CN108115140B - Method and apparatus for producing thermally deformed magnet - Google Patents
Method and apparatus for producing thermally deformed magnet Download PDFInfo
- Publication number
- CN108115140B CN108115140B CN201611061875.8A CN201611061875A CN108115140B CN 108115140 B CN108115140 B CN 108115140B CN 201611061875 A CN201611061875 A CN 201611061875A CN 108115140 B CN108115140 B CN 108115140B
- Authority
- CN
- China
- Prior art keywords
- hot
- preform
- pressing
- isostatic pressing
- extrusion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 74
- 238000007731 hot pressing Methods 0.000 claims abstract description 50
- 238000001513 hot isostatic pressing Methods 0.000 claims abstract description 42
- 239000000843 powder Substances 0.000 claims abstract description 33
- 238000001125 extrusion Methods 0.000 claims description 45
- 238000010791 quenching Methods 0.000 claims description 23
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 14
- 230000002457 bidirectional effect Effects 0.000 claims description 11
- 239000002775 capsule Substances 0.000 claims description 8
- 239000011261 inert gas Substances 0.000 claims description 8
- 229910052786 argon Inorganic materials 0.000 claims description 7
- 230000004323 axial length Effects 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 4
- 230000000171 quenching effect Effects 0.000 description 20
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 238000010438 heat treatment Methods 0.000 description 8
- 239000000956 alloy Substances 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 5
- 229910052761 rare earth metal Inorganic materials 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 239000006247 magnetic powder Substances 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 230000009977 dual effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 239000008833 migu Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/20—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by extruding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/003—Apparatus, e.g. furnaces
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/12—Both compacting and sintering
- B22F3/14—Both compacting and sintering simultaneously
- B22F3/15—Hot isostatic pressing
-
- H—ELECTRICITY
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/20—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by extruding
- B22F2003/208—Warm or hot extruding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
- B22F2998/10—Processes characterised by the sequence of their steps
Abstract
The present invention relates to a method and apparatus for producing a heat-deformable magnet, in which, in a hot pressing process, a hot isostatic pressing is performed on a rapid-quenched powder to obtain a preform; and performing thermal deformation on the preform during the thermal deformation to obtain a thermally deformed magnet.
Description
Technical Field
The present invention relates to a method and apparatus for producing a heat-deformable magnet, in which, in a hot pressing process, a hot isostatic pressing is performed on a rapid-quenched powder to obtain a preform; and performing thermal deformation on the preform during the thermal deformation to obtain a thermally deformed magnet.
Background
The rare earth/iron/boron-based permanent magnet is widely applied to the fields of household appliances, electric tools, wind power generation, pure electric vehicles/hybrid electric vehicles and the like. The heat-deformable rare earth/iron/boron-based magnet can maintain excellent magnetic properties without containing or containing a low content of heavy rare earth elements such as Dy and Tb due to the nanostructure microstructure as compared with sintered magnets and bonded magnets, and particularly has a better temperature stability as compared with sintered magnets.
The existing hot deformed magnet is generally prepared through two steps of a hot pressing process and a hot deforming process, wherein the hot pressing process is carried out in a cold pressing and hot pressing mode, only one preform can be produced each time, the efficiency is low, and the production efficiency needs to be improved.
Disclosure of Invention
The present invention aims to solve the above problems of the prior art, in particular by using hot isostatic pressing to prepare hot-pressed preforms, thereby significantly improving the production efficiency of the preforms and at the same time improving the homogeneity of the preforms.
The object can be achieved by a method of producing a thermally deformable magnet, comprising: a hot pressing step of subjecting the rapid-quenched powder to hot isostatic pressing to obtain a preform, and a hot deforming step of subjecting the preform to hot deformation to obtain a hot deformed magnet.
On the other hand, the object can be achieved by an apparatus for producing a thermally deformable magnet, comprising: hot pressing means for hot isostatic pressing the quenched powder to obtain a preform; and a thermal deformation device for performing thermal deformation on the preform to obtain a thermally deformed magnet.
Various aspects of the invention are set forth in greater detail below with respect to the accompanying figures.
