material is melted and cast under argon.

3. The method of making a sintered samarium cobalt magnet of claim 1, wherein the samarium cobalt alloy starting material is formulated in the following weight percentages: (Sm)_1-xR_x): 25-26.8%, Fe: 8-20%, Zr: 2-3.5%, Cu: 5.5-7 percent of Co, and the balance of Co, wherein x is more than or equal to 0 and less than or equal to 0.9.

4. The method of making a sintered samarium cobalt magnet of claim 1 wherein the hydrogen introduced in step 4) has a purity of 99.999999%.

5. The method of making a sintered samarium cobalt magnet of claim 1 wherein the size of the powder after crushing in step 4) is 3 to 20 μm.

6. The method of making a sintered samarium cobalt magnet of claim 1 wherein in step 6) the orientation forming magnetic field strength is 1.6T and the cold isostatic pressure is 220 MPa.

7. The method of making a sintered samarium cobalt magnet of claim 1, wherein in step 7) the green body is pre-sintered by maintaining the temperature at 1160-1190 ℃ for 0.5-2 hours, sintered by heating to 1190-1220 ℃ for 1-5 hours to densify, then cooled to 1160-1180 ℃ for 2-10 hours of high temperature solution treatment, finally cooled to 1130-1150 ℃ for 2-10 hours of low temperature solution treatment, and rapidly air-cooled to room temperature; and then heating to 800-900 ℃, keeping the temperature for 5-40 h, cooling to 620 ℃ at the speed of 0.6-1 ℃/min, keeping the temperature for 2-5 h, cooling to 400 ℃ at the speed of 0.6-1 ℃/min, keeping the temperature for 1-20 h, and air-cooling to room temperature to obtain the sintered samarium-cobalt magnet.

8. A sintered samarium cobalt magnet obtained by the process of any of claims 1 to 7.

Technical Field

The present invention relates to a magnetic material. More particularly, the invention relates to a method of making a sintered samarium cobalt magnet.

Background

As a second generation 2:17 type samarium cobalt permanent magnet material, the samarium cobalt permanent magnet material is widely applied to microwave tubes, gyroscopes, accelerators, magnetic bearings, sensors and other instruments due to higher magnetic performance, extremely low temperature coefficient and high Curie temperature, but the mechanical performance is poorer, so that the processing difficulty and cost are increased, and as the samarium cobalt material is applied to the field of high-precision materials, the research on the mechanical performance is compelled to be urgent, how to make the samarium cobalt material have higher magnetic performance and better mechanical performance is required, and the development of the samarium cobalt material is increasingly restricted by the problem.

The conventional preparation method of the 2:17 type sintered samarium-cobalt magnet comprises the following steps: batching → smelting ingot casting → mechanical crushing → jet milling/ball fan → magnetic field orientation forming → sintering solid solution and aging. At present, most of the samarium cobalt preparation processes of domestic manufacturers adopt an air flow mill process, however, due to the structural characteristics of air flow mill equipment, all qualified magnetic powder cannot be collected in the powder preparation process, the waste of rare earth can be caused due to long-term accumulation of residual materials, in addition, the maintenance cost of the air flow mill equipment is high, the production period is long, and great cost pressure is caused to manufacturers, the invention patent with the application publication number of CN 107316726A discloses a recycling method of leftover materials and waste materials of samarium cobalt, and finally, the air flow mill process cannot be avoided, so that a method for efficiently preparing samarium cobalt is found, and the method for efficiently utilizing rare earth and reducing the cost of preparing samarium cobalt are necessary. Patent application publication nos. CN 105304249 a and CN 106531383 a disclose a method for preparing samarium cobalt by hydrogen fracturing process, but alloy powder obtained by hydrogen fracturing still needs to be subjected to gas stream milling process, and the process period for preparing magnet is relatively long and the cost is relatively high.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and to provide at least the advantages described later.

Still another object of the present invention is to provide a method for producing a sintered samarium cobalt magnet, in which hydrogen is absorbed at medium pressure, and the powder is mixed in an oxygen atmosphere, and the sintered samarium cobalt magnet having good magnetic properties and good mechanical properties is directly produced without a jet milling process.

