CN114883105A - Thermal deformation neodymium iron boron magnet and preparation method thereof - Google Patents
Thermal deformation neodymium iron boron magnet and preparation method thereof Download PDFInfo
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- 229910001172 neodymium magnet Inorganic materials 0.000 title claims abstract description 143
- 238000002360 preparation method Methods 0.000 title claims abstract description 21
- 239000000843 powder Substances 0.000 claims abstract description 175
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 claims abstract description 78
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 claims abstract description 58
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 56
- 238000010791 quenching Methods 0.000 claims abstract description 53
- 230000000171 quenching effect Effects 0.000 claims abstract description 53
- 239000011812 mixed powder Substances 0.000 claims abstract description 37
- 238000007731 hot pressing Methods 0.000 claims abstract description 33
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 27
- 238000000034 method Methods 0.000 claims abstract description 23
- 238000002156 mixing Methods 0.000 claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 claims abstract description 7
- 239000010941 cobalt Substances 0.000 claims description 16
- 229910017052 cobalt Inorganic materials 0.000 claims description 16
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 16
- 239000002245 particle Substances 0.000 claims description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 3
- 239000001301 oxygen Substances 0.000 claims description 3
- 229910052760 oxygen Inorganic materials 0.000 claims description 3
- 230000005291 magnetic effect Effects 0.000 abstract description 23
- 230000008569 process Effects 0.000 abstract description 11
- 230000005389 magnetism Effects 0.000 abstract description 5
- 229910000531 Co alloy Inorganic materials 0.000 description 41
- 239000011521 glass Substances 0.000 description 40
- KGWWEXORQXHJJQ-UHFFFAOYSA-N [Fe].[Co].[Ni] Chemical compound [Fe].[Co].[Ni] KGWWEXORQXHJJQ-UHFFFAOYSA-N 0.000 description 34
- 238000005303 weighing Methods 0.000 description 20
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- QVYYOKWPCQYKEY-UHFFFAOYSA-N [Fe].[Co] Chemical compound [Fe].[Co] QVYYOKWPCQYKEY-UHFFFAOYSA-N 0.000 description 6
- 230000005347 demagnetization Effects 0.000 description 6
- 238000012360 testing method Methods 0.000 description 5
- 230000001808 coupling effect Effects 0.000 description 4
- 125000004430 oxygen atom Chemical group O* 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
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- 238000012545 processing Methods 0.000 description 3
- 229910052761 rare earth metal Inorganic materials 0.000 description 3
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- 229910000990 Ni alloy Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005294 ferromagnetic effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
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- 229910000828 alnico Inorganic materials 0.000 description 1
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0266—Moulding; Pressing
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0576—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together pressed, e.g. hot working
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- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
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Abstract
The invention relates to a thermal deformation neodymium iron boron magnet and a preparation method thereof. The preparation method of the thermal deformation neodymium iron boron magnet comprises the following steps: providing iron-nickel alloy powder, wherein the mass fraction of the nickel element in the iron-nickel alloy powder is more than or equal to 15%; and providing neodymium iron boron quick quenching powder, mixing the neodymium iron boron quick quenching powder with the iron nickel alloy powder to obtain mixed powder, and carrying out hot pressing and thermal deformation treatment on the mixed powder under a vacuum condition to obtain a thermal deformation neodymium iron boron magnet, wherein the mass fraction of the iron nickel alloy powder in the mixed powder is less than or equal to 3%. The preparation method of the thermal deformation neodymium iron boron magnet can effectively improve the residual magnetism and the magnetic energy product of the thermal deformation neodymium iron boron magnet, thereby optimizing the magnetic performance of the thermal deformation neodymium iron boron magnet, and the preparation method is simple in process and can be widely applied to the actual production of the thermal deformation neodymium iron boron magnet.
Description
Technical Field
The invention relates to the technical field of rare earth permanent magnet materials, in particular to a thermal deformation neodymium iron boron magnet and a preparation method thereof.