Drawings
FIG. 1 is a schematic illustration of a hot pressing process according to one embodiment of the present invention;
FIG. 2 is a schematic view illustrating a hot deformation process according to an embodiment of the present invention;
FIG. 3 is a schematic view illustrating a hot deformation process according to another embodiment of the present invention;
FIG. 4 is a schematic view showing a hot deformation process according to another embodiment of the present invention, in which lateral extrusion is performed immediately after upsetting;
FIG. 5 is a schematic view showing a hot deformation process according to another embodiment of the present invention, in which lateral extrusion is performed through two discharge ports opposite to each other immediately after upsetting;
fig. 6 is a schematic view showing a hot deformation process according to another embodiment of the present invention, in which lateral extrusion is performed via two discharge ports opposite to each other immediately after upsetting, which may have (a) a chamfer, (b) a convex chamfer, or (c) a concave chamfer.
Detailed Description
Unless otherwise indicated, all publications, patent applications, patents, and other references mentioned in this application are herein incorporated by reference in their entirety and for all purposes to be considered as if fully set forth herein.
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. In case of conflict, the present specification, including definitions, will control.
When an amount, concentration, or other value or parameter is expressed in terms of a range, preferred range, or upper preferable numerical value and lower preferable numerical value, it is understood that any range defined by any pair of upper range limits or preferred numerical values in combination with any lower range limits or preferred numerical values is specifically disclosed, regardless of whether the range is specifically disclosed. Unless otherwise indicated, numerical ranges set forth herein are intended to include the endpoints of the ranges, and all integers and fractions within the ranges.
The present invention relates to a method for producing a thermally deformed magnet, the method comprising: a hot pressing step of subjecting the rapid-quenched powder to hot isostatic pressing to obtain a preform, and a hot deforming step of subjecting the preform to hot deformation to obtain a hot deformed magnet.
Quick-quenching powder
The rapid quenching powder used in the method according to the present invention is not particularly limited, and for example, a rapid quenching ribbon may be obtained by a melt rapid quenching method, and then the rapid quenching ribbon is crushed to obtain a rapid quenching powder. Commercially available quick-hardening powders, such as MQU series magnetic powders available from migu magnet (tianjin) ltd, may also be used. The rapid hardening powder used in the method according to the present invention may have a nano-scale grain size or may be amorphous and crystallized during thermal deformation.
The alloy composition of the rapid quenching powder used in the method according to the present invention is not particularly limited, and for example, RE may be used2Fe14B single phase alloys, in which RE represents Nd or other rare earth elements or combinations thereof, it is also possible to use dual phase alloys, for example made of RE2Fe14B phase and RE-rich phase, or from RE2Fe14B phase and soft magnetic phase.
Hot pressing step
In the hot pressing step of the method of the invention, the quenched powder is subjected to hot isostatic pressing to obtain a preform.
The hot isostatic pressing technology is characterized in that powder is densified through pressure of gas in all directions, so that a formed blank has high and uniform density, and the size of the blank formed by hot isostatic pressing is limited only by the size of a working cylinder of a press, so that the blank can be made into a large size, such as phi 800 x 1200 mm.
In the hot pressing step, preferably, the rapid quenching powder is filled into a sheath with a proper size in advance, air in the sheath is pumped out, the sheath in a vacuum state is sealed, and then the sheath filled with the rapid quenching powder is placed into a pressure-resistant container of a hot pressing device to perform the hot isostatic pressing. The sheath can be made of a metallic material, such as Al, Cu, but also other materials. The material is selected so that the capsule can be deformed at the temperature and pressure of the hot isostatic pressing without breaking, thereby completing the densification process. The sheath filled with the rapid quenching powder can be a cuboid, a cylinder or a cylinder with other cross sections.
In the hot pressing step, it is preferable to evacuate the pressure-resistant container of the hot pressing apparatus, for example, to less than 1X 10-1Pa, preferably less than 6X 10-2Pa and then the hot isostatic pressing is carried out using an inert gas, preferably argon.
In the hot pressing step, the hot isostatic pressing may be carried out at a temperature of 600 to 800 ℃, preferably 620 to 750 ℃, more preferably 650 to 700 ℃. The temperature rise rate employed in the hot-pressing step is not particularly limited, and may be, for example, 5 to 10 deg.C/min, preferably about 6 to 8 deg.C/min.
