Method for producing a dissolving raw material, and dissolving raw material

Abstract

To provide a production method of a molten raw material in which an alloy powder used for, for example, metal lamination molding, powder compacting, powder metallurgy and metal injection molding with respect to an alloy powder containing a high melting point element may be stably produced, and to provide the molten raw material.SOLUTION: A production method of a molten raw material comprises a pressure sintering step of sintering mixed powders comprising a plurality of kinds of raw material powders at a temperature of 2 MPa min / 3 or more and a pressure of 5 MPa or more where the melting point of an element having the lowest melting point among the elements constituting the raw material powder is MPmin (°C). The raw material powder contains a high melting point metal element having a melting point of 1600°C or higher.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a method for producing a dissolving raw material and to the dissolving raw material itself, and more particularly to a method for producing a dissolving raw material containing a high melting point element and to the dissolving raw material itself. [Background technology]

[0002] Metal powders are important basic materials in the field of material forming, used in processes such as powder compaction, powder metallurgy, and metal injection molding (MIM). These material forming technologies using metal powders are suitable for various industrial products due to their excellent strength and mass-producibility. Furthermore, in recent years, they have also come to be used as raw materials in metal additive manufacturing (metal 3D printing), enabling moldless material forming, and their importance is increasing.

[0003] Numerous alloys have been used as metal powders in such material forming technologies, including steel, aluminum alloys, copper alloys, nickel-based alloys, and titanium alloys. Furthermore, attempts have been made to dramatically improve heat resistance and other properties by adding high-melting-point elements (metals) such as tungsten, molybdenum, and niobium.

[0004] Patent Document 1 discloses a method in which a raw material powder, a mixture of titanium powder and aluminum powder, is formed into a rod-shaped compacted material by cold forming, and this rod-shaped material is then pulverized by a gas atomization method. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2002-241807

[0006] However, in the method disclosed in Patent Document 1, when materials with poor cold workability, such as high-melting-point elements (high-melting-point metals), are included, voids tend to form inside the cold-formed molded body. When the molded body is melted, these voids can cause damage to the molded body, or the air remaining in the voids can destabilize the melting of the molded body, making it difficult to stably produce alloy powder. [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the object of the present invention is to provide a melting raw material and a method for producing the same, which can stably produce alloy powders containing high melting point elements for use in processes such as metal additive manufacturing, powder compaction, powder metallurgy, and metal injection molding. [Means for solving the problem]

[0008] The present invention A method for producing dissolving raw materials for manufacturing high-entropy alloy powder, A mixed powder consisting of multiple types of raw material powders is prepared by determining the melting point of the element with the lowest melting point among the elements constituting the raw material powders, using MP min When (°C), 2MP min A method for producing a molten raw material, comprising a pressure sintering step in which sintering is performed at a temperature of 1 / 3 or higher and at a pressure of 5 MPa or higher, wherein the raw material powder contains a high-melting-point metal element with a melting point of 1600°C or higher.

[0009] Furthermore, it is preferable that at least one of the aforementioned multiple raw material powders contains two or more high-melting-point metal elements.

[0010] Furthermore, it is preferable to use a hot isotropic pressurized sintering method in the aforementioned pressurized sintering process.

[0011] Furthermore, the present invention relates to a melting raw material used to obtain alloy powder by melting and spraying, characterized in that it contains at least two high-melting-point metal elements with a melting point of 1600°C or higher and is a sintered body with a porosity of less than 5%. Furthermore, the raw materials used for melting are high-entropy alloys composed of high-melting-point metal elements with melting points of 1600°C or higher.

Advantages of the Invention

[0012] According to the present invention, for alloy powders containing high melting point elements, for example, a method for producing a melting raw material capable of stably producing alloy powders used in metal additive manufacturing, powder pressing molding, powder metallurgy, metal injection molding, etc., and a melting raw material can be provided.

Brief Description of the Drawings

[0013] [Figure 1] It is a process diagram showing an example of a method for producing metal powder according to the present invention. [Figure 2] It is a schematic diagram showing an embodiment of a melting and spraying process for a method for producing metal powder according to the present invention. [Figure 3] It is a schematic diagram showing another embodiment of a melting and spraying process for a method for producing metal powder according to the present invention. [Figure 4] It is a cross-sectional schematic diagram showing an example of the configuration of a laminated manufacturing apparatus and a laminated manufacturing method of a selective laser melting method. [Figure 5] It is a cross-sectional schematic diagram showing an example of the configuration of a laminated manufacturing apparatus and a laminated manufacturing method of a laser beam powder cladding method.