Background
The neodymium iron boron material has the characteristics of uniform magnetic property, high corrosion resistance, vibration resistance, impact resistance and the like, so that the neodymium iron boron material has great market value in the fields of wind power generation, electronic products and the like. Compared with sintered neodymium iron boron, the thermal deformation neodymium iron boron magnet has the technical advantages of small rare earth usage amount, short process flow, low processing temperature, near net shaping, high yield and the like, and has greater market competitive advantages in the preparation of special magnets such as magnetic rings and the like.
The traditional thermal deformation neodymium iron boron magnet adopts a plastic deformation mode to obtain orientation, but due to the fact that components and stress of all parts of the neodymium iron boron magnet are not uniform in the thermal deformation process, crystalline grains are irregularly arranged, the orientation degree of the thermal deformation neodymium iron boron magnet is poor, and the residual magnetism of the thermal deformation neodymium iron boron magnet is low. Although the magnetic performance of the thermal deformation neodymium iron boron magnet can be improved by coating or plating the soft magnetic substance on the surface of the neodymium iron boron rapid quenching powder by a method of compounding the soft magnetic material and the permanent magnetic material, the method has limited improvement effect on the residual magnetism and the magnetic energy product of the thermal deformation neodymium iron boron magnet, and the process is complex and is not suitable for industrial production.
Disclosure of Invention
In view of the above, it is necessary to provide a thermally deformed ndfeb magnet and a method for manufacturing the same; the preparation method of the thermal deformation neodymium iron boron magnet can effectively improve the residual magnetism and the magnetic energy product of the thermal deformation neodymium iron boron magnet, thereby optimizing the magnetic performance of the thermal deformation neodymium iron boron magnet, and the preparation method is simple in process and can be widely applied to the actual production of the thermal deformation neodymium iron boron magnet.
A preparation method of a thermal deformation neodymium iron boron magnet comprises the following steps:
providing iron-nickel alloy powder, wherein the mass fraction of nickel element in the iron-nickel alloy powder is more than or equal to 15%; and
providing neodymium iron boron quick quenching powder, mixing the neodymium iron boron quick quenching powder with the iron-nickel alloy powder to obtain mixed powder, and carrying out hot pressing and thermal deformation treatment on the mixed powder under the vacuum condition to obtain a thermal deformation neodymium iron boron magnet, wherein the mass fraction of the iron-nickel alloy powder in the mixed powder is less than or equal to 3%.
In one embodiment, the iron-nickel alloy powder further contains cobalt, and the mass fraction of the cobalt in the iron-nickel alloy powder is less than or equal to 20%.
In one embodiment, the mass fraction of the cobalt element in the iron-nickel alloy powder is 10% -20%.
In one embodiment, the mass fraction of the nickel element in the iron-nickel alloy powder is 15% -28%.
In one embodiment, the mass fraction of the iron-nickel alloy powder in the mixed powder is 1% -3%.
In one embodiment, the average grain diameter of the iron-nickel alloy powder is less than 5 μm.
In one embodiment, before the step of mixing the neodymium iron boron rapid quenching powder and the iron-nickel alloy powder, the iron-nickel alloy powder is subjected to oxygen removal pretreatment.
In one embodiment, the hot pressing temperature is 600-700 ℃, the pressure is 3-6 MPa, and the vacuum degree is greater than or equal to 5 x 10 -2 Pa；
And/or the thermal deformation temperature is 750-850 ℃, the pressure is 4-6 MPa, and the vacuum degree is more than or equal to 5 multiplied by 10 -2 Pa。
In one embodiment, in the step of thermally deforming, the amount of deformation is 65% to 75%.
The thermal deformation neodymium iron boron magnet is prepared by the preparation method of the thermal deformation neodymium iron boron magnet.