To achieve these objects and other advantages in accordance with the purpose of the invention, there is provided a method of manufacturing a sintered samarium cobalt magnet, comprising:

1) samarium cobalt alloy raw materials are prepared according to the following weight percentages: (Sm)_1-xR_x): 25-27%, Fe: 8-25%, Zr: 2-4%, Cu: 3-8% of Co, and the balance of Co, wherein x is more than or equal to 0 and less than or equal to 0.9; wherein R is one or more of Ce, Pr, Nd, Gd, Tb, Dy, Ho and Er;

smelting and casting a prepared samarium cobalt alloy raw material in an inert atmosphere, and then mechanically crushing and crushing under the protection of nitrogen to prepare alloy powder a with the size of 0.05-1 mm;

2) cleaning and drying the waste material with the components consistent with the alloy powder a, and then mechanically crushing the waste material under the protection of nitrogen to obtain an auxiliary material b with the size of 0.05-1 mm;

3) mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1: 0.2-0.5 for 0.5-3 h to obtain alloy powder c;

4) introducing hydrogen into the alloy powder c at normal temperature, keeping the pressure at 0.5-5 MPa and the pressure maintaining time at 6-24 h to allow the alloy powder c to absorb hydrogen to be saturated, then heating to 100-250 ℃, keeping the temperature and the pressure for 6-48 h to further absorb hydrogen, finally keeping the temperature and the pressure at 300-500 ℃ for 3-5 h, and dehydrogenating to prepare alloy powder d;

5) adding lubricant with the total weight of 0.1-0.5 per mill into the alloy powder d, and simultaneously supplementing 3000-20000 ppm of oxygen, and mixing for 0.5-3 h to obtain alloy magnetic powder e;

6) directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the strength of an orientation molding magnetic field is 1.2-2T, and then carrying out cold isostatic pressing, wherein the cold isostatic pressing pressure is 200-300 MPa, so as to prepare a green body;

7) pre-sintering the green body at 1160-1190 ℃ for 0.5-2 h, heating to 1190-1220 ℃, sintering for 1-5 h for densification, cooling to 1130-1180 ℃ for 2-10 h for solid solution treatment, and quickly cooling to room temperature by air; and then heating to 800-900 ℃, keeping the temperature for 5-40 h, cooling to 400 ℃ by controlling the temperature, keeping the temperature for 1-20 h, and cooling to room temperature by air to obtain the sintered samarium-cobalt magnet.

Preferably, the samarium cobalt alloy raw material in the step 1) is smelted and cast under the protection of argon.

Preferably, the samarium cobalt alloy raw material is prepared according to the following weight percentage: (Sm)_1-xR_x): 25-26.8%, Fe: 8-20%, Zr: 2-3.5%, Cu: 5.5-7 percent of Co, and the balance of Co, wherein x is more than or equal to 0 and less than or equal to 0.9.

Preferably, the purity of the hydrogen gas introduced in the step 4) is 99.999999%.

Preferably, the particle size of the powder crushed in the step 4) is 3-20 μm.

Preferably, the orientation molding magnetic field intensity in the step 6) is 1.6T, and the cold isostatic pressure is 220 MPa.

Preferably, in the step 7), the green body is subjected to heat preservation for 0.5-2 hours at the temperature of 1160-1190 ℃ for presintering, is heated to the temperature of 1190-1220 ℃ for sintering for 1-5 hours for densification treatment, is cooled to the temperature of 1160-1180 ℃ for high-temperature solid solution treatment for 2-10 hours, is finally cooled to the temperature of 1130-1150 ℃ for low-temperature solid solution treatment for 2-10 hours, and is quickly air-cooled to the room temperature; and then heating to 800-900 ℃, keeping the temperature for 5-40 h, cooling to 620 ℃ at the speed of 0.6-1 ℃/min, keeping the temperature for 2-5 h, cooling to 400 ℃ at the speed of 0.6-1 ℃/min, keeping the temperature for 1-20 h, and air-cooling to room temperature to obtain the sintered samarium-cobalt magnet.

The sintered samarium cobalt magnet obtained by the preparation method.

The invention at least comprises the following beneficial effects:

firstly, the invention adopts the medium-pressure hydrogen absorption process, and the sintered samarium-cobalt magnets with different performance grades are prepared by a method without an air flow milling process, thereby meeting various commercial application requirements, and having the advantages of simple method, low cost, good economic benefit and wide application prospect;

secondly, the powder can be fully passivated by a proper oxygen supplementing process in the powder mixing process, so that the material weighing and pressing can be carried out in the air without atmosphere protection, and the production process is simplified; the oxidation resistance of the powder is improved, the performance deterioration caused by severe oxidation of the powder is avoided, the storage period of the powder is greatly prolonged, and the prepared magnet has better mechanical property;

thirdly, the method is easy to operate, control and industrialize, the prepared sintered samarium-cobalt magnet is excellent in performance, the magnetic performance covers a high-performance, high-use-temperature and low-temperature coefficient type samarium-cobalt magnet, the oxygen content is 3000-10000 ppm, the bending strength is greater than 120MPa, and the compressive strength is greater than 200 MPa.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

FIG. 1 is a flow chart of the preparation method of the present invention.

Detailed Description

The present invention is further described in detail below with reference to examples to enable those skilled in the art to practice the invention with reference to the description.