Embodiments for Carrying Out the Invention

[0014] <� First, the present inventors have intensively studied a method for producing metal powders containing a large amount of high melting point elements that are difficult to uniformly melt in existing melting (dissolving) equipment. As a result, a plurality of raw material powders containing metal elements with a melting point of 1600°C or higher are uniformly mixed to have a target composition, and a sintered body (sometimes referred to as a raw material bar) having substantially the same composition as the metal powder to be produced is produced by sintering this at a predetermined temperature and pressure. And it has been found that an alloy powder (pre-alloy powder) having a desired composition can be stably obtained by pulverizing the melt obtained by locally melting this sintered body.

[0015] <Method for Producing Melting Raw Material> Hereinafter, embodiments of the manufacturing method of the present invention will be described with reference to FIG. 1. FIG. 1 is a process diagram showing a method for manufacturing a molten raw material according to an embodiment of the present invention and a suitable manufacturing method for obtaining alloy powder using the molten raw material.

[0016] [Pressure sintering step (S101)] First, the raw material powder will be described. Raw material powders containing a high melting point metal are mixed according to the composition of the desired alloy powder to obtain a mixed powder. At this time, one raw material powder contains a metal element (high melting point metal element) having a melting point of 1600°C or higher, and by mixing two or more such raw material powders, a mixed powder containing at least two or more high melting point metal elements is obtained. Examples of high melting point metal elements include tungsten (W), rhenium (Re), osmium (Os), tantalum (Ta), molybdenum (Mo), niobium (Nb), iridium (Ir), ruthenium (Ru), hafnium (Hf), technetium (Tc), rhodium (Rh), vanadium (V), chromium (Cr), zirconium (Zr), thorium (Th), titanium (Ti), etc. The mixing method is not particularly limited, and for example, various powder mixers such as a ball mill can be used. As the method for manufacturing the raw material powder, depending on the raw material, a chemical reduction method, a pulverization method, etc. are selected. Also, the raw material powder may include powders manufactured by an atomization method.

[0017] In addition, the raw material powder may be one in which powders containing high melting point metal elements are pre-mixed in advance, and a raw material powder containing two or more high melting point metal elements in advance may be used. As the mixing method, as described above, it is preferable to uniformly mix using various powder mixers such as a ball mill.

[0018] The average particle size of the raw material powder is preferably set to be 1 μm or more and 1 mm or less. When the average particle size is 1 μm or more, the fluidity of the powder can be ensured and the powder can be prevented from flying up. And by setting the average particle size to 1 mm or less, it is possible to suppress the remaining voids between the powders in the pressure sintering step described later.

[0019] Next, we will explain a method for producing a molten raw material by pressurizing and sintering a mixed powder. In this specification, the raw material for melting is used to obtain alloy powder by melting and spraying. It is obtained by mixing raw material powders to create a mixed powder containing at least two high-melting-point metal elements, which is then pressure-sintered. Therefore, it refers to the sintered body, but it can also be referred to as the raw material for melting, raw material rod, or consumable electrode. The shape of the sintered body is not particularly limited, but a rod shape is preferable because it is easier to handle in the melting and spraying process. In the following description, the pressure sintering process (S101) to the melting and spraying process (S103) will be explained using the sintered body as a rod, and will be referred to as the raw material rod.

[0020] The pressurized sintering process involves using the MP (Metal Pressure) to determine the melting point of the element with the lowest melting point among the elements that make up the raw material powder. min When (°C), 2MP min This process involves pressurizing and sintering a mixed powder at a temperature of 3 / 3 or higher and a pressure of 5 MPa or higher to obtain a raw material rod. The melting point of the element with the lowest melting point among the elements constituting the raw material powder is MPa. min By setting the temperature to 2 / 3 or more of the above and the pressure to 5 MPa or higher, the porosity of the sintered body can be reduced to less than 5%. This is preferable because it prevents damage to the sintered body and the incorporation of air during the melting and spraying process in which the sintered body is melted and turned into powder. A more preferable temperature is MPa min The temperature is 5 / 7 or higher, and more preferably 3 / 4 or higher. A more preferable pressure is 20 MPa or higher, and even more preferable is 40 MPa or higher. There is no particular upper limit to the temperature, but the temperature should be MPa. min Keeping the pressure below a certain level is preferable because it makes it less likely for liquid-phase reactions to occur between the raw material powders, thus making it easier to ensure uniformity of composition. The upper limit of the pressure depends on the strength of the furnace body and is approximately 300 MPa.

