Metal wire supply apparatus, and metal powder spheroidization apparatus and manufacturing method using the same

Abstract

The objective of the present invention is to provide a metal powder manufacturing apparatus and a metal powder manufacturing method capable of producing economical and highly clean spherical metal powder. To achieve the above objective, a metal wire supply device used in a metal spherical powder manufacturing apparatus according to the present invention may include: a wire supply chamber capable of lowering pressure; two spools spaced apart from each other at the top inside the chamber and discharged to the bottom while unwinding the wound wire; a cleaning device for cleaning the surface of the wire supplied from the spools with an organic solvent; a heating device for drying and preheating the cleaned wire; and a wire alignment device installed to support the wire adjacent to the apex and movable in three axes to adjust the wire's approach position to the apex.

Description

Technology Field

[0001] The present invention relates to an apparatus and method for manufacturing metal spherical powder, and more specifically, to a metal wire feeding device capable of manufacturing economical and high-purity metal spherical powder, and an apparatus and method for manufacturing metal spherical powder using the same. Background Technology

[0003] Many pieces of equipment used in the aerospace and defense industries, particularly military weapons including propulsion systems such as torpedoes and rockets, require a high degree of safety and reliability. Therefore, the defense industry requires high-quality metal powders to prevent defects during the manufacturing of such military weapons.

[0004] Conventionally, the Gas Atomization (GA) method was primarily applied as a process for manufacturing metal powders or spherical metal powders. However, GA often resulted in low sphericity and a large amount of satellite powder, which frequently caused defects in additive manufacturing or molded body manufacturing processes using metal powders. This was recognized as a critical disadvantage in the defense industry, which requires high reliability.

[0005] In addition, the GA process had the disadvantage of being expensive because it uses a large amount of inert gas (argon, nitrogen, etc.).

[0006] Meanwhile, the metal spherical powder manufacturing process utilizing the wire arc melting plasma atomization method, known as PA (Plasma Atomization), produces metal powder by simultaneously melting the wire using a plasma jet and atomizing the molten metal into fine droplets. This process is relatively economical due to its high Gas-to-Metal Ratio (GMR). However, while it is crucial to produce finely spherical powder of high purity when manufacturing metal spherical powder, the PA method still requires a large amount of inert gas, and there were issues regarding the potential inclusion of impurities when the wire is loaded. Prior art literature

[0008] Republic of Korea Published Patent Application No. 10-2023-0113730 (Publication Date: August 1, 2023) Republic of Korea Published Patent Application No. 10-2021-0016588 (Publication Date: February 16, 2021) The problem to be solved

[0009] The objective of the present invention, which is to solve the conventional problems described above, is to provide a metal powder manufacturing apparatus and a metal powder manufacturing method capable of producing economical and highly clean spherical metal powder. means of solving the problem

[0011] To achieve the above objective, a metal wire supply device used in a metal spherical powder manufacturing apparatus according to the present invention may include: a wire supply chamber capable of lowering pressure; two spools spaced apart from each other at the top inside the chamber and discharged to the bottom while unwinding the wound wire; a cleaning device for cleaning the surface of the wire supplied from the spools with an organic solvent; a heating device for drying and preheating the cleaned wire; and a wire alignment device installed to support the wire adjacent to the apex and movable in three axes to adjust the wire's approach position to the apex.

[0012] In addition, in a metal wire supply device used in a metal spherical powder manufacturing apparatus according to the present invention, the wire supply chamber is characterized by being connected to a rotary pump to lower the internal pressure to 0.01 torr or less.

[0013] In addition, the metal wire feeding device used in the metal spherical powder manufacturing apparatus according to the present invention is characterized by further including a straightener that supplies the wire discharged from both spools in a straight line to the apex.

[0014] In addition, in the metal wire feeder used in the metal spherical powder manufacturing apparatus according to the present invention, the organic solvent is characterized as being one of ethanol, acetone, isopropyl alcohol (IPA), and methyl ethyl ketone (MEK).

[0016] In addition, to achieve the above objective, a metal wire supply device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention comprises: a wire supply chamber capable of lowering pressure; two spools spaced apart from each other at the top inside the chamber and discharged to the bottom while unwinding a wound wire; a cleaning device for cleaning the surface of a wire supplied from the spools with an organic solvent; a heating device for drying and preheating the cleaned wire; and a wire alignment unit that analyzes an image of a wire approaching the apex to determine whether it is located within a preset wire reference alignment range and aligns the position of the wire so that it is located within the reference alignment range.

[0017] In addition, in a metal wire supply device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention, the wire alignment unit comprises: a wire IR camera mounted in a viewport of the wire supply chamber to photograph the wire approaching the apex; a wire alignment stage that supports both wires adjacent to the apex and aligns both wires approaching the apex by moving them in three axes; and a drive control unit that analyzes the image captured by the IR camera and controls the drive of the wire alignment stage so that the wire is positioned within the reference alignment position range when the position of the wire deviates from a preset reference alignment position range.