In the hot pressing step, the hot isostatic pressing may be carried out at a pressure of greater than or equal to 80MPa, preferably 90 to 200MPa, more preferably 100 to 180MPa, particularly preferably 120 to 150 MPa.
In the hot pressing step, after the predetermined temperature and pressure are reached, a suitable time may be maintained, and for example, may be 10 to 120 minutes, preferably 20 to 90 minutes, and more preferably 30 to 60 minutes.
In the hot pressing step, the hot isostatic pressing may be carried out until more than 70%, preferably more than 80%, more preferably more than 90%, especially preferably the full density of the preform is reached.
In the hot-pressing step, after the hot isostatic pressing process has been completed, the heating is stopped and the pressure is relieved, and the capsule containing the preform is allowed to cool naturally or by force, preferably using an inert gas, such as Ar or N2. After the temperature is lower than 200 ℃, taking out the sheath with the preform, opening the sheath to obtain the preform, machining the preform to a proper size according to the size requirement of the heat-deformed magnet, and then sending the preform to the heat-deforming step. The preform can be cut, for example, with a wire saw to accommodate the size of the hot deformation process.
Step of thermal deformation
In the hot deformation step of the method of the present invention, the preform is subjected to hot deformation to obtain a hot deformed magnet.
In one embodiment of the method according to the invention, in the hot deformation step, the preform is upset by bi-directional extrusion and/or is laterally extruded by bi-directional extrusion through one or more discharge ports. In the method according to the invention, the bi-directional extrusion means that the upper and lower extrusion heads move towards the middle simultaneously. Because the pressures borne by the two surfaces of the magnet in the thermal deformation process are symmetrically distributed, the uniformity of the magnetic performance of the magnet is greatly improved.
In another embodiment of the method according to the invention, the preform is subjected to hot deformation at a temperature of 650 to 950 ℃, preferably 700 to 950 ℃, more preferably 750 to 950 ℃ in the hot deformation step. In the hot deformation step, the preform is preferably hot deformed at a pressure of at most 500MPa, or at most 400MPa, or from 20 to 200MPa, or from 50 to 180MPa, or from 80 to 150 MPa.
The protective atmosphere used in the hot deformation step is not particularly limited, and for example, a vacuum may be applied before heating, for example, less than 1X 10-1Pa, preferably less than 6X 10-2Pa and then filled with an inert gas, e.g. Ar. The temperature rise rate employed in the hot deformation step is not particularly limited, and may be, for example, 50 to 200 deg.C/min, preferably about 100 deg.C/min. After reaching the predetermined heat distortion temperature, the heat may be appropriately preserved or not preserved. The holding time employed in the heat deformation step is not particularly limited, and may be, for example, 2 to 4 minutes, preferably about 3 minutes. After reaching a predetermined holding time, the thermal deformation is started.
In another embodiment of the method according to the invention, said upsetting is carried out to an upsetting rate of at most 95%, preferably from 10% to 90%, alternatively from 20% to 80%, alternatively from 30% to 70%, alternatively from 40% to 60%.
In another embodiment of the method according to the invention, in the case of upsetting the preform by bidirectional extrusion and side extrusion of the preform through one or more discharge ports by bidirectional extrusion, the side extrusion is carried out immediately after the upsetting by continuous bidirectional extrusion, thereby improving production efficiency.
In a further embodiment of the method according to the invention, the lateral extrusion is carried out via a plurality of discharge openings which are uniformly distributed in the radial direction.
In a further embodiment of the method according to the invention, the lateral extrusion is carried out via two outlet openings opposite to each other.
In another embodiment of the method according to the invention, the discharge opening is located axially near the middle of the axial length of the preform. Particularly in the case of upsetting the preform by the bidirectional extrusion and performing the lateral extrusion of the preform through one or more discharge ports by the bidirectional extrusion, the middle portion of the preform having the largest upset deformation is preferentially subjected to the lateral extrusion, which is advantageous for improving the magnetic performance, particularly the remanence, of the magnet.
In another embodiment of the method according to the invention, the discharge opening has a chamfer. The chamfer is preferably selected from the group consisting of: bevel chamfer, convex chamfer and concave chamfer.