[0021] As a method for manufacturing such a raw material bar by pressure sintering, a powder sintering method, a uniaxial pressure sintering method (hot press, spark plasma sintering (SPS), or hot isostatic pressing (HIP)) can be used. However, from the viewpoint of sintering density and the like, it is preferable to use a uniaxial pressure sintering method or a hot isostatic pressing method that can compress uniformly.

[0022] Among the pressure sintering methods, it is particularly preferable to use a uniaxial pressure sintering method (hot press, SPS method) or a hot isostatic pressing method (HIP method) that can compress uniformly. With these pressure sintering methods, the voids between the raw material powders can be more effectively reduced, and a raw material bar with a porosity of less than 2% can be obtained, which is more preferable. In addition, the hot isostatic pressing method that can apply pressure isotropically is even more preferable because it can shrink and solidify the material uniformly. A sintered body produced through such a pressure sintering process can further suppress the occurrence of defects in the melting and spraying process (S103). Note that the porosity referred to in this specification is the ratio of the area occupied by voids to the observed region (field of view area). For example, an arbitrary portion of the obtained molten raw material (sample) is cut, and the cut surface is polished. The polished sample surface is observed using an optical microscope or the like at a magnification of 200 to 1000 times, and the observed region is acquired as image data such as a photograph. Since the void portions are shown in black in the image, the area occupied by the black portions, that is, the area occupied by the voids, can be calculated by binarizing the image or the like.

[0023] The case of using the HIP method in the pressure sintering process will be described more specifically. First, the raw material powder is enclosed in a capsule (container) that matches the size of the raw material bar, degassed, and sealed. The size of the capsule is appropriately set in consideration of the shape shrinkage after HIP treatment. Then, it is loaded into a HIP device, and the set temperature and set pressure, that is, when the melting point of the element with the lowest melting point is MP min (°C), 2MP minThe material is subjected to HIP treatment at a temperature of 3 / 3 or higher and a pressure of 5 MPa or higher. After treatment, the capsules are removed to obtain the raw rod material. Alternatively, the raw rod material can also be produced using a capsule-free method (open HIP method), in which the raw rod material is pre-formed using other methods instead of capsules, and then subjected to HIP treatment.

[0024] The pressurized sintering conditions are as described above, but for example, a capsule containing a high-melting-point material, which is the raw material powder, is degassed to 0.01 MPa or less and sealed. Then, the capsule is placed in a HIP (High-Intensity Pressurization) facility and pressurized at a temperature of 100°C to 2000°C and a pressure of 10 MPa to 200 MPa for about 1 to 10 hours to solidify the raw material powder inside the capsule and produce the raw material rod.

[0025] The raw material rods are set to have a diameter of 10 mm to 500 mm and a length of 10 mm to 3000 mm, depending on the equipment used in the dissolution and spraying process. The voids between the raw material powders, as determined by evaluating the void area through cross-sectional observation of the obtained raw material rods, can be less than 5%, more preferably less than 2%. Such raw material rods are suitable because they can prevent damage to the rods and the incorporation of air during the dissolution and spraying process. The raw material rods obtained in this process have excellent mechanical strength.

[0026] [Dissolution / spraying process (S103)] Next, a suitable melting and spraying process for obtaining alloy powder using raw material rods will be explained with reference to Figures 2 and 3. Figure 2 shows a preferred form of the melting and spraying process in the method for manufacturing alloy powder, which is the direct melting gas atomization method. Figure 3 shows another form of the melting and spraying process, which is the plasma arc heating method. The direct melting gas atomization method and the plasma arc heating method described below are preferred because the melt does not come into contact with the crucible, etc., and the cleanliness of the melt can be ensured. First, an embodiment of the case where the direct dissolution gas atomization method is applied will be described using Figure 2.

[0027] First, the raw material rod 11 is placed in the induction heating device 13 of the powder manufacturing apparatus 12. The raw material rod may be fixed in place with its central axis aligned with the induction heating device, or it may be rotated around its central axis to ensure uniform heating of the raw material rod 11.

[0028] Subsequently, the atmosphere inside the powder manufacturing apparatus 12 is changed to a reduced-pressure atmosphere such as a vacuum or an inert gas atmosphere, and one end of the raw material rod 11 is melted by the induction heating device 13. A molten liquid 14 is formed from the melted end of the raw material rod 11 and falls downward due to gravity. At this time, the molten liquid 14 is uniformly stirred by the flow field created by induction heating. Then, the molten liquid 14 that has fallen downward is sprayed with a high-pressure gas 16 such as argon, nitrogen, or air ejected from a gas nozzle 15, and the molten liquid 14 is cooled and solidified during the spraying process to obtain sprayed powder 17.

[0029] More specifically, the obtained raw material rod 11 can be used to produce alloy powder 17 by applying the direct melting gas atomization method. The raw material rod 11 is placed in a direct melting gas atomization apparatus, and the atmosphere is reduced to a pressure atmosphere of 0.01 MPa or less. Then, the end of the raw material rod 11 is melted using an induction heating device placed near the end of the raw material rod 11 to obtain a molten material. Pure argon gas at 2 to 20 MPa and 100 to 1500 L / min is blown onto the molten material falling downwards to spray the molten material, and the sprayed powder can be obtained by cooling and solidifying the molten material during the spraying process.

[0030] In this case, the arrangement of the gas nozzles, as well as the gas flow rate, flow velocity, and pressure, can be appropriately adjusted to achieve the desired particle size distribution of the sprayed powder 17. In this embodiment, the sprayed powder 17 can be obtained without the molten raw material rod 11 coming into contact with a crucible or the like, and the cleanliness of the sprayed powder 17 can be ensured. Furthermore, the high-pressure gas 16 is not particularly limited, and an inert gas such as argon gas or nitrogen gas can be appropriately selected considering its reactivity with high-temperature molten material.

[0031] In the dissolution and spraying process, it is preferable to use high-frequency induction heating or plasma arc heating as a method for locally dissolving (melting) one end of the raw material rod 11. This makes it possible to hold one end of the raw material rod 11 while melting the other end without contact, allowing the molten material to be supplied without contact with a crucible or the like, thereby suppressing the inclusion of impurities.

[0032] Furthermore, the molten rod 11 may also be used in a plasma arc heating method. In the plasma arc heating method, the molten rod is melted by plasma arc heat, but by exposing the obtained molten material to a high-pressure gas or by using a rotating electrode method in which the raw material rod is melted while rotating, the molten material can be scattered by centrifugal force or ultrasonic waves can be applied to the molten material. As a specific example, the rotating electrode method will be explained. In the rotating electrode method, the raw material rod 11 is melted while rotating by plasma arc heat, the obtained molten material is scattered by centrifugal force, and solidified during scattering to obtain spray powder. These can be selected in conjunction with the melting method, and in either case, the molten material can be solidified without contact with a crucible or the like, thus suppressing the inclusion of impurities. Here, the centrifugal force and micro-vibrations applied to the molten material can be provided by equipping the raw material rod with a rotation mechanism or vibration mechanism, and these mechanisms can be appropriately set according to the particle size and circularity of the spray powder.

[0033] More specifically, as shown in Figure 3, the raw material rod 21 is fixed to the electrode rotation mechanism 23 of the powder manufacturing apparatus 22 so that it can rotate around its axis. Then, the atmosphere is changed to a vacuum atmosphere or an inert gas atmosphere, and the raw material rod 21 is rotated at a high speed of 10,000 rpm or more around its central axis. This rotation speed is used to control the particle size of the sprayed powder 26. With the raw material rod 21 rotating, one end of the raw material rod 21 is melted by the plasma heating device 24, and the resulting molten liquid 25 is immediately scattered by the centrifugal force applied by the rotation. Then, the molten liquid is cooled and solidified during scattering to obtain the sprayed powder 26.

[0034] The raw material rod is placed in the electrode rotation mechanism 23, and the atmosphere is reduced to a pressure of 0.01 MPa or less. The raw material rod 21 is then rotated around its long axis at a rotation speed of, for example, 10,000 rpm. A plasma heating device placed near the end of the raw material rod 21 melts the end of the rotating rod to obtain a molten material, which is then scattered laterally by the centrifugal force generated by the rotation of the raw material rod 21. The molten material is then cooled and solidified during scattering to obtain spray powder 26.

[0035] The above melting and spraying process has the advantage of allowing the spray powder to be obtained directly from the molten sintered body (raw material rod), ensuring the cleanliness of the spray powder. Furthermore, since the spray powder can be formed without interaction with high-pressure gas, it is possible to produce spray powder with higher sphericity compared to alloy powder obtained by the gas atomization method.