[0018] In addition, a metal wire feeding device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention is characterized by further including a straightener that supplies wires discharged from both spools in a straight line to an apex.

[0019] In addition, in a metal wire feeder used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention, the organic solvent is characterized as being one of ethanol, acetone, isopropyl alcohol (IPA), and methyl ethyl ketone (MEK).

[0020] In addition, in a metal wire supply device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention, the drive control unit comprises: an image acquisition unit that collects an IR image captured by the IR camera; an image analysis unit that analyzes the image collected by the image acquisition unit to determine whether the wire is located within a preset reference alignment position range; and a stage drive control unit that drives and controls the wire alignment stage so that the wire is located within the reference alignment position range when the image analysis unit determines that the wire is not located within the reference alignment position range.

[0022] And, to achieve the above objective, a metal wire feeder used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention is characterized by comprising: the metal wire feeder described above; a first vacuum pump that reduces the pressure of the wire feed chamber; a plasma module that sprays a plasma jet toward an apex; a main chamber into which fine metal droplets fall; and a main chamber pressure maintaining device that regulates the pressure of the main chamber.

[0023] In addition, in a metal wire feeding device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention, the first vacuum pump is a rotary pump, and the pressure inside the wire feeding chamber is 0.01 torr or less.

[0024] In addition, in a metal wire supply device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention, the wire supply chamber is,

[0025] A metal wire feeding device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention is characterized by further including a straightener that supplies wires discharged from both spools in a straight line to an apex.

[0026] In a metal wire feeding device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention, the main chamber pressure maintaining device is characterized by comprising a second vacuum pump, a cyclone for primarily removing impurities, a filter for secondarily removing impurities, and a pressure maintaining valve.

[0027] In a metal wire feeding device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention, the pressure maintaining valve is characterized by maintaining the main chamber at a pressure of 200 torr or more and 500 torr or less.

[0028] In a metal wire feeding device used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention, the pressure maintaining valve is characterized as being a dry pump.

[0030] And, to achieve the above objective, a method for manufacturing metal spherical powder according to another embodiment of the present invention is characterized in that, in a method for manufacturing metal powder using the metal spherical powder manufacturing apparatus described above, it comprises: (a) a step of supplying the wire to the apex within the wire supply chamber; (b) a step of spraying a plasma jet by a plasma torch; and (c) a step of reducing the pressure of the main chamber. Effects of the invention

[0032] According to the present invention, an apparatus and method are provided for producing an economical and highly clean metal spherical powder.

[0033] In addition, according to the present invention, contaminants such as lubricating oil, oxides, and moisture are completely removed from the wire surface through organic solvent washing and drying / preheating processes, thereby reducing the thickness of the oxide layer during metal powder manufacturing and maintaining a smooth surface, which significantly improves the quality and cleanliness of the final product.

[0034] In addition, according to the present invention, by correcting the wire position in real time through an alignment stage capable of 3-axis movement and an image-based position control function, the plasma arc discharge is maintained stably for a long time and the deterioration of production quality due to discharge instability is prevented.

[0035] In addition, according to the present invention, by applying a straightener to the wire feed path to ensure straightness and maintaining a precise alignment state, molten droplets are induced to form and fly uniformly, thereby obtaining high-quality metal powder with high sphericity and a narrow particle size distribution.

[0036] In addition, according to the present invention, surface defects and satellite powder adhesion phenomena during droplet formation are minimized by removing wire surface impurities and ensuring alignment stability, thereby improving the fluidity and packing density of the final powder and lowering the defect rate in additive manufacturing and molding processes.

[0037] In addition, according to the present invention, thanks to the automatic correction function of the wire alignment unit, the alignment state can be maintained without opening the chamber, thereby reducing the time required for vacuum re-formation and inert gas consumption, and enabling continuous operation for a long time, which increases the equipment utilization rate.

[0038] In addition, according to the present invention, the alignment state can be maintained without manual intervention by a worker in a high-temperature and vacuum environment, thereby increasing work safety and reducing the burden on manpower and operational fatigue by eliminating the need for continuous monitoring or manual adjustment by skilled workers.

[0039] In addition, according to the present invention, the production yield increases due to the reduction in the defect rate and the improvement in production efficiency, and the economic efficiency of the device operation can be maximized by simultaneously improving the utilization rate and reducing operating costs.