It should be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified.

A method of making a sintered samarium cobalt magnet, comprising:

1) preparation of alloy powder a:

samarium cobalt alloy raw materials are prepared according to the following weight percentages: (Sm)_1-xR_x): 25-27%, Fe: 8-25%, Zr: 2-4%, Cu: 3-8% of Co, and the balance of Co, wherein x is more than or equal to 0 and less than or equal to 0.9; wherein R is one or more of Ce, Pr, Nd, Gd, Tb, Dy, Ho and Er;

the total mass percentage of the rare earth Sm or the mixture of Sm and R in the alloy raw materials is 25-27%, and the preparation of samarium cobalt magnets with different performance requirements such as low temperature coefficient and the like can be realized by adding different kinds of rare earth elements;

smelting and casting the prepared samarium cobalt alloy raw material in a high-purity inert atmosphere (preferably argon), effectively preventing volatilization of Sm and oxidation of an ingot, smelting in a medium-frequency smelting furnace, casting in a cold water copper mold of a disc to prepare an alloy ingot, and mechanically crushing and crushing the alloy ingot under the protection of nitrogen to prepare alloy powder a with the size of 0.05-1 mm;

2) preparing an auxiliary material b:

washing waste (the oxygen content of the waste is 2000-6000 ppm) with the components consistent with that of the alloy powder a by oxalic acid, then ultrasonically washing the waste in warm water (20-40 ℃), drying the waste, mechanically crushing the dried waste under the protection of nitrogen, and finely crushing the waste to obtain an auxiliary material b with the size of 0.05-1 mm;

3) mixing materials:

mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1: 0.2-0.5 for 0.5-3 h to obtain alloy powder c with the granularity of 0.05-1 mm;

4) preparing alloy powder d by a hydrogen decrepitation process:

introducing high-purity hydrogen (preferably with the purity of 99.999999%) into the alloy powder c at normal temperature, keeping the pressure at 0.5-5 MPa and the pressure maintaining time for 6-24 h to ensure that the alloy powder c absorbs hydrogen until the alloy powder c is saturated, then heating to 100-250 ℃, keeping the temperature and the pressure for 6-48 h to further absorb hydrogen, finally keeping the temperature and the pressure at 300-500 ℃ for 3-5 h, and carrying out dehydrogenation to prepare alloy powder d with the particle size of 3-20 mu m;

in the hydrogen breaking process, if the hydrogen pressure is too low, the hydrogen absorption breaking of the powder is uneven, if high-pressure hydrogen absorption is adopted, great requirements are met on equipment, and the safety is low;

5) powder passivation treatment:

adding a lubricant with the total weight of 0.1-0.5 per mill into the alloy powder d, and simultaneously supplementing 3000-20000 ppm of oxygen, so as to ensure uniform mixing, wherein the powder mixing time is 0.5-3 h, and the alloy magnetic powder e with the particle size of 4-10 mu m is prepared;

magnet prepared by conventional jet milling process, oxygenLower content, but poorer mechanical properties due to less rare earth-rich phase (Sm)₂O₃) Proper oxygen is supplemented in the powder mixing process, so that the magnet can be fully combined with the oxygen, and therefore, in the subsequent sintering process, a uniformly distributed rare earth-rich phase is formed in the magnet, and the rare earth-rich phase can absorb a large amount of energy in a mechanical experiment and reduce the stress concentration of the material, so that the mechanical property of the material is improved, and the sintered samarium-cobalt magnet with better mechanical property is obtained;

6) magnetic field forming, isostatic pressing:

the alloy powder is effectively passivated by adopting an oxygen supplementing technology in the powder mixing process, so that the mixed alloy powder can be weighed in the air, then is directionally molded in an open press, and then is subjected to cold isostatic pressing to prepare a green body, wherein the method specifically comprises the following steps of: directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the strength of an orientation molding magnetic field is 1.2-2T, and then carrying out cold isostatic pressing, wherein the cold isostatic pressing pressure is 200-300 MPa, so as to prepare a green body;

7) sintering solid solution and aging treatment:

pre-sintering the green body at 1160-1190 ℃ for 0.5-2 h, heating to 1190-1220 ℃, sintering for 1-5 h for densification, then cooling to 1160-1180 ℃ for 2-10 h of high-temperature solid solution treatment, finally cooling to 1130-1150 ℃ for 2-10 h of low-temperature solid solution treatment, and quickly cooling to room temperature by air; and then heating to 800-900 ℃, keeping the temperature for 5-40 h, cooling to 620 ℃ at the speed of 0.6-1 ℃/min, keeping the temperature for 2-5 h, cooling to 400 ℃ at the speed of 0.6-1 ℃/min, keeping the temperature for 1-20 h, and air-cooling to room temperature to obtain the sintered samarium-cobalt magnet.

