TW201907017A - Additively-manufactured article - Google Patents

Abstract

A copper alloy powder is a copper alloy powder for additive manufacturing. The copper alloy powder contains more than 1.00 mass% and not more than 2.80 mass% of chromium, and a balance of copper.

Description

Laminated shape

The present invention relates to a copper alloy powder, a method for producing a laminate, and a laminate.

Japanese Laid-Open Patent Publication No. 2011-21218 discloses a laser laminate forming device (also referred to as a "3D printer") for metal powder.

As a processing technology for metal products, a laminate method for metal powder has attracted attention. According to the laminated method, it is possible to realize the creation of a complicated shape that cannot be realized by cutting. A manufacturing example based on a laminate of a ferroalloy powder, an aluminum alloy powder, a titanium alloy powder, or the like has been reported so far. That is, a laminate including a ferroalloy, an aluminum alloy, or a titanium alloy is reported. However, there are no reports of laminates containing copper alloys. It is an object of the present invention to provide a laminate comprising a copper alloy. [1] A copper alloy powder for forming a copper alloy powder. The copper alloy powder contains more than 1.00% by mass and 2.80% by mass or less of chromium, and the balance of copper. [2] The copper alloy powder may contain more than 1.05 mass% and 2.80 mass% or less of chromium. [3] The copper alloy powder may contain more than 1.00% by mass and 2.00% by mass or less of chromium. [4] The copper alloy powder may further contain more than 1.05 mass% and 2.00 mass% or less of chromium. [5] The manufacturing method of the laminated product includes the following first step and second step. The first step; the copper alloy powder according to any one of the above [1] to [4]. The second step; manufacturing a laminate product using copper alloy powder. The laminate is produced by sequentially repeating (i) forming a powder layer containing a copper alloy powder, and (ii) forming a shaped layer by solidifying a copper alloy powder at a specific position due to the powder layer, and forming a layer Carry out the layering. [6] The method for producing a laminate may further include a third step of heat-treating the laminate. [7] In the third step, the laminate may be heat-treated at a temperature of 300 ° C or higher. [8] In the third step, the laminate may be heat-treated at a temperature of 400 ° C or higher. [9] In the third step, the laminate may be heat-treated at a temperature of 700 ° C or lower. [10] In the third step, the laminate may be heat-treated at a temperature of 600 ° C or lower. [11] The build-up material comprises a laminate of a copper alloy. The laminate product contains more than 1.00% by mass and 2.80% by mass or less of chromium, and the rest of the copper. The laminate has a relative density of 96% or more and 100% or less with respect to the theoretical density of the copper alloy, and has a conductivity of 10% IACS or more. [12] The laminate may also contain more than 1.05 mass% and 2.80 mass% or less of chromium. [13] The laminate may also contain more than 1.00% by mass and 2.00% by mass or less of chromium. [14] The laminate may also contain more than 1.05 mass% and 2.00 mass% or less of chromium. [15] The laminate may also have a conductivity of 30% IACS or more. [16] The laminate may also have a conductivity of 50% IACS or more. [17] The laminate may also have a conductivity of 70% IACS or more. The above and other objects, features, aspects and advantages of the present invention will become apparent from

Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described. However, the following description does not limit the scope of the invention. First, the passage of this embodiment will be described. More copper is used in mechanical parts that require mechanical strength and higher electrical conductivity. Examples of the mechanical component including copper include a welding gun, a component of a power distribution device, and the like. First, the researchers studied the fabrication of laminates from pure copper powder. However, the desired laminate is not obtained by pure copper powder. Specifically, the laminate formed of pure copper powder has a large number of voids, and the density of the dense melted material is greatly reduced. The decrease in density means a decrease in mechanical strength (e.g., tensile strength, etc.). Further, the electrical conductivity of the molten material is also greatly reduced relative to the dense molten material. In order to improve density and conductivity, the researchers studied various manufacturing conditions. However, the processing properties are unstable under any of the manufacturing conditions, and it is difficult to achieve an improvement in density and conductivity. Therefore, researchers have studied copper alloy powder. As a result, it has been found that by using a copper alloy powder having a specific composition, a laminate having a practical density and conductivity can be produced; and further, by using a heat treatment of the laminate on a specific temperature or higher, the mechanical strength of the laminate can be remarkably improved. Conductivity. The present embodiment will be described in detail below. <Copper alloy powder> The copper alloy powder of the present embodiment corresponds to a toner or ink of a two-dimensional printer. In the present embodiment, the method for producing the copper alloy powder having the specific composition described below is not particularly limited. The copper alloy powder can be produced, for example, by a gas atomization method or a water atomization method. For example, a molten copper alloy is first prepared. Place the melt in the feed tank. The melt is added dropwise from the feed tank. The molten metal in the dropwise addition is brought into contact with a high pressure gas or high pressure water. Thereby, the melt is quenched and solidified to form a copper alloy powder. Further, a copper alloy powder can also be produced by a plasma atomization method, a centrifugal force atomization method, or the like. In the present embodiment, a copper alloy powder having a specific composition is used. That is, the copper alloy powder contains a powder of more than 1.00% by mass and 2.80% by mass or less of chromium (Cr) and the remaining copper (Cu) copper alloy. The remainder may contain impurity elements in addition to Cu. The impurity element may be, for example, an element (hereinafter referred to as "addition element") which is intentionally added at the time of manufacture of the copper alloy powder. That is, the remaining portion may also contain Cu and added elements. Examples of the additive element include nickel (Ni), zinc (Zn), tin (Sn), silver (Ag), beryllium (Be), zirconium (Zr), aluminum (Al), cerium (Si), and cobalt (Co). ), titanium (Ti), magnesium (Mg), tellurium (Te), and the like. The impurity element may be, for example, an element which is inevitably mixed in the production of the copper alloy powder (hereinafter referred to as "inevitable impurity element"). That is, the remaining portion may also contain Cu and inevitable impurity elements. Examples of the unavoidable impurity element include oxygen (O), phosphorus (P), and iron (Fe). The remainder may also contain Cu, added elements, and inevitable impurity elements. The copper alloy powder may contain, for example, a total of less than 0.30% by mass of an additive element and an unavoidable impurity element. For example, the oxygen content of the copper alloy powder can be measured by the method of "JIS H 1067: Oxygen quantification method in copper". The Cr content of the copper alloy powder is measured by an ICP (Inductively Coupled Plasma) luminescence analysis method in accordance with "JIS H 1071: Method for Quantizing Chromium in Copper and Copper Alloys". The Cr content was measured at least 3 times. The average value of at least 3 times is used as the Cr content. The Cr content may be 1.01% by mass or more, or may be more than 1.05% by mass, or may be 1.10% by mass or more, or may be 1.20% by mass or more, or may be 1.22% by mass or more, or may be 1.78% by mass or more. The Cr content may be 2.70% by mass or less, or may be 2.60% by mass or less, or may be 2.30% by mass or less, or may be 2.00% by mass or less, or may be 1.90% by mass or less, or may be 1.80% by mass or less, or 1.78% by mass or less, or 1.46% by mass or less. The Cu content of the copper alloy powder can be measured by