[0041] Of course, the scope of the present invention is not limited by these effects, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the attached drawings. Brief explanation of the drawing

[0043] FIG. 1 is a schematic diagram of the configuration of a wire feeder used in a metal spherical powder manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing the block configuration of a metal wire feeder used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention. FIG. 3 is a schematic diagram of a metal spherical powder manufacturing apparatus equipped with a metal wire feeding device according to an embodiment of the present invention. FIG. 4 is a diagram showing the detailed flow of a method for manufacturing spherical metal powder according to another embodiment of the present invention. Figure 5 is a photograph of metal powder produced using a conventional metal spherical powder manufacturing device that is not equipped with a cleaning device. FIG. 6 is a photograph of metal powder produced using a metal spherical powder manufacturing device according to an embodiment of the present invention equipped with a washing device and a heating device. Specific details for implementing the invention

[0044] Before describing the present invention in detail, it should be understood that the terms and words used in this specification should not be interpreted as being limited to their ordinary or dictionary meanings, and that the inventor of the present invention may appropriately define and use the concepts of various terms to best describe their invention, and furthermore, that these terms and words should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0045] In other words, it should be understood that the terms used in this specification are used merely to describe preferred embodiments of the present invention and are not intended to specifically limit the content of the present invention, and that these terms are defined in consideration of various possibilities of the present invention.

[0046] In addition, it should be noted that in this specification, singular expressions may include plural expressions unless the context clearly indicates a different meaning, and that even if they are expressed in a similarly plural form, they may include a singular meaning.

[0047] Throughout this specification, where it is stated that a component "includes" another component, unless specifically stated otherwise, this may mean that it does not exclude any other component but may include any other component.

[0048] Furthermore, it should be noted that where it is stated that a component "exists inside or is installed in connection with" another component, this component may be installed in direct connection or contact with the other component, or it may be installed at a certain distance apart; in the case where it is installed at a certain distance apart, a third component or means for fixing or connecting the component to the other component may exist, and a description of this third component or means may be omitted.

[0049] On the other hand, where it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that a third component or means does not exist.

[0050] Likewise, other expressions describing the relationship between each component, such as “between” and “right between”, or “adjacent to” and “directly adjacent to”, should be interpreted as having the same intent.

[0051] In addition, it should be understood that in this specification, terms such as "one side," "other side," "one side," "other side," "first," and "second," if used, are intended to clearly distinguish one component from another component, and that the meaning of the component is not restricted by such terms.

[0052] In addition, position-related terms such as "up," "down," "left," and "right" used in this specification should be understood as indicating the relative position of the corresponding component in the drawing, and unless an absolute position is specified, these position-related terms should not be understood as referring to an absolute position.

[0053] Furthermore, in specifying the reference numerals for each component of each drawing in this specification, the same component has the same reference numeral even if it is shown in different drawings; that is, the same reference numeral throughout the specification indicates the same component.

[0054] In the drawings attached to this specification, the size, position, connection relationships, etc., of each component constituting the present invention may be described in a partially exaggerated, reduced, or omitted manner for the convenience of explanation or to sufficiently clearly convey the concept of the present invention, and therefore, the proportions or scale may not be strictly accurate.

[0055] In addition, in the following description of the present invention, detailed descriptions of components that are deemed to unnecessarily obscure the essence of the present invention, such as known technologies including prior art, may be omitted.

[0057] Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

[0058] FIG. 1 is a schematic diagram of the configuration of a wire feeder used in a metal spherical powder manufacturing apparatus according to an embodiment of the present invention.

[0059] As shown in FIG. 1, the wire feeder used in the metal spherical powder manufacturing apparatus according to an embodiment of the present invention may be configured to include a wire feed chamber (180), a spool (130), a washing device (123), a heating device (125), and a wire alignment device.

[0060] The wire feeder used in the metal spherical powder manufacturing apparatus according to the embodiment of the present invention provides a device capable of simultaneously addressing causes of quality instability (wire surface contamination, residual solvent, and apex position variation) in the metal spherical powder manufacturing process (wire arc melting - plasma spraying).

[0061] In addition, the wire supply device according to an embodiment of the present invention provides a composite wire supply device that ① inlines organic solvent washing and drying / preheating processes within a pressure-reducing wire supply chamber (180), and ② maintains and corrects the approach position (gap / angle) with a wire alignment device capable of 3-axis (X·Y·Z) alignment correction near the apex.

[0062] More specifically, as shown in FIG. 1, the wire supply chamber (180) is a chamber device capable of lowering pressure, and can maintain the inside of the chamber in a reduced pressure state (0.01 torr or less) and suppress the inflow of external air, moisture, and oxygen.

[0063] Additionally, the wire supply chamber (180) may be a chamber device that provides an environment in which the solvent evaporating after washing is quickly removed, moisture and oxygen re-adsorbed on the surface are minimized, and the metal wire (110) transfer, alignment, and apex formation steps can be performed continuously in the same atmosphere.

[0064] Here, the wire supply chamber (180) maintains a low-pressure atmosphere to suppress the oxide layer and maintain a clean surface of the metal wire (110), thereby stabilizing the wettability / surface tension behavior during the sphericalization of the metal powder and improving sphericity.

[0065] And, as shown in FIG. 1, the spool (130) is a cylindrical tool shaped like a ball of yarn that winds and stores a metal wire (110), and the spool (130) can rotate to unwind the wound metal wire (110) and supply it to the apex.

