JP2017126751A - Method and apparatus for manufacturing heat deformation magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a heat deformation magnet, which can be applied even to a magnet of other shapes, such as a flat plate shape and a circular arc-shape, other than a magnetic ring by improving uniformity of magnetic performance of a magnet and the yield of a process.SOLUTION: There is provided a method for manufacturing a heat deformation magnet in which a preform is obtained by executing hot press to quenched powder in a hot press step, and a heat deformation magnet is obtained by executing heat deformation to the preform in a heat deformation step. Using two extrusion heads 2 and 3 which are moved relative to each other, the preform is extruded and molded via one or more deliver ports positioned in the extrusion head 3.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method and apparatus for manufacturing a heat-deformed magnet.

  Fe-B rare earth permanent magnets are widely used in fields such as household electric appliances, electric tools, wind power generation, electric vehicles / hybrid vehicles. Compared to sintered magnets and bonded magnets, heat-deformed Fe-B rare earth magnets do not contain magnetic anisotropy, heavy rare earth elements such as Dy and Tb, or low contents, and are a near net shape process. It is attracting more and more attention due to advantages such as manufacturing.

  Conventional thermal deformation processes include stamping, extrusion, roll compression, etc., but the magnetic performance of the magnets produced is poor, the process yield is low, and the process is hot-pressed continuously. However, there is still a problem that the manufacturing process of other shape magnets such as flat plate and arc shape is not yet complete, although the conventional product shape is mainly a magnetic ring. .

  An object of the present invention is to solve the above-described problems in the prior art.

  The object is realized by a method of manufacturing a heat-deformed magnet, and in the hot press step, the method obtains a preform by performing hot press on the quenched powder, and in the heat deform step, Obtaining a heat-deformed magnet by performing heat deformation on the preform, and by means of two mutually moving extrusion heads, the preform is provided with one or more delivery ports located in the extrusion head. Extrude through.

  On the other hand, the object is realized by a device that manufactures a heat-deformed magnet, and the device is a hot press apparatus that obtains a preform by performing hot pressing on rapidly cooled powder, and heat deformation of the preform. A heat-deformation device that obtains a heat-deformable magnet by carrying out the step, the heat-deformation device having two extruding heads that move relative to each other, and the extruding head has one or more feeding heads. The preform has an outlet, and the two extrusion heads extrude the preform through the outlet.

  Hereinafter, each aspect of the present invention will be described in more detail with reference to the drawings.

It is a real photograph which shows the hot press metal mold | die a), the heat deformation extrusion head b), and the heat deformation magnet c) which concern on one Embodiment of this invention. FIG. 2 shows X-ray diffraction (XRD) spectra on both sides of the magnet shown in FIG. It is the schematic which shows the hot press and thermal deformation process which concern on other embodiment of this invention. It is the schematic which shows the hot press and thermal deformation process which concern on other embodiment of this invention. It is the schematic which shows the hot press and thermal deformation process which concern on other embodiment of this invention. It is the schematic which shows the hot press and thermal deformation process which concern on other embodiment of this invention.

  Unless stated otherwise, all publications, patent applications, patents and other references mentioned in this application are incorporated by reference in their entirety and are herein incorporated by reference. To do.

  All technical and scientific terms used in this application have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs unless otherwise defined. In case of conflict, the definitions in this specification shall be followed.

  Where an amount, concentration, or other value or parameter is indicated in the form of a range, preferred range, or preferred numerical upper limit and preferred numerical lower limit, any pair of upper or preferred range It should be understood that any range combining a numerical value with the lower limit of any range or a suitable numerical range is equivalent to being specifically disclosed, and whether or not the range is specifically disclosed. Do not consider. Numerical ranges listed herein are intended to include the endpoints of the range, all integers and fractions within the range, unless otherwise specified.

  The present invention relates to a method for producing a heat-deformed magnet, which includes obtaining a preform by performing hot pressing on rapidly cooled powder in the hot pressing step, and thermally deforming the preform in the heat deforming step. The preform is extruded through one or more delivery ports located in the extrusion head by two relatively moving extrusion heads. .