The oxygen content of the prepared sintered samarium-cobalt magnet is 3000-10000 ppm, the bending strength is greater than 120MPa, and the compressive strength is greater than 200 MPa.

< example 1>

A method of making a sintered samarium cobalt magnet, comprising:

1) preparation of alloy powder a:

the alloy powder consists of the following components: 25.3 percent of Sm, 20 percent of Fe, 2.5 percent of Zr, 6 percent of Cu and the balance of Co.

The preparation method of the alloy particles comprises the following steps: preparing samarium cobalt alloy raw materials; smelting and casting the prepared raw materials in a high-purity helium atmosphere, wherein the smelting is carried out in an intermediate frequency smelting furnace, and the casting is carried out in a cold water copper mould of a disc to prepare an alloy ingot with the average thickness of 10 mm; then mechanically crushing the alloy cast ingot under the protection of nitrogen, and finely crushing to prepare alloy particles a with the size of 0.08 mm;

2) preparing an auxiliary material b:

washing waste (oxygen content of the waste is 3000ppm) with the same components as the alloy powder a by oxalic acid, ultrasonically washing the waste in warm water (30 ℃), drying the waste by blowing, mechanically crushing the dried waste under the protection of nitrogen, and finely crushing the waste to obtain an auxiliary material b with the size of 0.08 mm;

3) mixing materials:

mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1:0.2 for 2.5 hours to obtain alloy powder c with the granularity of 0.08 mm;

4) preparing alloy powder d by a hydrogen decrepitation process:

introducing high-purity hydrogen (the purity is 99.999999%) into the alloy powder c at normal temperature, keeping the pressure at 4MPa for 20h to ensure that the alloy powder c absorbs hydrogen until saturation, then heating to 220 ℃, keeping the temperature and pressure for 40h to further absorb hydrogen, finally keeping the temperature and pressure at 420 ℃ for 5h, and dehydrogenating to prepare alloy powder d with the particle size of 8.5 microns;

5) powder passivation treatment:

adding lubricant with the weight of 0.35 per mill of the alloy powder d into the alloy powder d, and simultaneously supplementing 9000ppm of oxygen, wherein in order to ensure uniform mixing, the powder mixing time is 3 hours, and the alloy magnetic powder e with the particle size of 8.5 mu m is prepared;

6) magnetic field forming, isostatic pressing:

directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the orientation molding magnetic field intensity is 1.6T, then carrying out cold isostatic pressing, and the cold isostatic pressing pressure is 220MPa, thus preparing a green body;

7) sintering solid solution and aging treatment:

pre-sintering the green body at 1160 ℃ for 2h, heating to 1200 ℃ for sintering for 2h for densification, then cooling to 1180 ℃ for 6h high-temperature solution treatment, finally cooling to 1130 ℃ for 8h low-temperature solution treatment, and quickly cooling to room temperature by air; and then heating to 830 ℃, keeping the temperature for 40h, cooling to 620 ℃ at the speed of 0.8 ℃/min, keeping the temperature for 5h, cooling to 400 ℃ at the speed of 0.7 ℃/min, keeping the temperature for 10h, and cooling to room temperature by air to obtain the sintered samarium-cobalt magnet.

The magnetic performance of the prepared sintered samarium cobalt magnet is as follows: remanence B_r11.01kGs magnetic product (BH)_max29.01MGOe, intrinsic coercivity H_cj> 25 kOe. The magnet oxygen content was 6000 ppm. Bending strength is 180MPa, and compressive strength is 360 MPa.

< example 2>

A method of making a sintered samarium cobalt magnet, comprising:

1) preparation of alloy powder a:

the alloy powder consists of the following components: 25.6 percent of Sm, 17 percent of Fe, 2.7 percent of Zr, 5.9 percent of Cu and the balance of Co.

The preparation method of the alloy particles comprises the following steps: preparing samarium cobalt alloy raw materials; smelting and casting the prepared raw materials in a high-purity helium atmosphere, wherein the smelting is carried out in an intermediate frequency smelting furnace, and the casting is carried out in a cold water copper mould of a disc to prepare an alloy ingot with the average thickness of 10 mm; then mechanically crushing the alloy cast ingot under the protection of nitrogen, and finely crushing to prepare alloy particles a with the size of 0.075 mm;

2) preparing an auxiliary material b:

washing waste (the oxygen content of the waste is 3500ppm) with the same components as the alloy powder a by oxalic acid, ultrasonically washing the waste in warm water (35 ℃), drying the waste by blowing, mechanically crushing the dried waste under the protection of nitrogen, and finely crushing the waste to obtain an auxiliary material b with the size of 0.075 mm;

