Copper alloy powder for additive manufacturing, copper alloy additive manufactured body, and method for manufacturing copper alloy additive manufactured body

Abstract

The present invention makes it possible to manufacture an additively-manufactured copper alloy article having high strength by efficiently producing a Corson alloy from nickel and silicon. This copper alloy powder for additive manufacturing is used to manufacture an additively-manufactured article by additive manufacturing, the copper alloy powder for additive manufacturing containing nickel and silicon with the remainder made up by copper and unavoidable impurities, the value obtained by dividing the nickel content (wt%) by the silicon content (wt%) being 3.3 to 7.2. This copper alloy additively-manufactured article is additively manufactured by an additive manufacturing device, the copper alloy additively-manufactured article containing 1.5 wt% to 6.0 wt% of nickel and 0.35 wt% to 1.5 wt% of silicon with the remainder made up by copper and unavoidable impurities, and being such that the value obtained by dividing the nickel content (wt%) by the silicon content (wt%) is 3.3 to 7.2.

Description

[Technical Field]

[0001] The present invention relates to a copper alloy powder for additive manufacturing, a copper alloy additive manufactured body, and a method for manufacturing a copper alloy additive manufactured body. [Background technology]

[0002] In the above technical field, Patent Document 1 discloses a copper-based alloy powder for additive manufacturing, which contains nickel and silicon elements in addition to copper. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-017639 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technique described in the above document does not efficiently produce a Corson alloy from nickel and silicon, and therefore it was not possible to manufacture a high-strength copper alloy additive manufacturing object.

[0005] An object of the present invention is to provide a technique for solving the above-mentioned problems. [Means for solving the problem]

[0006] In order to achieve the above object, the copper alloy powder for additive manufacturing according to the present invention comprises: By additive manufacturing Conductivity of 30% IACS or more and Vickers hardness of 200Hv or more A copper alloy powder for additive manufacturing used to manufacture an additive manufacturing body, containing nickel and silicon, with the balance being copper and unavoidable impurities; the value obtained by dividing the nickel content (wt%) by the silicon content (wt%) is 3.3 or more and 7.2 or less, 50% particle size is 70 μm or more and 200 μm or less, The nickel content is 1.5% by weight or more and 6.0% by weight or less, The silicon content is 0.35% by weight or more and 1.5% by weight or less, The apparent density of the powder measured according to the JIS Z 2504 (ISO 3923-1) measurement method is 3.5 g / cm 3 That is all, The adhesive strength of the copper alloy powder obtained from the fracture envelope obtained by the shear test is 0.600 kPa or less. Copper alloy powder for additive manufacturing.

[0007] In order to achieve the above object, a copper alloy additive manufacturing object according to the present invention is A copper alloy additive manufacturing object manufactured by additive manufacturing using the copper alloy powder for additive manufacturing using an additive manufacturing device, The value obtained by dividing the nickel content (wt%) by the silicon content (wt%) is 3.3 or more and 7.2 or less.

[0008] In order to achieve the above object, the method for producing a copper alloy additive manufacturing object according to the present invention comprises: an additive manufacturing process of additively manufacturing a copper alloy additive manufacturing body using the copper alloy powder for additive manufacturing by an additive manufacturing device; an aging treatment step of holding the copper alloy additive manufacturing body at 450°C or higher and 550°C or lower; Includes. [Effects of the Invention]

[0009] According to the present invention, a high-strength copper alloy additive manufacturing object can be produced by efficiently producing a Corson alloy from nickel and silicon. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the properties of the copper alloy additive manufacturing bodies of Examples 1 to 6 and Comparative Examples 5 to 12. [Figure 2] FIG. 1 is a diagram showing changes in the properties of copper alloy additive manufacturing bodies due to aging treatment in Examples 1 to 6. [Figure 3] FIG. 1 is a diagram showing the properties of the copper alloy additive manufacturing bodies of Examples 10 to 19. [Figure 4] FIG. 10 is a diagram showing changes in the properties of copper alloy additive manufacturing bodies due to aging treatment in Examples 10 to 19. [Figure 5]FIG. 1 is a diagram showing the properties of copper alloy additive manufacturing bodies of Examples 1 to 6 and 10 to 19 and Comparative Examples 21 to 34 and 41 to 54. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the components described in the following embodiments are merely examples and are not intended to limit the technical scope of the present invention.

[0012] [First embodiment] In this embodiment, we will describe a copper alloy powder for additive manufacturing that contains nickel and silicon, with the remainder being copper and unavoidable impurities, and a copper alloy additive manufacturing body that is additively manufactured using this copper alloy powder for additive manufacturing.

[0013] <Production of copper alloy powder for additive manufacturing> The method for producing the copper alloy powder for additive manufacturing of this embodiment is not particularly limited, but a method in which powder particles are rapidly cooled and solidified from a molten state, such as gas atomization, water atomization, centrifugal atomization, plasma atomization, or plasma rotating electrode method, is preferred. From the viewpoint of mass production, gas atomization is particularly preferred. The produced powder can be classified under predetermined classification conditions using a known classification method to adjust the copper alloy powder for additive manufacturing to an appropriate particle size. An air classifier can be suitably used as a classification device for performing classification.

[0014] (Conditions of metals contained in the copper alloy powder for additive manufacturing of this embodiment) In Corson alloy, a precipitation-strengthened copper alloy, nickel and silicon, which are supersaturated in the copper matrix, form a nickel-silicon intermetallic compound and precipitate during aging treatment, improving the strength of the copper alloy.

[0015] To obtain copper alloy AM bodies with high mechanical strength, a nickel content of 1.5 wt% or more is preferable. If the nickel content is less than 1.5 wt%, the amount of precipitation during aging treatment will be insufficient, and the strength improvement effect will not be fully achieved. The solid solubility limits of Ni2Si, one of the nickel-silicon intermetallic compounds in Corson alloy, are said to be approximately 4.2 wt% for nickel and 1.0 wt% for silicon. However, if a powder production method such as atomization, in which metal is melted and rapidly solidified, is used, nickel-silicon intermetallic compounds exceeding the solid solubility limit can be incorporated into the copper matrix without precipitating.