According to the preparation method of the thermal deformation neodymium iron boron magnet, a certain amount of iron-nickel alloy powder containing nickel elements is mixed with neodymium iron boron quick quenching powder, the iron-nickel alloy powder containing the nickel elements can be distributed at Nd-Fe-B crystal boundaries and strips in the hot pressing and thermal deformation processes, and the content of ferromagnetic substances in the thermal deformation neodymium iron boron crystal boundaries and the crystal grains is greatly increased by utilizing the characteristic that the nickel elements in the iron-nickel alloy powder are easy to diffuse, so that the exchange coupling effect among the Nd-Fe-B crystal grains is enhanced, and the remanence and the magnetic energy product of the thermal deformation neodymium iron boron magnet are improved. Meanwhile, nickel atoms can enter the Nd-Fe-B matrix and replace iron atoms to cause lattice change, so that the mechanical processing performance of the thermal deformation neodymium iron boron magnet is improved, and the practicability of the thermal deformation neodymium iron boron magnet is improved.
Therefore, the thermal deformation neodymium iron boron magnet obtained by the preparation method has higher remanence and magnetic energy product, the magnetic performance is more excellent, the preparation process of the thermal deformation neodymium iron boron magnet is simple, and the thermal deformation neodymium iron boron magnet can be widely applied to the actual production of the thermal deformation neodymium iron boron magnet.
Drawings
Fig. 1 is a back scattering diagram and an EDS elemental surface distribution diagram of the thermally deformed ndfeb magnet prepared in example 1;
fig. 2 is a graph showing demagnetization curves of the thermally deformed ndfeb magnets prepared in examples 1 and 2 and comparative examples 1 and 2, wherein a is a graph showing demagnetization curves of the thermally deformed ndfeb magnet prepared in example 1; b is a demagnetization curve chart of the thermally deformed ndfeb magnet prepared in example 2; c is a demagnetization curve chart of the thermally deformed neodymium-iron-boron magnet prepared in comparative example 1; d is a demagnetization graph of the thermally deformed neodymium-iron-boron magnet prepared in comparative example 2.
Detailed Description
In order to facilitate an understanding of the present invention, the present invention will be described in more detail below. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments or examples set forth herein. Rather, these embodiments or examples are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments or examples only and is not intended to be limiting of the invention.
The invention provides a preparation method of a thermal deformation neodymium iron boron magnet, which comprises the following steps:
s1, providing iron-nickel alloy powder, wherein the mass fraction of nickel element in the iron-nickel alloy powder is more than or equal to 15%;
s2, providing neodymium iron boron quick quenching powder, mixing the neodymium iron boron quick quenching powder with the iron-nickel alloy powder to obtain mixed powder, and carrying out hot pressing and thermal deformation treatment on the mixed powder under the vacuum condition to obtain a thermal deformation neodymium iron boron magnet, wherein the mass fraction of the iron-nickel alloy powder in the mixed powder is less than or equal to 3%.
In step S1, the iron-nickel alloy powder is selected, and the nickel atoms have the advantage of smaller size, so that the nickel element in the iron-nickel alloy powder can be more easily diffused, thereby facilitating the enhancement of the coupling effect between the crystal grains.
In order to further enhance the coupling effect between grains, the mass fraction of the nickel element in the iron-nickel alloy powder is preferably 15% to 28%, and more preferably 20% to 28%.
In order to further improve the physical properties of the iron-nickel alloy powder, make the iron-nickel alloy have a shape memory effect, and is beneficial to improving rheological properties of a magnet during thermal deformation, and optimize a magnet texture so as to improve the magnetic properties of the magnet, in an embodiment, the iron-nickel alloy powder further contains a cobalt element, and the mass fraction of the cobalt element in the iron-nickel alloy powder is less than or equal to 20%, preferably 10% to 20%, and further preferably 10% to 17%.
Since smaller particle size iron-nickel alloy powders are more conducive to good crystallographic texture, in one embodiment, the average particle size (D) of the iron-nickel alloy powders 50 ) Less than 5 μm, preferably the average particle diameter (D) of the iron-nickel alloy powder 50 ) Less than 1 μm.