In another aspect, the present invention also relates to an apparatus for producing a thermally deformable magnet, the apparatus comprising: hot pressing means for hot isostatic pressing the quenched powder to obtain a preform; and a thermal deformation device for performing thermal deformation on the preform to obtain a thermally deformed magnet.
Quick-quenching powder
The rapid quenching powder used in the apparatus according to the present invention is not particularly limited, and for example, a rapid quenching strip may be obtained by a melt rapid quenching method, and then the rapid quenching strip may be crushed to obtain a rapid quenching powder. Commercially available quick-hardening powders, such as MQU series magnetic powders available from migu magnet (tianjin) ltd, may also be used. The rapid quenching powder used in the apparatus according to the present invention may have a nano-scale grain size or may be amorphous and crystallized in a thermal deformation device.
The alloy composition of the rapid quenching powder used in the apparatus according to the present invention is not particularly limited, and for example, RE may be used2Fe14B single phase alloys, in which RE represents Nd or other rare earth elements or combinations thereof, it is also possible to use dual phase alloys, for example made of RE2Fe14B phase and RE-rich phase, or from RE2Fe14B phase and soft magnetic phase.
Hot press device
The apparatus according to the invention comprises a hot pressing device for subjecting the powder to hot isostatic pressing to obtain a preform.
The hot isostatic pressing technology is characterized in that powder is densified through pressure of gas in all directions, so that a formed blank has high and uniform density, and the size of the blank formed by hot isostatic pressing is limited only by the size of a working cylinder of a press, so that the blank can be made into a large size, such as phi 800 x 1200 mm.
Preferably, the rapid quenching powder is filled into a sheath with a proper size in advance, air in the sheath is pumped out, the sheath in a vacuum state is sealed, then the sheath filled with the rapid quenching powder is placed into a pressure-resistant container of a hot pressing device, and the hot isostatic pressing is carried out. The sheath can be made of a metallic material, such as Al, Cu, but also other materials. The material is selected so that the capsule can be deformed at the temperature and pressure of the hot isostatic pressing without breaking, thereby completing the densification process. The sheath filled with the rapid quenching powder can be a cuboid, a cylinder or a cylinder with other cross sections.
The pressure-resistant container of the hot-pressing apparatus is preferably evacuated, for example to less than 1X 10-1Pa, preferably less than 6X 10-2Pa and then the hot isostatic pressing is carried out using an inert gas, preferably argon.
The hot pressing arrangement may perform the hot isostatic pressing at a temperature of 600 to 800 ℃, preferably 620 to 750 ℃, more preferably 650 to 700 ℃. The rate of temperature rise employed in the hot press apparatus is not particularly limited, and may be, for example, 5 to 10 ℃/min, preferably about 6 to 8 ℃/min.
The hot pressing arrangement may carry out the hot isostatic pressing at a pressure of greater than or equal to 80MPa, preferably from 90 to 200MPa, more preferably from 100 to 180MPa, particularly preferably from 120 to 150 MPa.
The hot press apparatus may be maintained for a suitable time after reaching the predetermined temperature and pressure, for example, may be 10 to 120 minutes, preferably 20 to 90 minutes, and more preferably 30 to 60 minutes.
The hot pressing device may perform the hot isostatic pressing until more than 70%, preferably more than 80%, more preferably more than 90%, of the full density of the preform is reached, particularly preferably the full density of the preform is reached.
In a hot-pressing apparatus, after the hot isostatic pressing process is completed, the heating is stopped and the pressure is relieved, so that the capsule with the preform is cooled naturally or forciblyCooling is preferably carried out using an inert gas, e.g. Ar or N2. After the temperature is lower than 200 ℃, taking out the sheath with the preform, opening the sheath to obtain the preform, machining the preform to a proper size according to the size requirement of the heat-deformed magnet, and then feeding the preform into a heat-deforming device. The preform can be cut, for example, with a wire saw to accommodate the size of the hot deformation process.
Thermal deformation device
The apparatus according to the invention comprises a hot deformation device for hot deforming said preform to obtain a hot deformed magnet.