[0036] As described above, with the embodiment of the alloy powder manufacturing method, alloy powder can be manufactured without using a crucible. Therefore, alloys containing molten high-melting-point metals are not left in the crucible, preventing undissolved residue and non-uniformity of composition due to reactions with the crucible, and allowing for the production of spray powder (sometimes called alloy powder) with the desired composition.

[0037] [Classification process (S105)] It is preferable to add a classification step (S105) after the above steps (S101 to S103). The atomized powder (alloy powder) obtained in the melting and atomizing step (S103) is preferably processed to adjust the particle size distribution using methods such as sieving classification or swirling airflow classification. Specifically, the average particle size of the alloy powder is preferably between 10 μm and 200 μm from the viewpoint of handling and packing properties. If the average particle size is less than 10 μm, the alloy powder tends to fly up, which can lead to a decrease in the shape accuracy of the additively manufactured body. On the other hand, if the average particle size exceeds 200 μm, not only does the surface roughness of the additively manufactured body increase, but it can also lead to insufficient melting of the alloy powder 20, especially if it has a high melting point. Furthermore, the preferred average particle size varies depending on the manufacturing method used. For example, in the case of metal additive manufacturing, a thickness of 10 μm to 50 μm is more preferable for selective laser melting (SLM), and 45 μm to 105 μm is more preferable for electron beam melting (EBM).

[0038] Furthermore, in the laser beam powder deposition (LMD) method, a thickness of 50 μm to 200 μm is recommended.

[0039] Furthermore, using the alloy powder manufacturing method of this embodiment, it is also possible to manufacture alloy powders of high-entropy alloys (HEA) composed of Nb, Mo, Ta, W, etc., which contain a variety of high-melting-point elements.

[0040] As described above, one embodiment of the method for producing the melting raw materials allows for the production of HEA alloy powder containing high-melting-point metals. Furthermore, it is expected to suppress the segregation of relatively high-melting-point metals such as Ta and W from relatively low-melting-point metals such as Nb and Mo, which was a problem when mixing high-melting-point pure metal powders and melting them using the SLM method. It is also expected to suppress concentration fluctuations in additively manufactured bodies obtained by additive manufacturing of alloy powders.

[0041] <Alloy Powder> The above-described embodiment of the preferred method for producing alloy powder makes it possible to obtain alloy powder containing two or more high-melting-point elements, specifically high-melting-point metallic elements with a melting point of 1600°C or higher. Furthermore, it is also possible to obtain alloy powder with a circularity of 0.5 or higher, preferably 0.7 or higher, and an average particle size of 10 μm or more and less than 200 μm. The composition of the alloy powder can be evaluated by inductively coupled plasma atomic emission spectrometry.

[0042] Using the alloy powder described above, it is also possible to additively fabricate a component using the SLM method with a powder bed fusion apparatus as shown in Figure 4. For example, the fabrication conditions can be set to laser power: 100W to 300W, laser scanning speed: 50 to 300 mm / second, and scanning interval: 0.01 to 0.10 mm, but are not particularly limited.

[0043] Furthermore, for example, the obtained alloy powder can be used to additively fabricate a component using the LMD method with a powder bed fusion apparatus as shown in Figure 5. While the fabrication conditions are not particularly limited, they can be applied as follows: laser power: 0.6~2.4kW, scanning speed: 100~1500mm / min, scanning interval: 0.5~3.0mm, and powder supply rate: 4~14g / min.

[0044] [Applications / Products] The alloy powder produced by the above-described preferred manufacturing method is particularly effective for alloys mainly composed of high-melting-point metals and can be suitably used in metal additive manufacturing, powder compaction, powder metallurgy, metal injection molding, etc., but the applications and products are not particularly limited.

[0045] Examples of applications for molded and fabricated products using the alloy powder of the present invention include molds, electrode components, heating sources, heat treatment furnaces and reaction furnace internal structures, X-ray and particle beam filters, and processing tools used in high-temperature environments. In this specification, "manufactured products" refers collectively to these machines, equipment, components, molds, parts, etc. [Examples]

[0046] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to these examples.

[0047] [Experiment 1] (Preparation of a mixed powder of A1 and A2) Mixed powders A1 and A2 were prepared by mixing multiple raw material powders in the mass ratios shown in Table 1. All raw material powders were pure alloy powders obtained by chemical reduction, and as shown in Table 1, all contained 10% by mass or more of metal element powders with a melting point of 1600°C or higher. Mixing was performed using a V-mixer for more than 30 minutes to uniformly mix multiple raw material powders with different specific gravities within each powder.