It should be noted that, in step S2, if an excessive amount of fe-ni alloy powder is introduced, during the hot pressing and hot deformation process, a large amount of submicron-sized fe-ni alloy powder containing nickel element is concentrated at the strip, so as to limit the formation of the crystal texture of the hot-deformed ndfeb magnet, resulting in the reduction of the magnetic performance of the hot-deformed ndfeb magnet.
Therefore, a certain amount of the iron-nickel alloy powder containing the nickel element is mixed with the neodymium iron boron quick quenching powder, the iron-nickel alloy powder containing the nickel element can be distributed at the Nd-Fe-B crystal boundary and the strip in the hot pressing and hot deformation processes, and the content of ferromagnetic substances in the hot deformation neodymium iron boron crystal boundary and the crystal grain is greatly increased by utilizing the characteristic that the nickel element in the iron-nickel alloy powder is easy to diffuse, so that the exchange coupling effect among the Nd-Fe-B crystal grains is enhanced, and the remanence and the energy product of the hot deformation neodymium iron boron magnet are improved.
Meanwhile, the nickel element contained in the iron-nickel alloy powder can also solve the problems of uneven mixing and the like caused by easy agglomeration of the powder in the mixing process of the iron-nickel alloy powder and the neodymium iron boron quick quenching powder, thereby improving the mechanical processing performance of the thermal deformation neodymium iron boron magnet and improving the practicability of the thermal deformation neodymium iron boron magnet.
Specifically, the mass fraction of the iron-nickel alloy powder in the mixed powder is preferably 1% to 3%.
Because the affinity of the neodymium iron boron quick quenching powder and oxygen is strong, the introduction of oxygen atoms can influence the rare earth elements in the neodymium iron boron quick quenching powder, thereby reducing the magnetic performance of the thermal deformation neodymium iron boron magnet. Therefore, in order to avoid oxygen atoms introduced in the process of preparing the thermal deformation neodymium iron boron magnet as far as possible and reduce the water content in the iron-nickel alloy powder, the iron-nickel alloy powder is pretreated before the step of mixing the neodymium iron boron quick quenching powder with the iron-nickel alloy powder so as to remove the oxygen atoms in the iron-nickel alloy powder.
Because hot pressing and thermal deformation are all carried out under vacuum condition, and can avoid the introduction of oxygen atom to the greatest extent under vacuum condition, so, in an embodiment, will neodymium iron boron rapid quenching powder with before the step that iron-nickel alloy powder mixes, can be earlier with iron-nickel alloy powder puts into vacuum condition and handles and preserve, then directly mixes iron-nickel alloy powder and neodymium iron boron rapid quenching powder under vacuum condition, obtains mixed powder.
In order to fully and uniformly mix the neodymium iron boron quick quenching powder and the iron-nickel alloy powder, the mixing time of the neodymium iron boron quick quenching powder and the iron-nickel alloy powder is preferably 15min-30 min.
In one embodiment, theThe hot pressing temperature is 600-700 deg.C, the pressure is 3-6 MPa, and the vacuum degree is greater than or equal to 5 × 10 -2 Pa; the thermal deformation temperature is 750-850 ℃, the pressure is 4-6 MPa, and the vacuum degree is more than or equal to 5 multiplied by 10 -2 Pa。
It should be noted that the vacuum degree is an absolute value of a difference between the actual system air pressure and the external air pressure, and the vacuum degree is higher when the actual system air pressure is smaller and the difference between the actual system air pressure and the external air pressure is larger.
In one embodiment, in the thermal deformation process, the degree of deformation of the thermally deformed ndfeb magnet is 65% to 75%.
The invention also provides the thermal deformation neodymium iron boron magnet prepared by the preparation method of the thermal deformation neodymium iron boron magnet.