[0016] Furthermore, when using powder bed fusion additive manufacturing, the melting and rapid solidification process involves using a laser or electron beam, making it possible to fabricate a shaped body without precipitating nickel-silicon intermetallic compounds beyond the solid solubility limit. However, if the nickel content exceeds 6.0 wt%, although further improvement in mechanical strength is achieved, it also results in a significant decrease in electrical conductivity. Therefore, it is preferable that the nickel content be 6.0 wt% or less.

[0017] Silicon is a major element that contributes to improving the strength of copper alloys by forming and precipitating nickel-silicon intermetallic compounds together with nickel. If the silicon content is less than 0.35 wt%, the amount of precipitation during aging treatment is insufficient, and the strength improvement effect cannot be fully achieved. On the other hand, if the silicon content is more than 1.5 wt%, the electrical conductivity decreases significantly and coarse precipitates are formed, resulting in a decrease in strength. Therefore, it is preferable that the silicon content be within the range of this embodiment.

[0018] Nickel and silicon are the main elements that contribute to improving electrical conductivity and strength by forming nickel-silicon intermetallic compounds. However, to improve both electrical conductivity and strength, it is necessary to include nickel and silicon in a ratio that is effective for forming nickel-silicon intermetallic compounds within their respective content ranges. This ratio, obtained by dividing the nickel content (wt%) by the silicon content (wt%), is preferably within the range of 3.3 to 7.2. If this ratio exceeds 7.2 and nickel is contained in excess relative to silicon, the excess nickel will dissolve in the copper matrix, significantly reducing electrical conductivity. On the other hand, if the ratio is less than 3.3 and silicon is contained in excess relative to nickel, the excess silicon will dissolve in the copper matrix, significantly reducing electrical conductivity.

[0019] (Conditions for physical properties possessed by the copper alloy powder for additive manufacturing of this embodiment) Powders used in AM must be compatible with each step of the AM process, including the supply from a hopper to the build stage, the formation of a uniformly distributed powder layer with a certain thickness, and the melting and solidification process. To achieve this, the following conditions are required: particle size adjusted within an appropriate range, apparent density within an appropriate range, and powder flowability that allows supply from a supply hopper and the formation of an appropriate powder layer.

[0020] The 50% particle size of copper alloy powder for additive manufacturing (AM) refers to the 50% particle size of the particle size distribution measured by laser diffraction, and is preferably in the range of 3 μm to 200 μm. If the 50% particle size is less than 3 μm, the powder lacks fluidity, making it impossible to form a powder layer even in an AM laser-based powder bed fusion (PBF) AM device. Furthermore, when a laser is irradiated on powder with a 50% particle size less than 3 μm, the powder and the droplets generated by the melted powder scatter, making it unsuitable for AM. If the 50% particle size is greater than 100 μm when AM laser-based PM bed fusion is used, or greater than 200 μm when AM electron beam PM bed fusion is used, the surface of the powder layer becomes rough, preventing the formation of a powder layer suitable for AM. Furthermore, the melt pool generated in the powder layer during electron beam irradiation does not reach the solidified layer directly below, resulting in insufficient melting and solidification, making it unsuitable for AM.

[0021] In laser powder bed fusion, the 50% particle size is preferably 3 μm to 100 μm, more preferably 5 μm to 75 μm, and even more preferably 10 μm to 45 μm. In electron beam powder bed fusion, the 50% particle size is preferably 10 μm to 200 μm, more preferably 25 μm to 150 μm, and even more preferably 45 μm to 105 μm.

[0022] Copper alloy powder suitable for additive manufacturing using additive manufacturing equipment must have an apparent density (AD) of 3.0 g / cm when measured using the JIS Z 2504 measurement method, which conforms to ISO 3923-1. 3 The apparent density must be 3.0 g / cm or more. 3 If the density is less than 3.5 g / cm, the powder packing rate of the powder layer spread by squeegeeing will decrease, making it impossible to form an appropriate powder layer. In addition, a decrease in the powder packing rate will cause voids to form in the molded body, reducing the density of the molded body. In order to obtain a high-density additive manufacturing body, the apparent density of the copper alloy powder for additive manufacturing should be 3.5 g / cm. 3 More preferably, it is equal to or greater than this.

[0023] In additive manufacturing, fluidity is a particularly important powder property. In powder bed fusion, in particular, it is the most important powder property, directly linked to the quality of the object, as it determines the supply of powder from the supply hopper, the supply of powder from the recoater, and the formation of the powder layer on the build stage. In powder bed fusion, the powder must be spread evenly on the build stage with a certain thickness. This process of spreading the powder is called squeegeeing, and the quality of the powder's spreading ability is called squeegeeing ability. Powders used in additive manufacturing require sufficient squeegeeing ability, which requires the powder to have appropriate fluidity.

[0024] The flow rate (FR) of metal powders is measured using the flow rate (FR) defined in JIS Z 2502, "Metal Powders - Flow Rate Measurement Method," based on ISO 4490. However, for fine powders with a 50% particle size of 50 μm or less, which are primarily used for laser-assisted powder bed fusion (LPF), the powder may not flow out of the measuring container, making measurement impossible. Therefore, the adhesive strength of powders obtained by the single-plane shear test (hereinafter referred to as shear test) specified in the Japan Powder Process Industry and Engineering Association standard (SAP15-13:2013), "Single-plane Shear Test Method for Powders," is an effective indicator of the flowability of fine powders. The adhesive strength can be determined from the fracture envelope of the powder layer obtained by measuring the shear stress generated when a powder layer formed by vertical compaction is subjected to vertical pressure and then slid horizontally.

