JP6491289B2 - Method for producing metal product - Google Patents

Description

  The present invention relates to a method for manufacturing a metal product, and more particularly, to a method for manufacturing a metal product for applying a high-frequency current.

  2. Description of the Related Art Conventionally, a metal product that conducts a high-frequency high current is manufactured by processing a material having excellent conductivity. Such a metal product is expected to be produced using additive manufacturing technology of metal using a 3D printer or the like.

  As a method for producing such a metal product, at least one of chromium (Cr) and silicon (Si) is contained in an amount of 0.10% by mass to 1.00% by mass, and the total amount of chromium and silicon is 1. There is known a manufacturing method of a layered object using a copper alloy powder which is equal to or less than 00% by mass and the balance is made of copper (for example, Patent Document 1).

Japanese Patent No. 6030186

  However, in the above-described example, a metal product made of a copper alloy or the like is insufficient in electrical conductivity as a metal product that conducts a high-frequency current as compared with a metal material such as pure copper. Moreover, when using metal materials, such as pure copper, as a raw material, density increase is difficult and the subject remains in practical use.

  In light of the above circumstances, the present invention provides a method for producing a metal product that can provide high-frequency conductivity equivalent to that of a metal material such as pure copper, even if a metal material that is less conductive than a metal material such as pure copper is used. The purpose is to provide.

  In order to achieve the above object, the present invention is a method for manufacturing a metal product for energizing a high-frequency current, and includes a layered manufacturing process for layered modeling of a modeled product of a first metal material, and plating the modeled product At least a plating step of forming a layer of a second metal material by performing a treatment, wherein the second metal material has a higher conductivity with respect to a high-frequency current than the first metal material, and the modeled object is the second metal material. It is characterized in that the metal product is formed so as to have a dimension according to the thickness of the metal material layer.

［式中、ｄは厚さ(ｍｍ)であり、ｆは高周波電流の周波数(ＭＨｚ)であり、μは第２金属素材の透磁率(Ｈ／ｍ)であり、σは第２金属素材の導電率(Ｓ／ｍ)である。］を満たすことが好適である。 The thickness (d) of the second metal material layer is expressed by the following formula 1).

[Where d is the thickness (mm), f is the frequency (MHz) of the high frequency current, μ is the permeability (H / m) of the second metal material, and σ is the second metal material. Conductivity (S / m). ] Is preferable.

  Moreover, the manufacturing method of the metal product which concerns on this invention shall be the form which further includes the cutting process which cuts the outer surface of the said molded object only the thickness of the layer of the said 2nd metal raw material before the said plating process. Can do.

Moreover, in the said plating process, the bath temperature shall be 20-27 degreeC in the copper sulfate bath which contains 50-80 g / L copper sulfate and 160-250 g / L sulfuric acid in the said molded article, and cathode current density It is preferable to form the second metal material layer by performing thick plating under the condition of ¹ to 3 A / dm ² .

  The additive manufacturing process includes a powder layer forming process for forming a powder layer containing the powder of the first metal material, and solidifying the powder by irradiating a laser at a predetermined position of the powder layer. It is preferable that the modeling object of a 1st metal raw material is laminate-modeled by repeating the said powder layer formation process and the said modeling layer formation process sequentially including the modeling layer formation process which forms a modeling layer.

  The high-frequency current has a frequency of 10 kHz or more and less than 100 kHz, and the first metal material is copper, aluminum, titanium, iron, carbon, silicon, phosphorus, sulfur, chromium, nickel, molybdenum, tungsten, vanadium, manganese , Zirconium, tin, tantalum, niobium, and cobalt, a nonmagnetic alloy composed of two or more metal elements, wherein the second metal material is pure copper, and the second metal material layer The thickness is preferably 0.66 mm or more.

  The high-frequency current is a frequency of 100 kHz or more, the first metal material is a chromium copper alloy containing 0.1 to 5% by mass of chromium, and the second metal material is pure copper. And the thickness of the second metal material layer is preferably 0.2 mm or more.

  ADVANTAGE OF THE INVENTION According to this invention, even if it uses the metal raw material which is inferior to metal materials, such as pure copper, the manufacturing method of the metal preparation which can provide high frequency electroconductivity comparable as metal materials, such as pure copper, is provided.

FIG. 1 is a conceptual diagram showing a preferred metal product manufactured in the first embodiment of the method for manufacturing a metal product according to the present invention. FIG. 2 is a conceptual diagram showing a cross-section of FIG. 1 for explaining the first embodiment of the method for producing a metal product according to the present invention. FIG. 3A and FIG. 3B are schematic views for explaining one step of the method for producing a metal product according to the present invention. FIG. 4 is a conceptual diagram showing a cross section of a metal product for explaining the second embodiment of the method of manufacturing the metal product according to the present invention.

  Hereinafter, an embodiment of a method for producing a metal product according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by embodiment described below.

1. First embodiment 1.1. Metal Product First, FIG. 1 schematically shows a metal product 1 manufactured by the method for manufacturing a metal product according to the present invention. As shown in FIG. 1, the metal product 1 has a substantially ring shape, and includes a shaped product 3 made of a first metal material and a layer 5 of a second metal material in its cross-sectional shape. In addition, the metal product 1 has a hollow portion 7 for circulating a coolant such as water in order to remove heat generated during use. The size and shape of the metal product may be any size and shape that can be used for high-frequency induction heating, high-frequency antennas, and other uses. The metal product can be suitably used for a coil for high-frequency induction heating.

  The first metal material is a metal that can be layered by an additive manufacturing technique, has non-magnetic properties and conductivity, and has a lower electrical conductivity for high frequencies than the second metal material. Examples of the first metal material include copper (Cu), aluminum (Al), titanium (Ti), iron (Fe), carbon (C), silicon (Si), phosphorus (P), sulfur (S), chromium ( Cr), nickel (Ni), molybdenum (Mо), tungsten (W), vanadium (V), manganese (Mn), zirconium (Zr), tin (Sn), tantalum (Ta), niobium (Nb) and cobalt ( It is a nonmagnetic alloy composed of two or more metal elements selected from the group consisting of Co).

  Specifically, as the first metal material, copper-based alloys such as brass, phosphor bronze, and chromium-copper alloys, aluminum-based alloys such as AlSi12 (Al112) and AlSi10Mg, titanium-based alloys such as Ti6Al4V (ASTM B348 Gr5), Inconel Nickel alloys such as 618 (registered trademark), Inconel 625 (registered trademark), Inconel 718 (registered trademark), SUS304 (X10CrNi18-9), SUS316L (X2CrNiM 17-17-2, 17-12-3, 18-13) 4, ferrous alloys such as SUS630 (X5CrNiCuNb16-4), maraging steel, etc. The chromium-copper alloy contains 0.1 mass% to 5 mass% of chromium, and the balance is mainly made of copper. Among these, from a practical viewpoint, the first metal material is preferably a chromium copper alloy.

  The second metal material may be any metal that has non-magnetic properties and conductivity and has a better conductivity with respect to high frequency than the first metal material. Examples of such second metal material include metals such as pure copper. Among these, from the practical viewpoint, the second metal material is preferably pure copper, more preferably 99.95% or more pure copper, and even more preferably 99.99% or more pure copper.

  The first metal material and the second metal material may contain inevitable impurities. Examples of such impurities include the aforementioned elements, oxygen (O), and the like. In general, inevitable impurities are mixed in the first metal material and / or the second metal material before, during or after the production of the metal product described in the present specification. It is part of the rest.

1.2. Laminated modeling process and plating process Next, the manufacturing method of the metal preparation 1 which has the said structure is demonstrated with reference to FIG. As shown in FIG. 2, in the manufacturing method of the metal product according to the present embodiment, the model 3 is layered by the layered modeling process, and then the second metal material layer 5 is formed by the plating process. A metal product 1 is produced.

  First, the modeling object 3 which consists of a 1st metal raw material is modeled using an additional manufacturing technique. In the example shown in FIG. 2, in the cross-sectional shape, the four outer surfaces of the shaped article 3 are formed so as to be smaller by the thickness (d) of the second metal layer. Moreover, the molded article 3 in the figure has a hollow portion 7 as a coil for high-frequency induction heating. The four outer surfaces of the modeled object 3 in the figure correspond to the outer surfaces of the modeled object 3 having a three-dimensional shape. That is, in this step, the layered modeling is performed so that the outer surface of the modeled article 3 having a predetermined three-dimensional shape is thinned by the thickness (d) of the second metal material layer. In other words, in this process, the dimension of the three-dimensional shaped object 3 is set to the thickness (d) of the second metal material layer so that the dimension (D) of the metal product after the plating process becomes a desired dimension. ) Make it smaller in advance.

  Next, a second metal material layer (plating layer) 5 having a substantially uniform thickness (d) is formed on the outer surface of the modeled object 3 by plating the modeled object 3. Thereby, the metal product 1 is produced. In the example shown in FIG. 2, in the cross-sectional shape, a second metal material layer 5 having a thickness (d) is formed on each of the four outer surfaces of the shaped article 3. Moreover, the metal preparation 1 which makes a desired dimension (D) is produced by the dimension of the molded article 3 and the thickness (d) of the layer of the second metal material. The four outer surfaces of the second metal material layer 5 in the figure correspond to the outer surfaces of the three-dimensionally shaped metal product 1. That is, in this step, the plating process is performed so that the second metal material layer 5 is formed over the outer surface of the three-dimensional shaped object 3. In other words, in this step, the layer 5 of the second metal material is formed so as to cover the three-dimensional shaped object 3. In addition, the layer 5 of the 2nd metal raw material should just be formed only in the part which the high frequency current of the molded article 3 conduct | electrically_connects. For example, when used for high-frequency induction heating, in FIG. 2, the layer 5 of the second metal material only needs to be formed on at least one of the four outer surfaces of the shaped article 3, and in FIG. The layer 5 of two metal materials should just be formed in the surface of the radial inside of the molded article 3 at least. Thereby, the metal product 1 can be efficiently manufactured by a minimum plating process.

  A plating process such as electroplating or chemical plating can be employed for the plating process. Of these, electroplating is preferable from a practical viewpoint. For example, in copper plating for forming a copper layer as the second metal material layer, the shaped object is immersed in a plating bath such as a copper sulfate bath, a copper borofluoride bath, a copper pyrophosphate bath, a copper cyanide bath, Energize under specified conditions. Thereby, copper is deposited on the surface of the modeled object, and a layer of the second metal material can be formed. Further, in order to improve the uniformity of the plating layer, stirring by mechanical stirring, air stirring, vibration, jet flow or the like can be performed during the plating process.

The conditions for the plating treatment may be any conditions as long as the second metal material layer can be formed on the surface of the modeled object made of the first metal material. Moreover, the conditions for performing copper plating should just be the conditions which can form a copper layer as a 2nd metal raw material layer. For example, in copper plating, a shaped article is immersed in a copper sulfate bath containing 50 to 80 g / L of copper sulfate and 160 to 250 g / L of sulfuric acid, the cathode current density is 1 to 3 A / dm ² , and the bath temperature is 20 It can be carried out under a condition of ˜27 ° C.

  The metal product 1 obtained as described above has excellent conductivity as compared with the conductivity of the shaped object made of the first metal material. For example, when the conductivity of a shaped object made of the first metal material described in this specification is about 30% LACS, the conductivity of the metal product obtained after the plating process can be improved to 100% LACS. it can. In addition, the electroconductivity described in the present specification can be measured, for example, based on a unit defined as 100% IACS for the conductivity of annealed standard annealed copper (IACS: International Annealed Copper Standard).

  It can be estimated that such an effect is due to the skin effect of the metal product 1. In consideration of the skin effect, the thickness (d) of the layer of the second metal material for obtaining good conductivity with respect to the high frequency can be determined by a table shown in the following formula 1), for example.

［式中、ｄは第２金属素材の層の厚み(ｍｍ)であり、ｆは周波数(ＭＨｚ)であり、μは第２金属素材の透磁率(Ｈ／ｍ)であり、σは、第２金属素材の導電率(Ｓ／ｍ)である。］

[Where d is the thickness (mm) of the layer of the second metal material, f is the frequency (MHz), μ is the permeability (H / m) of the second metal material, and σ is the first It is the electrical conductivity (S / m) of two metal materials. ]

Considering equation (1), regarding the lower limit value of the thickness of the second metal material layer, for example, the second metal material is pure copper, and the copper conductivity (σ) is 5.82 × 10 ⁷ S / m. Assuming × 10 ⁻⁷ H / m, the thickness of the layer for supplying a current of 1 kHz or more is 2 mm or more, and the thickness of the layer for supplying a current of 10 kHz or more is 0.66 mm or more. The thickness of the layer for supplying a current of 100 kHz or more is 0.209 mm or more, and the thickness of the layer for supplying a current of 400 kHz or more is 0.104 mm or more. In other words, if the thickness of the layer is 2 mm or more, a current of less than 10 kHz can be passed, and if the thickness of the layer is 0.66 mm or more, a current of less than 100 kHz can be passed, and if the thickness of the layer is 0.209 mm or more. A current of less than 400 kHz can be applied. In this specification, “high-frequency current” intends a current having a frequency of 1 kHz or more. The frequency of the high-frequency current is preferably 10 kHz or more and 400 kHz or less, and more preferably 100 kHz or more and 400 kHz or less from a practical viewpoint.

  In addition, regarding the upper limit of the thickness (d) of the second metal material layer, the thickness of the second metal material layer is preferably 1 mm or less, and more preferably 0.2 mm or less. If the thickness (d) of the second metal material layer exceeds 1 mm, it may be difficult to maintain the properties of plating.

  Next, the layered manufacturing process will be described in more detail with reference to FIGS. 3 (A) and 3 (B). In the additive manufacturing process, additive manufacturing technology is used to additively manufacture the three-dimensional shaped object 3 from a powder metal material based on the modeling conditions calculated from the desired three-dimensional shaped object. The modeling conditions can be created using an application such as 3D-CAD / CAM. The desired three-dimensional shape data is converted into STL format data, and further converted into slice data divided into n pieces (n is an integer). By forming n modeling layers based on the slice data, the three-dimensional model 3 is layered. For the additive manufacturing technology, an apparatus capable of layering a desired three-dimensional shaped object from a powdered metal material can be employed. For example, laser sintering (SLS), direct metal laser sintering (DMLS) ), A laser melting method (SLM), an electron beam melting method (EBM), or the like can be used.

  As shown in FIG. 3A, the powder of the first metal material is spread on a modeling table 120 that is configured to dispose powdered metal and includes an elevating unit 122 that can be moved up and down. Thereby, the first metal powder layer L1 made of the powder of the first metal material is formed. Next, the laser irradiation unit 130 irradiates a predetermined position on the first metal powder layer L1. Laser output, scanning speed, energy density, and the like are controlled together with an optical system such as a lens and a mirror (not shown) that are optionally provided based on modeling conditions. By irradiating the controlled laser to the first metal powder layer L1, the first metal powder layer L1 is sintered or melted and solidified. The solidified powder layer forms the first modeling layer M1.

The laser may be any laser that can solidify the powder layer made of the first metal material, such as a gas laser such as a CO ₂ laser, a solid-state laser such as an ytterbium (Yb) laser, a YAG laser, a semiconductor laser, an electron beam, or the like. . The output of the laser, the scanning speed, and the energy density may be in a range where the first modeling layer can be solidified. For example, the power of the laser is about 100 to about 1000 W, its energy density is about 100 to about 1000 J / mm ³ , and its scanning speed can be about 100 to about 1000 mm / s.

  Next, as shown in FIG. 3B, after forming the first modeling layer M <b> 1, the modeling table 120 is lowered together with the lowering of the elevating part 122 to form the second modeling layer. The powdered first metal material is spread on the lowered modeling table 120 on the first modeling layer M1. Thereby, the 2nd metal powder layer L2 is formed on the 1st modeling layer M1. The second modeling layer M2 is formed by irradiating a predetermined position of the second metal powder layer L2 with a laser from the laser irradiation unit 130. In this way, by repeating the powder layer forming step of forming the powder layer and the modeling layer forming step of forming the modeling layer sequentially n times, the three-dimensional shaped object 3 composed of n modeling layers is layered. be able to. In order to form the nth metal powder layer, the powder of the first metal material can be spread using a roller or the like (not shown). Moreover, the thickness of each layer of n modeling layers should just be the thickness which can laminate-model a modeling thing based on modeling conditions, for example, is about 10-200 micrometers.

The additive manufacturing process as described above is preferably performed in an inert atmosphere in order to prevent oxidation of the first metal material. In this specification, the inert atmosphere is an atmosphere in a vacuum state or a reduced pressure state in the presence of an inert gas such as argon (Ar), helium (He), or nitrogen (N ₂ ).

  Moreover, the higher the density of the shaped object described in this specification, the better from the viewpoint of mechanical strength. For example, the relative density of the shaped object can be 95% or more. The relative density of the modeled object can be measured by, for example, the Archimedes method based on JIS Z 2501 (ISO / DIS 2738).

  The shape and size of the powder of the first metal material may be any shape and size that allows the modeling object 3 to be layered from the first metal material. The shape of the powder may be a regular shape such as a spherical shape or an irregular shape. The magnitude | size of the powder of a 1st metal raw material can be suitably adjusted as a particle size distribution by manufacturing conditions, classification, etc. The average particle diameter of the powder of the first metal material may be in a range where the fluidity of the powder can be secured and the layer can be formed, and is, for example, in the range of about 20 to 200 μm, 100 to 200 μm, 50 to 100 μm, or 5 to 5. It can be about 50 μm. The average particle diameter of the powder of the first metal material can be adjusted in accordance with the interval (lamination pitch) of the nth layer and the (n + 1) th layer when modeling the model 3. In this specification, the average particle size is intended to be the particle size (“d50”) at an integrated value of 50% in the particle size distribution measured by the laser diffraction / scattering method.

2. Second Embodiment Next, a second embodiment of the metal product according to the present invention will be described with reference to FIG. As shown in FIG. 4, the metal workpiece 10 according to the present embodiment includes a shaped article 13 </ b> A made of the first metal material and a layer 15 of the second metal material in its cross-sectional shape. Moreover, the metal product 10 has a hollow portion 17 for circulating a refrigerant such as water in order to remove heat generated during use. The manufacturing method of the metal product according to the present embodiment is mainly different from the first embodiment in that it further includes a cutting process after the additive manufacturing process and before the polishing process. The description of the same configuration as in the first embodiment is omitted.

2.1. Layered modeling step In the layered modeling step, the shaped article 13 made of the first metal material is formed using an additive manufacturing technique. The four outer surfaces of the shaped article 13 in the figure correspond to the outer surfaces of the three-dimensional shaped article 13. In this step, the modeling conditions are adjusted so that the dimension of the modeled article 13 having a predetermined three-dimensional shape is the metal product 10 having a desired three-dimensional dimension (D). That is, in this step, adjusting the modeling conditions so that the dimension of the metal product after the plating process described in the first embodiment becomes a desired dimension is omitted. The dimension of the shaped article 13 may be at least the dimension (D) of the metal product 10 and may be equal to or greater than the dimension (D) of the metal product 10.

2.2. Cutting process In the cutting process, the outer surface of the modeled article 13 after the layered modeling process is cut so as to be thinned by the thickness (d) of the layer of the second metal material. In the example shown in FIG. 4, in the cross-sectional shape, the four outer surfaces of the shaped article 13 are cut so as to be thinned by the thickness (d) of the layer 15 of the second metal material. Thereby, the modeled product 13A is formed. The cutting thickness in this step may be a thickness such that the dimension of the metal product after the plating process becomes a desired dimension (D), as in the additive manufacturing process of the first embodiment. , 0.2 mm or more. The cutting process can be performed by cutting the outer surface of the modeled object using a tool such as a buff including a cutting tool, a milling cutter, and abrasive grains, or a lathe or a milling machine equipped with the tool. The cutting step is preferably performed using a lathe.

  In the above-described embodiment, the additive manufacturing process for performing additive manufacturing is exemplified by sintering or melting the object from the powder-shaped first metal material. The present invention is not limited to this. The layered modeling process may be any method that can model a desired model from the first metal material. For example, a modeling method defined in ASTM International Standard (ASTM F2792) can be appropriately employed. For example, while supplying a non-powder or powder-shaped first metal material from a nozzle, a directional energy deposition method (DMP) in which materials are selectively combined and layered to form or a non-powder-shaped first metal material is formed into a sheet. By adopting a sheet lamination (SL) method that cuts out and laminates, a desired three-dimensional shaped object can be formed.

  Moreover, in the above-mentioned embodiment, the plating process which forms the film | membrane of a 2nd metal raw material by plating process was illustrated. The present invention is not limited to this. In addition to the plating process, a process capable of forming a layer of the second metal material having a uniform film thickness on the molded object made of the first metal material can be employed. For example, by adopting processes such as physical vapor deposition (PVD) such as sputtering, ion plating, and vacuum vapor deposition, and chemical vapor deposition (CVD), a shaped article made of the first metal material A layer of the second metal material can be formed.

  Hereinafter, the present invention will be described more specifically with reference to examples. The method for producing a metal product according to the present invention is not limited by the following examples.