The thermal deformation neodymium iron boron magnet obtained by the preparation method has higher remanence and magnetic energy product, the magnetic performance is more excellent, the preparation process of the thermal deformation neodymium iron boron magnet is simple, and the thermal deformation neodymium iron boron magnet can be widely applied to the actual production of the thermal deformation neodymium iron boron magnet.
Hereinafter, the thermally deformed ndfeb magnet and the method for manufacturing the same will be further described with reference to the following specific examples.
Example 1
Putting the iron-nickel-cobalt alloy powder with the average grain diameter of 1 mu m into a glove box, vacuumizing the glove box, and storing the glove box in which the mass fraction of nickel element in the iron-nickel-cobalt alloy powder is 28% and the mass fraction of cobalt element in the iron-nickel-cobalt alloy powder is 17%.
Weighing 29.7g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box, weighing 0.3g of iron nickel cobalt alloy powder in the glove box, putting the iron nickel cobalt alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 20 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and vacuum-pressing at 5 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 670 ℃ and the external pressure is 4Mpa to obtain a block blank; placing the block blank into a hot-deformation die under a vacuum degree of 5 × 10 -2 Thermally deforming at a temperature of 830 ℃ and an applied pressure of 5MPa in PaThe deformation amount is about 70%, and the thermal deformation neodymium iron boron magnet is obtained.
The prepared heat-deformed neodymium-iron-boron magnet is subjected to element distribution test, and the test result is shown in figure 1. According to fig. 1, it can be known that each element of the fe-ni-co alloy powder in the thermally deformed ndfeb magnet is uniformly distributed, and the element enrichment phenomenon does not occur.
Example 2
Putting the iron-nickel-cobalt alloy powder with the average grain diameter of 1 mu m into a glove box, vacuumizing the glove box, and storing the glove box in which the mass fraction of nickel element in the iron-nickel-cobalt alloy powder is 28% and the mass fraction of cobalt element in the iron-nickel-cobalt alloy powder is 17%.
Weighing 29.1g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box, weighing 0.9g of iron nickel cobalt alloy powder in the glove box, putting the iron nickel cobalt alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 20 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and heating to vacuum degree of 5 × 10 -2 Hot pressing at the temperature of 670 ℃ and the external pressure of 4Mpa to obtain a block blank; placing the block blank into a hot-deformation die under a vacuum degree of 5 × 10 -2 And (3) carrying out thermal deformation under the conditions of Pa, 830 ℃ and 5MPa of external pressure, wherein the deformation amount is about 70 percent, and obtaining the thermal deformation neodymium-iron-boron magnet.
Example 3
Putting the iron-nickel-cobalt alloy powder with the average grain diameter of 1 mu m into a glove box, vacuumizing the glove box, and storing the glove box in which the mass fraction of nickel element in the iron-nickel-cobalt alloy powder is 15% and the mass fraction of cobalt element in the iron-nickel-cobalt alloy powder is 20%.
Weighing 29.76g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box, weighing 0.24g of iron nickel cobalt alloy powder in the glove box, putting the iron nickel cobalt alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 20 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and vacuum-pressing at 5 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 670 ℃ and the external pressure is 4Mpa to obtain a block blank; placing the block blank into a thermal deformation mold, and vacuumizingDegree of 5X 10 -2 And (3) carrying out thermal deformation under the conditions of Pa, 830 ℃ and 5MPa of external pressure, wherein the deformation amount is about 70 percent, and obtaining the thermal deformation neodymium-iron-boron magnet.
Example 4
Putting the iron-nickel-cobalt alloy powder with the average grain diameter of 1 mu m into a glove box, vacuumizing the glove box, and storing the glove box in which the mass fraction of nickel element in the iron-nickel-cobalt alloy powder is 20% and the mass fraction of cobalt element in the iron-nickel-cobalt alloy powder is 10%.