[0025] The shear test can be measured, for example, using a powder rheometer FT4 manufactured by Freeman Technology. For copper alloy powders for additive manufacturing, if their adhesive strength is 0.600 kPa or less, they can be judged to have sufficient fluidity to spread a uniform powder layer and to have good squeegeeability. This allows for the production of high-density, homogeneous additive manufacturing products. If the adhesive strength is greater than 0.600 kPa, the copper alloy powder for additive manufacturing does not have sufficient fluidity, resulting in poor squeegeeability and making it impossible to form an appropriate powder layer. Therefore, for copper alloy powders for additive manufacturing, it is desirable that the adhesive strength of the copper alloy powder determined from the fracture envelope obtained by the shear test be 0.600 kPa or less.

[0026] <Production of copper alloy additive manufacturing object using copper alloy powder for additive manufacturing of this embodiment> Various known metal additive manufacturing techniques can be used to manufacture copper alloy additive manufacturing products. For example, in powder bed fusion, metal powder is spread evenly on a building stage using a blade or roller to form a powder layer, and then a laser or electron beam is irradiated at a predetermined position on the powder layer to sinter and melt the metal powder, repeatedly producing an additive manufacturing product. In the metal additive manufacturing process, a large number of process parameters must be controlled to obtain high-quality products.

[0027] In laser-based powder bed fusion, there are many scanning conditions, such as laser output and laser scanning speed. Therefore, to set the optimal scanning conditions, the main parameters are adjusted using the energy density, which is an index that summarizes the main parameters. Energy density E (J / mm 3 ) is determined by E = P / (v × s × t), where P (W) is the laser output, v (mm / s) is the laser scanning speed, s (mm) is the laser scanning pitch, and t (mm) is the powder layer thickness. In laser-based powder bed fusion, the energy density is 150 J / mm 3 More than 450J / mm 3 The energy density is preferably 150 J / mm or less. 3If the energy density is less than 450 J / mm, the powder layer will not melt or will not fuse properly, resulting in defects such as voids in the molded object. 3 If the powder density exceeds 100%, sputtering occurs, making the surface of the powder layer unstable and resulting in defects such as voids in the molded body.

[0028] On the other hand, in electron beam powder bed fusion (EBPM), when the powder layer is irradiated with an electron beam, negative charges accumulate in the powder layer, causing the powder to rise into a mist, resulting in a "smoke" phenomenon and insufficient melting. Therefore, to prevent this charge-up, a preliminary step of preheating and pre-sintering the powder layer is required. However, if the preheating temperature is too high, sintering progresses, causing necking, making it difficult to remove the remaining powder from inside the sintered body after shaping. For this reason, it is preferable to set the preheating temperature for copper alloy powders for AM to between 300°C and 800°C.

[0029] Although the metal additive manufacturing technology using the powder bed fusion method has been exemplified here, the general additive manufacturing method for producing an additive manufacturing body using the copper alloy powder for additive manufacturing of this embodiment is not limited to this, and for example, an additive manufacturing method using the directed energy deposition method may also be adopted.

[0030] (Aging treatment of copper alloy additive manufacturing body) By subjecting the copper alloy additive manufacturing body to aging treatment, supersaturated solid solution nickel and silicon are precipitated, improving the strength and electrical conductivity of the additive manufacturing body. Therefore, the aging treatment step is essential for obtaining the high strength and high electrical conductivity characteristics of this embodiment. The aging treatment can be performed by heating the additive manufacturing body to a predetermined temperature and holding it for a predetermined time. The aging treatment is preferably performed in a reducing atmosphere or in an inert gas, or in a vacuum.

[0031] The effect of aging treatment is determined by the combination of aging temperature and aging time, so it is important to set appropriate conditions by balancing the desired properties and efficiency. The aging temperature is preferably 450°C or higher and 550°C or lower, and more preferably 450°C or higher and 500°C or lower. If it is desired to particularly improve mechanical strength, a temperature of 500°C is preferred. If it is desired to obtain particularly high electrical conductivity, a temperature of 550°C can also be used. If the aging temperature is 450°C or higher, the aging time is preferably set to 0.5 hours or higher and 3 hours or lower.

[0032] If the aging treatment time is shorter than the set time, the precipitation of nickel and silicon will be insufficient. Furthermore, if the aging treatment time exceeds the set time, over-aging will occur, causing the precipitated nickel-silicon intermetallic compounds to coarsen, resulting in a decrease in hardness. If the aging treatment temperature is less than 450°C, it will take a long time to achieve the aging effect, which is not practical. Furthermore, if the aging treatment temperature exceeds 550°C, over-aging will occur, causing the precipitated nickel-silicon intermetallic compounds to coarsen, resulting in a decrease in strength.

[0033] In copper alloy additive manufacturing products manufactured using the copper alloy powder for additive manufacturing of this embodiment, the nickel-silicon intermetallic compound is easily precipitated due to the thermal strain introduced by the rapid melting and solidification process, which is a characteristic of additive manufacturing. Therefore, it is possible to sufficiently improve the electrical conductivity and mechanical strength by aging for about one hour at an aging temperature of 450°C to 550°C.

[0034] The Vickers hardness of the copper alloy additive manufacturing product of this embodiment is measured by a method conforming to JIS Z 2244: Vickers hardness test - test method. The Vickers hardness can be measured, for example, using a microhardness tester HMV-G21-DT manufactured by Shimadzu Corporation.

[0035] Furthermore, the copper alloy additive manufacturing product of this embodiment has a conductivity of 30% IACS or more. The conductivity can be measured, for example, by an eddy current conductivity meter. Examples of eddy current conductivity meters include the high-performance eddy current conductivity meter Sigma Check manufactured by Nihon Matec Co., Ltd. Note that IACS (International Annealed Copper Standard) is an internationally adopted standard for conductivity, which is based on annealed standard soft copper (volume resistivity: 1.7241 × 10 -2 The electrical conductivity is defined as 100% IACS (μΩm). The electrical conductivity can be adjusted by aging treatment, and it is preferable to adjust it appropriately depending on the desired Vickers hardness. The electrical conductivity is preferably 35% IACS or higher, and more preferably 40% IACS or higher.