[0066] Additionally, the spool (130) is positioned at the top of the chamber for stable supply of the metal wire (110) and provides a structure that allows the metal wire (110) wound on both spools (130) to be supplied diagonally downward to the apex, which is the intersection point.

[0067] In addition, by connecting the wire supply chamber (180) to a rotary pump to maintain the internal pressure at an ultra-low pressure (high vacuum) of 0.01 torr or less, the reoxidation and re-adsorption of moisture on the surface of the metal wire (110) can be fundamentally prevented, and the rapid evaporation of residual organic solvent after washing can be made possible.

[0068] By allowing the metal wire (110) to be transported, aligned, and supplied in an ultra-low pressure environment in this way, the quality stability and reproducibility of the metal spherical powder manufacturing process can be significantly improved compared to the supply method performed in an existing atmospheric pressure or low pressure environment.

[0069] More specifically, the following effects can be obtained by reducing the pressure of the wire supply chamber (180).

[0070] 1) Maintaining surface cleanliness: Preventing atmospheric oxygen, moisture, and contaminant particles from reattaching to the surface of the cleaned metal wire (110) minimizes the generation of oxides and inclusions during plasma arc melting.

[0071] 2) Improved solvent drying speed: Organic solvents used for cleaning are rapidly evaporated and removed under vacuum conditions, reducing the risk of sparks, bubbles, and spatter caused by residual solvents when an arc occurs.

[0072] 3) Improvement of arc discharge stability: Since the surface of the metal wire (110) is kept dry and clean in a high vacuum state, the electrical characteristics in the discharge gap are kept constant, so stable arc discharge is possible for a long time.

[0073] 4) Improvement in process efficiency and quality: The defect rate caused by oxidation and contamination is reduced, improving the sphericity, particle size distribution, and fluidity of the final spherical metal powder, and increasing the production yield over the same period of time.

[0074] And, as shown in FIG. 1, the cleaning device (123) may be a cleaning device (123) that cleans the surface of a metal wire (110) supplied from a spool (130) with an organic solvent.

[0075] That is, the cleaning device (123) may be formed as a tubular device capable of passing a metal wire (110) supplied from a spool (130) through it, and may be a device for dissolving and removing lubricating oil and organic contaminants attached during the manufacturing and winding process of the metal wire (110) using an organic solvent.

[0076] Additionally, the cleaning device (123) may use an organic solvent as the cleaning solution, such as ethanol / acetone / IPA / MEK, which rapidly elutes and degreases the surface contaminated layer and allows the solvent to evaporate rapidly under reduced pressure.

[0077] That is, as an organic solvent, it is preferable to use one of ethanol, acetone, isopropyl alcohol (IPA), or methyl ethyl ketone (MEK).

[0078] By specifying that the organic solvent used in the cleaning process through the wire cleaning device (123) be selected from ethanol, acetone, isopropyl alcohol (IPA), and methyl ethyl ketone (MEK), a highly volatile and highly clean solvent can be used to effectively remove lubricating oil, oil, organic contaminants, dust, etc. from the surface of the metal wire (110) and leave almost no residue after cleaning.

[0079] This is because it enables washing and drying within a short time while minimizing chemical damage to various metal materials, thereby guaranteeing the quality of the pretreatment stage in the metal spherical powder manufacturing process.

[0080] In this way, by providing a cleaning device (123) in the metal wire supply device according to an embodiment of the present invention, the collection of oxygen and carbon-based impurities can be reduced, thereby reducing oxygen content and non-metallic inclusions, improving flowability and charge density, and reducing the probability of instability of contamination-derived discharge, spatter, and satellite powder generation.

[0081] In addition, the metal wire supply device according to an embodiment of the present invention may further include a straightener (120) that supplies the metal wire (110) discharged from both spools (130) in a straight line to the apex, as shown in FIG. 1.

[0082] That is, the embodiment of the present invention is equipped with a straightener (120) to supply the metal wire (110) discharged from both spools (130) to the apex while maintaining it in a straight state, thereby allowing for the removal of residual curvature, twisting, bending deformation, etc. that occurs during the winding of the spool (130) in advance.

[0083] Through such a straightener (120), the supply path of the metal wire (110) is maintained in a straight line and stably during the plasma arc melting and spraying process, thereby suppressing fluctuations in the arc contact position and ensuring uniformity of droplet formation.

[0085] And, as shown in FIG. 1, the heating device (125) may be a device for drying and preheating the cleaned metal wire (110).

[0086] That is, the heating device (125) may be a secondary cleaning device configured to remove (dry) residual solvent after cleaning and preheat the metal wire (110) to mitigate plasma / arc thermal shock.

[0087] The heating device (125) can simultaneously perform the functions of secondary cleaning and preheating by evaporating the solvent on the surface through radiation, convection heating, or contact with a heater block, and simultaneously raising the temperature of the metal wire (110) to a predetermined range for preheating.