[0048] [Table 1]

[0049] [Experiment 2] <Manufacturing of raw material rods B1 and B2> 10 kg each of the mixed powders A1 and A2 prepared in Experiment 1 were sealed in capsules (120 mm in diameter, 600 mm in height, made of SUS304) and degassed to less than 0.01 MPa. These capsules were then placed in a HIP (High-Intensity Pressurization) facility and held at 1250°C under a pressurized atmosphere of 110 MPa for 5 hours to solidify the raw material powders inside the capsules. This yielded raw material rods B1 and B2, corresponding to A1 and A2, with a diameter of 100 mm and a length of 500 mm.

[0050] (Examples) Cross-sectional observation of the obtained raw material rods revealed that raw material rod B1 had a void ratio of 4%, and raw material rod B2 had a void ratio of 1%. Although both used powders with high melting point compositions, they were able to solidify into rods with sufficiently low void ratios through HIP treatment under high temperature and pressure.

[0051] (Comparative Example 1) Based on A1, we attempted to produce raw material rods using cold pressing (room temperature (22°C), 100 MPa, 10 minutes), but the pressed raw materials did not solidify due to the lack of bonding between the powder particles, and therefore we were unable to obtain rods.

[0052] (Comparative Example 2) Based on A1, we attempted to produce raw material rods by hot pressing (100 MPa, 10 minutes) at 300°C, which is less than 2 / 3°C from the melting point of Zr (1855°C), the element with the lowest melting point among the elements constituting the raw material powder. However, the porosity was high and the material did not solidify, so we were unable to obtain dense rods. As a result of evaluating the porosity of the porosity by cross-sectional observation of this raw material rod, the porosity was found to be 28%.

[0053] The embodiments and examples described above are explained to aid in understanding the present invention, and the present invention is not limited to the specific configurations described. For example, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In other words, the present invention allows for the deletion, substitution, or addition of parts of the configurations of the embodiments and examples specified herein. By such modifications of embodiments, the alloy powders disclosed in the present invention can be applied to the manufacture of high-melting-point metal parts used in high-temperature components, plant equipment, mold components, and the like. [Explanation of symbols]

[0054] 11: Raw material bar 12: Powder manufacturing equipment 13: Induction heating device 14: Melt 15: Gas nozzle 16: High-pressure gas 17: Spray powder 22: Powder manufacturing equipment 23: Electrode rotation mechanism 24: Plasma heating device 25: Melt 26: Spray powder 100: SLM Powder Bed Metallurgy System 101: Molding component 102: Stage 103: Base plate 104: Powder supply container 105: Alloy powder 106: Ricohta 107: Powder bed (layered powder) 108: Laser Oscillator 109: Laser beam 110: Galvanometer Mirror 111: Container for recovering unmelted powder 112:2D slice shape solidified layer 200: Powder bed fusion fusion machine 201: Laser Head 202: Modeling base material 203: Vice (fixing jig) 204: Table 205: Laser Oscillator 206: Powder feeding machine 210: Equipment outer wall 211: Full-length door 212: Control Panel 220: Nozzle 221: Powder 222: Shielding gas 223: Sculptural body

Claims

1. A method for producing a dissolution raw material for producing high-entropy alloy powder, A mixed powder consisting of multiple types of raw material powders is prepared by determining the melting point of the element with the lowest melting point among the elements constituting the raw material powders, using MP (Metal Multiplier). ｍｉｎ When set to (°C), 2 MP ｍｉｎ The process includes a pressure sintering step in which sintering is performed at a temperature of 3 or higher and at a pressure of 5 MPa or higher. A method for producing a dissolving raw material, characterized in that the raw material powder consists of a high-melting-point metal element having a melting point of 1600°C or higher.

2. Of the aforementioned multiple types of raw material powders, at least one raw material powder contains two or more of the aforementioned high-melting-point metal elements. A method for producing a dissolving raw material according to claim 1.

3. In the aforementioned pressurized sintering process, a hot isotropic pressurized sintering method is used. A method for producing a dissolving raw material according to claim 1 or 2.

4. A dissolving raw material used to obtain alloy powder by dissolving and spraying, It is a high-entropy alloy composed of high-melting-point metallic elements with a melting point of 1600°C or higher. It is a sintered body with a porosity of less than 5%. A dissolving raw material characterized by the following features.

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