In one embodiment of the apparatus according to the invention, the hot deformation device has two independently movable extrusion heads, wherein the die cavity of the hot deformation device has additional space in addition to receiving the preform, so that upsetting can be performed on the preform by bidirectional extrusion; and/or the die cavity of the thermal deformation device has one or more discharge ports on the sidewall to enable lateral extrusion of the preform by bi-directional extrusion. In the apparatus according to the present invention, the bi-directional extrusion means that the upper and lower extrusion heads are simultaneously moved toward the middle. Because the pressures borne by the two surfaces of the magnet in the thermal deformation process are symmetrically distributed, the uniformity of the magnetic performance of the magnet is greatly improved.
In another embodiment of the apparatus according to the invention, the hot deforming device performs the hot deforming of the preform at a temperature of 650 to 950 ℃, preferably 700 to 950 ℃, more preferably 750 to 950 ℃. The hot deforming device preferably hot deforms the preform at a pressure of at most 500MPa, or at most 400MPa, or from 20 to 200MPa, or from 50 to 180MPa, or from 80 to 150 MPa.
The protective atmosphere used in the thermal deformation apparatus is not particularly limited, and for example, a vacuum may be applied before heating, for example, less than 1X 10-1Pa, preferably less than 6X 10-2Pa and then filled with an inert gas, e.g. Ar. The rate of temperature rise employed in the thermal deformation apparatus is not particularly limited, and may be, for example, 50 to 200 ℃/min, preferably about100 ℃/min. After reaching the predetermined heat distortion temperature, the heat may be appropriately preserved. The holding time employed in the hot deformation apparatus is not particularly limited, and may be, for example, 2 to 4 minutes, preferably about 3 minutes. After reaching a predetermined holding time, the thermal deformation is started.
In another embodiment of the apparatus according to the invention, the die cavity of the hot deforming device has additional space in the radial direction in addition to receiving the preform, so that the upsetting rate is at most 95%, preferably 10% to 90%, or 20% to 80%, or 30% to 70%, or 40% to 60%.
In another embodiment of the apparatus according to the present invention, in case the die cavity of the hot deforming device has an additional space in addition to receiving the preform and has one or more discharge ports on the side wall, the die cavity of the hot deforming device has the additional space and the discharge ports arranged in such a way that the upsetting can be performed by continuous bi-directional extrusion followed by the lateral extrusion, thereby increasing the production efficiency.
In a further embodiment of the apparatus according to the invention, the mould cavity of the hot deformation device has a plurality of discharge openings on the side wall, which are uniformly distributed in the radial direction.
In a further embodiment of the apparatus according to the invention, the mould cavity of the hot deformation device has two outlet openings on the side wall opposite to each other.
In another embodiment of the apparatus according to the invention, the discharge opening is located axially near the middle of the axial length of the preform. Particularly, in the case that the inner die cavity of the hot deformation device has extra space besides accommodating the preform and the inner die cavity of the hot deformation device has one or more discharge ports on the side wall, the middle part of the preform with the largest upset deformation is preferentially subjected to lateral extrusion, which is beneficial to improving the magnetic performance, particularly the remanence, of the magnet.
In another embodiment of the device according to the invention, the discharge opening has a chamfer. The chamfer is preferably selected from the group consisting of: bevel chamfer, convex chamfer and concave chamfer.
Example 1
Hot pressing
Fig. 1 is a schematic diagram of the hot pressing process of the present embodiment.
The commercially available MQU-F magnetic powder is filled into a sheath, air in the sheath is pumped out, the sheath is sealed, and then the sheath filled with the rapid quenching powder is placed into a pressure-resistant container of a hot-pressing device. Evacuating the pressure-resistant container to below 6X 10-2Pa, and then hot isostatic pressing was carried out using argon, wherein heating was carried out at a ramp rate of about 8 ℃/min, during which the pressure was gradually increased, and after the temperature reached 650 ℃ and the pressure reached 147MPa, holding the pressure for 45 minutes, and then closing the heating system and the pressurizing system. The capsule containing the preform is cooled by means of a flow of argon and, after a temperature lower than 200 ℃, the capsule is removed and opened to obtain the preform. The preform is cut with a wire saw to accommodate the dimensions of the thermal deformation process.