the method of "JIS H 1051: Method for Quantifying Copper in Copper and Copper Alloys". The Cu content was measured at least 3 times. The average of at least 3 times is used as the Cu content. The Cu content may be, for example, more than 97.9 mass% and less than 99.0 mass%. The copper alloy powder may have an average particle diameter of, for example, 1 to 200 μm. The "average particle diameter" indicates a particle diameter which is 50% accumulated from the particle side in the particle size distribution of the volume basis measured by the laser diffraction scattering method. The following average particle diameter can also be referred to as "d50". D50 can be adjusted, for example, by gas pressure, classification, or the like at the time of gas atomization. D50 can also be adjusted according to the lamination distance of the laminate. D50 may be, for example, 5 to 50 μm, or may be 50 to 100 μm, or may be 100 to 200 μm. The shape of the particles is not particularly limited. The particles may be substantially spherical or may be irregularly shaped. <Manufacturing Method of Laminated Shaped Article> Fig. 1 is a flow chart showing the outline of a method for producing a laminated formed article of the present embodiment. The manufacturing method of this embodiment includes the first step (S100) and the second step (S200). The manufacturing method of the present embodiment may further include the third step (S300) after the second step (S200). The steps are described in order below. <<First Step (S100)>> In the first step (S100), the copper alloy powder is prepared. <<Second Step (S200)>> In the second step (S200), a layered shaped article is produced from a copper alloy powder. The powder bed fusion bonding method will be described here. Additional manufacturing methods other than the powder bed fusion bonding method can also be used. For example, a directional energy deposition method or the like can also be used. Cutting can also be carried out in the forming process. The aspect in which the copper alloy powder is cured by laser is described here. The laser is only an example, and the curing mechanism is not limited to the laser as long as the copper alloy powder can be cured. For example, an electron beam, a plasma, or the like can also be used. (Data Processing (S201)) First, three-dimensional shape data is produced by 3D-CAD or the like. The three-dimensional shape data can also be converted into STL data, for example. Figure 2 is an example of STL data. In the STL data, for example, element division using the finite element method (so-called "meshing") can be performed. Sliced data was made from STL data. Figure 3 is an example of slice data. The STL data is divided into n layers. That is, the STL data is divided into the first forming layer p1, the second forming layer p2, and the nth forming layer pn. The thickness (slice thickness d) of each layer may be, for example, 10 to 150 μm. (Formation of Powder Layer (S202)) A powder layer containing a copper alloy powder is formed. Fig. 4 is a first schematic view showing a manufacturing process of a laminate. The laser laminated forming apparatus 100 includes a piston 101, a stage 102, and a laser output unit 103. Stage 102 is supported by piston 101. The piston 101 is constructed in such a manner as to be able to lift the table 102. The laminate is shaped on the stage 102. The formation of the powder layer (S202) and the formation of the following shaped layer (S203) can also be carried out, for example, in an inert gas atmosphere. Used to suppress oxidation of laminates. The inert gas may be, for example, argon (Ar), nitrogen (N ₂ ), helium (He) or the like. A reducing gas atmosphere can also be used instead of the inert gas atmosphere. The reducing gas is, for example, hydrogen (H ₂ ) or the like. Further, a reduced pressure atmosphere may be used instead of the inert gas atmosphere. Based on the slice data, the piston 101 lowers the stage 102 by one layer. One layer of copper alloy powder is spread on the stage 102. Thereby, the first powder layer 1 containing the copper alloy powder is formed. For example, the surface of the first powder layer 1 may be smoothed by a compacting blade (not shown) or the like. The first powder layer 1 may also be formed substantially only of a copper alloy powder. The first powder layer 1 may contain a laser absorbing material (for example, a resin powder or the like) in addition to the copper alloy powder. (Formation of a forming layer (S203)) A forming layer is then formed. The shaped layer forms part of the laminated body. Fig. 5 is a second schematic view showing a manufacturing process of a laminate. The laser output unit 103 irradiates the laser beam to the specific position of the first powder layer 1 based on the slice data. The first powder layer 1 may be heated in advance before the irradiation of the laser light. The copper alloy powder irradiated with the laser light is