[0036] It is known that electrical conductivity and thermal conductivity are approximately proportional to each other in metals, as is known from the Wiedemann-Franz law. Therefore, a copper alloy additive manufacturing object manufactured by additive manufacturing using the copper alloy powder for additive manufacturing of this embodiment with an additive manufacturing device has high electrical conductivity, and therefore can also be used as a copper alloy additive manufacturing object with high thermal conductivity.

[0037] [Second embodiment] In this embodiment, we will describe a copper alloy powder for additive manufacturing that contains nickel and silicon, as well as one or more other metal elements selected from iron, silver, magnesium, manganese, tin, and zinc, with the remainder consisting of copper and unavoidable impurities, and a copper alloy additive manufacturing body that is additively manufactured using this copper alloy powder for additive manufacturing.

[0038] In addition to containing nickel and silicon, the copper alloy powder for additive manufacturing of this embodiment may contain one or more elements selected from iron, silver, magnesium, manganese, tin, and zinc, as necessary. The effects of containing these metal elements will be described below.

[0039] The inclusion of iron has the effect of refining the structure of the copper alloy additive manufacturing product of this embodiment and improving its strength. Furthermore, by combining with silicon, iron forms an iron-silicon compound. Therefore, it is possible to improve the mechanical properties and heat resistance without significantly reducing the electrical conductivity. The iron content is preferably adjusted to a range of 0.01% by weight to 1.00% by weight, and more preferably adjusted to a range of 0.05% by weight to 0.30% by weight.

[0040] The inclusion of silver is believed to increase the electrical conductivity of the copper alloy additive manufacturing product of this embodiment and to increase its strength through solid solution strengthening. It also increases the chemical potential of nickel, enhancing the repulsive interaction between elements and promoting the precipitation of nickel-silicon intermetallic compounds. When the silver content exceeds 1.0 wt%, the silver ratio increases, but increasing the silver content does not significantly improve the properties, and the excessive inclusion of expensive silver increases costs. Therefore, the silver content is preferably adjusted to a range of 0.01 wt% to 1.00 wt%, and more preferably to a range of 0.05 wt% to 0.30 wt%.

[0041] The inclusion of magnesium has the effect of increasing strength through solid solution strengthening and improving stress relaxation resistance. Furthermore, magnesium has little effect on electrical conductivity when contained in a copper alloy. Furthermore, magnesium promotes the precipitation of nickel-silicon intermetallic compounds. The magnesium content is preferably adjusted to a range of 0.01% by weight to 1.00% by weight, and more preferably to a range of 0.05% by weight to 0.35% by weight.

[0042] Manganese acts as a deoxidizer, combining with oxygen to form compounds that reduce the quality degradation effect. It also has the effect of refining the structure and improving strength. The manganese content is preferably adjusted to a range of 0.01% to 1.00% by weight, and more preferably to a range of 0.05% to 0.20% by weight.

[0043] The inclusion of tin and zinc has the effect of increasing strength through solid solution strengthening. It also has the effect of improving stress relaxation resistance, heat resistance, and corrosion resistance. However, excessive tin and zinc content reduces electrical conductivity. Therefore, the tin content is preferably adjusted to a range of 0.01% to 1.00% by weight, and more preferably to a range of 0.05% to 0.50% by weight. The zinc content is preferably adjusted to a range of 0.01% to 1.00% by weight, and more preferably to a range of 0.05% to 0.50% by weight.

[0044] However, if the content of iron, silver, magnesium, manganese, tin, and zinc exceeds 1.0 wt%, the electrical conductivity will decrease significantly, so it is preferable that the total content of these elements be 1.0 wt% or less.

[0045] [Third embodiment] In this embodiment, the results of a comparison of the properties of a copper alloy additive manufacturing body produced by additive manufacturing and a copper alloy additive manufacturing body produced by conventional arc melting or rolling processing will be described.

[0046] Corson alloy is known to have excellent properties such as high strength, electrical conductivity, and thermal conductivity when it is subjected to severe plastic processing such as rolling or forging after solution treatment to add strain, and then heat treated to precipitate fine nickel-silicon intermetallic compounds.

[0047] Known methods for producing these Corson alloys include hot forging a cast Corson alloy ingot, followed by solution heat treatment and aging. Another known method involves blooming and hot finish processing of a cast Corson alloy ingot by forging or rolling, quenching after solution treatment, machining, and aging. Another known method involves hot working a cast Corson alloy ingot, annealing it, and aging it after cooling. Still another known method involves hot forging a cast Corson alloy ingot, solution treating it, cold plastic working, and aging.

[0048] However, since the Corson alloy ingot is cast, plastically processed (forged or rolled), and subjected to a solution treatment, and then aging is performed after these processes, there are problems in that the processed shape is limited, and the number of processing steps is large because plastically processed (forged or rolled) and a solution treatment are required.

[0049] As described above, according to this embodiment, a Corson alloy made of nickel and silicon is efficiently produced, making it possible to manufacture a high-strength copper alloy additive manufacturing object.

[0050] Furthermore, according to this embodiment, by adding other metal elements such as iron, silver, magnesium, manganese, tin, and zinc to nickel and silicon, it is possible to produce a copper alloy additive manufacturing body with further improved conductivity and strength.

[0051] Furthermore, according to this embodiment, it is possible to provide a copper alloy powder for additive manufacturing that can be used to manufacture a copper alloy additive manufacturing body that combines high electrical conductivity, high thermal conductivity, and excellent mechanical strength without requiring a solution treatment or plastic working process, and an additively manufactured copper alloy additive manufacturing body.

[0052] Furthermore, by using the copper alloy powder for additive manufacturing of this embodiment for additive manufacturing, copper alloy molds for die casting or plastic molding, or electrodes for resistance welding, etc. can be manufactured with high efficiency, while achieving high electrical conductivity, high thermal conductivity, and high strength, without undergoing solution treatment or plastic processing processes.

[0053] [Other embodiments] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the technical scope of the present invention. Furthermore, any combination of the separate features included in each embodiment is also included in the technical scope of the present invention. [Example]

[0054] The following describes the characteristics of the copper alloy powder for additive manufacturing and the copper alloy additive manufacturing body shown in this embodiment based on examples and comparative examples that are experimental results according to this embodiment. The following examples and comparative examples are merely specific examples intended to facilitate understanding of the technical content, and the technical scope is not limited by these specific examples.

[0055] <Example of copper alloy powder for additive manufacturing containing nickel and silicon> Copper alloy powders for additive manufacturing containing nickel and silicon were produced by varying the content and content ratio of nickel and silicon, and then copper alloy additive manufactured bodies were produced by additive manufacturing using the copper alloy powders for additive manufacturing, and their properties were measured.

[0056] (Production and property measurement of copper alloy powder for additive manufacturing) Copper alloy powders for additive manufacturing were produced by gas atomization, each containing nickel and silicon as shown in Table 1. The obtained copper alloy powders for additive manufacturing were then classified to have particle sizes of 10 μm or more and 45 μm or less for laser powder bed fusion and 45 μm or more and 105 μm or less for electron beam powder bed fusion.

[0057] The contents of the component elements in the obtained copper alloy powder for additive manufacturing were measured by ICP atomic emission spectroscopy. In addition, the apparent density (AD) (g / cm) of the obtained copper alloy powder for additive manufacturing was measured in accordance with JIS Z 2504. 3 ) was measured. In addition, the flow rate (FR) (sec / 50g) of the obtained copper alloy powder for additive manufacturing was measured in accordance with JIS Z 2502. In addition, the 50% particle size (D50) (μm) was measured by laser diffraction method (Microtrac MT3300: manufactured by Microtrac Bell Co., Ltd.).

[0058] A shear test was carried out using a powder rheometer FT4 (manufactured by Freeman Technology) to measure the adhesive force (kPa) of the obtained copper alloy powder for additive manufacturing. The squeegeeing properties of the obtained copper alloy powder for additive manufacturing were evaluated by actually spreading the powder to be used in the manufacturing test on the manufacturing stage of a 3D additive manufacturing machine (powder sintering additive manufacturing / laser method or electron beam method) to form a powder layer. The measurement results of each property for the copper alloy powder for additive manufacturing of Examples 1 to 6 and Comparative Examples 1 to 12 are shown in Table 1. In Table 1, the underlined property values ​​indicate values ​​that do not meet the condition range (expected value) for the copper alloy powder for additive manufacturing.

[0059] [Table 1]

[0060] (Determination of squeegeeability of copper alloy powder for additive manufacturing) In Examples 1 to 6 and Comparative Examples 5 to 12, the squeegeeing properties were sufficient, and copper alloy layer shaped objects were successfully produced.

[0061] On the other hand, the copper alloy powders of Comparative Examples 1 to 4 had poor squeegeeability, making it impossible to carry out normal additive manufacturing. For example, the copper alloy powder of Comparative Example 1 was unable to be spread evenly, making it impossible to manufacture. The copper alloy powder of Comparative Example 1 met the conditions for the nickel and silicon content and ratio, and 50% particle size (D50), but did not meet the conditions for apparent density (AD) and adhesive strength.

[0062] The copper alloy powder of Comparative Example 2 failed to form a powder layer. The copper alloy powder of Comparative Example 2 met the conditions for the nickel and silicon content and ratio, but did not meet the conditions for the 50% particle size (D50), apparent density (AD), and adhesive strength. The copper alloy powder of Comparative Example 3 was able to be spread, but there were many sparse areas in the powder layer. The copper alloy powder of Comparative Example 3 met the conditions for the nickel and silicon content and ratio, 50% particle size (D50), and apparent density (AD), but did not meet the conditions for adhesive strength. The copper alloy powder of Comparative Example 4 had insufficient packing in the powder layer, resulting in low density. The copper alloy powder of Comparative Example 4 met the conditions for the nickel and silicon content and ratio, 50% particle size (D50), and adhesive strength, but did not meet the conditions for the apparent density (AD).

[0063] (Manufacturing copper alloy additive manufacturing bodies using copper alloy powder for additive manufacturing) Using the copper alloy powders for additive manufacturing of Examples 1 to 5 and Comparative Examples 5 to 12, additively manufactured objects to be tested were produced using a 3D powder additive manufacturing machine (SLM Solutions GmbH, SLM280HL) equipped with a Yb fiber laser with a wavelength of 1064 nm. The additive manufacturing was carried out under the following conditions: a layer thickness of 25 μm to 50 μm, a laser output of 300 W to 700 W, a scanning speed of 900 mm / sec to 1500 mm / sec, and an energy density of 150 J / mm 3 More than 450J / mm 3 The test was carried out under the following conditions:

[0064] Using the copper alloy powder for additive manufacturing in Example 6, an additive manufacturing object to be tested was manufactured using an electron beam-equipped 3D powder additive manufacturing machine (ArcamAB, EBM A2X). The additive manufacturing was performed under the following conditions: a layer thickness of 50 μm to 100 μm, an electron beam voltage of 60 kV, and a preheating temperature of 300°C to 700°C. For additive manufacturing, a cylindrical additive manufacturing object with a diameter of 14 mm and a height of 10 mm was manufactured using the 3D powder additive manufacturing machine.

[0065] (Measurement of copper alloy additive manufacturing properties) The relative densities (%) of the layered manufactured bodies produced using the copper alloy powders for layered manufacturing of Examples 1 to 6 and Comparative Examples 5 to 12 were measured by the Archimedes method using helium gas as the substitution medium (AccuPyc1330: manufactured by Shimadzu Corporation). The measurement results are shown in Table 2.