3) mixing materials:

mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1:0.25 for 2 hours to obtain alloy powder c with the particle size of 0.075 mm;

4) preparing alloy powder d by a hydrogen decrepitation process:

introducing high-purity hydrogen (the purity is 99.999999%) into the alloy powder c at normal temperature, keeping the pressure at 3.5MPa, keeping the pressure for 18h to ensure that the alloy powder c absorbs hydrogen until the alloy powder c is saturated, then heating to 200 ℃, keeping the temperature and the pressure for 28h to further absorb hydrogen, finally keeping the temperature and the pressure at 400 ℃ for 4h, and dehydrogenating to prepare alloy powder d with the granularity of 7.2 mu m;

5) powder passivation treatment:

adding lubricant with the total weight of 0.35 per mill into the alloy powder d, and simultaneously supplementing 7000ppm oxygen, so as to ensure uniform mixing, wherein the powder mixing time is 3h, and the alloy magnetic powder e with the particle size of about 7.2 mu m is prepared;

6) magnetic field forming, isostatic pressing:

directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the orientation molding magnetic field intensity is 1.8T, then carrying out cold isostatic pressing, and the cold isostatic pressing pressure is 240MPa, thus preparing a green body;

7) sintering solid solution and aging treatment:

pre-sintering the green body at 1160 ℃ for 1.5h, heating to 1200 ℃, sintering for 3h for densification, then cooling to 1175 ℃ for 5h high-temperature solution treatment, finally cooling to 1140 ℃ for 6h low-temperature solution treatment, and quickly cooling to room temperature by air; and then heating to 840 ℃, keeping the temperature for 20h, cooling to 620 ℃ at the speed of 0.75 ℃/min, keeping the temperature for 3h, cooling to 400 ℃ at the speed of 0.7 ℃/min, keeping the temperature for 10h, and cooling to room temperature by air to obtain the sintered samarium-cobalt magnet.

The magnetic performance of the prepared sintered samarium cobalt magnet is as follows: remanence B_r10.80kGs magnetic product (BH)_max27.35MGOe, intrinsic coercivity H_cj> 25 kOe. The magnet oxygen content was 5000 ppm. Bending strength is 160MPa, and compressive strength is 320 MPa.

< example 3>

A method of making a sintered samarium cobalt magnet, comprising:

1) preparation of alloy powder a:

the alloy powder consists of the following components: 26% of Sm, 16% of Fe, 3% of Zr, 6% of Cu and the balance of Co.

The preparation method of the alloy particles comprises the following steps: preparing samarium cobalt alloy raw materials; smelting and casting the prepared raw materials in a high-purity helium atmosphere, wherein the smelting is carried out in an intermediate frequency smelting furnace, and the casting is carried out in a cold water copper mould of a disc to prepare an alloy ingot with the average thickness of 10 mm; then mechanically crushing the alloy ingot under the protection of nitrogen, and finely crushing to prepare alloy particles a with the size of 0.072 mm;

2) preparing an auxiliary material b:

washing waste (the oxygen content of the waste is 3200ppm) with the same components as the alloy powder a by oxalic acid, ultrasonically washing the waste in warm water (30 ℃), blow-drying the waste, mechanically crushing the blow-dried waste under the protection of nitrogen, and finely crushing the waste to obtain an auxiliary material b with the size of 0.072 mm;

3) mixing materials:

mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1:0.3 for 3 hours to obtain alloy powder c with the granularity of 0.072 mm;

4) preparing alloy powder d by a hydrogen decrepitation process:

introducing high-purity hydrogen (the purity is 99.999999%) into the alloy powder c at normal temperature, keeping the pressure at 3MPa for 20h to allow the alloy powder to absorb hydrogen until saturation, heating to 200 ℃, keeping the temperature and pressure for 24h to further absorb hydrogen, finally keeping the temperature and pressure at 380 ℃ for 4h, and dehydrogenating to prepare alloy powder d with the particle size of 6.8 microns;

5) powder passivation treatment:

adding lubricant 0.3 per mill of the total weight of the alloy powder d, and simultaneously supplementing 6000ppm of oxygen, and mixing for 3 hours to ensure uniform mixing to obtain alloy magnetic powder e with the particle size of 6.8 mu m;

6) magnetic field forming, isostatic pressing:

directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the orientation molding magnetic field intensity is 1.7T, then carrying out cold isostatic pressing, and the cold isostatic pressing pressure is 260MPa, thus preparing a green body;

7) sintering solid solution and aging treatment:

pre-sintering the green body at 1190 ℃ for 0.5h, heating to 1205 ℃ for 2h to densify, cooling to 1165 ℃ for 5h to perform high-temperature solid solution treatment, cooling to 1145 ℃ to perform low-temperature solid solution treatment for 6h, and quickly cooling to room temperature by air; and then heating to 855 ℃, keeping the temperature for 20h, cooling to 620 ℃ at the speed of 0.8 ℃/min, keeping the temperature for 2.5h, cooling to 400 ℃ at the speed of 0.75 ℃/min, keeping the temperature for 8h, and cooling to room temperature by air to obtain the sintered samarium-cobalt magnet.