Weighing 29.55g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box, weighing 0.45g of iron nickel cobalt alloy powder in the glove box, putting the iron nickel cobalt alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 20 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and vacuum-pressing at 5 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 670 ℃ and the external pressure is 4Mpa to obtain a block blank; putting the block blank into a hot deformation die, and placing the block blank into a hot deformation die under the vacuum degree of 5 multiplied by 10 -2 And (3) carrying out thermal deformation under the conditions of Pa, 830 ℃ and 5MPa of external pressure, wherein the deformation amount is about 70 percent, and obtaining the thermal deformation neodymium-iron-boron magnet.
Example 5
Putting the iron-nickel alloy powder with the average grain diameter of 4 mu m into a glove box, vacuumizing the glove box, and storing the iron-nickel alloy powder in the glove box, wherein the mass fraction of nickel element in the iron-nickel alloy powder is 50%.
Weighing 29.7g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box together, weighing 0.3g of iron-nickel alloy powder in the glove box, putting the iron-nickel alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 25 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and vacuum-pressing at 6 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 675 ℃ and the external pressure is 5Mpa to obtain a block blank; placing the block blank into a hot-deformation die under vacuum of 6 × 10 -2 And (3) thermally deforming the neodymium iron boron magnet at the temperature of 835 ℃ and the external pressure of 6MPa, wherein the deformation amount is about 60 percent, and thus obtaining the thermally deformed neodymium iron boron magnet.
Example 6
Putting the iron-nickel alloy powder with the average grain diameter of 4 mu m into a glove box, vacuumizing the glove box, and storing the iron-nickel alloy powder in the glove box, wherein the mass fraction of nickel element in the iron-nickel alloy powder is 15%.
Weighing 29.55g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box, weighing 0.45g of iron-nickel alloy powder in the glove box, putting the iron-nickel alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 25 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and vacuum-pressing at 6 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 675 ℃ and the external pressure is 5Mpa to obtain a block blank; placing the block blank into a hot-deformation die under vacuum of 6 × 10 -2 And (3) carrying out thermal deformation under the conditions that the temperature is 835 ℃ and the external pressure is 6MPa, wherein the deformation amount is about 70 percent, and obtaining the thermal deformation neodymium iron boron magnet.
Example 7
Putting the iron-nickel alloy powder with the average grain diameter of 4 mu m into a glove box, vacuumizing the glove box, and storing the iron-nickel alloy powder in the glove box, wherein the mass fraction of nickel element in the iron-nickel alloy powder is 20%.
Weighing 29.1g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box, weighing 0.9g of iron-nickel alloy powder in the glove box, putting the iron-nickel alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 25 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and vacuum-pressing at 6 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 675 ℃ and the external pressure is 5Mpa to obtain a block blank; placing the block blank into a hot-deformation die under vacuum of 6 × 10 -2 And (3) carrying out thermal deformation under the conditions that the temperature is 835 ℃ and the external pressure is 6MPa, wherein the deformation amount is about 70 percent, and obtaining the thermal deformation neodymium iron boron magnet.
Comparative example 1
30g of neodymium iron boron quick quenching powder is weighed and filled into a hot pressing die, and the vacuum degree is 5 multiplied by 10 -2 Carrying out hot pressing under the conditions that the temperature is 670 ℃ and the external pressure is 4Mpa to obtain a block blank; placing the block blank into a hot-deformation die under a vacuum degree of 5 × 10 -2 Pa, the temperature is 830 ℃, and the external pressure is 5MPaPerforming thermal deformation under the condition (1), wherein the deformation amount is about 70%, and obtaining the thermal deformation neodymium iron boron magnet.
Comparative example 2
Putting the iron-nickel-cobalt alloy powder with the average grain diameter of 1 mu m into a glove box, vacuumizing the glove box, and storing the glove box in which the mass fraction of nickel element in the iron-nickel-cobalt alloy powder is 28% and the mass fraction of cobalt element in the iron-nickel-cobalt alloy powder is 17%.