[0066] The electrical conductivity (%IACS) of the copper alloy additive manufacturing bodies of Examples 1 to 6 and Comparative Examples 5 to 12, which were manufactured using a 3D powder additive manufacturing machine, was measured using an eddy current conductivity meter (high-performance eddy current conductivity meter Sigma Check, manufactured by Nihon Matec Co., Ltd.). The Vickers hardness (Hv) of the copper alloy additive manufacturing bodies was measured using a microhardness tester (microhardness tester HMV-G21-DT, manufactured by Shimadzu Corporation).

[0067] The produced copper alloy additive manufacturing bodies were subjected to aging treatment for one hour in an inert atmosphere at temperatures set to 400°C, 500°C, 600°C, and 700°C. The conductivity of the aged copper alloy additive manufacturing bodies was measured using an eddy current conductivity meter. The Vickers hardness was also measured using a microhardness tester. Table 2 shows the evaluation results of various properties for the additive manufacturing bodies of Examples 1 to 6 and Comparative Examples 5 to 12, which were produced using a 3D powder additive manufacturing machine. In Table 2, the property values ​​enclosed in bold frames indicate values ​​that meet the required range for a copper alloy additive manufacturing body. The underlined property values ​​indicate values ​​that do not meet the required range for a copper alloy additive manufacturing body even after aging treatment at 500°C, or values ​​that do not meet the required range for a copper alloy powder for additive manufacturing.

[0068] [Table 2]

[0069] In Examples 1 to 6, the nickel and silicon content, ratio, and properties of the copper alloy powder for additive manufacturing were within the specified range, so that copper alloy additive manufacturing bodies having sufficient conductivity (30% IACS or more) and strength (Vickers hardness: 200 Hv or more) could be produced by the specified aging treatment.

[0070] On the other hand, in Comparative Example 5, the nickel and silicon contents were excessive and outside the condition range, so the Vickers hardness was high but the electrical conductivity was low. In Comparative Example 6, the nickel and silicon contents were too low and outside the condition range, so the electrical conductivity was high but the Vickers hardness was low. In Comparative Example 7, the nickel content was excessive, and in Comparative Example 9, the silicon content was excessive, so the Vickers hardness was high but the electrical conductivity was low. In Comparative Example 8, the nickel content was too low, and in Comparative Example 10, the silicon content was too low, so the electrical conductivity was high but the Vickers hardness was low.

[0071] The value (ratio) obtained by dividing the nickel content (wt%) by the silicon content (wt%) exceeded 7.2 in Comparative Example 11, while it was below 3.3 in Comparative Example 12. Therefore, although the Vickers hardness was high, the electrical conductivity was low.

[0072] FIG. 1 is a diagram plotting the properties of Examples 1 to 6 and Comparative Examples 5 to 12, with electrical conductivity (% IACS) after aging at 500° C. on the X axis and Vickers hardness (Hv) on the Y axis.

[0073] It is clear that while the electrical conductivity and Vickers hardness of the copper alloy additive manufacturing bodies of Examples 1 to 6 meet the required range, the electrical conductivity and Vickers hardness of the copper alloy additive manufacturing bodies of Comparative Examples 5 to 12 do not meet the required range.

[0074] FIG. 2 is a graph plotting electrical conductivity (% IACS) or Vickers hardness (Hv) characteristics when the aging temperature was changed from 400° C. to 700° C. in Examples 1 to 6.

[0075] It can be seen that the temperature range of the aging treatment in Examples 1 to 6 is preferably 450°C or more and 550°C or less, with 550°C being preferred if high electrical conductivity is desired, and 500°C being preferred if high Vickers hardness is desired.

[0076] <Example of copper alloy powder for additive manufacturing containing nickel, silicon, and other metal elements> Copper alloy powders for additive manufacturing were produced by varying the content and content ratio of nickel and silicon, and the content of other metal elements. Copper alloy additive manufacturing bodies were then produced by additive manufacturing using the copper alloy powders for additive manufacturing, and their properties were measured.

[0077] (Production and property measurement of copper alloy powder for additive manufacturing) Copper alloy powders for additive manufacturing were produced by gas atomization, which were copper alloys containing nickel and silicon and other metal elements as shown in Table 3. The obtained copper alloy powders for additive manufacturing were then classified to have particle sizes of 10 μm or more and 45 μm or less for laser powder bed fusion and 45 μm or more and 105 μm or less for electron beam powder bed fusion.

[0078] The contents of the component elements in the obtained copper alloy powder for additive manufacturing were measured by ICP atomic emission spectroscopy. In addition, the apparent density (AD) (g / cm) of the obtained copper alloy powder for additive manufacturing was measured in accordance with JIS Z 2504. 3 ) was measured. In addition, the flow rate (FR) (sec / 50g) of the obtained copper alloy powder for additive manufacturing was measured in accordance with JIS Z 2502. In addition, the 50% particle size (D50) (μm) was measured by laser diffraction method (Microtrac MT3300: manufactured by Microtrac Bell Co., Ltd.).

[0079] A shear test was performed using a powder rheometer FT4 (manufactured by Freeman Technology) to measure the adhesive force (kPa) of the obtained copper alloy powder for additive manufacturing. The squeegeeing properties of the obtained copper alloy powder for additive manufacturing were evaluated by actually spreading the powder to be used in the manufacturing test on the manufacturing stage of a 3D additive manufacturing machine (powder sintering additive manufacturing / laser method or electron beam method) to form a powder layer. The measurement results of each property for the copper alloy powder for additive manufacturing of Examples 10 to 19 are shown in Table 3.

[0080] [Table 3]

[0081] (Manufacturing copper alloy additive manufacturing bodies using copper alloy powder for additive manufacturing) Using the copper alloy powders for additive manufacturing of Examples 10 to 13 and 15 to 19, additively manufactured objects to be tested were produced using a 3D powder additive manufacturing machine (SLM Solutions GmbH, SLM280HL) equipped with a Yb fiber laser with a wavelength of 1064 nm. The additive manufacturing was carried out under the following conditions: a layer thickness of 25 μm to 50 μm, a laser output of 300 W to 700 W, a scanning speed of 900 mm / sec to 1500 mm / sec, and an energy density of 150 J / mm 3 More than 450J / mm 3 The test was carried out under the following conditions:

[0082] Using the copper alloy powder for additive manufacturing in Example 14, an additive manufacturing object to be tested was manufactured using an electron beam-equipped 3D powder additive manufacturing machine (ArcamAB, EBM A2X). The additive manufacturing was performed under the following conditions: a layer thickness of 50 μm to 100 μm, an electron beam voltage of 60 kV, and a preheating temperature of 300°C to 700°C. For additive manufacturing, a cylindrical additive manufacturing object with a diameter of 14 mm and a height of 10 mm was manufactured using the 3D powder additive manufacturing machine.

[0083] (Measurement of copper alloy additive manufacturing properties) The relative densities (%) of the layered manufactured bodies produced using the copper alloy powders for layered manufacturing of Examples 10 to 19 were measured by the Archimedes method using helium gas as the substitution medium (AccuPyc1330: manufactured by Shimadzu Corporation). The measurement results are shown in Table 4.

[0084] The electrical conductivity (%IACS) of the copper alloy additive manufacturing bodies of Examples 10 to 19, which were manufactured using a 3D powder additive manufacturing machine, was measured using an eddy current conductivity meter (high-performance eddy current conductivity meter Sigma Check, manufactured by Nihon Matec Co., Ltd.). In addition, the Vickers hardness (Hv) of the copper alloy additive manufacturing bodies was measured using a microhardness tester (microhardness tester HMV-G21-DT, manufactured by Shimadzu Corporation).

[0085] The produced copper alloy additive manufacturing bodies were subjected to an aging treatment for one hour in an inert atmosphere at temperatures set to 400°C, 500°C, 600°C, and 700°C. The conductivity of the aged copper alloy additive manufacturing bodies was measured using an eddy current conductivity meter. The Vickers hardness was also measured using a microhardness tester. Table 4 shows the evaluation results of various properties of the additive manufacturing bodies of Examples 10 to 19 produced using the 3D powder additive manufacturing machine. In Table 4, the property values ​​enclosed in bold frames indicate values ​​that meet the condition range for a copper alloy additive manufacturing body.

[0086] [Table 4]

[0087] In Examples 10 to 19, the nickel and silicon content and ratio, as well as the properties of the copper alloy powder for additive manufacturing, were within the specified range, and therefore copper alloy additive manufacturing bodies having sufficient conductivity (30% IACS or more) and strength (Vickers hardness: 200 Hv or more) could be produced by the specified aging treatment.

[0088] FIG. 3 is a diagram in which the properties of Examples 10 to 19 are plotted, with the electrical conductivity (% IACS) after aging at 500° C. on the X axis and the Vickers hardness (Hv) on the Y axis.

[0089] It is clear that the electrical conductivity and Vickers hardness of the copper alloy additive manufacturing bodies of Examples 10 to 19 meet the required range, while the electrical conductivity and Vickers hardness of the copper alloy additive manufacturing bodies of Comparative Examples 5 to 12 do not meet the required range.

[0090] Furthermore, Examples 10 and 11, which are copper alloy additive manufacturing bodies containing nickel, silicon, and iron, have significantly improved Vickers hardness regardless of the aging treatment temperature while suppressing the decrease in electrical conductivity compared to Example 1, which is a copper alloy additive manufacturing body containing equivalent amounts of nickel and silicon but no iron.

[0091] Example 15, which is a copper alloy additive manufacturing product containing nickel, silicon, and silver, has approximately the same Vickers hardness but improved electrical conductivity compared to Example 1, which is a copper alloy additive manufacturing product containing the same amount of nickel and silicon but no silver. Example 16 also has improved Vickers hardness while maintaining the same electrical conductivity.

[0092] Example 17, which is a copper alloy additive manufacturing body containing nickel, silicon, and magnesium, has improved Vickers hardness while suppressing the decrease in electrical conductivity compared to Example 2, which is a copper alloy additive manufacturing body containing equivalent amounts of nickel and silicon but no magnesium.

[0093] Example 18, which is a copper alloy additive manufacturing body containing nickel, silicon, magnesium, and manganese, has a significantly improved Vickers hardness after aging at 500°C compared to Example 1, which is a copper alloy additive manufacturing body containing the same amount of nickel and silicon but no magnesium or manganese.

[0094] Example 19, which is a copper alloy additive manufacturing body containing nickel, silicon, tin, and zinc, has improved Vickers hardness regardless of the heat treatment conditions compared to Example 3, which is a copper alloy additive manufacturing body containing equivalent amounts of nickel and silicon but no tin or zinc.

[0095] FIG. 4 is a graph plotting electrical conductivity (% IACS) or Vickers hardness (Hv) characteristics when the aging temperature was changed from 400° C. to 700° C. in Examples 10 to 19.

[0096] It can be seen that the temperature range of the aging treatment in Examples 10 to 19 is preferably 450°C or more and 550°C or less, with 550°C being preferred if high electrical conductivity is desired, and 500°C being preferred if high Vickers hardness is desired.

[0097] <Comparative Example of Copper Alloy Shaped Body Containing Nickel and Silicon by Arc Melting or Rolling> (Arc-melted material) In order to compare the properties of a copper alloy (Corson alloy) produced using a conventional manufacturing method in which a cast Corson alloy ingot is subjected to plastic working and solution treatment with the properties of the copper alloy additive manufacturing bodies of Examples 1 to 6 and 10 to 19, the properties of the Corson alloy produced using the conventional method were evaluated using the following method. Instead of the cast material production method, an arc melting method, a well-known method for producing ingot material, was used.