Quenching powder The quenching powder used in the method according to the present invention is not particularly limited. For example, after obtaining a quenching zone by a melt / quenching method, the quenching zone can be pulverized to obtain a quenching powder. Commercially available quenched powder, for example, magnetic powder of a series such as MQU purchased from Magnequench (Tianjin) Co., Ltd. can also be used. The quenched powder used in the method according to the present invention may have a nano-order grain size, may be in an amorphous state, and crystallizes during the thermal deformation step.

The alloy composition of the quenched powder used in the method according to the present invention is not particularly limited, and for example, a RE ₂ Fe ₁₄ B single phase alloy may be used, where RE is Nd or other rare earth elements or these A two-phase alloy may be used as a representative of the combination, and the two-phase alloy is composed of, for example, a RE ₂ Fe ₁₄ B phase and a rich RE phase, or a RE ₂ Fe ₁₄ B phase and a soft magnetic phase.

Hot press step In one embodiment according to the method of the present invention, in the hot press step, the quenched powder is hot pressed at a pressure of 50 to 200 MPa at a hot press temperature of 600 to 750 ° C.

The protective atmosphere used in the hot pressing step is not particularly limited, and can be, for example, a vacuum before heating, for example, less than 1 × 10 ⁻¹ Pa, preferably less than 6 × 10 ⁻² Pa. The temperature raising rate used in the hot pressing step is not particularly limited, and can be, for example, 50 to 200 ° C./min, and preferably about 100 ° C./min. After reaching a predetermined hot press temperature, heat insulation can be appropriately performed. The heat retention time used in the hot pressing step is not particularly limited, and can be, for example, 0 to 120 seconds, and preferably about 1 minute. The preform may be a rectangle, a cylinder, or a columnar body having a cross section of another shape.

  When the hot pressing step and the thermal deformation step are performed in contact with each other, the preform is directly fed into the deformation step after reaching a predetermined heat retention time in the hot pressing step.

When the hot pressing step and the thermal deformation step are performed apart from each other, in the hot pressing step, after reaching a predetermined heat retention time, the heating is stopped, the pressure is unloaded, and the preform is naturally Cool, preferably with an inert gas such as Ar or N ₂ . After the temperature is lower than 200 ° C., the preform is taken out and then sent to the thermal deformation step.

Thermal deformation step In another embodiment according to the method of the present invention, in the thermal deformation step, the preform is subjected to thermal deformation at a pressure of 50 to 200 MPa under a heat deformation temperature of 750 to 950 ° C.

The protective atmosphere used in the thermal deformation step is not particularly limited, and can be, for example, a vacuum before heating, for example, less than 1 × 10 ⁻¹ Pa, preferably less than 6 × 10 ⁻² Pa, Thereafter, an inert gas such as Ar is filled. The temperature increase rate used in the thermal deformation step is not particularly limited, and can be, for example, 50 to 200 ° C./min, preferably about 100 ° C./min. After reaching a predetermined heat deformation temperature, the heat may be directly deformed without being kept warm, or the heat may be appropriately kept. The heat retention time used in the thermal deformation step is not particularly limited, and can be, for example, 2 to 4 minutes, preferably about 3 minutes. After reaching a predetermined heat retention time, the thermal deformation is started.

  In another embodiment of the method of the present invention, the hot pressing step and the thermal deformation step are performed in contact with each other, and the extrusion head used for the hot pressing step is a part of the inner wall of the mold used for the thermal deformation step. It is used as.

  When the hot press step and the heat deformation step are performed in contact with each other, the hot press step and the heat deformation step are performed at a hot press temperature and a heat deformation temperature, respectively. Specifically, the hot press mold used for the hot press step and the thermal deformation mold used for the thermal deformation step are in contact with each other, but the hot press mold is hot pressed at the hot press temperature. Thus, the heat deformation mold performs heat deformation at a heat deformation temperature.

  In another embodiment of the method of the present invention, one of the two extrusion heads has a delivery port. Specifically, in the two extrusion heads, one has a delivery port and the other does not have a delivery port.

  In another embodiment according to the method of the present invention, each of the two extrusion heads has a delivery port.

  In another embodiment according to the method of the invention, one of the two extrusion heads is moving to perform the extrusion and the other is stationary.