solidified by melting or sintering. Thereby, the first shaped layer p1 is formed. That is, the shaped layer is formed by solidifying the copper alloy powder at a specific position in the powder layer. The laser output 103 can be a general purpose laser device. The light source of the laser light may be, for example, a fiber laser, a YAG (Yttrium Aluminum Garnet) laser, a CO ₂ laser, a semiconductor laser, a green laser, or the like. The output of the laser light may be, for example, 20 to 1000 W, or may be 200 to 500 W. The scanning speed of the laser light can be adjusted, for example, in the range of 50 to 2000 mm/s. The energy density of the laser light can be adjusted within the range of 10 to 2000 J/mm ³ . The energy density is calculated by the following formula (I): E=P÷(v×s×d)·(I). In the formula (I), "E" represents the energy density of the laser light [unit: J/mm ³ ]. "P" indicates the output of the laser [unit: W]. "v" indicates the scanning speed [unit: mm/s]. "s" indicates the scanning width [unit: mm]. "d" indicates the slice thickness [unit: mm]. Fig. 6 is a third schematic view showing a manufacturing process of a laminated formed article. After the first forming layer p1 is formed, the piston 101 lowers the stage 102 by one layer. The second powder layer 2 is formed in the same order as described above, and then the second shaped layer p2 is formed. Thereafter, the formation of the powder layer (202) and the formation of the shaped layer (203) are repeated in this order, and the formed layer is laminated to produce a laminate. Fig. 7 is a fourth schematic view showing a manufacturing process of a laminate. Finally, the build-up article 10 is completed by laminating the n-th build layer pn. In the present embodiment, since the copper alloy powder having a specific composition is used, the laminated formed article 10 can have a relatively high relative density. <<Third Step (S300)>> The manufacturing method of the present embodiment may further include a third step of heat-treating the laminated shaped object (S300). Thereby, it is expected that the mechanical strength (for example, tensile strength, Vickers hardness, etc.) of the laminated shaped article and the electrical conductivity of the laminated shaped article are drastically improved. In the present embodiment, a general heat treatment furnace can be used. The heat treatment temperature was measured by a temperature sensor attached to the heat treatment furnace. For example, when the set temperature of the heat treatment furnace is 300 ° C, it is considered that the laminate is heat-treated at 300 ° C. The laminate may be heat treated for, for example, 1 minute or more and 10 hours or less, or may be heat treated for 10 minutes or more and 5 hours or less, or may be heat treated for 30 minutes or more and 3 hours or less, or may be accepted for 1 hour. Heat treatment above and below 2 hours. The atmosphere of the heat treatment may be, for example, air, nitrogen, argon, hydrogen, vacuum, or the like. In the third step, the laminate may be heat-treated at a temperature of 300 ° C or higher, or may be heat-treated at a temperature of 400 ° C or higher, or may be heat-treated at a temperature of 450 ° C or higher. Thereby, further improvement in mechanical strength and electrical conductivity can be expected. In the third step, the laminate may be heat-treated at a temperature of 700 ° C or lower, or may be heat-treated at a temperature of 600 ° C or lower, or may be heat-treated at a temperature of 550 ° C or lower. Thereby, for example, the balance between the mechanical strength and the electrical conductivity can be expected to be improved. The laminate may also be heat treated using a temperature in excess of 700 °C. However, the use of a temperature exceeding 700 ° C also has the possibility that the effect of improving mechanical strength and electrical conductivity becomes small. <Laminated molded article> The laminated formed article of the present embodiment is typically produced by the above-described production method. The laminated article of the present embodiment may have a complicated shape that cannot be realized by cutting. Further, the laminate product of the present embodiment is excellent in both mechanical strength and electrical conductivity. An example of the laminated article of the present embodiment may be a plasma gun. (Composition) The laminate product contains a copper alloy. The laminate product contains more than 1.00% by mass and 2.80% by mass or less of Cr, and the remainder of Cu. Like the above copper alloy powder, the remaining portion may also contain at least one of an additive element and an unavoidable impurity element. The Cr content of the laminate was measured by the same measurement method as the method for measuring the Cr content of the copper alloy powder. The Cr content may be 1.01% by mass or more, or may be more than 1.05% by mass, or may be 1.10% by