The magnetic performance of the prepared sintered samarium cobalt magnet is as follows: remanence B_r10.65kGs magnetic product (BH)_max26.05MGOe, intrinsic coercivity H_cj> 25 kOe. The magnet oxygen content was 4400 ppm. Bending strength 150MPa, compression strength 300 MPa.

< example 4>

A method of making a sintered samarium cobalt magnet, comprising:

1) preparation of alloy powder a:

the alloy powder consists of the following components: 26.2% of Sm, 13% of Fe, 3% of Zr, 6% of Cu and the balance of Co.

The preparation method of the alloy particles comprises the following steps: preparing samarium cobalt alloy raw materials; smelting and casting the prepared raw materials in a high-purity helium atmosphere, wherein the smelting is carried out in an intermediate frequency smelting furnace, and the casting is carried out in a cold water copper mould of a disc to prepare an alloy ingot with the average thickness of 10 mm; then mechanically crushing the alloy cast ingot under the protection of nitrogen, and finely crushing to prepare alloy particles a with the size of 0.092 mm;

2) preparing an auxiliary material b:

washing waste (the oxygen content of the waste is 4000ppm) with the same components as the alloy powder a by oxalic acid, ultrasonically washing the waste in warm water (30 ℃), drying the waste by blowing, mechanically crushing the dried waste under the protection of nitrogen, and finely crushing the waste to obtain an auxiliary material b with the size of 0.092 mm;

3) mixing materials:

mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1:0.3 for 3 hours to obtain alloy powder c with the granularity of 0.092 mm;

4) preparing alloy powder d by a hydrogen decrepitation process:

introducing high-purity hydrogen (with the purity of 99.999999%) into the alloy powder c at normal temperature, keeping the pressure at 3MPa for 20h to ensure that the alloy powder c absorbs hydrogen until saturation, then heating to 200 ℃, keeping the temperature and pressure for 30h to further absorb hydrogen, finally keeping the temperature and pressure at 350 ℃ for 5h, and dehydrogenating to prepare alloy powder d with the particle size of 5.5 microns;

5) powder passivation treatment:

adding lubricant with the total weight of 0.35 per mill into the alloy powder d, and simultaneously supplementing 5000ppm oxygen, and mixing for 3h to obtain alloy magnetic powder e with the particle size of 5.5 μm for ensuring uniform mixing;

6) magnetic field forming, isostatic pressing:

directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the orientation molding magnetic field intensity is 1.4T, then carrying out cold isostatic pressing, and the cold isostatic pressing pressure is 270MPa to prepare a green body;

7) sintering solid solution and aging treatment:

pre-sintering the green body at 1175 ℃ for 1.5h, heating to 1208 ℃ for sintering for 2h for densification, then cooling to 1165 ℃ for 4h for high-temperature solid solution treatment, finally cooling to 1145 ℃ for 6h for low-temperature solid solution treatment, and quickly cooling to room temperature by air; and then heating to 865 ℃, preserving heat for 10h, cooling to 620 ℃ at the speed of 0.8 ℃/min, preserving heat for 3h, cooling to 400 ℃ at the speed of 0.7 ℃/min, preserving heat for 5h, and cooling to room temperature by air to obtain the sintered samarium-cobalt magnet.

The magnetic performance of the prepared sintered samarium cobalt magnet is as follows: remanence B_r10.41kGs magnetic product (BH)_max24.35MGOe, intrinsic coercivity H_cj> 25 kOe. The magnet oxygen content was 3600 ppm. Bending strength 140MPa and compression strength 280 MPa.

< example 5>

A method of making a sintered samarium cobalt magnet, comprising:

1) preparation of alloy powder a:

the alloy powder consists of the following components: 22 percent of Sm, 2 percent of Dy, 2.5 percent of Gd, 14 percent of Fe, 3 percent of Zr, 6 percent of Cu and the balance of Co.