[0088] By providing such a heating device (125), residual solvent can be vaporized and sparks and bubbles can be suppressed to improve arc stability.

[0089] In addition, by mitigating the thermal gradient, the melting start is smooth and the reproducibility of droplet separation is improved, which not only narrows the particle size distribution but also reduces the energy required for initial melting, thereby shortening the start-up time and saving energy such as gas and electricity.

[0090] And, as shown in FIG. 1, the wire alignment device may be a stage drive device that is movable in three axes to support and install a metal wire (110) adjacent to an apex and to adjust the apex approach position of the metal wire (110).

[0091] That is, the wire alignment device may be a stage drive device capable of mechanically supporting two metal wires (110) in the section immediately preceding the apex and precisely correcting the approach position (gap, offset, and intersection angle) with X, Y, and Z degrees of freedom.

[0092] In this way, the wire alignment device can align the apex position to the center of the target plasma jet through left-right / front-back offset correction by moving along the X and Y axes.

[0093] In addition, the discharge impedance and thermal field distribution can be maintained constant through fine-tuning of the tip gap and intersection angle via Z-axis movement.

[0094] In addition, long-term drift caused by deformation or changes in linearity of the spool (130) winding can be corrected during the process through such a wire alignment device.

[0095] In this way, the metal wire supply device according to an embodiment of the present invention can secure co-axial alignment with the arc / plasma through a wire alignment device, thereby reducing scattering and wall collision of droplets and increasing collection efficiency.

[0096] In addition, the embodiment of the present invention enables realignment during process continuity (reducing chamber opening frequency), thereby improving the operating rate and enhancing yield and economic efficiency. Furthermore, by maintaining the process capability (Cp / Cpk) of the apex position and gap even during long-term operation, quality can be stabilized.

[0097] Thus, through the combined configuration of the cleaning device (123), heating device (125), and wire alignment device of the metal wire supply device according to the embodiment of the present invention, continuous inline processing of cleaning + drying / preheating + reduced pressure atmosphere can simultaneously reduce contamination, moisture, and residual solvent, thereby essentially improving arc stability.

[0098] In addition, the combined configuration of the embodiment of the present invention can achieve long-term stabilization of the apex position and gap by combining geometric stability formed by the arrangement of the upper spacing spool (130) and dynamic correction of the 3-axis alignment device.

[0099] In this way, the combined configuration of the metal wire supply device according to the embodiment of the present invention ensures that the thermal and fluid conditions of droplet formation, separation, and flight are constant, thereby increasing sphericity, reducing satellite powder, narrowing the particle size distribution, and increasing operating rate and economic efficiency.

[0101] FIG. 2 is a diagram showing the block configuration of a metal wire feeder used in a metal spherical powder manufacturing apparatus according to another embodiment of the present invention.

[0102] As shown in FIG. 2, a metal wire supply device according to an embodiment of the present invention may be configured to include a wire supply chamber (180), a spool (130), a washing device (123), a heating device (125), and a main chamber pressure maintaining device.

[0103] The wire supply chamber (180), spool (130), cleaning device (123), and heating device (125) are identical or similar to the embodiment of FIG. 1, so the following description will focus on the wire alignment unit (500).

[0104] As shown in FIG. 2, the metal wire supply device according to an embodiment of the present invention, unlike the embodiment of FIG. 1, is equipped with an image-based automatic wire alignment unit (500) to monitor and analyze the relative positions of two metal wires (110) approaching the apex in real time and to automatically correct them so that they are always located within a preset reference alignment range.

[0105] This resolves alignment errors, drift during long-term operation, and process interruptions caused by chamber opening that occurred with conventional manual or simple mechanical adjustment methods, and can maintain continuous arc stability in a non-contact and non-open state.

[0106] That is, the metal wire (110) according to the embodiment of the present invention illustrated in FIG. 2 has the following effects.

[0107] 1) Improved alignment precision: By determining the position through image analysis, high-precision alignment of ±0.1 mm or less can be maintained, so the thermal and electrical conditions of the arc contact location are kept constant.

[0108] 2) Maximizing arc stability: By continuously maintaining alignment within the standard range, the occurrence of droplet scattering, satellite powder formation, and uneven melting caused by arc discharge instability is minimized.

[0109] 3) Ensuring process continuity: Since there is no need to open the chamber for alignment correction, vacuum re-forming time and gas consumption are reduced, and continuous operation for a long time is possible.

[0110] 4) Improvement in quality uniformity: Even during long-term operation, the sphericity, particle size distribution, and surface cleanliness of the spherical powder are maintained consistently, and quality variation between product lots is reduced.

[0111] 5) Improvement in work efficiency and safety: Manual adjustment by workers is not required, reducing the burden on labor and minimizing hazardous work in high temperature and vacuum conditions.