1. Manufacture of metal products [Test Example 1]
As a nonmagnetic first metal material of Test Example 1, a chromium copper alloy containing 5.0% by mass of chromium was prepared. The first metal material of Test Example 1 is layered using a 3D printer (manufactured by EOS, model number: EOS M 290) to form a three-dimensional shaped object having a ring shape (diameter 82 mm × height 10 mm). did. The obtained model was used as the metal product of Test Example 1.

[Test Example 2]
As the nonmagnetic first metal material of Test Example 2, the same chromium copper alloy as in Test Example 1 was prepared. The first metal material of Test Example 2 was layered using a 3D printer to form a three-dimensional shaped object having a ring shape (diameter 82 mm × height 10 mm). Next, as a plating treatment, the model obtained by the 3D printer is set to a bath temperature of 20 to 27 ° C. in a copper sulfate bath containing 50 to 80 g / L of copper sulfate and 160 to 250 g / L of sulfuric acid. Copper thick plating was performed by plating under conditions where the cathode current density was 1 to 3 A / dm ² . Thus, a pure copper layer (plating layer) was formed as a second metal material layer on the outer surface of the modeled object. The metal product of Test Example 2 was obtained. The relative density of Test Example 2 was 95%.

2. Measurement of Conductivity For the metal products of Test Examples 1 and 2 modeled with a 3D printer, their high-frequency conductivity was measured based on IACS units. An overcurrent conductivity meter was used to measure the conductivity.

  The conductivity of Test Example 1 was 30% IACS. On the other hand, the electrical conductivity of Test Example 2 was 100% IACS, which was the same as that of annealed standard annealed copper. From this, it was found that the conductivity of the metal product of Test Example 2 was almost the same as that of pure copper. Moreover, it turned out that the electrical conductivity of the test example 2 which performed the plating process improves 70% IACS compared with the test example 1 which does not perform a plating process.

  According to the method for producing a metal product according to the present invention, even when a metal material that is inferior in conductivity to a metal material such as pure copper is used, high-frequency conductivity comparable to that of a metal material such as pure copper can be imparted. .

1, 10 Metal product 3, 13, 13A Model 5, 15 Second metal material layer (plating layer)
7, 17 Hollow part

Claims (7)

A method of manufacturing a metal product for energizing a high-frequency current,
Additive manufacturing process for additive manufacturing of a model of chromium copper alloy that is the first metal material;
After the additive manufacturing process, at least a plating process for forming a layer of pure copper , which is the second metal material , by plating the modeled object,
The conductivity of the second metal material with respect to the high-frequency current is higher than that of the first metal material,
The method of manufacturing a metal product, wherein the shaped article is formed so as to have a dimension of the metal product by the thickness of the layer of the second metal material. The thickness (d) of the second metal material layer is represented by the following formula 1):

[Where d is the thickness (mm), f is the frequency (MHz) of the high frequency current, μ is the permeability (H / m) of the second metal material, and σ is the second metal material. Conductivity (S / m). ]
The method for producing a metal product according to claim 1, wherein:   The metal product manufacturing method according to claim 1 or 2, further comprising a cutting step of cutting the outer surface of the shaped object by the thickness of the layer of the second metal material before the plating step. Method. In the plating step, in the copper sulfate bath containing 50 to 80 g / L copper sulfate and 160 to 250 g / L sulfuric acid, the bath temperature is set to 20 to 27 ° C., and the cathode current density is 1 in the plating step. The metal-made product according to any one of claims 1 to 3, wherein the second metal material layer is formed by performing thick plating under a condition of ~ 3 A / dm ^2. Method. The additive manufacturing process includes a powder layer forming process of forming a powder layer containing the powder of the first metal material,
A modeling layer forming step of forming a modeling layer by irradiating a laser on a predetermined position of the powder layer to solidify the powder; and
Including
The metal according to any one of claims 1 to 4, wherein the modeling object of the first metal material is layered and manufactured by sequentially repeating the powder layer forming step and the modeling layer forming step. Production method of product. The high-frequency current is frequencies below 10kHz or 100kH z,
Before Symbol thickness of the second metal material layers, the manufacturing method of the metal work product according to any one of claims 1-5, characterized in that at least 0.66 mm. The high-frequency current has a frequency of 100 kHz or more;
The first metal material is a chromium copper alloy containing 0.1% by mass or more and 5% by mass or less of chromium,
Before Symbol thickness of the second metal material layers, the manufacturing method of the metal work product according to any one of claims 1 to 5, wherein the at 0.2mm or more.

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