Thermal deformation
Fig. 2 is a schematic view illustrating a thermal deformation process according to the present embodiment.
The preform is loaded into a hot deformable mold, which is placed in a furnace along with the preform. Vacuum-pumping to below 6X 10-2And after Pa, filling argon as a protective gas. Heating was then started at a ramp rate of about 100 ℃/min and after the temperature reached 800 to 860 ℃, the temperature was maintained at that temperature for 3 minutes. The hydraulic system of the hot deformation process is then activated to upset the preform by bi-directional extrusion. After the upsetting process is completed, the heating system and the hydraulic system are turned off. And after naturally cooling to room temperature, demolding. In the demolding process, the two extrusion heads respectively exit from the thermal deformation mold, then the thermal deformation mold together with the thermal deformation magnet exits from the side direction, and finally the thermal deformation magnet is taken out.
Example 2
FIG. 3 is a schematic view illustrating a thermal deformation process according to the present embodiment.
In this example, the hot pressing process and the hot deformation process were performed in a similar manner to example 1 except that during the demolding of the hot deformation process, the two extrusion heads were moved in the same direction together with the hot deformation magnet until the hot deformation magnet was pushed out of the hot deformation mold, and finally the hot deformation magnet was taken out.
Example 3
Fig. 4 is a schematic view illustrating a thermal deformation process according to the present embodiment.
In this example, a hot pressing process and a hot deforming process were performed in a similar manner to example 1, except that the bidirectional extrusion was continued after the upsetting, thereby performing the lateral extrusion through one discharge port immediately thereafter.
Example 4
FIG. 5 is a schematic view illustrating a thermal deformation process according to the present embodiment.
In this example, a hot pressing process and a hot deformation process were carried out in a similar manner to example 3, except that the bidirectional extrusion was continued after the upsetting, so that the lateral extrusion was carried out immediately through two discharge ports opposite to each other.
Example 5
Fig. 6 is a schematic view illustrating a thermal deformation process according to the present embodiment.
In this example, the hot pressing process and the hot deformation process were performed in a similar manner to example 4 except that the discharge port had (a) a bevel chamfer, (b) a convex chamfer, or (c) a concave chamfer.
The particular embodiments described above are illustrative of the principles of the present application and should not be construed as limiting the scope of the invention in any way. Rather, it is to be clearly understood that resort may be had to other embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to those skilled in the art without departing from the spirit of the present invention.
Claims (26)
1. A method of producing a thermally deformed magnet, the method comprising:
a hot pressing step of subjecting the quenched powder to hot isostatic pressing to obtain a preform, and
a hot deformation step of subjecting the preform to hot deformation to obtain a hot deformed magnet,
upsetting the preform by bi-directional extrusion and laterally extruding the preform through one or more discharge ports by bi-directional extrusion in a hot deformation step,
said upsetting is carried out by continuous bidirectional extrusion followed by said lateral extrusion.
2. The method according to claim 1, characterized in that in the hot pressing step the hot isostatic pressing is carried out at a temperature of 600 to 800 ℃.
3. The method according to claim 1 or 2, characterized in that in the hot pressing step the hot isostatic pressing is carried out at a pressure of greater than or equal to 80 MPa.
4. The method according to claim 1 or 2, characterized in that in the hot pressing step, the hot isostatic pressing is carried out using an inert gas.
5. The method according to claim 4, characterized in that in the hot pressing step, the hot isostatic pressing is carried out using argon.
6. The method according to claim 1 or 2, characterized in that in the hot pressing step, rapid powder is packed into the capsule in advance, and then the hot isostatic pressing is performed.
7. Method according to claim 1 or 2, characterized in that in the hot pressing step the hot isostatic pressing is carried out until more than 70% of the full density of the preform is reached.
8. Method according to claim 1 or 2, characterized in that in the hot deformation step the preform is hot deformed at a temperature of 650 to 950 ℃.
9. The method according to claim 1 or 2, characterized in that the upsetting is performed to an upsetting rate of at most 90%.
10. Method according to claim 1 or 2, characterized in that the lateral extrusion is carried out via a plurality of discharge openings which are evenly distributed in the radial direction and/or the discharge openings are located axially near the axial length midpoint of the preform.