mass or more, or may be 1.20% by mass or more, or may be 1.22% by mass or more, or may be 1.78% by mass or more. The Cr content may be 2.70% by mass or less, or may be 2.60% by mass or less, or may be 2.30% by mass or less, or may be 2.00% by mass or less, or may be 1.90% by mass or less, or may be 1.80. The mass% or less may be 1.78% by mass or less, or may be 1.46% by mass or less. The Cu content of the laminate can also be measured by the same measurement method as the method for measuring the Cu content of the copper alloy powder. The Cu content may be, for example, more than 97.9 mass% and less than 99.0 mass%. (Relative Density) The laminate has a relative density of 96% or more and 100% or less with respect to the theoretical density of the copper alloy. The "relative density" is calculated by dividing the measured density of the laminated object by the theoretical density. The theoretical density indicates the density of the molten material having the same composition as the laminate. The measured density was measured by the method of "JIS Z 2501: sintered metal material - density, oil content, and open porosity test method". The liquid uses water. The relative density was measured at least 3 times. The average of at least 3 times is used as the relative density. A laminate having a relatively high density is suitable for parts requiring higher airtightness. Moreover, the higher the relative density, the more mechanical strength can be expected. The relative density may be 97% or more, or may be 98% or more, or may be 99% or more, or may be 99.2% or more, or may be 99.4% or more, or may be 99.8% or more. (Mechanical strength) The laminate can have excellent mechanical strength. For example, the laminate may have a tensile strength of 250 MPa or more. That is, the laminated article of the present embodiment may have a tensile strength equal to or higher than that of oxygen-free copper (Unified Numbering System No. C10200). The "tensile strength" was measured by the following procedure. In the measurement, a tensile test device of a grade 1 or higher specified in "JIS B 7721: Tensile Tester, Compression Tester - Calibration Method and Verification Method of Force Measurement System" is used. Fig. 8 is a plan view of a test piece used in a tensile test. The dumbbell-shaped test piece 20 shown in Fig. 8 was prepared. The dumbbell-shaped test piece 20 was attached to a jig of a tensile test apparatus. A shape suitable for the shape of the dumbbell-shaped test piece 20 is used for the jig. The dumbbell-shaped test piece 20 is attached in such a manner as to apply tensile stress to its axial direction. The dumbbell-shaped test piece 20 was pulled at a speed of 2 mm/min. The tension was continuously pulled until the dumbbell-shaped test piece 20 was broken. The maximum tensile stress exhibited until the dumbbell-shaped test piece 20 was broken was measured. The tensile strength was calculated by dividing the maximum tensile stress by the cross-sectional area of the parallel portion 21. The cross-sectional area of the parallel portion 21 is 9.616 mm ² (= π × 3.5 mm × 3.5 mm ÷ 4). The tensile strength was measured at least 3 times. The average of at least 3 times is used as the tensile strength. Further, the dimensions of the respective portions of the dumbbell-shaped test piece 20 are as follows. Total length (L0) of the dumbbell-shaped test piece 20: 36 mm Length of the parallel portion 21 (L1): 18 ± 0.5 mm Diameter of the parallel portion 21 (D1): 3.5 ± 0.05 mm Radius of the shoulder portion 23 (R): 10 mm Length of the grip portion 22 (L2): 4.0 mm Diameter of the grip portion 22 (D2): 6.0 mm The tensile strength can be adjusted by the heat treatment temperature of the third step. The tensile strength may be, for example, 300 MPa or more, or may be 400 MPa or more, or may be 600 MPa or more, or may be 700 MPa or more. The tensile strength may be, for example, 800 MPa or less, or may be 750 MPa or less. The laminate can have a Vickers hardness of 90 HV or more. "Vickers hardness" is measured by the method of "JIS Z 2244: Vickers hardness test - test method". The Vickers hardness can also be adjusted by the heat treatment temperature of the third step. The Vickers hardness may be, for example, 100 HV or more, or may be 150 HV or more, or may be 200 HV or more, or may be 250 HV or more. The Vickers hardness may be, for example, 300 HV or less. (Electrical conductivity) The laminate has a conductivity of 10% IACS or more. "Electrical conductivity" is measured by a commercially available eddy current conductivity meter. The electrical conductivity of the Annealed Copper Standard (IACS) was used as a reference to evaluate the electrical conductivity. That is, the electrical conductivity of the laminate is expressed as a percentage of the electrical conductivity of the IACS. For example, the conductivity of the laminate is 50% IACS means that the conductivity of the laminate is one-half the conductivity of the IACS. The conductivity was measured at least 3 times. The average value of at least 3 times is used as the conductivity. The conductivity can be adjusted by the heat treatment temperature of the third step. The laminate may have a conductivity of 20% IACS or more, or may have a conductivity of 30% IACS or more, or may have a conductivity of 50% IACS or more, or may have a conductivity of 70% IACS or more, or It may also have a conductivity of 80% IACS or more, or may have a conductivity of 90% IACS or more. The laminate may, for example, also have a conductivity of 100% IACS or less. [Examples] Hereinafter, examples will be described. However, the following examples do not limit the scope of the invention. A laminate is produced according to the flow chart shown in FIG. First, copper alloy powders A1 to A7 (S100) containing the chemical components shown in Table 1 below were prepared. These copper alloy powders are produced by a specific atomization method. Pure copper powder X and copper alloy powder Y were also prepared for comparison. Pure copper powder X is a powder based on commercially available pure copper. The copper alloy powder Y is a powder of a commercially available copper alloy (product name "AMPCO 940"). Hereinafter, these powders are collectively referred to as "metal powders". [Table 1] Prepare the laser laminate forming device of the following specifications. Laser: Fiber laser, maximum output 400 W Dot diameter: 0.05 to 0.20 mm Scanning speed: ~7000 mm/s Laminated distance: 0.02 to 0.08 mm Dimensions: 250 mm × 250 mm × 280 mm 1. Pure copper powder X In three-dimensional shape data (S201). The (i) formation of the powder layer containing the metal powder (S202), and (ii) formation of the shaped layer by solidification of the metal powder at a specific position by the powder layer (S203), and lamination of the shaped layer. Thus, a laminate of No. X-1 to X-40 (S200) was produced from pure copper powder X. The laminated body is a cylinder with a diameter of 14 mm × a height of 15 mm (the same laminated material is the same unless otherwise specified). The manufacturing conditions of the laminate are shown in Tables 2 and 3 below. The relative density and conductivity of the laminate were measured according to the above method. The results are shown in Tables 2 and 3 below. [Table 2] [table 3] As shown in the above Tables 2 and 3, in the laminate product produced by the pure copper powder X, even if the production conditions are fixed, the physical properties of the workpiece are unstable, and the range is not uniform. In the column of "relative density" in Tables 2 and 3, "unmeasurable" means that the laminated body has a large number of voids, so that it is impossible to measure the density with high reliability. It is considered that pure copper has a conductivity of 100% IACS. The laminate produced by pure copper powder X has a significantly lower electrical conductivity than pure copper. It is considered that it is difficult to manufacture a practical mechanical part by pure copper powder X. 2. Copper alloy powder Y (powder of commercially available copper alloy) A laminate of No. Y-1 to Y-7 was produced in the same manner as described above by the production conditions shown in Table 4 below. The laminate was subjected to heat treatment for 3 hours in a nitrogen atmosphere by using the temperature shown in the column of "heat treatment temperature" in Table 4 below (S300). The laminate formed as "None" in the column of "heat treatment temperature" is not subjected to heat treatment. The relative density and conductivity of the laminate were measured according to the above method. The results are shown in Table 4 below. [Table 4] As shown in the above Table 4, the electrical conductivity of the laminate formed by the copper alloy powder Y (a commercially available copper alloy powder) was significantly lower than that of the commercially available copper alloy (about 45.5% IACS). 3. Copper alloy powder A1 (Cr content: 0.22% by mass) A laminate product of No. A1-1 to A1-14 was produced in the same manner as described above by the production conditions shown in Table 5 below. The laminate was heat-treated for 3 hours in a nitrogen atmosphere by using the temperature shown in the column of "heat treatment temperature" in Table 5 below. The relative density, electrical conductivity and tensile strength were measured according to the methods described above. The tensile strength was measured in a separately prepared dumbbell-shaped test piece 20 (see Fig. 8) (the same applies hereinafter). The results are shown in Table 5 below. [table 5] As shown in the above Table 5, the unevenness of the processed physical properties was suppressed in the laminated body produced by the copper alloy powder A1. These laminates are believed to have mechanical strength and electrical conductivity that can be used as mechanical parts. 