[0098] Arc-melted materials were produced by arc melting using copper alloy powders for additive manufacturing similar to those in Examples 1 to 5, 10 to 13, and 15 to 19. The arc-melted materials were produced as follows. First, the copper alloy powders for additive manufacturing of Examples 1 to 5, 10 to 13, and 15 to 19 were press-molded to produce green compacts. The produced green compacts were arc-melted in an argon atmosphere using a vacuum arc melting furnace manufactured by Nisshin Giken Co., Ltd. to produce arc-melted materials. These arc-melted materials were designated Comparative Examples 21 to 34. Note that Example 6 had the same composition as Example 1, and Example 14 had the same composition as Example 10, so arc-melted materials were not produced using copper alloy powders for additive manufacturing similar to those in Examples 6 and 14.

[0099] The electrical conductivity (%IACS) of the arc-melted materials of Comparative Examples 21 to 34, which were produced by arc melting, was measured using an eddy current conductivity meter (high-performance eddy current conductivity meter Sigma Check: manufactured by Nihon Matec Co., Ltd.), and the Vickers hardness (Hv) was measured using a microhardness tester (microhardness tester HMV-G21-DT: manufactured by Shimadzu Corporation).

[0100] The arc-melted materials were then aged for one hour in an inert atmosphere at temperatures of 400, 500, 600, and 700°C. The electrical conductivity of the aged arc-melted materials was measured using an eddy current conductivity meter. The Vickers hardness was also measured using a microhardness tester.

[0101] The evaluation results of various properties of the arc-melted materials of Comparative Examples 21 to 34 are shown in Table 5. In Table 5, the underlined property values ​​indicate values ​​that do not satisfy the condition range for a copper alloy shaped body even after aging treatment at 500°C. [Table 5]

[0102] (rolled arc-melted material) Next, the obtained arc-melted materials of Comparative Examples 21 to 34 were rolled at a processing rate of 50% using a rolling mill to perform plastic processing. The rolled bodies were subjected to solution treatment at a temperature of 950°C in an inert atmosphere for 1 hour. The arc-melted materials that had been subjected to this rolling processing were designated Comparative Examples 41 to 54.

[0103] For the arc-melted materials of Comparative Examples 41 to 54, which were obtained by rolling the arc-melted materials of Comparative Examples 21 to 34, the electrical conductivity (%IACS) was measured using an eddy current conductivity meter (high-performance eddy current conductivity meter Sigma Check: manufactured by Nihon Matec Co., Ltd.) and the Vickers hardness (Hv) was measured using a microhardness tester (microhardness tester HMV-G21-DT: manufactured by Shimadzu Corporation).

[0104] The rolled, arc-melted materials were aged for one hour in an inert atmosphere at temperatures of 400, 500, 600, and 700°C. The electrical conductivity of the aged, arc-melted, rolled materials was measured using an eddy current conductivity meter. The Vickers hardness was also measured using a microhardness tester.

[0105] The evaluation results of various properties of the arc-melted materials subjected to rolling in Comparative Examples 41 to 54 are shown in Table 6. In Table 6, the underlined property values ​​indicate values ​​that do not satisfy the condition range for a copper alloy shaped body even after aging treatment at 500°C. [Table 6]

[0106] FIG. 5 is a graph plotting the properties of the copper alloy additive manufacturing bodies of Examples 1 to 6 and 10 to 19, the arc-cast materials of Comparative Examples 21 to 34, and the arc-cast materials subjected to rolling processing of Comparative Examples 41 to 54, after aging treatment at 500°C, with electrical conductivity (%IACS) on the X axis and Vickers hardness (Hv) on the Y axis.

[0107] The arc-melted materials of Comparative Examples 21 to 34 were not subjected to severe processing to add strain after solution treatment, and therefore, even after heat treatment, their properties were inferior to those of Examples 1 to 6 and 10 to 19. Compared with the properties of the arc-melted materials of Comparative Examples 41 to 54, which were subjected to rolling processing to simulate conventional manufacturing methods, the copper alloy additive manufacturing bodies of Examples 1 to 6 and 10 to 19 achieved properties that compare favorably.

[0108] From the above, it was confirmed that Examples 1 to 6 and 10 to 19 make it possible to provide copper alloy powder for additive manufacturing and copper alloy additive manufacturing bodies that combine high electrical conductivity (thermal conductivity) and excellent mechanical strength without the need for solution treatment and plastic processing.

Claims

1. A copper alloy powder for additive manufacturing used to manufacture an additive manufacturing body having a conductivity of 30% IACS or more and a Vickers hardness of 200 Hv or more by an additive manufacturing method, containing nickel and silicon, with the balance being copper and unavoidable impurities; the value obtained by dividing the nickel content (wt%) by the silicon content (wt%) is 3.3 or more and 7.2 or less, 50% particle size is 70 μm or more and 200 μm or less, The nickel content is 1.5% by weight or more and 6.0% by weight or less, The silicon content is 0.35% by weight or more and 1.5% by weight or less, The apparent density of the powder measured by the method of JIS Z 2504 (ISO 3923-1) is 3.5 g / cm 3 or more, A copper alloy powder for additive manufacturing, in which the adhesive strength of the copper alloy powder obtained from the fracture envelope obtained by a shear test is 0.600 kPa or less.

2. 2. The copper alloy powder for additive manufacturing according to claim 1, further comprising one or more selected from iron, silver, magnesium, manganese, tin and zinc in a total amount of up to 1.0 wt% (excluding cases where iron, silver, magnesium, manganese, tin and zinc are 0 wt%).

3. A copper alloy additive manufacturing object manufactured by additive manufacturing using the copper alloy powder for additive manufacturing according to claim 1, the value obtained by dividing the nickel content (wt%) by the silicon content (wt%) is 3.3 or more and 7.2 or less, The nickel is contained in an amount of 1.5 wt % or more and 6.0 wt % or less, and the silicon is contained in an amount of 0.35 wt % or more and 1.5 wt % or less, with the remainder being copper and unavoidable impurities, A copper alloy additive manufacturing body having a conductivity of 30% IACS or more and a Vickers hardness of 200 Hv or more.

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