[0112] More specifically, as shown in FIG. 2, the wire alignment unit (500) may be configured to include an IR camera (190), a wire alignment stage (175), and a stage drive control unit (550).

[0113] This configuration resolves the issues of chamber opening, vacuum re-establishment, and production interruption that were inevitable with conventional manual adjustment methods, and enables the stable maintenance of arc position precision and quality uniformity for extended periods, even under high temperature and vacuum conditions.

[0114] Here, the IR camera (190) may be a device mounted in the viewport of the wire supply chamber (180) to photograph the metal wire (110) approaching the apex.

[0115] That is, the IR camera (190) can convert infrared signals emitted from the metal surface into image data so that the condition of the internal metal wire (110) can be visually recognized from the outside even in a high temperature and vacuum environment.

[0116] Through such an IR camera (190), the position of the metal wire (110) can be monitored in real time in a non-contact manner, and the surface temperature and position of the metal wire (110) can be determined simultaneously even in a high-temperature environment, and continuous monitoring can be performed without interrupting production, thereby allowing for early detection of alignment errors.

[0117] The wire alignment stage (175) may be a device that mechanically supports both metal wires (110) near the apex and corrects the alignment position by moving them finely in the X, Y, and Z axis directions.

[0118] Additionally, the wire alignment stage (175) can correct left-right and front-back offsets by moving along the X and Y axes, and adjust the apex gap and intersection angle by moving along the Z axis.

[0119] Additionally, the wire alignment stage (175) can be driven precisely according to a position control signal by reflecting the analysis results of the IR camera (190).

[0120] Through such a wire alignment stage (175), the arc contact position precision can be maintained with a position correction of ±0.1 mm or less, long-term drift caused by uneven supply of metal wire (110) or deformation of spool (130) winding can be corrected in real time, and the uniformity of droplet formation and spraying quality can be improved by ensuring alignment stability.

[0121] And, as shown in FIG. 2, the stage drive control unit (550) may be a device that controls the drive of the wire alignment stage (175) so that when the position of the metal wire (110) deviates from a preset reference alignment position range by analyzing an image captured by an IR camera (190), the metal wire (110) is positioned within the reference alignment position range.

[0122] That is, the stage drive control unit (550) performs the function of calculating the position coordinates of the metal wire (110) through an image analysis algorithm, calculating the error direction and correction value by comparing it with a reference range, and transmitting it to the 3-axis stage drive motor.

[0123] Through such a stage drive control unit (550), worker intervention can be minimized by implementing fully automated alignment, and arc instability can be prevented in advance through an immediate correction response, as well as the alignment state maintenance rate can be improved even during long-term operation, thereby reducing production quality deviations.

[0124] In addition, through organic combination with the detailed configuration of the wire alignment unit (500) described above, a closed-loop control structure can be formed in which the IR camera (190) provides real-time image data, the stage drive control unit (550) performs analysis and judgment, and the alignment stage immediately corrects the position.

[0125] In addition, this enables the achievement of comprehensive effects such as continuous quality control without process interruption, maximized arc stability, reduced satellite powder, and improved sphericity.

[0126] In particular, in long-term mass production environments, reducing the frequency of chamber opening and shortening vacuum re-forming time can significantly improve overall equipment utilization and economic efficiency.

[0127] More specifically, the stage drive control unit (550) may be configured to include an image collection unit (510) that collects IR images captured by an IR camera (190), an image analysis unit (530) that analyzes the images collected by the image collection unit (510) to determine whether the metal wire (110) is located within a preset reference alignment position range, and a stage drive control unit (550) that drives the wire alignment stage (175) so that the metal wire (110) is located within the reference alignment position range when the image analysis unit (530) determines that the position of the metal wire (110) is not located within the reference alignment position range.

[0128] Thus, the metal wire supply device according to an embodiment of the present invention provides a structure that clearly separates functions into an image acquisition unit (510), an image analysis unit (530), and a stage drive control unit (550), thereby accurately measuring, analyzing, and determining the position of the metal wire (110) approaching the apex, and automatically performing correction control when necessary.

[0129] This hierarchical configuration systematizes the flow of image data acquisition, position analysis, and correction operations, thereby ensuring alignment precision, process stability, and quality uniformity even during long-term operation in high-temperature and vacuum environments.

[0130] In this embodiment of the present invention, the image acquisition unit (510) provides a high-quality IR image, the image analysis unit (530) performs a precise position determination based thereon, and the stage drive control unit (550) performs an immediate correction, thereby enabling the maintenance of high-precision alignment without interruption of the process.

[0131] As a result, sphericity, particle size distribution, and surface cleanliness are maintained consistently over the long term in the metal spherical powder manufacturing process, and comprehensive effects such as reduced satellite powder generation, lower defect rates, and improved productivity can be achieved.