11. Method according to claim 10, characterized in that the lateral extrusion is carried out via two mutually opposite outlet orifices.
12. Method according to claim 1 or 2, characterized in that the discharge opening has a chamfer.
13. The method of claim 12, wherein the chamfer is selected from the group consisting of: bevel chamfer, convex chamfer and concave chamfer.
14. An apparatus for producing a thermally deformable magnet, the apparatus comprising:
hot pressing means for hot isostatic pressing the quenched powder to obtain a preform; and
a heat deforming means for heat deforming the preform to obtain a heat deformed magnet,
the hot deformation device is provided with two extrusion heads capable of moving independently, wherein the inner cavity of the die of the hot deformation device has an additional space besides accommodating the preform so as to upset the preform by bidirectional extrusion; and the mold cavity of the thermal deformation device has one or more discharge ports on the sidewall so that the preform can be laterally extruded by bi-directional extrusion,
the additional space and the arrangement of the outlet openings enable the upsetting to be carried out by continuous bidirectional extrusion followed by the lateral extrusion.
15. The apparatus of claim 14, wherein said hot pressing means performs said hot isostatic pressing at a temperature of 600 to 800 ℃.
16. The apparatus of claim 14 or 15, wherein the hot pressing means performs the hot isostatic pressing at a pressure greater than or equal to 80 MPa.
17. The apparatus of claim 14 or 15, wherein the hot pressing means performs the hot isostatic pressing using an inert gas.
18. The apparatus of claim 17, wherein the hot pressing device performs the hot isostatic pressing using argon gas.
19. The apparatus of claim 14 or 15, wherein said hot pressing means performs said hot isostatic pressing on a powder of rapid quench pre-packed in a capsule.
20. The apparatus of claim 14 or 15, wherein the hot pressing device performs the hot isostatic pressing until more than 70% of a full density of the preform is reached.
21. The apparatus according to claim 14 or 15, characterized in that the hot deforming device performs hot deforming on the preform at a temperature of 650 to 950 ℃.
22. The apparatus according to claim 14 or 15, characterized in that the die cavity of the hot deforming device has additional space in the radial direction in addition to receiving the preform, so that the upsetting rate is at most 90%.
23. Apparatus according to claim 14 or 15, characterized in that the mould cavity of the hot deformation device has a plurality of discharge openings on the side wall, which are evenly distributed in the radial direction, and/or the discharge openings are located in the axial direction near the middle point of the axial length of the preforms.
24. The apparatus according to claim 23, wherein the mold cavity of the thermal deformation device has two discharge ports on a side wall thereof opposite to each other.
25. The apparatus of claim 14 or 15, wherein the spout has a chamfer.
26. The apparatus of claim 25, wherein the chamfer is selected from the group consisting of: bevel chamfer, convex chamfer and concave chamfer.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611061875.8A CN108115140B (en) | 2016-11-28 | 2016-11-28 | Method and apparatus for producing thermally deformed magnet |
| JP2017226748A JP6985119B2 (en) | 2016-11-28 | 2017-11-27 | Manufacturing method and equipment for thermally deformable magnetic material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611061875.8A CN108115140B (en) | 2016-11-28 | 2016-11-28 | Method and apparatus for producing thermally deformed magnet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108115140A CN108115140A (en) | 2018-06-05 |
| CN108115140B true CN108115140B (en) | 2021-07-27 |
Family
ID=62223760
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611061875.8A Active CN108115140B (en) | 2016-11-28 | 2016-11-28 | Method and apparatus for producing thermally deformed magnet |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP6985119B2 (en) |
| CN (1) | CN108115140B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113223846A (en) * | 2021-04-26 | 2021-08-06 | 北京工业大学 | Method for preparing anisotropic neodymium iron boron magnet through one-step heating |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101145442A (en) * | 2006-09-06 | 2008-03-19 | 大同特殊钢株式会社 | Process of producing permanent magnet and permanent magnet |
