JP2022078510A - Manufacturing method for laminated rare earth magnet and laminated rare earth magnet - Google Patents

Abstract

To reduce man-hours, make effective use of materials, and make it possible to further reduce the thickness of a rare earth magnet layer.SOLUTION: A manufacturing method includes the steps of: forming a laminate 10 by alternately stacking a material layer 11 including rare earth metals and an insulator layer 12 using additive manufacturing (AM) technology; applying a magnetic field to the laminate 10 to orient it; and sintering the oriented laminate 10 to form a sintered body. The step of forming the laminate 10 includes the steps of: using a binder injection 3D printer to inject a first binder onto a predetermined portion of the surface of a powder bed 101 filled with a material powder 100 to form a material layer 11 in which a portion of the material powder 100 is solidified by the first binder; and forming the insulator layer 12 by injecting a mixture of the insulator powder and the second binder and depositing the mixture to cover at least a portion of the surface of the powder bed 101.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for manufacturing a laminated rare earth magnet and a laminated rare earth magnet, and more particularly to a method for manufacturing laminated rare earth magnets by additive manufacturing.

Conventionally, rare earth magnets such as neodymium magnets have been provided. Rare earth magnets have a strong magnetic force and are used in various applications such as IT equipment, industrial motors, and automobiles. When used in a high frequency region, rare earth magnets may be provided as laminated rare earth magnets in which thin plates of magnets are laminated with an insulator in between in order to suppress the generation of eddy currents and maintain the characteristics of the magnet. be.

Laminated rare earth magnets are oriented by applying a magnetic field to the powder of the pressed material and then sintered to produce a block of rare earth magnet, and the block of the magnet is cut and cut to form a thin plate of a predetermined shape, and the thin plate is insulated. It is manufactured by laminating with an adhesive that becomes a body layer to form a laminated body. In addition, the mold of the rare earth magnet material is filled in a mold separated by a partition plate so as to form a thin plate of a predetermined shape, oriented by applying a magnetic field, and the powder of the material from which the mold is removed is sintered together with the partition plate. Also disclosed is a technique for forming a laminated rare earth magnet by laminating thin plates of magnets formed by increasing the density during sintering (see Patent Document 1). A technique is also disclosed in which a partition plate of a mold is formed of an insulator, and powder of a material from which the mold has been removed is sintered together with the partition plate to form a sintered body in which a magnet and an insulator are laminated. See Patent Document 2).

On the other hand, there is provided a technique of additive manufacturing (AM) in which materials are combined and laminated using a 3D printer to form a model. For example, a 3D printer using a binder jetting method can form a three-dimensional object by injecting a liquid binder onto a powder bed and selectively joining and laminating the powder. (See Patent Document 3).

Japanese Unexamined Patent Publication No. 2006-19521 International Publication No. 2015/012412 Special Table 2002-528375 Gazette

However, in order to manufacture a laminated rare earth magnet, a shaping process of cutting and cutting a sintered rare earth magnet into a thin plate having a predetermined shape is required, and in these steps, a part of the material of the rare earth magnet is used as chips. It was lost. Further, it is difficult to make the thin plate of the magnet thin, and there is a limit to the thinness of the rare earth magnet layer constituting the laminated rare earth magnet, for example, 2 mm is the limit. Similarly, it was difficult to thin the thin plate of the magnet by the technique of using the mold separated by the partition plate like molding the thin plate and the technique of forming the partition plate with an insulator.

The present invention has been proposed in view of the above circumstances, and is a method for manufacturing a laminated rare earth magnet capable of reducing the number of steps, effectively using the material, and further thinning the rare earth magnet layer. It is an object of the present invention to provide a laminated rare earth magnet.

In order to solve the above-mentioned problems, the method for manufacturing a laminated rare earth magnet according to this application alternates between a material layer in which powder of a material containing a rare earth metal is deposited and an insulator layer in which powder of an insulator is deposited by additional manufacturing. It includes a step of laminating the laminated body to form a laminated body, a step of applying a magnetic field to the laminated body to align the laminated body, and a step of sintering the oriented laminated body to form a sintered body.

In the step of forming the laminate, a 3D printer of the binder injection method is used to inject the first binder onto a predetermined part of the surface of the powder bed filled with the powder of the material, and a part of the powder of the material is first. 1 The step of forming a powder layer of the material solidified with the binder and the injection of the mixture of the insulator powder and the second binder to deposit the mixture so as to cover at least a part of the surface of the powder bed. It may include a step of forming an insulator layer.

In the step of forming the material layer and the step of forming the insulator layer, in the laminate extending in the depth direction of the powder bed, the material layer and the insulator layer are solidified with the first binder and the second binder, respectively. May form a side surface. In the laminated body, the powder of the material constituting the material layer may be solidified with the first binder from the outer periphery to a predetermined thickness, and may be covered with an insulator layer solidified with the second binder at the top and bottom. The powder of the material that fills the powder bed may be formed into a predetermined particle size by binding the powder of the material with an organic binder.

The laminated rare earth magnet according to this application is manufactured by the above method, includes a rare earth magnet layer and an insulator layer, and the rare earth magnet layer and the insulator layer form a laminated body in which the rare earth magnet layer and the insulator layer are alternately laminated. It constitutes an integral sintered body.

The rare earth magnet layer may contain at least one kind of cerium, praseodymium, neodymium, samarium, terbium and dysprosium as rare earth metals. The rare earth magnet layer may further contain at least one of boron, iron, cobalt, nickel, copper and zirconium.

The insulator layer may contain at least one kind of metal oxide and metal nitride. The metal oxide may contain at least one kind of alumina and silica. The insulator layer may further contain a rare earth metal. Rare earth metals may include at least one of praseodymium, neodymium, samarium, terbium and dysprosium.

A dysprosium layer sandwiched between the rare earth magnet layer and the insulator layer may be further included. It may be formed in a V-shaped, U-shaped or ellipsoidal shape.

According to the present invention, the man-hours are reduced because the cutting and cutting steps are not required, and the material of the rare earth magnet is not lost as chips in these steps, so that the material can be effectively used. Further, the thickness of the rare earth magnet layer of the laminated rare earth magnet can be further reduced, and can be made thinner than, for example, 2 mm.

It is a flowchart which shows a series of steps of the manufacturing method of a laminated rare earth magnet. It is sectional drawing which shows the laminated body formed in the powder bed of a 3D printer. It is an enlarged sectional view which shows the powder of the material solidified by the 1st binder. It is an external view of a laminated body. It is a figure which shows the process of orientation and sintering. It is a figure which shows the manufacturing process of the comparative example 1. FIG. It is a figure which shows the manufacturing process of the comparative example 1. FIG. It is a figure which shows the manufacturing process of the comparative example 1. FIG. It is a figure which shows the manufacturing process of the comparative example 2. It is a figure which shows the manufacturing process of the comparative example 2. It is a figure which shows the manufacturing process of the comparative example 2. It is a figure which shows the manufacturing process of the comparative example 3. FIG. It is a figure which shows the manufacturing process of the comparative example 3. FIG.

Hereinafter, the method for manufacturing the laminated rare earth magnet and the laminated rare earth magnet according to the present embodiment will be described in detail with reference to the drawings. In this embodiment, a neodymium magnet having a composition of Nd ₂ Fe ₁₄ B is assumed as a rare earth magnet, but the present invention is not limited to this, and can be applied to other types of rare earth magnets such as samarium-cobalt magnets. .. Further, the method for manufacturing a laminated rare earth magnet according to the present embodiment assumes that a laminated body is formed by using a 3D printer by a binder injection method in the additive manufacturing (AM) technique. If it is an additional manufacturing technique using the above, not only the binder injection but also other methods such as material injection, material extrusion, and sheet laminating may be applied.

FIG. 1 is a flowchart showing a series of steps of the manufacturing method of the present embodiment. As shown in FIG. 1, the laminated rare earth magnet of the present embodiment is manufactured by the steps of addition manufacturing in step S1, orientation in step S2, sintering in step S3, and finishing in step S4. Hereinafter, these manufacturing processes will be described in order.

The process of additional manufacturing in step S1 will be described with reference to FIGS. 2 to 4. FIG. 2 is a cross-sectional view showing a laminated body formed in a powder bed of a 3D printer. In FIG. 2, the shape and the like are simplified to explain the structure and manufacturing method of the laminated body 10, but as will be described later, the laminated body 10 is shaped like the laminated rare earth magnet of the finished product. Will be done. The same applies to the laminated body 10 shown in FIGS. 4 and 5 (a).

In the present embodiment, the laminate 10 is formed in the powder bed 101 of the 3D printer by the binder injection method. In a 3D printer, a container 104 formed by a vertically movable bottom plate 102 and a side wall 103 surrounding the bottom plate contains powder 100 of a material containing a rare earth metal to form a powder bed 101. The powder 100 of the material constituting the powder bed 101 is filled up to the upper edge of the container 104, and the surface is flattened.

The bottom plate 102 is initially located near the upper edge of the container 104 and is stepped down so that the object to be modeled is made from the powder 100 of the material in the powder bed 101 in units of layers of a predetermined height. do. The powder bed 101 descends as the bottom plate 102 descends, and each time the powder 100 of the material is replenished so as to reach the upper edge of the container 104, the surface of the powder bed 101 is leveled.

The material powder 100 contains the rare earth metal neodymium, as well as iron and boron, to make neodymium magnets with the composition of Nd ₂ Fe ₁₄ B. Not limited to this, the material powder 100 contains at least one kind of rare earth metal such as samarium, placeodim, samarium, terbium and dysprosium in order to produce other kinds of rare earth magnets such as samarium-cobalt magnet. It may be present, or it may further contain at least one kind of boron, iron, cobalt, nickel, copper, and zirconium. The material powder 100 may have a particle size of several μm, for example 2-3 μm. The powder 100 of the material may be granulated into spherical particles of, for example, 50 to 60 μm using a resin binder such as a polyvinyl alcohol (PVA) binder which is an organic binder in order to secure fluidity.

The additional manufacturing in step S1 includes a step of depositing the material powder 100 to form the material layer 11 of the laminate 10 and a step of depositing the insulator powder to form the insulator layer 12 of the laminate 10. Have. In the step of forming the material layer 11, a liquid first binder is sprayed toward the surface of the powder bed 101 from a nozzle (not shown) provided directly above the powder bed 101 to permeate the powder bed 101, and a predetermined cross section is formed. The powder 100 of the material constituting the powder bed 101 is bonded from the outer periphery to a predetermined thickness and solidified to form a material layer so as to form the side surface 10a having the contour of the shape.

In the present specification, solidification means that powders are bonded to each other with a binder and fixed to form a solid state in order to form a desired object. The thickness t1 of the material layer 11 may be 1 to 2 mm. The thickness t3 from the outer circumference of the material layer 11 for solidifying the powder 100 of the material may be, for example, 0.5 mm.

The resin used as the first binder has a low viscosity because it is ejected from a nozzle, and quickly penetrates into the powder 100 of the material forming the powder bed 101. Further, the adhesive strength is high and the rigidity as its own strength is high so that the powder 100 of the material sprayed with the first binder can be quickly solidified to form the material layer 11 of the laminated body 10.

FIG. 3 is an enlarged cross-sectional view showing a portion of the material layer 11 solidified by the first binder. In the powder 100 of the material constituting the material layer 11, the granules 110 having a predetermined particle size infiltrated and solidified by the first binder are densely formed, and the powder 100 of the material is solidified. Can be seen.

Referring to FIG. 2 again, in the step of forming the insulator layer 12, a liquid mixture of the insulator powder and the second binder is applied to the surface of the powder bed from a nozzle (not shown) provided directly above the powder bed 101. The powder bed 101 is sprayed toward the surface and deposited on the surface of the powder bed 101 to form an insulator layer 12 formed of a mixture of the powder of the insulator and the second binder at a predetermined thickness on the surface of the powder bed 101. The thickness t2 of the insulator layer 12 may be 20 to 40 μm. The insulator layer 12 forms an outer periphery so as to be continuous with the outer periphery of the material layer 11 so as to form a side surface 10a having a common predetermined cross-sectional shape contour of the laminate 10 together with the material layer 11.

The resin used as the second binder has a viscosity such that a mixture with the powder of the insulator can be ejected from the nozzle and the mixture can be deposited on the powder 100 of the material forming the powder bed 101 without penetrating. have. Further, the adhesive strength is high and the rigidity is high as its own strength so that the mixture with the insulator powder quickly solidifies to form the insulator layer 12 of the laminate 10.

The powder of the insulator may be a metal oxide, a metal nitride or the like. The metal oxide may be silica, alumina or the like. The insulator powder may have a flaky structure such as mica. Further, the insulator powder may contain a rare earth metal so as to improve the characteristics of the magnet by infiltrating the magnet surface at the time of sintering. The rare earth metal may be at least one kind of praseodymium, neodymium, samarium, terbium and dysprosium. The powder of the insulator may have a particle size of several μm, for example, a particle size of 2 to 3 μm.

The steps of forming the laminate 10 include a step of depositing the material powder 100 to form the material layer 11 and a step of depositing the insulator material to form the insulator layer 12 in the powder bed 101 of the 3D printer. Are alternately repeated to form a laminated body 10 by laminating a material layer 11 having a predetermined thickness and an insulator layer 12 respectively. In this step, a common side surface 10a extending in the direction in which the laminated bodies 10 are laminated is formed. The diameter D of the side surface 10a may differ depending on the orientation, and may be, for example, 6.3 to 51.5 mm.

Further, the lower end and the upper end of the laminated body 10 are formed by the insulator layer 12. The upper and lower parts of the material layer 11 are covered with the insulator layer 12, respectively. Further, in the material layer 11, a predetermined thickness from the side surface 10a of the laminated body 10 is solidified by the first binder. Therefore, the powder 100 of the non-solidified material in the material layer 11 is surrounded by the solidified insulator layer 12 and the side surface 10a and is confined in the material layer 11.

FIG. 4 is an external view showing the laminated body 10. In FIG. 4, the insulator layer 12 is shown transparent among the material layer 11 and the insulator layer 12 constituting the laminate so that the structure of the laminate 10 can be easily seen. The same applies to FIG. 5 (a). The laminated body 10 of FIG. 4 is obtained by taking out the laminated body 10 formed from the powder bed 101 of the 3D printer shown in FIG. 2 and laying it on its side.

The laminate 10 is configured by alternately laminating a material layer 11 formed of the material powder 100 and an insulator layer 12 formed of the insulator layer 12 powder. Further, the laminated body 10 is formed with a side surface 10a common to the material layer 11 and the insulator layer 12. The side surface 10a is formed based on the contour of a predetermined cross-sectional shape. When the laminate 10 is taken out from the powder bed 101, the powder 100 of the material not used for modeling the laminate 10 is left in the container 104 containing the powder 100 of the material constituting the powder bed 101, but the residue remains. The powder 100 of the obtained material can be recovered and reused.

Next, the steps of the orientation of step S2, the sintering of step S3, and the sintering of step S4 shown in FIG. 1 will be described. FIG. 5 is a diagram showing a process of orientation and sintering. As described above, the laminated body 10 of FIG. 5A has a simplified shape and the like in order to explain the structure and manufacturing process of the laminated body 10. The actual laminated body 10 is formed into a shape similar to that of the finished laminated rare earth magnet.

As shown in FIG. 5A, the laminated body 10 is installed between the opposing magnetic poles of an electromagnet (not shown), and a pulse magnetic field or a static magnetic field is applied to the laminated body 10 to orient the material layer 11 of the laminated body 10. .. In the material layer 11, a portion having a predetermined thickness from the side surface 10a is solidified by the first binder, but the powder 100 of the unfixed material is contained in the range surrounded by the solidified portion. The powder 100 of this material is oriented according to the applied external magnetic field H.

As shown in FIG. 5B, the oriented laminated body 10 is stored in an electric furnace 105 and heated by a heater 106 to form a sintered body 20. The sintering temperature may be about 1000 ° C. The first binder obtained by solidifying the powder 100 of the material of the material layer 11 in the laminate 10 and the second binder deposited as a mixture together with the powder of the insulator in the insulator layer 12 are both before sintering. It is disassembled and sublimated.

The sintered body 20 shown in FIG. 5 (c) is a laminated rare earth magnet of a finished product. The rare earth magnet layer 21 and the insulator layer 22 of the sintered body 20 are obtained by sintering the material layer 11 and the insulator layer 12 of the laminated body 10, respectively. The size of the sintered body 20 is slightly smaller than that of the laminated body 10 because the density of the laminated body 10 before sintering is improved by sintering, but the sintered body 20 has substantially the same shape as the laminated body 10. The direction of the magnetization M is also shown in the figure.

Since the sintered body 20 has the shape of a laminated rare earth magnet as a finished product, it does not require a shaping step such as cutting or cutting. The size of the sintered body 20 may be such that the height h in the figure is 6.3 mm, the width w is 51.5 m, and the length l is 42 mm. These height h or width w may correspond to the diameter D of the laminated body 10 shown in FIGS. 2 and 4. Further, as the finishing process of step S4, each surface may be finished if necessary.

As described above, the laminated rare earth magnet produced by the manufacturing method of the present embodiment forms a laminated body in which the rare earth magnet layer 21 and the insulator layer 22 are alternately laminated, and the laminated body is integrally laminated. Consists of. The rare earth magnet layer 21 is composed of neodymium magnets having a composition of Nd ₂ Fe ₁₄ B, but is a samarium magnet such as SmCo ₅ or Sm ₂ (Co, Fe, Cu, Zr) ₁₇ , or cerium, placeodim, terbium. Alternatively, it may be composed of a magnet containing dysprosium. In the laminated rare earth magnet of the present embodiment, the thickness of the rare earth magnet layer 21 can be made as thin as 1 to 2 mm, so that it is possible to suppress the generation of eddy current even in a high frequency region and secure good characteristics.

As described above, in the present embodiment, the laminated body 10 in which the material layer 11 and the insulator layer 12 are alternately laminated is produced by the additive manufacturing (AM) technique. In the present embodiment, a laminated body 10 having the same shape as the finished laminated rare earth magnet can be produced by a 3D printer by a binder injection method. Therefore, by sintering the laminated body 10, a sintered body of the finished laminated rare earth magnet can be obtained immediately. Finishing may be performed when necessary.

In the present embodiment, since the laminated rare earth magnet of the finished product is obtained by sintering the laminated body 10, shaping such as cutting and cutting so that the block of the magnet has a desired shape in order to form the laminated rare earth magnet. There is no need to do or paste. Therefore, the shaping process and the bonding process such as cutting and cutting are not required, and the man-hours are reduced. Further, since the shaping process is not required, the chips generated in the shaping process are not generated, and the material of the rare earth magnet can be effectively used.

In the present embodiment, a 3D printer by a binder injection method is used, and the material layer 11 and the insulator layer 12 of the laminate 10 are formed by injecting a binder and solidifying them to deposit them. Therefore, the thickness of both the material layer 11 and the insulator layer 12 can be reduced. For example, the thickness of the material layer 11 can be 1 to 2 mm, and the thickness of the insulator layer 12 can be 20 to 40 μm. Also in the sintered body 20 of the laminated rare earth magnet obtained by sintering the laminated body 10 thus produced, the rare earth magnet layer 21 corresponding to the material layer 11 and the insulator layer 22 corresponding to the insulator layer 12 are also used. All of them have the same thickness. Therefore, even in the high frequency region, it is possible to suppress the generation of eddy currents and secure the performance of the laminated rare earth magnet.

In the present embodiment, in the powder bed 101 of the 3D printer of the binder injection method, the powder 100 of the material not used for producing the laminate 10 can be recovered from the container 104 and reused. Therefore, the material of the rare earth magnet can be effectively used.

In the laminated rare earth magnet of the present embodiment, the rare earth magnet layer 21 and the insulator layer 12 are directly laminated, but a dysprosium layer may be sandwiched between them. In this case, a laminated rare earth magnet can be produced by sintering the laminated body 10 deposited so as to sandwich the dysprosium layer between the material layer 11 and the insulator layer 12. By sandwiching the dysprosium layer in this way, the heat resistance of the laminated rare earth magnet can be improved.

Further, the laminated rare earth magnet of the present embodiment can be formed into a specific shape by additional manufacturing in order to improve the magnetic field efficiency when used as a permanent magnet of a field magnet in an electric motor. For example, it may be formed in a U-shape, a V-shape, or an ellipsoidal shape.

In the following, in order to compare with the present embodiment, a method for manufacturing a laminated rare earth magnet different from the present embodiment is shown as a comparative example.

[Comparative Example 1]
6 to 8 are views showing a process of a method for manufacturing a laminated rare earth magnet of Comparative Example 1. In Comparative Example 1, as shown in FIG. 6A, the die 41 and the punch 42 of the press for molding the powder 31 of the material of the rare earth magnet are between the magnetic poles 43 of the opposing electromagnet around which the coil 45 is wound. It is installed in. The material powder 31 is formed by the die 41 and the punch 42, and at the same time, is oriented by the magnetic field H applied from the magnetic pole 43.

As shown in FIG. 6B, the powder of the molded and oriented material is heated by a heater 48 in an electric furnace 47 and sintered to form a block magnet 32. As shown in FIG. 6C, the block magnet 32 is cut by the blade 49 to form a small block magnet 34. In the figure, the direction of the magnetization M is shown. The same applies to the following. As shown in FIGS. 7 (b) and 7 (c), the small block magnet 34 as shown in FIG. 7 (a) is machined into the shape of a motor magnet 35 for which a motor is used. ..

The motor magnet 35 shown in FIG. 8A is cut into a thin plate magnet 37 having a thickness of 2 mm, and 21 thin plate magnets 37 are further bonded with an adhesive. The thickness of the thin plate magnet 37 of 2 mm is the limit for thinning the thin plate magnet 37. As a result, a finished laminated rare earth magnet 39 in which the thin plate magnet 37 and the insulator layer 38 made of the solidified adhesive are laminated is obtained. The size of the laminated rare earth magnet 39 may be 6.3 mm in height h, 51.5 mm in width w, and 42 mm in length l in the figure.

[Comparative Example 2]
9 to 11 are views showing a process of a method for manufacturing a laminated rare earth magnet of Comparative Example 2. Comparative Example 2 corresponds to the manufacturing method disclosed in Patent Document 1.

As shown in FIG. 9A, the partition plate 63 is fitted into the cavity 62 of the mold 61 at predetermined intervals. The partition plate 63 may be made of ceramic or the like so as to withstand high heat. The cavity 62 is formed in a shape similar to that of a finished motor magnet. As shown in FIG. 9B, the cavity 62 of the mold 61 into which the partition plate 63 is fitted is filled with the powder 51 of the rare earth magnet material. As shown in FIG. 9C, the upper lid of the mold 61 is fitted to the powder 51 of the material filled in the cavity 62, and the magnetic field H generated in the electromagnet 64 is applied to the powder 51 of the material for orientation.

As shown in FIG. 10A, the mold 61 surrounding the oriented material powder 51 is removed, and as shown in FIG. 10B, the laminated body 52 composed of the material powder 51 and the partition plate 63 is formed. Take it out. The removed mold 61 is reused. As shown in FIG. 10 (c), the laminated body 52 is sintered by the heater 66 in the electric furnace 65.

The thin plate of the powder 51 of the material constituting the laminated body 52 becomes a thin plate magnet 53 made of a sintered body whose density has been increased by sintering and whose size has been reduced. The thin plate magnet 53 may have a thickness of 2 mm. The thickness of 2 mm is the limit for thinning the thin plate magnet 53. The partition plate 63 is removed from the sintered laminate 52 to obtain a thin plate magnet 53. The removed partition plate 63 is reused.

When the thin plate magnet 53 shown in FIG. 11 (a) is bonded with an adhesive, as shown in FIG. 11 (b), the laminated rare earth magnet of the finished product in which the thin plate magnet 53 and the insulator layer 55 made of the solidified adhesive are laminated. 56 is obtained. The size of the laminated rare earth magnet 56 may be 6.3 mm in height h, 51.5 mm in width w, and 42 mm in length l in the figure.

Comparing Comparative Example 2 and Comparative Example 1, since the powder 51 of the material is formed on the laminated body 52 to improve the density at the time of sintering, the pressing step is not required. Further, since the material powder 51 is formed in the shape of the motor magnet of the finished product when the mold 61 is filled, the step of cutting and cutting the magnet block into the shape of the motor magnet is not required.

[Comparative Example 3]
12 and 13 are diagrams showing a process of a method for manufacturing a laminated rare earth magnet of Comparative Example 3. Comparative Example 3 corresponds to the manufacturing method disclosed in Patent Document 2.

As shown in FIG. 12A, the partition plate 83 of the insulator is fitted into the cavity 82 of the mold 81 at predetermined intervals. The partition plate 83 constitutes an insulator layer in the finished laminated rare earth magnet. The cavity 82 is formed in a shape similar to that of a finished motor magnet. As shown in FIG. 12B, the cavity 82 of the mold 81 into which the partition plate 83 is fitted is filled with the powder 71 of the rare earth magnet material. As shown in FIG. 12 (c), the upper lid of the mold 81 is fitted to the powder 71 of the material filled in the cavity 82, and the magnetic field H generated in the electromagnet 84 is applied to the powder 71 of the material for orientation.

As shown in FIG. 13 (a), the mold 81 surrounding the oriented material powder 71 is removed, and as shown in FIG. 13 (b), the material powder 71 and the partition plate 83 are laminated. Take out the body 72. The removed mold 81 is reused. Then, as shown in FIG. 13 (c), the laminated body 72 is sintered by the heater 86 in the electric furnace 85 to obtain the sintered body 73.

In the sintered body 73, the thin plate and the partition plate 83 of the material powder 71 in the laminated body 72 become the rare earth magnet layer 74 and the insulator layer 75, respectively, by sintering. The rare earth magnet layer 74 may have a thickness of 2 mm. The thickness of 2 mm is the limit for thinning the rare earth magnet layer 74. The sintered body 73 is formed by laminating a rare earth magnet layer 74 and an insulator layer 75 to form a finished laminated rare earth magnet 76. The size of the laminated rare earth magnet 76 may be 6.3 mm in height h, 51.5 mm in width w, and 42 mm in length l in the figure.

Comparing Comparative Example 3 and Comparative Example 1, since the powder 71 of the material is formed in the laminated body 72 to improve the density at the time of sintering, the pressing step is not required. Further, since the material powder 71 is formed in the shape of the motor magnet of the finished product when the mold 81 is filled, the process of cutting and cutting for shaping the magnet block into the shape of the motor magnet is not required. .. Further, since the partition plate 83 is formed on the insulator layer 75 of the laminated rare earth magnet 76 by sintering, the step of adhering the thin plate magnet is not required.

INDUSTRIAL APPLICABILITY The present invention can be used for manufacturing laminated rare earth magnets used in applications such as IT equipment, industrial motors, and automobiles.

10 Laminate 11 Material layer 12 Insulator layer 20 Sintered body 21 Rare earth magnet layer 22 Insulator layer 100 Material powder 101 Powder floor 102 Bottom plate 103 Side wall 104 Container

Claims (14)

A method for manufacturing laminated rare earth magnets.
A process of alternately laminating a material layer in which powder of a material containing a rare earth metal is deposited and an insulator layer in which powder of an insulator is deposited by additional manufacturing to form a laminate, and
The step of applying a magnetic field to the laminated body to orient it, and
A method including a step of sintering the oriented laminated body to form a sintered body. In the step of forming the laminate, a 3D printer of the binder injection method was used.
A step of spraying a first binder onto a predetermined portion of the surface of a powder bed filled with the powder of the material to form a powder layer of the material in which a part of the powder of the material is solidified with the first binder. When,
A claim comprising a step of injecting a mixture of the insulator powder and a second binder to deposit the mixture so as to cover at least a part of the surface of the powder bed to form the insulator layer. The method according to 1. In the step of forming the material layer and the step of forming the insulator layer, in the laminated body extending in the depth direction of the powder bed, the material layer and the insulator layer are separated into the first binder and the insulator layer, respectively. The method according to claim 2, wherein an aspect formed by solidifying with a second binder is formed. In the laminate, the powder of the material constituting the material layer is solidified with the first binder from the outer periphery to a predetermined thickness, and the upper and lower parts are covered with the insulator layer solidified with the second binder. The method according to claim 3. The method according to any one of claims 2 to 4, wherein the powder of the material that fills the powder bed is formed by binding the powder of the material with an organic binder to form a predetermined particle size. A laminated rare earth magnet manufactured by the method according to any one of claims 1 to 5.
Rare earth magnet layer and
A laminated rare earth magnet including an insulator layer, wherein the rare earth magnet layer and the insulator layer are alternately laminated to form a laminated body, and the laminated body constitutes an integral sintered body. The laminated rare earth magnet according to claim 6, wherein the rare earth magnet layer contains at least one kind of cerium, praseodymium, neodymium, samarium, terbium and dysprosium as the rare earth metal. The laminated rare earth magnet according to claim 7, wherein the rare earth magnet layer further includes at least one kind of boron, iron, cobalt, nickel, copper, and zirconium. The laminated rare earth magnet according to any one of claims 6 to 8, wherein the insulator layer contains at least one kind of a metal oxide and a metal nitride. The laminated rare earth magnet according to claim 9, wherein the metal oxide contains at least one kind of alumina and silica. The laminated rare earth magnet according to claim 9 or 10, wherein the insulator layer contains a rare earth metal. The laminated rare earth magnet according to claim 11, wherein the rare earth metal contains at least one kind of praseodymium, neodymium, samarium, terbium and dysprosium. The laminated rare earth magnet according to any one of claims 6 to 12, further comprising a dysprosium layer sandwiched between the rare earth magnet layer and the insulator layer. The laminated rare earth magnet according to any one of claims 6 to 13, which is formed in a V-shaped, U-shaped or ellipsoidal shape.

Images