The preparation method of the alloy particles comprises the following steps: preparing samarium cobalt alloy raw materials; smelting and casting the prepared raw materials in a high-purity helium atmosphere, wherein the smelting is carried out in an intermediate frequency smelting furnace, and the casting is carried out in a cold water copper mould of a disc to prepare an alloy ingot with the average thickness of 10 mm; then mechanically crushing the alloy cast ingot under the protection of nitrogen, and finely crushing to prepare alloy particles a with the size of 0.088 mm;

2) preparing an auxiliary material b:

washing the waste (the oxygen content of the waste is 3600ppm) with the components consistent with the alloy powder a by oxalic acid, ultrasonically washing the waste in warm water (30 ℃), drying the waste, mechanically crushing the dried waste under the protection of nitrogen, and finely crushing the waste to obtain an auxiliary material b with the size of 0.088 mm;

3) mixing materials:

mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1:0.32 for 3 hours to obtain alloy powder c with the granularity of 0.088 mm;

4) preparing alloy powder d by a hydrogen decrepitation process:

introducing high-purity hydrogen (the purity is 99.999999%) into the alloy powder c at normal temperature, keeping the pressure at 3MPa for 20h to allow the alloy powder to absorb hydrogen until saturation, heating to 200 ℃, keeping the temperature and pressure for 24h to further absorb hydrogen, finally keeping the temperature and pressure at 350 ℃ for 4h, and dehydrogenating to prepare alloy powder d with the particle size of 5.3 mu m;

5) powder passivation treatment:

adding lubricant with the total weight of 0.28 per mill into the alloy powder d, and simultaneously supplementing 5000ppm oxygen, and mixing for 3h to obtain alloy magnetic powder e with the particle size of about 5.3 μm in order to ensure uniform mixing;

6) magnetic field forming, isostatic pressing:

directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the orientation molding magnetic field intensity is 1.3T, then carrying out cold isostatic pressing, and the cold isostatic pressing pressure is 280MPa, thus preparing a green body;

7) sintering solid solution and aging treatment:

preserving heat of the green body at 1170 ℃ for 1h for presintering, heating to 1215 ℃ for sintering for 2h for densification, then cooling to 1175 ℃ for 5h high-temperature solid solution treatment, finally cooling to 1150 ℃ for 6h low-temperature solid solution treatment, and quickly cooling to room temperature by air; and then heating to 830 ℃, keeping the temperature for 20h, cooling to 620 ℃ at the speed of 0.8 ℃/min, keeping the temperature for 3h, cooling to 400 ℃ at the speed of 0.75 ℃/min, keeping the temperature for 10h, and cooling to room temperature by air to obtain the sintered samarium-cobalt magnet.

The magnetic performance of the prepared sintered samarium cobalt magnet is as follows: remanence B_r9.98kGs magnetic product (BH)_max21.02MGOe, intrinsic coercivity H_cj> 25 kOe. The magnet oxygen content was 4000 ppm. Bending strength is 160MPa, and compression strength is 290 MPa.

< example 6>

A method of making a sintered samarium cobalt magnet, comprising:

1) preparation of alloy powder a:

the alloy powder consists of the following components: 26.5 percent of Sm, 8 percent of Fe, 3.1 percent of Zr, 7 percent of Cu and the balance of Co.

The preparation method of the alloy particles comprises the following steps: preparing samarium cobalt alloy raw materials; smelting and casting the prepared raw materials in a high-purity helium atmosphere, wherein the smelting is carried out in an intermediate frequency smelting furnace, and the casting is carried out in a cold water copper mould of a disc to prepare an alloy ingot with the average thickness of 10 mm; then mechanically crushing the alloy cast ingot under the protection of nitrogen, and finely crushing to prepare alloy particles a with the size of 0.095 mm;

2) preparing an auxiliary material b:

washing waste (the oxygen content of the waste is 2800ppm) with the components consistent with the alloy powder a by oxalic acid, ultrasonically washing the waste in warm water (40 ℃), drying the waste, mechanically crushing the dried waste under the protection of nitrogen, and finely crushing the waste to obtain an auxiliary material b with the size of 0.095 mm;

3) mixing materials:

mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1:0.4 for 3 hours to obtain alloy powder c with the granularity of 0.095 mm;

4) preparing alloy powder d by a hydrogen decrepitation process:

introducing high-purity hydrogen (the purity is 99.999999%) into the alloy powder c at normal temperature, keeping the pressure at 5MPa for 16h to ensure that the alloy powder c absorbs hydrogen until saturation, then heating to 200 ℃, keeping the temperature and pressure for 40h to further absorb hydrogen, finally keeping the temperature and pressure at 350 ℃ for 5h, and dehydrogenating to prepare alloy powder d with the particle size of 4.8 mu m;

5) powder passivation treatment:

adding lubricant of 0.45 per mill of the total weight of the alloy powder d, and simultaneously supplementing 4000ppm of oxygen, and mixing for 3 hours to obtain alloy magnetic powder e with the granularity of 4.8 mu m in order to ensure uniform mixing;

6) magnetic field forming, isostatic pressing:

directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the orientation molding magnetic field intensity is 1.65T, then carrying out cold isostatic pressing, and the cold isostatic pressing pressure is 255MPa, thus preparing a green body;

7) sintering solid solution and aging treatment:

preserving heat of the green body at 1165 ℃ for 2h for presintering, heating to 1210 ℃ for sintering for 2h for densification, then cooling to 1150 ℃ for 4h for low-temperature solid solution treatment, and quickly cooling to room temperature by air; and then heating to 830 ℃, preserving heat for 10 hours, cooling to 400 ℃, preserving heat for 5 hours, and cooling to room temperature by air to obtain the sintered samarium-cobalt magnet.