Weighing 28.5g of neodymium iron boron quick quenching powder, putting the weighed neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle together into a glove box, weighing 1.5g of iron nickel cobalt alloy powder in the glove box, putting the iron nickel cobalt alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 20 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and vacuum-pressing at 5 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 670 ℃ and the external pressure is 4Mpa to obtain a block blank; placing the block blank into a hot-deformation die under a vacuum degree of 5 × 10 -2 And (3) thermally deforming at the temperature of 830 ℃ and the external pressure of 5MPa under the condition of Pa, wherein the deformation amount is about 70 percent, so as to obtain the thermally deformed neodymium-iron-boron magnet.
The results of element analysis of the thermally deformed ndfeb magnet are shown in fig. 2, which shows that a large amount of nickel and cobalt in the iron-nickel-cobalt alloy powder are enriched at the strip, and an obvious segregation phenomenon of elements occurs.
Comparative example 3
Putting the iron-nickel-cobalt alloy powder with the average grain diameter of 1 mu m into a glove box, vacuumizing the glove box, and storing the glove box in which the mass fraction of nickel element in the iron-nickel-cobalt alloy powder is 10% and the mass fraction of cobalt element in the iron-nickel-cobalt alloy powder is 17%.
Weighing 29.1g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box, weighing 0.9g of iron nickel cobalt alloy powder in the glove box, putting the iron nickel cobalt alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 20 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and vacuum-pressing at 5 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 670 ℃ and the external pressure is 4Mpa to obtain a block blank; placing the block blank into a thermal deformation mold, and vacuumizingDegree of 5X 10 -2 And (3) thermally deforming at the temperature of 830 ℃ and the external pressure of 5MPa under the condition of Pa, wherein the deformation amount is about 70 percent, so as to obtain the thermally deformed neodymium-iron-boron magnet.
Comparative example 4
Putting the iron-cobalt alloy powder with the average grain diameter of 10 mu m into a glove box, vacuumizing the glove box, and storing the iron-cobalt alloy powder in the glove box, wherein the mass fraction of cobalt in the iron-cobalt alloy powder is 35.5%.
Weighing 28.5g of neodymium iron boron quick quenching powder, putting the neodymium iron boron quick quenching powder into a glass bottle, putting the glass bottle and the glass bottle into a glove box together, weighing 1.5g of iron cobalt alloy powder in the glove box, putting the iron cobalt alloy powder into the glass bottle containing the neodymium iron boron quick quenching powder, and shaking up and mixing for 20 minutes to obtain mixed powder. Loading the mixed powder into hot-pressing mold, and heating to vacuum degree of 5 × 10 -2 Carrying out hot pressing under the conditions that the temperature is 670 ℃ and the external pressure is 4Mpa to obtain a block blank; placing the block blank into a hot-deformation die under a vacuum degree of 5 × 10 -2 And (4) thermally deforming at the temperature of 830 ℃ under the external pressure of 5MPa under the condition of Pa and the deformation amount of about 70 percent to obtain the thermally deformed neodymium iron boron magnet.
The performance tests of the thermally deformed ndfeb magnets prepared in examples 1 to 7 and comparative examples 1 to 4 were performed, and the test results are shown in table 1 below.
TABLE 1
According to table 1, the remanence and the magnetic energy product of the thermal deformation neodymium iron boron magnet prepared by the iron-nickel alloy powder are obviously improved. In example 1, when the mass fraction of the iron-nickel-cobalt alloy powder in the mixed powder is 1%, the remanence of the prepared hot deformed ndfeb magnet reaches 14.38kG, and the magnetic energy product is 49.71 MGoe. Compared with the thermal deformation neodymium iron boron magnet prepared by not adding the iron-nickel alloy powder in the comparative example 1, the remanence of the thermal deformation neodymium iron boron magnet in the example 1 is improved by about 5%, and a certain coercive force can be maintained.