4. Copper alloy powder A2 (Cr content: 0.51% by mass) A laminate product of No. A2-1 to A2-12 was produced in the same manner as described above by the production conditions shown in Table 6 below. The laminate was heat-treated for 3 hours in a nitrogen atmosphere by using the temperature shown in the column of "heat treatment temperature" in Table 6 below. The relative density, electrical conductivity and tensile strength were measured according to the methods described above. The results are shown in Table 6 below. [Table 6] As shown in the above Table 6, the unevenness of the processed physical properties was suppressed in the laminated body produced by the copper alloy powder A2. These laminates are believed to have mechanical strength and electrical conductivity that can be used as mechanical parts. 5. Copper alloy powder A3 (Cr content: 0.94% by mass) A laminate product of No. A3-1 to A3-7 was produced in the same manner as described above by the production conditions shown in Table 7 below. The laminate was heat-treated for 3 hours in a nitrogen atmosphere by using the temperature shown in the column of "heat treatment temperature" in Table 7 below. The relative density, electrical conductivity and tensile strength were measured according to the methods described above. The results are shown in Table 7 below. [Table 7] As shown in the above Table 7, the unevenness of the processed physical properties was suppressed in the laminated body produced by the copper alloy powder A3. These laminates are believed to have mechanical strength and electrical conductivity that can be used as mechanical parts. 6. Study of Heat Treatment Temperature A laminate product was produced by the production conditions shown in Tables 8, 9, and 10 below. The relative density of the laminates was measured by the above method. Further, the laminate was subjected to heat treatment for 1 hour in a nitrogen atmosphere by using the temperatures shown in the columns of "heat treatment temperatures" in Tables 8, 9, and 10 below. After the heat treatment, the tensile strength, electrical conductivity, and Vickers hardness of the laminate were measured. Further, the method of measuring the Vickers hardness is as described above. The results are shown in Tables 8, 9, and 10 below. [Table 8] [Table 9] [Table 10] As shown in the above Tables 8, 9 and 10, the laminate product containing a copper alloy and having a Cr content of more than 1.00% by mass and 2.80% by mass or less has a stable relative density of 99% or more and 100% or less. It has been confirmed that the mechanical strength and the electrical conductivity are greatly improved by further heat-treating the laminated shaped article by using a temperature of 300 ° C or higher. The results will be described below with reference to Figs. In Figs. 9 to 11, for example, "1.5Cr" as an example means that the Cr content is 1.46% by mass. For convenience, it is rounded off to the second decimal place in the case. The laminate formed without heat treatment is considered to have been heat-treated at 25 ° C and made into a graph. Fig. 9 is a graph showing the relationship between the heat treatment temperature and the electrical conductivity in the third step. In the range where the heat treatment temperature is 300 ° C or more, the electrical conductivity of the laminate is remarkably improved. When the heat treatment temperature is 700 ° C, the effect of improving the conductivity can also be confirmed. Therefore, the upper limit of the heat treatment temperature may also be 700 °C. Among them, it is expected that an effect of improving conductivity can be obtained in a range in which the heat treatment temperature exceeds 700 °C. Fig. 10 is a graph showing the relationship between the heat treatment temperature and the tensile strength in the third step. As shown in Fig. 10, in the range of the heat treatment temperature of 300 ° C or more, the tensile strength of the laminate was remarkably improved. The increase in the tensile strength at the heat treatment temperature from 400 ° C to 450 ° C is particularly remarkable. The tensile strength peaked around 500 ° C and then decreased steadily thereafter. Fig. 11 is a graph showing the relationship between the heat treatment temperature and the Vickers hardness in the third step. Vickers hardness also shows the same tendency as tensile strength. 9 to 11, from the viewpoint of the balance between the mechanical strength and the electrical conductivity, the heat treatment temperature may be 300 ° C or more and 700 ° C or less, or may be 400 ° C or more and 600 ° C or less, or may be 450. °C or more and 550 ° C or less, or 450 ° C or more and 500 ° C or less. The embodiments of the present invention have been described above, but the embodiments disclosed herein are intended to be illustrative and not restrictive. It is intended that the scope of the invention be defined by the scope of the claims