  In another embodiment of the method of the present invention, one of the two extrusion heads has a delivery port and is moved to perform extrusion, and the other has a delivery port. Not standing and still.

  In another embodiment according to the method of the present invention, the two extrusion heads both move to perform the extrusion.

  In another embodiment according to the method of the present invention, each of the two extrusion heads has a delivery port and moves to perform extrusion.

  In another embodiment according to the method of the present invention, the delivery port has a cross section whose shape can be freely designed, for example, a rectangular or arc-shaped cross section.

  On the other hand, the present invention further relates to an apparatus for producing a heat-deformed magnet, and the apparatus performs a hot deformation on the preform and a hot press apparatus that obtains a preform by performing a hot press on the rapidly cooled powder. A heat deformation device for obtaining a heat-deformable magnet, and the heat deformation device has two extrusion heads that move relative to each other, and the extrusion head has one or more outlets. The two extrusion heads extrude the preform through the delivery port.

Quenching powder The quenching powder used in the apparatus according to the present invention is not particularly limited. For example, after obtaining a quenching zone by a melt / quenching method, the quenching zone can be pulverized to obtain a quenching powder. Commercially available quenched powder, for example, magnetic powder of a series such as MQU purchased from Magnequench (Tianjin) Co., Ltd. can also be used. The quenched powder used in the device according to the present invention may have a nano-order crystal grain size, may be in an amorphous state, and crystallizes in a thermal deformation apparatus.

The alloy composition of the quenching powder used in the apparatus according to the present invention is not particularly limited, and for example, a RE ₂ Fe ₁₄ B single phase alloy may be used, where RE is Nd or other rare earth elements or these. A two-phase alloy may be used, and the two-phase alloy includes, for example, a RE ₂ Fe ₁₄ B phase and a rich RE phase, or a RE ₂ Fe ₁₄ B phase and a soft magnetic phase.

Hot press apparatus In one Embodiment which concerns on the apparatus of this invention, the said hot press apparatus hot-presses the said quenching powder with the pressure of 50-200 MPa under the hot press temperature of 600-750 degreeC.

The protective atmosphere used in the hot press apparatus is not particularly limited, and can be, for example, a vacuum before heating, for example, less than 1 × 10 ⁻¹ Pa, preferably less than 6 × 10 ⁻² Pa. The temperature increase rate used in the hot press apparatus is not particularly limited, and can be, for example, 50 to 200 ° C./min, and preferably about 100 ° C./min. After reaching a predetermined hot press temperature, heat insulation can be appropriately performed. The heat retention time used in the hot press apparatus is not particularly limited, and can be, for example, 0 to 120 seconds, preferably about 1 minute. The preform may be a rectangle, a cylinder, or a columnar body having a cross section of another shape.

  When the hot press apparatus and the thermal deformation apparatus are in contact with each other, the hot press process is completed in the hot press apparatus, and after reaching a predetermined temperature, the preform is directly fed into the thermal deformation apparatus.

When the hot press device and the thermal deformation device are separated from each other, after reaching a predetermined heat retention time in the hot press device, heating is stopped, pressure is unloaded, and the preform is allowed to cool naturally. , preferably cooled with an inert gas, such as Ar or _{N 2.} After the temperature is lower than 200 ° C., the preform is taken out and then fed into the thermal deformation apparatus.

Thermal deformation apparatus In another embodiment according to the apparatus of the present invention, the thermal deformation apparatus performs thermal deformation on the preform at a pressure of 50 to 200 MPa at a thermal deformation temperature of 750 to 950 ° C.

The protective atmosphere used in the thermal deformation apparatus is not particularly limited, and can be evacuated before heating, for example, less than 1 × 10 ⁻¹ Pa, preferably less than 6 × 10 ⁻² Pa, Thereafter, an inert gas such as Ar is filled. The temperature raising rate used in the thermal deformation apparatus is not particularly limited, and can be, for example, 50 to 200 ° C./min, and preferably about 100 ° C./min. After reaching a predetermined heat deformation temperature, the heat deformation may be performed directly, or the heat may be appropriately maintained so that the temperature becomes more uniform. The heat retention time used for the thermal deformation apparatus is not particularly limited and can be, for example, 2 to 4 minutes, preferably about 3 minutes. After reaching a predetermined heat retention time, the thermal deformation is started.

  In another embodiment of the apparatus of the present invention, the hot press device and the thermal deformation device are in contact with each other, and the extrusion head of the hot press device is a part of the inner wall of the mold of the thermal deformation device. It is used as.

  When the hot press apparatus and the thermal deformation apparatus are in contact with each other, the hot press apparatus and the thermal deformation apparatus are performed at the hot press temperature and the thermal deformation temperature, respectively. Specifically, the hot press mold used in the hot press apparatus and the thermal deformation mold used in the thermal deformation apparatus are in contact with each other. The hot press mold performs hot pressing at the hot press temperature. The thermal deformation mold is subjected to thermal deformation at the thermal deformation temperature.

  In another embodiment of the apparatus of the present invention, one of the two extrusion heads has a delivery port. Specifically, in the two extrusion heads, one has a delivery port and the other does not have a delivery port.

  In another embodiment of the apparatus of the present invention, each of the two extrusion heads has a delivery port.

  In another embodiment of the apparatus of the present invention, one of the two extrusion heads is moving to perform the extrusion and the other is stationary.

  In another embodiment of the apparatus of the present invention, one of the two extrusion heads has a delivery port and is moved to perform extrusion, and the other has a delivery port. Not standing and still.

  In another embodiment of the apparatus of the present invention, the two extrusion heads both move to perform extrusion.

  In another embodiment of the apparatus of the present invention, each of the two extrusion heads has a delivery port and moves to perform extrusion.

  In another embodiment of the apparatus of the present invention, the delivery port has a cross section whose shape can be freely designed, for example, a rectangular or arc-shaped cross section.

Example 1
FIG. 1 is an actual photograph showing a hot press die a), a heat deformation extrusion head b) and a heat deformation magnet c) used in this embodiment.

Hot press Commercially available MQU-F magnetic powder is charged into a hot press mold shown in FIG. 1a), and the hot press mold is put into a hot press machine together with the magnetic powder. Heating is started when evacuating to less than 6 × 10 ⁻² Pa. In the period of heating at a rate of temperature increase of about 100 ° C./min, a pressure of 50 MPa or more is applied to the hot press mold. After the temperature reaches 670 ° C., the temperature is kept for 1 minute, and then the heating system and the hydraulic system are turned off. The preform sample is cooled with Ar gas, and after the temperature is lower than 200 ° C., the preform sample is taken out.

Heat deformation A preform is charged into a heat deformation mold, and the heat deformation mold is placed in a furnace together with the preform. After evacuating to less than 6 × 10 ⁻² Pa, Ar gas is filled as a shielding gas. Thereafter, heating is started at a rate of temperature increase of about 100 ° C./min. After the temperature reaches 800 to 860 ° C., the temperature is kept for 3 minutes. Then, the hydraulic system in the thermal deformation process is started, and the extrusion molding is started by the thermal deformation extrusion head shown in FIG. 1b), and the gap between the extrusion heads is used as a delivery port. After completing the extrusion process, turn off the heating and hydraulic systems. After naturally cooling to room temperature, the heat deformation mold was opened to obtain the heat deformation magnet shown in FIG. 1c).

FIG. 2 shows X-ray diffraction (XRD) spectra on both sides of the magnet obtained in this example. The ratio value of I ₍₀₀₆₎ / I ₍₁₀₅₎ shown in FIG. 2 is evaluated as a measure of crystal grain orientation. The ratio values on both sides of the obtained magnet are approximately equal, which indicates that both sides of the obtained magnet have uniform grain orientation uniformity.

Example 2
FIG. 3 is a schematic view showing a hot press and thermal deformation process of the present embodiment.

  In this embodiment, a continuous hot extrusion process is realized by combining the hot pressing process and the thermal deformation process, and this is an important difference from the conventional process as shown in FIG.

  The entire system is kept within the heat distortion temperature range of 750-950 ° C. As shown in FIG. 3 (a), the quenched powder is charged into a hot press die 4. Thereafter, as shown in FIG. 3B, the extrusion head 1 starts to perform hot pressing. In the hot pressing process, the rapidly cooled powder is heated and compacted. By controlling the process parameters, full density is reached when the preform is heated to the heat distortion temperature. Thereafter, as shown in FIG. 3C, the extrusion head 2 moves to the left, and the preform descends to the extrusion mold. Thereafter, as shown in FIG. 3 (d), the extrusion heads 2 and 3 move relative to each other, thereby extruding the preform through the delivery port in the extrusion head 3. As shown in FIG. 3 (e), in the extrusion process, a plate-like magnet is pushed out through a delivery port in the extrusion head 3. By providing a cutter device outside the extrusion head 3, the heat-deformed magnet is cut into a lump (not shown). As shown in FIG. 3 (f), after extruding one preform, the extrusion head 1 is lifted, and the extrusion heads 2 and 3 are moved to their initial positions, charged with fresh quenching powder, and the next The cycle begins. The remainder of the preform in the extrusion head 3 is extruded by the next preform. The entire process is continuously performed in this manner, thereby producing a heat-deformed magnet with high efficiency.

  By designing the thermal deformation extrusion head 3, a near net shape process is realized.

  By changing the cross-sectional shape of the outlet of the heat deformation extrusion head 3, a plate-shaped and arc-shaped heat deformation magnet can be easily obtained. Also, by designing the extrusion head, mold and processing system, it is possible to obtain heat deforming magnets of other shapes correspondingly.

Example 3
FIG. 4A is a schematic diagram showing a hot press and thermal deformation process of the present embodiment.

  In this example, the processing process becomes more efficient by using an extrusion head different from that in Example 2. As shown to Fig.4 (a), the number of the delivery ports of an extrusion head exceeds one. Since the heat deformation extrusion head has two or more outlets, it extrudes more than one heat deformation magnet in one cycle.

  Moreover, the shape of the final magnet can also be easily changed by changing the cross-sectional shape of the delivery port.

Example 4
FIG. 4B is a schematic diagram showing the hot press and thermal deformation process of the present example.

  In this embodiment, as shown in FIG. 4B, each of the two extrusion heads has one or more delivery ports. As the two extrusion heads move relative to each other, the preform is extruded from two directions through the outlets in the two extrusion heads.

  Moreover, the shape of the final magnet can be easily changed by changing the cross-sectional shape of the delivery port.

Example 5
FIG. 5 is a schematic view showing the thermal deformation process of the present embodiment.

  As shown in FIG. 5, in this embodiment, the hot pressing process and the thermal deformation process are provided separately. As shown in FIG. 5 (a), the preform is hot pressed / cooling pressed to full density, which is performed by conventional pressing techniques. As shown in FIG. 5B, the preform is charged into an extrusion mold, and the entire extrusion mold and extrusion head system is maintained within a heat deformation temperature range of 750 to 950 ° C. The preform in the mold is heated by heat exchange with the mold. As shown in FIG. 5 (c), when the temperature of the preform reaches the heat distortion temperature, the extrusion heads 2 and 3 move relative to each other to push out the magnet. Since the extrusion head moves in two directions and the pressure distribution in the magnet is extruded in one direction (for example, stamping, front extrusion, etc.), the crystal grain orientation of the magnet is also more uniform. After extruding one preform, the extrusion heads 2 and 3 move to their initial positions. As shown in FIG. 5 (d), the extrusion head 1 is lifted, a new preform is charged, and a new cycle starts. The remainder of the preform in the extrusion head 3 is extruded by a new preform.

  In addition, by using different molds / extrusion heads in a similar process, other shapes of heat-deformed magnets can be obtained.

Example 6
FIG. 6 is a schematic view showing the thermal deformation process of the present embodiment.

  The front extrusion process is as shown in FIG. The preform is compacted to a high density by a cooling press / hot pressing process, which is performed by conventional pressing techniques. Then, as shown to Fig.6 (a), after preparing a preform in a metal mold | die, the extrusion head 1 is pushed down. The extrusion head 3 also moves upward, and the pressure distribution becomes more uniform by performing bidirectional extrusion. Thereafter, as shown in FIG. 6B, the preform is extruded. When the preform is extruded, the heat-deformed magnet is cut into a lump (not shown). In this case, a near net shape process is realized. As shown in FIG. 6 (c), one preform is extruded, and then, as shown in FIG. 6 (d), the extrusion head 1 is lifted and a new preform is charged. The remainder of the extrusion head 3 is pushed out by a new preform.

  The front extrusion process in this example is similar to the process of the Daido company, but the important difference with respect to the process of the Daido company is that the one used in this example is a bi-directional extrusion or floating process, and a uniform magnet It is advantageous to realize the sex.

  The specific embodiments described above are merely to interpret the concepts of the present application and should not be understood to limit the scope of the present invention in any way. On the contrary, after viewing the specification of the present application, it should be clearly understood that those skilled in the art can implement other technical proposals and make changes and the like without departing from the spirit of the present invention. It is.

Claims (20)

A method of manufacturing a heat-deformed magnet comprising:
In the hot pressing step, obtaining a preform by performing hot pressing on the quenched powder;
In the heat deformation step, obtaining a heat deformable magnet by performing heat deformation on the preform,
A method of extruding the preform through one or more delivery ports located in the extrusion head using two extrusion heads that move relative to each other.   The method according to claim 1, wherein in the hot pressing step, the quenched powder is hot pressed at a temperature of 600 to 750 ° C. and a pressure of 50 to 200 MPa.   The method according to claim 1 or 2, wherein in the thermal deformation step, the preform is subjected to thermal deformation at a pressure of 50 to 200 MPa at a temperature of 750 to 950 ° C.   The hot pressing step and the thermal deformation step are performed in contact with each other, and the extrusion head used for the hot pressing step is used as a part of an inner wall of a mold used for the thermal deformation step. 4. The method according to any one of items 1 to 3.   The method according to claim 1, wherein a delivery port is provided in one of the two extrusion heads.   The method according to claim 1, wherein both of the two extrusion heads have a delivery port.   7. A method according to any one of the preceding claims, wherein one of the two extrusion heads is moved to perform the extrusion and the other is stationary.   One of the two extrusion heads has a delivery port and is moving to perform extrusion, and the other has no delivery port and is stationary. The method according to claim 7.   The method according to claim 1, wherein the two extrusion heads are moved to perform extrusion.   The method according to claim 9, wherein each of the two extrusion heads has a delivery port and moves to perform extrusion. An apparatus for manufacturing a heat-deformed magnet,
A hot press apparatus that obtains a preform by hot pressing the rapidly cooled powder;
A thermal deformation apparatus that obtains a thermal deformation magnet by performing thermal deformation on the preform,
The thermal deformation apparatus has two extrusion heads that move relative to each other, and has one or more delivery ports in the extrusion head, and the preform is formed using the two extrusion heads. An apparatus for extrusion molding through the delivery port.   The apparatus according to claim 11, wherein the hot press apparatus performs hot pressing on the quenched powder at a pressure of 50 to 200 MPa at a temperature of 600 to 750 ° C.   The apparatus according to claim 11 or 12, wherein the thermal deformation apparatus performs thermal deformation on the preform at a pressure of 50 to 200 MPa at a temperature of 750 to 950 ° C.   The hot press apparatus and the thermal deformation apparatus are in contact with each other, and an extrusion head of the hot press apparatus is used as a part of an inner wall of a mold of the thermal deformation apparatus. The device according to any one of the above.   The apparatus according to any one of claims 11 to 14, wherein a delivery port is provided in one of the two extrusion heads.   The apparatus according to claim 11, wherein both of the two extrusion heads have a delivery port.   17. An apparatus according to any one of claims 11 to 16, wherein one of the two extrusion heads is moved to perform extrusion and the other is stationary.   One of the two extrusion heads has a delivery port and is moving to perform extrusion, and the other has no delivery port and is stationary. The device according to claim 17.   The apparatus according to any one of claims 11 to 16, wherein the two extrusion heads are moved to perform extrusion.   20. The apparatus according to claim 19, wherein each of the two extrusion heads has a delivery port and moves to perform extrusion.