The thermally deformed ndfeb magnets prepared in examples 1 to 2 and comparative examples 1 to 2 were subjected to magnetization test, and the test results are shown in fig. 2. From the demagnetization curve shown in fig. 2, it can be further clearly observed that the remanence of the thermal deformation ndfeb magnet prepared by using 1% of the iron-nickel-cobalt alloy powder is the best, while the remanence of the thermal deformation ndfeb magnet prepared by not adding the iron-nickel alloy powder and the thermal deformation ndfeb magnet prepared by using 5% of the iron-nickel-cobalt alloy powder is poor.
In comparative example 3, since the mass fraction of the nickel element in the alnico powder was low, the diffusion effect was not as good as in examples 1-2, resulting in a decrease in the magnetic properties of the thermally deformed ndfeb magnet. In comparative example 4, the thermal deformation neodymium iron boron magnet is prepared by mixing the iron-cobalt alloy powder and the neodymium iron boron quick quenching powder, and obviously, the magnetic performance of the thermal deformation neodymium iron boron magnet is lower than that of the thermal deformation neodymium iron boron magnet prepared in examples 1-7.
In conclusion, the thermal deformation neodymium iron boron magnet obtained by the preparation method can effectively improve the residual magnetism and the magnetic energy product of the thermal deformation neodymium iron boron magnet, so that the magnetic performance of the thermal deformation neodymium iron boron magnet is optimized.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. The preparation method of the thermal deformation neodymium iron boron magnet is characterized by comprising the following steps:
providing iron-nickel alloy powder, wherein the mass fraction of nickel element in the iron-nickel alloy powder is more than or equal to 15%; and
providing neodymium iron boron quick quenching powder, mixing the neodymium iron boron quick quenching powder with the iron-nickel alloy powder to obtain mixed powder, and carrying out hot pressing and thermal deformation treatment on the mixed powder under the vacuum condition to obtain a thermal deformation neodymium iron boron magnet, wherein the mass fraction of the iron-nickel alloy powder in the mixed powder is less than or equal to 3%.
2. A method of producing a thermally deformed neodymium-iron-boron magnet according to claim 1, characterized in that the iron-nickel alloy powder further contains cobalt, and the mass fraction of the cobalt in the iron-nickel alloy powder is less than or equal to 20%.
3. The method for preparing a thermally deformed neodymium-iron-boron magnet according to claim 2, wherein the mass fraction of the cobalt element in the iron-nickel alloy powder is 10% -20%.
4. The method for preparing a thermally deformed neodymium-iron-boron magnet according to claim 1 or 2, wherein the mass fraction of the nickel element in the iron-nickel alloy powder is 15% -28%.
5. The method for preparing a thermally deformed neodymium-iron-boron magnet according to claim 1 or 2, wherein the mass fraction of the iron-nickel alloy powder in the mixed powder is 1% -3%.
6. A method of producing a thermally deformed neodymium-iron-boron magnet according to claim 1 or 2, characterized in that the average particle size of the iron-nickel alloy powder is less than 5 μm.
7. The method of manufacturing a thermally deformed neodymium-iron-boron magnet according to claim 1 or 2, characterized in that, before the step of mixing the neodymium-iron-boron quick quenching powder with the iron-nickel alloy powder, the iron-nickel alloy powder is subjected to an oxygen removal pretreatment.
8. The method of producing a thermally deformed neodymium-iron-boron magnet according to claim 1 or 2, wherein the hot pressing temperature is 600 ℃ to 700 ℃, the pressure is 3MPa to 6MPa, and the degree of vacuum is 5 x 10 or more -2 Pa；
And/or the thermal deformation temperature is 750-850 ℃, the pressure is 4-6 MPa, and the vacuum degree is more than or equal to 5 multiplied by 10 -2 Pa。
9. The method of producing a thermally deformed neodymium-iron-boron magnet according to claim 1 or 2, wherein in the step of thermally deforming, a deformation amount is 65% to 75%.
10. A thermally deformed ndfeb magnet prepared by the method for preparing a thermally deformed ndfeb magnet according to any one of claims 1 to 9.
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