1‧‧‧1st powder layer

2‧‧‧2nd powder layer

10‧‧‧Multilayered objects

20‧‧‧Dumbbell test piece

21‧‧‧Parallel

22‧‧‧Clamping Department

23‧‧‧ Shoulder

100‧‧‧Laser laminated device

101‧‧‧Piston

102‧‧‧

103‧‧‧Laser output

D‧‧‧ slice thickness

D1‧‧‧diameter of parallel section 21

D2‧‧‧diameter of the clamping portion 22

The total length of the L0‧‧‧ dumbbell test piece 20

Length of parallel section 21 of L1‧‧

L2‧‧‧ Length of the clamping portion 22

P1‧‧‧1st layer

P2‧‧‧2nd layer

Pn‧‧‧ nth layer

R‧‧‧ Radius of the shoulder 23

Fig. 1 is a flow chart showing the outline of a method for producing a laminated article according to an embodiment of the present invention. FIG. 2 is an example of an STL (Standard Template Library) data. Figure 3 is an example of slice data. Fig. 4 is a first schematic view showing a manufacturing process of a laminate. Fig. 5 is a second schematic view showing a manufacturing process of a laminate. Fig. 6 is a third schematic view showing a manufacturing process of a laminated formed article. Fig. 7 is a fourth schematic view showing a manufacturing process of a laminate. Fig. 8 is a plan view of a test piece used in a tensile test. Fig. 9 is a graph showing the relationship between the heat treatment temperature and the electrical conductivity in the third step. Fig. 10 is a graph showing the relationship between the heat treatment temperature and the tensile strength in the third step. Fig. 11 is a graph showing the relationship between the heat treatment temperature and the Vickers hardness in the third step.

Claims (7)

A laminated article comprising a copper alloy and containing more than 1.00% by mass and 2.80% by mass or less of chromium, and the balance of copper having a theoretical density of 96% or more and 100% or less with respect to the theoretical density of the copper alloy. Relative density, and has a conductivity of 10% IACS or more. The laminate according to claim 1, which contains more than 1.05 mass% and 2.80 mass% or less of chromium. The laminate according to claim 1, which contains more than 1.00% by mass and 2.00% by mass or less of chromium. The laminate according to claim 3, which contains more than 1.05 mass% and 2.00 mass% or less of chromium. A laminate according to claim 1 or 2 which has a conductivity of 30% IACS or more. A laminate according to claim 1 or 2 which has a conductivity of 50% IACS or more. A laminate according to claim 1 or 2 which has a conductivity of 70% IACS or more.