The magnetic performance of the prepared sintered samarium cobalt magnet is as follows: remanence B_r7.8kGs magnetic product (BH)_max12.03MGOe, intrinsic coercivity H_cj> 25 kOe. The magnet oxygen content was 3200 ppm. Bending strength is 130MPa, and compression strength is 220 MPa.

< example 7>

A method of making a sintered samarium cobalt magnet, comprising:

1) preparation of alloy powder a:

the alloy powder consists of the following components: 22.3 percent of Sm, 2.2 percent of Ce, 1 percent of Pr, 15 percent of Fe, 3.1 percent of Zr, 6 percent of Cu and the balance of Co.

The preparation method of the alloy particles comprises the following steps: preparing samarium cobalt alloy raw materials; smelting and casting the prepared raw materials in a high-purity helium atmosphere, wherein the smelting is carried out in an intermediate frequency smelting furnace, and the casting is carried out in a cold water copper mould of a disc to prepare an alloy ingot with the average thickness of 10 mm; then mechanically crushing the alloy cast ingot under the protection of nitrogen, and crushing the alloy cast ingot to prepare alloy particles a with the size of 0.09 mm;

2) preparing an auxiliary material b:

washing waste (oxygen content of the waste is 2600ppm) with the same components as the alloy powder a by oxalic acid, ultrasonically washing the waste in warm water (40 ℃), drying the waste by blowing, and mechanically crushing the dried waste under the protection of nitrogen to obtain an auxiliary material b with the size of 0.09 mm;

3) mixing materials:

mixing the alloy powder a and the auxiliary material b according to the weight ratio of 1:0.33 for 3 hours to obtain alloy powder c with the granularity of 0.09 mm;

4) preparing alloy powder d by a hydrogen decrepitation process:

introducing high-purity hydrogen (the purity is 99.999999%) into the alloy powder c at normal temperature, keeping the pressure at 5MPa for 15h to allow the alloy powder to absorb hydrogen until saturation, heating to 200 ℃, keeping the temperature and pressure for 36h to further absorb hydrogen, finally keeping the temperature and pressure at 350 ℃ for 5h, and dehydrogenating to prepare alloy powder d with the particle size of 3.8 microns;

5) powder passivation treatment:

adding lubricant with the total weight of 0.35 per mill into the alloy powder d, and simultaneously supplementing 3000ppm oxygen, so as to ensure uniform mixing, wherein the powder mixing time is 3h, and the alloy magnetic powder e with the particle size of about 3.8 mu m is prepared;

6) magnetic field forming, isostatic pressing:

directly weighing the alloy magnetic powder e in the air, then carrying out orientation molding in an open press, wherein the orientation molding magnetic field intensity is 1.55T, then carrying out cold isostatic pressing, and the cold isostatic pressing pressure is 248MPa to prepare a green body;

7) sintering solid solution and aging treatment:

the green body is preserved for 2 hours at 1165 ℃ for presintering, is heated to 1203 ℃ for sintering for 2 hours for densification treatment, is cooled to 1180 ℃ for 4 hours of high-temperature solid solution treatment, is finally cooled to 1150 ℃ for 4 hours of low-temperature solid solution treatment, and is quickly air-cooled to room temperature; and then heating to 830 ℃, keeping the temperature for 12h, cooling to 620 ℃ at the speed of 0.75 ℃/min, keeping the temperature for 2h, cooling to 400 ℃ at the speed of 0.7 ℃/min, keeping the temperature for 4h, and cooling to room temperature by air to obtain the sintered samarium-cobalt magnet.

The magnetic performance of the prepared sintered samarium cobalt magnet is as follows: remanence B_r10.45kGs magnetic product (BH)_max24.47MGOe, intrinsic coercivity H_cj> 25 kOe. The magnet oxygen content was 2800 ppm. Bending strength is 122MPa, and compressive strength is 235 MPa.

The number of apparatuses and the scale of the process described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is thus not to be limited to the details given herein and to the examples shown and described without departing from the generic concept as defined by the claims and their equivalents.