| CN101202143A (en) * | 2007-11-09 | 2008-06-18 | 钢铁研究总院 | High performance radial hot pressing magnet ring and preparation method thereof |
| JP4202164B2 (en) * | 2003-03-25 | 2008-12-24 | 山陽特殊製鋼株式会社 | Method for manufacturing damping material |
| CN103123843A (en) * | 2011-11-21 | 2013-05-29 | 中国科学院宁波材料技术与工程研究所 | Preparation method for fine grain anisotropy densified neodymium iron boron permanent magnet |
| CN103949642A (en) * | 2014-05-19 | 2014-07-30 | 上海交通大学 | Continuous pressing mould for annular magnet and pressing method of continuous pressing mould |
-
2016
- 2016-11-28 CN CN201611061875.8A patent/CN108115140B/en active Active
-
2017
- 2017-11-27 JP JP2017226748A patent/JP6985119B2/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4202164B2 (en) * | 2003-03-25 | 2008-12-24 | 山陽特殊製鋼株式会社 | Method for manufacturing damping material |
| CN101145442A (en) * | 2006-09-06 | 2008-03-19 | 大同特殊钢株式会社 | Process of producing permanent magnet and permanent magnet |
| CN101202143A (en) * | 2007-11-09 | 2008-06-18 | 钢铁研究总院 | High performance radial hot pressing magnet ring and preparation method thereof |
| CN103123843A (en) * | 2011-11-21 | 2013-05-29 | 中国科学院宁波材料技术与工程研究所 | Preparation method for fine grain anisotropy densified neodymium iron boron permanent magnet |
| CN103949642A (en) * | 2014-05-19 | 2014-07-30 | 上海交通大学 | Continuous pressing mould for annular magnet and pressing method of continuous pressing mould |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6985119B2 (en) | 2021-12-22 |
| CN108115140A (en) | 2018-06-05 |
| JP2018087378A (en) | 2018-06-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106964777B (en) | Method and apparatus for producing thermally deformed magnet | |
| CN103489619A (en) | Method for preparing dense fine-grain neodymium iron boron sintering magnet | |
| CN104505207A (en) | Radial hot-pressed permanent magnet ring with large length-diameter ratio and manufacturing method thereof | |
| CN105081314A (en) | Method for preparing titanium product through titanium hydride powder | |
| CN108115139B (en) | Method and apparatus for producing thermally deformed magnet | |
| CN111009408B (en) | Method for preparing rare earth permanent magnetic ring by adopting hot pressing-thermal deformation process and special die | |
| CN108115140B (en) | Method and apparatus for producing thermally deformed magnet | |
| JP2013098486A (en) | Manufacturing method of rare earth magnet | |
| JPWO2018088392A1 (en) | Rare earth magnet manufacturing method | |
| CN108615596B (en) | Special-shaped permanent magnet, preparation method thereof and equipment for preparing special-shaped permanent magnet | |
| CN107851506B (en) | Mold and method for forming permanent magnets from preforms and thermal deformation system | |
| JP6890424B2 (en) | Manufacturing method and equipment for heat-deformed magnets | |
| CN111326336B (en) | Preparation method of oscillation type thermal deformation and permeation integrated high-coercivity rare earth permanent magnet | |
| CN105957675A (en) | Preparation method of rare-earth permanent magnet material | |
| US7846378B2 (en) | Preparation of a dense, polycrystalline ceramic structure | |
| CN104167271A (en) | High-resistivity rare earth iron series R-Fe-B magnet and manufacturing method thereof | |
| CN111960652A (en) | Thermoforming apparatus, thermoforming method, glass member, housing, and electronic apparatus | |
| CN108231311B (en) | Device for preparing neodymium iron boron magnet, neodymium iron boron magnet and preparation method thereof | |
| JP3818397B2 (en) | Manufacturing method of multi-structure rare earth metal magnet body | |
| CN105525260A (en) | Production methods of Mo target blank and Mo target material | |
| JP4353489B2 (en) | Manufacturing method of iron-nickel magnetic alloy products | |
| KR20000017093U (en) | Heat-insulated chamber of hot press system | |
| CN111785504A (en) | Near-net-shape preparation method of rare earth permanent magnet | |
| CN115954201A (en) | Thermal deformation magnet and preparation method thereof | |
| CN113921260A (en) | Hot-pressing preparation method of rare earth permanent magnet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |