KR102601962B1 - Materials for 3d printing and 3d printer using the same - Google Patents

Abstract

The present invention is a material for three-dimensional printing using a laser, comprising: a core containing a magnetic material; and a coating material, including a shell covering the surface of the core, wherein the coating material has a higher laser absorption rate than the magnetic material in a predetermined wavelength range, a three-dimensional printing material, and a shell covering the surface of the core. It relates to a 3D printer using a 3D printing method and a magnetic material manufactured thereby.

Description

Materials for 3D printing and 3D printers using the same {MATERIALS FOR 3D PRINTING AND 3D PRINTER USING THE SAME}

The present invention relates to materials for 3D printing using lasers, and more specifically, to materials for 3D printing, 3D printers and printing methods using the same, and magnetic materials manufactured using the same.

3D printing is a process of constructing a 3D object by layering materials such as plastic, liquid, and powder particles based on a pre-designed 3D model. As precision and repeatability increase, it can be used from rapid modeling of prototypes to mass production of actual products. It has become possible.

Recently, as parts used in electric vehicles, robots, and electronic products become smaller and lighter, demand for high-performance motors of various shapes is increasing. Motors use magnetic materials. In the case of soft magnetic materials, they are manufactured in a two-dimensional form by laminating electrical steel sheets, or by charging soft magnetic powder into a mold and press-molding it to form a soft magnetic core. Hard magnetic materials are made of Al. Except for AlNiCo cast magnets, they are manufactured in the form of sintered magnets or bonded magnets through powder metallurgy using magnetic powder. However, magnets manufactured using conventional methods limit the structural design of motors that can be manufactured using them, which limits the improvement of motor performance and efficiency, and the shape of the motor is also limited, resulting in low mass production and high mold manufacturing costs. There was a problem that it was increasing.

Accordingly, attempts are being made to create products of various shapes through 3D printing using magnetic materials, but there are limits to the manufacture of magnetic materials using 3D printers due to the coercive force, iron loss, and mechanical properties of magnetic materials. there was. The following patent document relates to magnetic material powder for obtaining a magnetic core with high magnetic permeability through powder compaction. The magnetic core was manufactured by heating and curing a mixture of magnetic material powder and thermosetting resin. However, in the case of magnetic materials, their magnetic properties deteriorate when they undergo melting and hardening processes.

Therefore, research is continuing on materials for 3D printing that are suitable for mass production in desired shapes through 3D printing while preventing deterioration of the magnetic properties of magnetic materials.

Korean Patent Publication No. 2017-0009928

N.K. Tolochko et. al., Asorptance of powder materials suitable for laser sintering, Rapid Prototyp. J.Vol. 6 (2000) 155-161

The purpose of the present invention is to provide a material for 3D printing using a laser, which prevents melting of the magnetic material, prevents deterioration of the magnetic properties of the magnetic material, and has excellent shape freedom.

Additionally, an object of the present invention is to provide a 3D printer using the above 3D printing material.

Additionally, an object of the present invention is to provide a 3D printing method using the above 3D printing material and a magnetic body manufactured thereby.

A three-dimensional printing material according to one aspect of the present invention is for use in three-dimensional printing using a laser, and includes a core containing a magnetic material, a coating material, and a shell covering the surface of the core. wherein the coating material has a higher laser absorption rate than the magnetic material in a predetermined wavelength range.

Specifically, the coating material may be one or more types selected from the group consisting of non-ferrous metals and oxides of non-ferrous metals.

Specifically, the magnetic material is one or more soft magnetic materials selected from the group consisting of Fe, FeAl, FeSiAl, FeSi, FeSiAl, FeSiCr, FeCr, FeCo, FeNi, and FeNiP, and the coating material is Al, Si, Ti, Cu. It may be one or more types of oxides selected from the group consisting of , Zr, Sn, and Ba.

Specifically, the content of the coating material may be 0.1 to 20% by weight based on the total weight of the 3D printing material.

Specifically, the magnetic material may be one or more hard magnetic materials selected from the group consisting of AlNiCo, FeCrCo, FeCoV, CuNiFe, CuNiCo, PtCo, barium ferrite, strontium ferrite, SmCo5, SmCo17, NdFeB, NdFeN, and SmFeN.

Specifically, the content of the coating material may be 0.1 to 20% by weight based on the total weight of the 3D printing material.

Specifically, the material for three-dimensional printing includes a second coating material, and further includes a second shell covering a surface of the shell, wherein the second coating material is more sensitive to the laser than the magnetic material in a predetermined wavelength range. The absorption rate is higher and may have a different laser absorption rate than the coating material.

A three-dimensional printer according to another aspect of the present invention includes a core containing a magnetic material and a coating material, and a shell covering the surface of the core, wherein the coating material coats the magnetic material in a predetermined wavelength range. It includes a bed part where a three-dimensional printing material with a higher laser absorption rate is disposed, and a laser part that irradiates a laser of the wavelength range to a predetermined area of the three-dimensional printing material.

Specifically, the laser unit may include one or more laser irradiators that irradiate laser, and a controller that controls the operation of the laser irradiators.

Specifically, the laser unit includes a plurality of laser irradiators that irradiate lasers of different wavelength regions, and the controller can drive one of the plurality of laser irradiators to irradiate one laser.

Specifically, the laser unit includes a plurality of laser irradiators that irradiate lasers of different wavelength regions, and the controller can drive two or more of the plurality of laser irradiators to overlap and irradiate lasers.

Specifically, the laser unit may further include a wavelength conversion module that converts the wavelength of the laser radiated from the laser irradiator.

Specifically, the laser irradiator may include a wavelength conversion module that converts the wavelength of the laser radiated from the laser irradiator.

A three-dimensional printing method according to another aspect of the present invention includes a core containing a magnetic material and a coating material, and a shell covering the surface of the core, wherein the coating material prints the radiation in a predetermined wavelength range. It includes preparing a three-dimensional printing material with a higher laser absorption rate than a magnetic material, and irradiating the three-dimensional printing material with a laser having the wavelength range to melt the coating material to form a layer.

Another aspect of the present invention is a magnetic material manufactured by the above 3D printing method.

Another aspect of the present invention is a motor including the magnetic material.

The material for 3D printing according to the present invention is used for 3D printing using a laser and can be used to manufacture magnetic materials with excellent shape freedom.

In addition, the 3D printer according to the present invention adjusts the wavelength of the irradiating laser to selectively melt only the shell containing the coating material from the 3D printing material, thereby preventing deterioration of magnetic properties due to melting of the magnetic material. can do.

Figure 1a is a cross-sectional view of a material for 3D printing according to an embodiment of the present invention.
Figure 1b is a cross-sectional view of a material for 3D printing according to another embodiment of the present invention.
Figure 2a is a schematic diagram showing the process of 3D printing using a 3D printing material according to an embodiment of the present invention.
Figure 2b is a schematic diagram showing a layer formed after irradiating a laser to a printing material according to Figure 2a.
Figure 3 is a graph showing the wavelength range according to the type of laser and the absorption rate of the material accordingly.
Figure 4 is a schematic diagram showing a 3D printing according to another embodiment of the present invention.
Figure 5 is a schematic diagram showing the laser unit of a 3D printer according to another embodiment of the present invention.
Figure 6a is a schematic diagram showing the laser unit of a 3D print according to another embodiment of the present invention.
Figure 6b is a schematic diagram showing the laser unit of a 3D printer according to another embodiment of the present invention.

Hereinafter, each configuration of the present invention will be described in more detail so that those skilled in the art can easily implement it. However, this is only an example, and the scope of rights of the present invention is determined by the following contents. Not limited.

As used herein, the term “comprising” is used to list materials, compositions, devices, and methods useful in the present invention and is not limited to the listed examples.

In the present invention, “3D printing” involves placing a printing material and then melting and curing a predetermined area according to the design to form a layer, placing the printing material again on the layer, and melting and curing according to the design. This means producing a three-dimensional shape according to the design by forming a stacked structure of layers through a process. More specifically, 3D printing may be a powder bed fusion (PBF) method in which a material such as powder is placed on a bed and then the desired shape is manufactured through melting of the material, preferably using a laser. It may be a laser method of irradiating and melting the material, preferably a selective laser sintering (SLS) method.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. At this time, note that in the attached drawings, identical components are indicated by identical symbols whenever possible. Additionally, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention are omitted, and some components are exaggerated, omitted, or schematically shown in the drawings.

1A and 1B are cross-sectional views of materials 1 and 2 for three-dimensional printing according to an embodiment of the present invention, respectively.

Referring to FIG. 1A, the three-dimensional printing material 1 includes a core 10 containing a magnetic material and a coating material, and may include a shell 20 covering the surface of the core 10. . The shape of the shell 20 covering the surface of the core 10 is not limited, but the core 10 is preferably a spherical particle. More preferably, the three-dimensional print material 1 may be spherical particles having a core-shell structure.

Referring to FIG. 1B, the 3D printing material 2 may have a structure in which the surface of the 3D printing material 1 is additionally covered with a second shell 30. The shell 20 includes a coating material, and the second shell 30 may include a second coating material different from the coating material, preferably having a different absorption rate for the wavelength region of the laser, which will be described later. It may be.

The core 10 and the shell 20 may have a structure in which the magnetic material of the core 10 and the coating material of the shell 20 are combined through physical bonding. The shell 20 and the second shell 30 may also have a structure in which the coating material of the shell 20 and the second coating material of the second shell 30 are combined through physical bonding. For example, the spherical core 10 may be immersed in a molten coating material and then dried, or a core-shell structure may be formed by spraying the coating material onto the core 10. Additional coating materials may be selected for the core-shell structure to form a second shell 20 that covers the shell 20 using the same or different methods from the method of forming the shell 20. Although not shown, the surface of the second shell 20 may be further coated with an additional shell to form a core-multi-shell structure, but the present invention is not limited thereto.

The three-dimensional printing materials 1 and 2 of the powder bed melt method may have a diameter of 20 to 50 ㎛, and the thickness of the shell 20 or the shell 20 and the second shell 30 may be 0.01 to 1 ㎛. You can. If the thickness of the shell 20 or the shell 20 and the second shell 30 is less than 0.01㎛, the loss of the core 10 due to the laser increases rapidly, and the shell 20 or the shell 20 and the second shell 30 rapidly increase. 2 When the thickness of the shell 30 exceeds 1㎛, the arrangement between the plurality of cores 10 becomes uneven, and the magnetic properties of the manufactured magnetic material may appear uneven.

The core 10 may include a soft magnetic material or a hard magnetic material.

The soft magnetic material includes iron (Fe), iron-aluminum alloy (FeAl), iron-silicon-aluminum alloy (FeSiAl), iron-silicon alloy (FeSi), iron-silicon-chromium alloy (FeSiCr), and iron-chromium alloy. It may be one or more types selected from the group consisting of (FeCr), iron-cobalt alloy (FeCo), iron-nickel alloy (FeNi), and iron-nickel-phosphorus alloy (FeNiP).

The hard magnetic materials include aluminum-nickel-cobalt alloy (AlNiCo), iron-chromium-cobalt alloy (FeCrCo), iron-cobalt-vanadium alloy (FeCoV), copper-nickel-iron alloy (CuNiFe), and platinum-cobalt alloy ( PtCo), barium ferrite (Ba ferrite), strontium ferrite (Sr ferrite), samarium-cobalt alloy (SmCo5, SmCo17), neodymium-iron-boron alloy (NdFeB), neodymium-iron-nitrogen alloy (NdFeN), and samarium-iron. -It may be one or more types selected from the group consisting of nitrogen alloy (SmFeN).

The shell 20 and the second shell 30 each include a coating material, and the coating material may be one or more inorganic materials selected from the group consisting of non-ferrous metals and oxides of non-ferrous metals. The non-ferrous metal used as the coating material may be one or more selected from the group consisting of aluminum (Al), silicon (Si), titanium (Ti), copper (Cu), zirconium (Zr), tin (Sn), and barium (Ba). You can. The oxides of the non-ferrous metals include, for example, aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), copper oxide (CuO), zirconium oxide (ZrO ₂ ), tin oxide (SnO), and barium oxide (BaO). However, it is not limited to this. Preferably, the shell 20 and the second shell 30 do not contain an adhesive such as resin or an organic binder, thereby reducing the shape constraints on the magnetic material that can be manufactured with the three-dimensional printing materials 1 and 2, Deterioration of the magnetic properties of the final magnetic material due to residual organic substances can be prevented.

When the core 10 uses a soft magnetic material as a magnetic material, it is preferable to use the above-described non-ferrous metal oxide as the coating material for the shell 20, and the content of the coating material is the same as that of the three-dimensional printing material (1) It may be 0.1 to 20% by weight based on the total weight. Within the above content range, the non-ferrous metal oxide covers the surface of the core 10 to form an insulating film, and it is possible to minimize loss of the core 10 that occurs during laser irradiation, which will be described later. More preferably, the content of the coating material may be 0.1 to 5% by weight based on the total weight of the 3D printing material (1).

When the core 10 uses a hard magnetic material as a magnetic material, the content of the coating material may be 0.1 to 20% by weight based on the total weight of the 3D printing material 1. If the content of the coating material is less than 0.1% by weight, the coating material evaporates during the laser irradiation process, causing loss of the core 10, and if the content of the coating material exceeds 20% by weight, the magnetic material is shielded and ultimately The magnetic properties of the manufactured magnetic material may deteriorate. More preferably, the content of the coating material may be 0.1 to 10% by weight based on the total weight of the 3D printing material (1).

Figure 2a is a schematic diagram showing the process of preparing a material for 3D printing (1) according to the above-described embodiment and irradiating a laser (L1) for 3D printing, and Figure 2b is a schematic diagram showing the process of 3D printing using a laser according to Figure 2a. This is a schematic diagram showing the formation of layers after irradiation of the material.

In the three-dimensional printing material 1 according to the present invention, the coating material of the shell 20 may have a higher laser absorption rate than the magnetic material of the core 10 in a predetermined laser wavelength range. Additionally, the magnetic material may have a higher laser reflectivity than the laser absorption rate in the wavelength range. The 3D printer 100, which will be described later, can irradiate a laser L1 in a wavelength range capable of melting the coating material of the shell 20.

The laser (L1) that can be used in the present invention may be ArF, KrF, Nd:YAG, Nd:YVO ₄ , Yb:Fiber or CO ₂ , and the laser (L1) is used on the surface of the three-dimensional printing material (1). It may be reflected or reflected at the interface between the core 10 and the shell 20, but at least a portion may be absorbed into the shell 20 of the three-dimensional printing material 1 to at least partially melt the coating material. Alternatively, the laser L1 may be reflected from the surface of the three-dimensional printing material 1 or from the interface between the core 10 and the shell 20, but at least a portion of the laser L1 may be reflected from the coating material or agent of the shell 20. 2 The second coating material of shell 30 may be at least partially melted.

For example, the three-dimensional printing material 1 may include iron (Fe), a soft magnetic material, as the core 10, and silicon oxide (SiO ₂ ) as a coating material may be included in the shell 20. . Iron has an absorption rate of approximately 0.45 for CO ₂ laser (λ=10.6㎛), and silicon oxide has an absorption rate of approximately 0.96 for CO ₂ laser, so the coating material has a lower wavelength range of the laser than the magnetic material. Due to its high absorption rate, the coating material can absorb most of the irradiated laser and melt.

For example, the three-dimensional printing material 2 includes iron (Fe), a soft magnetic material, as the core 10, copper oxide (CuO) as a coating material in the shell 20, and a second As a coating material, silicon oxide (SiO ₂ ) may be included in the second shell 30 . Copper oxide has an absorption rate of CO ₂ laser of approximately 0.76, and the silicon oxide of the second shell 30 exposed to the outside from the 3D printing material 2 can preferentially absorb the laser, and at least part of the laser can absorb the laser. The laser can be absorbed by the copper oxide of the shell 20. In this case, the degree of melting of the shell 20 and the second shell 30 can be adjusted by adjusting the intensity of the laser, making it possible to configure various layers by adjusting the intensity even when using a single type of laser.

Referring to FIG. 2A, a plurality of 3D printing materials 1 can be placed on a flat substrate or on the bed 110 of the 3D printer 100, which will be described later, by irradiating the laser L1 in one direction. The coating material in the desired area can be melted. In this case, as shown in FIG. 2b, the coating material constituting the shell 20 of the adjacent three-dimensional printing material 1 melts and hardens to form a coating film 21 covering the plurality of cores 10. , it is possible to form a layer including a plurality of cores 10 covered with one or more coating films 21. Although not shown, a plurality of 3D printing materials 1 can be placed on top of the layer, and a plurality of layers can be formed and combined at the same time through the process of irradiating the laser L1 to the desired area. You can.

Referring to FIG. 3 and the non-patent document, the non-ferrous metal material exhibits a higher absorption rate in the wavelength range of the KrF laser compared to the magnetic material used in the core 10, for example iron, and the non-ferrous metal oxide material is used in the core 10. Compared to the magnetic materials used, for example iron, they exhibit a higher absorption rate in the wavelength range of the CO ₂ laser. Therefore, when using the three-dimensional printing material 2 including the second shell 30, the laser absorption rate of the coating material of the shell 20 and the second coating material of the second shell 30 are different from each other. By configuring it differently, different layers can be configured in one step, or the combination relationship of the layers can be adjusted during the layer stacking process.

Figure 4 is a schematic diagram showing a 3D printer 100 according to an embodiment of the present invention. The 3D printer 100 includes a bed unit 110 on which the above-described 3D printing materials 1 and 2 are disposed and a laser unit that irradiates a laser to a predetermined area of the 3D printing materials 1 and 2. It may include (120).

The bed portion 110 may further include a cylinder 111 on which the three-dimensional printing materials 1 and 2 can be placed. The cylinder 111 may provide a flat space where the three-dimensional printing materials 1 and 2 can be arranged in at least one layer. The cylinder 111 can move downward as the three-dimensional printing materials (1, 2) form a layer by a laser, and after additional three-dimensional printing materials (1, 2) are placed on top of the layer. Additional layers can be formed through laser irradiation. Referring to FIG. 4, as the laser irradiation is repeated, the laser is irradiated on the cylinder 111 and the coating material is melted and hardened to form an area where the coating film 21 is formed, and the laser is not irradiated, so the three-dimensional printing material (1) ) areas that remain the same can coexist.

In this way, the magnetic material can be manufactured by repeating the movement of the cylinder 111, the placement of the three-dimensional printing materials 1 and 2, and the laser irradiation, and the cylinder 111 is moved upward again after the final magnetic material is manufactured. The magnetic material may be discharged from the bed portion 110 by moving.

The laser unit 120 may include one or more laser irradiators 121 to 123 that irradiate lasers of unique wavelengths and a controller 124 that controls the operation of the laser irradiators 121 to 123. The plurality of laser irradiators may be divided into a first laser irradiator 121, a second laser irradiator 122, a third laser irradiator 123, etc., depending on the laser wavelength, but are not limited thereto. The controller 124 can control the operation of the laser irradiators 121 to 123 by receiving information about the design of the shape and the coating material of the 3D printing materials 1 and 2 used, and is located in the desired area. The laser L1 can be irradiated to melt only the desired coating material. For example, the controller 124 can drive only one laser irradiator 121 to irradiate the laser L1 having a desired wavelength.

Figures 5 and 6 are schematic diagrams showing the laser unit 120 of a 3D printer according to another embodiment of the present invention.

Referring to FIG. 5, the controller 124 controls two or more of the plurality of laser irradiators 121 to 123 to overlap or offset lasers in different wavelength regions to form and irradiate lasers of a desired wavelength. For example, the controller 124 overlaps a laser L1 having a first wavelength using the first laser irradiator 121 and a laser L2 having a second wavelength using the second laser irradiator 122. You can irradiate a laser (L'1) of a different desired wavelength.

Referring to FIG. 6, the laser unit 120 may further include a wavelength conversion module 125 that converts the wavelength of the laser irradiated from one or more laser irradiators 121 to 123. For example, referring to FIG. 6A, the wavelength conversion module 125 can be mounted on the part where the laser is irradiated from the laser irradiators 121 to 123, and converts it into a laser L'1 of a different desired wavelength. can be investigated.

Alternatively, referring to FIG. 6B, the laser irradiators 121 to 123 may include a wavelength conversion module 125. For example, the wavelength conversion module 125 may be installed inside the laser irradiators 121 to 123, and the controller 124 controls the operation of the wavelength conversion module 125 to select the desired wavelength of the irradiated laser. It can be irradiated by converting to a laser (L'1) of a different wavelength.

The present invention also includes preparing materials (1, 2) for three-dimensional printing according to an embodiment of the present invention, and irradiating a laser having the wavelength range to the materials (1, 2) for three-dimensional printing. Provided is a three-dimensional printing method including the step of melting a coating material to form a layer. The steps of preparing materials for 3D printing (1, 2) and forming layers can be repeated according to the design.

In this case, through selective laser melting of the shell 20 or the second shell 30 in the three-dimensional printing materials 1 and 2 of the core-shell structure, the degree of freedom of shape is excellent, and at the same time, the loss of the core 10 is achieved. Magnetic materials with minimal degradation of magnetic properties can be used to manufacture them. In addition, since the degree of freedom of shape of the motor is affected by the degree of freedom of shape of the magnetic material used in the motor, the motor including the magnetic material according to an embodiment of the present invention also has a high degree of freedom of shape and can be used in various electronic products such as electric vehicles. .

1, 2: Materials for 3D printing
10: core 20: shell
21: coating film 30: second shell
100: 3D printer 110: Bed unit
111: cylinder 120: laser unit
121: first laser irradiator 122: second laser irradiator
123: Third laser irradiator 124: Controller
125: Wavelength conversion module
L1, L2, L'1: Laser

Claims (16)

As a material for laser melting and sintering three-dimensional printing,
A core containing magnetic material;
a shell comprising a coating material and covering the surface of the core; and
comprising a second shell comprising a second coating material, the second shell covering the surface of the shell;
The laser is ArF, KrF, Nd:YAG, Nd:YVO ₄ , Yb:Fiber or CO ₂ ,
The coating material and the second coating material each have a higher absorption rate for the laser than the magnetic material and are at least one selected from the group consisting of non-ferrous metals and oxides of non-ferrous metals,
A material for laser melting and sintering three-dimensional printing, wherein the second coating material has a different absorption rate than the coating material. delete According to paragraph 1,
The magnetic material is one or more soft magnetic materials selected from the group consisting of Fe, FeAl, FeSiAl, FeSi, FeSiAl, FeSiCr, FeCr, FeCo, FeNi and FeNiP,
The coating material is a laser melting and sintering three-dimensional printing material that is one or more oxides selected from the group consisting of Al, Si, Ti, Cu, Zr, Sn, and Ba. According to paragraph 3,
A laser melting and sintering three-dimensional printing material wherein the content of the coating material is 0.1 to 20% by weight based on the total weight of the three-dimensional printing material. According to paragraph 1,
The magnetic material is a laser melted and sintered three-dimensional material that is one or more hard magnetic materials selected from the group consisting of AlNiCo, FeCrCo, FeCoV, CuNiFe, CuNiCo, PtCo, barium ferrite, strontium ferrite, SmCo5, SmCo17, NdFeB, NdFeN and SmFeN. Materials for printing. According to clause 5,
A laser melting and sintering three-dimensional printing material wherein the content of the coating material is 0.1 to 20% by weight based on the total weight of the three-dimensional printing material. delete A core containing magnetic material; a shell comprising a coating material and covering the surface of the core; and a second coating material, a bed portion on which a laser melting and sintering three-dimensional printing material including a second shell covering the surface of the shell is disposed; and
A laser melting and sintering type 3D printer including a laser unit that irradiates laser to the 3D printing material,
The laser is ArF, KrF, Nd:YAG, Nd:YVO ₄ , Yb:Fiber or CO ₂ ,
Each of the coating material and the second coating material has a higher absorption rate for the laser than the magnetic material and is at least one selected from the group consisting of non-ferrous metals and oxides of non-ferrous metals,
The laser melting and sintering three-dimensional printer, wherein the second coating material has a different absorption rate than the coating material. According to clause 8,
The laser unit,
One or more laser irradiators that irradiate a laser; and
A laser melting and sintering three-dimensional printer including a controller that controls the operation of the laser irradiator. According to clause 9,
The laser unit includes a plurality of laser irradiators that irradiate lasers of different wavelength ranges,
A laser melting and sintering type 3D printer wherein the controller drives one of the plurality of laser irradiators to irradiate one laser. According to clause 9,
The laser unit includes a plurality of laser irradiators that irradiate lasers of different wavelength ranges,
A laser melting and sintering type 3D printer in which the controller drives two or more of the plurality of laser irradiators to overlap and irradiate lasers. According to clause 9,
The laser unit further includes a wavelength conversion module that converts the wavelength of the laser irradiated from the laser irradiator. According to clause 9,
The laser irradiator is a laser melting and sintering type 3D printer including a wavelength conversion module that converts the wavelength of the laser irradiated from the laser irradiator. A core containing magnetic material; a shell comprising a coating material and covering the surface of the core; and a second coating material, comprising: preparing a material for laser melting and sintering three-dimensional printing, including a second shell covering the surface of the shell; and
Comprising the step of irradiating a laser to the three-dimensional printing material to melt the coating material to form a layer,
The laser is ArF, KrF, Nd:YAG, Nd:YVO ₄ , Yb:Fiber or CO ₂ ,
Each of the coating material and the second coating material has a higher absorption rate for the laser than the magnetic material and is at least one selected from the group consisting of non-ferrous metals and oxides of non-ferrous metals,
The laser melting and sintering three-dimensional printing method, wherein the second coating material has a different absorption rate than the coating material. A magnetic material manufactured by the 3D printing method of claim 14. A motor comprising the magnetic material of claim 15.

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