[0133] FIG. 3 is a schematic diagram of a metal spherical powder manufacturing apparatus equipped with a metal wire supply device according to an embodiment of the present invention, FIG. 4 is a diagram showing the detailed flow of a method for manufacturing metal spherical powder according to another embodiment of the present invention, FIG. 5 is a photograph of metal powder manufactured using a conventional metal spherical powder manufacturing apparatus not equipped with a washing device (123), and FIG. 6 is a photograph of metal powder manufactured using a metal spherical powder manufacturing apparatus according to an embodiment of the present invention equipped with a washing device (123) and a heating device (125).

[0134] As shown in FIG. 3, a metal spherical powder manufacturing apparatus according to an embodiment of the present invention may be configured to include the metal wire supply device described above, a first vacuum pump that reduces the pressure of the wire supply chamber (180), a plasma module (200) that sprays a plasma jet toward the apex, a main chamber (300) into which fine metal droplets fall, and a main chamber pressure maintaining device that regulates the pressure of the main chamber (300).

[0135] That is, a metal spherical powder manufacturing apparatus according to an embodiment of the present invention may be configured to include a wire supply device (100), a wire supply chamber vacuum pump (170), a plasma module (200), a main chamber (300), and a main chamber pressure maintaining device.

[0136] Referring to FIGS. 1 and 3, the wire supply device (100) may include a straightener (120), a spool (130), an arc discharge cable port (140), an inert gas inlet (150), a vacuum pump connection (160), and a wire supply chamber (180).

[0137] The wire supply chamber (180) can form the exterior or shape of the wire supply device (100), and the inside and outside of the wire supply chamber (180) can be blocked.

[0138] The step (S100) of supplying a metal wire (110) within a wire supply chamber (180) of a wire supply device (100) may include a step of reducing the pressure within the wire supply chamber (180).

[0139] As shown in FIG. 3, a metal spherical powder manufacturing apparatus according to one embodiment of the present invention may include a wire supply chamber vacuum pump (170) connected to a wire supply device (100). Specifically, the wire supply chamber vacuum pump (170) may be connected to a vacuum pump connection part (160) formed in a wire supply chamber (180).

[0140] In one embodiment, the wire supply chamber vacuum pump (170) may be a rotary pump.

[0141] The pressure inside the wire supply device (100) can be reduced by the wire supply chamber vacuum pump (170). In one embodiment, the pressure inside the wire supply device (100) may be 0.01 torr or less.

[0142] The metal wire (110) may be a metal material that will be arc-melted into a droplet as the process proceeds. At this time, the metal wire (110) may be wound on a spool (130).

[0143] As shown in FIG. 4, the step (S100) of supplying a metal wire (110) within a wire supply device (100) may include a step of straightening the metal wire (110) into a straight line.

[0144] That is, the metal wire (110) wound on the spool (130) can be straightened into a roughly straight shape through the straightener (120).

[0145] Multiple metal wires (110) can be straightened and supplied. In one embodiment, a pair (i.e., two) of metal wires (110) can be straightened into a roughly straight shape through a straightener (120) and supplied.

[0146] The step (S100) of supplying a metal wire (110) within a wire supply device (100) may include the step of supplying a metal wire (110) such that a plurality of metal wires (110) meet at an apex.

[0147] As described above, by straightening the metal wire (110) through the straightener (120), multiple metal wires (110) can be made to meet well (i.e., converge) at the apex. Only when multiple metal wires (110) converge at the apex can the plasma jet be sprayed into the apex and the micronization of the droplets proceed efficiently.

[0148] When a plurality of metal wires (110) are supplied, voltage may be applied. To this end, the wire supply device (100) may include an arc discharge cable port (140).

[0149] An arc discharge cable can be connected into the wire supply device (100) through the arc discharge cable port (140) and can supply voltage to the metal wire (110).

[0150] In one embodiment, a positive voltage may be applied to one metal wire (110) and a negative voltage may be applied to the other metal wire (110). As the two metal wires (110) with such voltages applied converge at the apex, they may cause an arc discharge and arc melt.

[0151] As shown in FIG. 1, the wire feed device (100) may include an inert gas inlet (150). Inert gas can be injected into the wire feed device (100) through the inert gas inlet (150).

[0152] There may be cases where the wire supply chamber (180) of the wire supply device (100) needs to be opened to service the interior. At this time, an inert gas can be injected to maintain the cleanliness of the interior.

[0153] In one embodiment, the inert gas injected through the inert gas inlet (150) may be argon (Ar).

[0154] In the step (S200) where a plasma jet is sprayed by a plasma torch, when a plurality of metal wires (110) converging at the apex are arc melted as described above, the plasma torch sprays a plasma jet toward the apex to produce fine metal powder.

[0155] Here, as shown in FIGS. 2 and 3, the plasma module (200) may include a plasma torch. The plasma torch includes a contraction-convergence nozzle (215), and a plasma jet may be generated through the contraction-convergence nozzle (215).

[0156] The miniaturization of droplets can be achieved by a plasma jet sprayed into the apex by a plasma torch.

[0157] The above-mentioned fine droplets may undergo a step of falling into the main chamber (300). That is, the main chamber (300) may be a space in which fine metal droplets scattered by a plasma jet fall and the droplets take on a final shape.

[0158] Before that, a step (S300) of reducing the pressure of the main chamber may be performed. The step (S300) of reducing the pressure of the main chamber may also be performed before the step (S100) of supplying a metal wire (110) within the wire supply device (100) and the step of spraying a plasma jet by a plasma torch.

[0159] The step of reducing the pressure of the main chamber (S300) may include driving the main chamber vacuum pump (410), filtering the gas sucked from the main chamber (300), and maintaining the pressure within the main chamber (300) constant.

[0160] Referring again to FIG. 3, the main chamber (300) may be connected to a main chamber pressure maintenance device. The main chamber pressure maintenance device may include a main chamber vacuum pump (410), a cyclone (420), a filter (430), and a pressure maintenance valve (440).

[0161] The main chamber vacuum pump (410) can regulate the pressure of the main chamber (300). In the step of driving the main chamber vacuum pump (410), the main chamber vacuum pump (410) can be driven to reduce the pressure of the main chamber (300).

[0162] In one embodiment, the main chamber vacuum pump (410) may be a dry pump. Specifically, the main chamber vacuum pump (410) used during the process may be a dry pump. That is, a vacuum pump other than the dry pump may be used during the process of lowering the pressure or purging.

[0163] At this time, the air inside the main chamber (300) may contain impurities. Therefore, to increase the lifespan and maximize the efficiency of the main chamber vacuum pump (410), a step of filtering the gas sucked from the main chamber (300) can be performed.

[0164] As shown in FIG. 3, air sucked in from the main chamber (300) can pass through a cyclone (420). The cyclone (420) can primarily remove relatively large impurities from the air sucked in from the main chamber (300).

[0165] Air that has been primarily filtered through the cyclone (420) can be secondarily filtered through the main chamber pressure maintenance device. The main chamber pressure maintenance device can remove fine impurities that the cyclone (420) failed to filter.

[0166] The pressure maintaining valve (440) can maintain the main chamber (300) at an appropriate pressure. In one embodiment, the pressure of the main chamber (300) may be 200 torr or higher and 500 torr or lower.

[0167] As described above, by maintaining the main chamber (300) at a low pressure, the speed of the plasma jet sprayed by the plasma torch can be increased. Therefore, the amount of gas injected can be reduced, and the gas-to-metal ratio can be improved.

[0168] In other words, process costs can be reduced due to the improvement in the gas-to-metal ratio. Additionally, since the increased velocity of the plasma jet enables the miniaturization of droplets, it is possible to form finer, more spherical metal powders with a low particle size distribution.

[0169] And, as shown in FIG. 4, the method for manufacturing metal spherical powder according to an embodiment of the present invention may be configured to include (a) a wire supply step (S100), a closed-loop control step (S150) of a wire alignment unit (500), a plasma jet spraying step (S200), and a main chamber pressure reduction step (S300).

[0170] More specifically, step (a) may be a wire supply step, which is a step of continuously supplying two strands of metal wire from left and right spools (130) downwardly within a wire supply chamber (180) to diagonally intersecting apex.

[0171] At this time, the wire supply device (100) is maintained in a reduced pressure state, and a straight wire with surface contamination and moisture removed through a washing device (123) (organic solvent), a heating device (125) (drying / preheating), and a straightener (120) approaches the apex.

[0172] The metal spherical powder shown in Fig. 5 was manufactured without the application of a cleaning device (123), and contaminants and impurities remain on the surface, and the spherical surface appears rough rather than smooth.

[0173] This contamination layer is formed when arc melting and spraying proceed without removing residual lubricant, oxides, and fine particles from the wire surface, causing quality degradation factors such as reduced powder sphericity, surface defects, and the adhesion of satellite powder.

[0174] On the other hand, the metal spherical powder of FIG. 6 is a product produced by a manufacturing device equipped with a washing device (123) and a heating device (125) according to an embodiment of the present invention, and has a smooth and clean surface with almost no traces of contaminants.

[0175] This is the result of effectively removing impurities and moisture from the wire surface through a first organic solvent washing and a second drying and preheating process, and stabilizing surface tension and solidification behavior during melting and spraying, thereby improving sphericity.

[0176] Therefore, the result of Fig. 6 has higher quality uniformity compared to Fig. 5, and the possibility of defects occurring in additive manufacturing or molding processes is significantly lower.

[0177] This step establishes clean, straight, and aligned conditions so that the subsequent arc / plasma spray can start stably.

[0178] The closed-loop control step (S150) of the wire alignment unit (500) may be a real-time closed-loop control that maintains and corrects the supplied wire so that it is always within a reference alignment range (e.g., X / Y offset ±0.1 mm, Z-gap ±50~200 μm range; example).

[0179] As shown in FIG. 4, the detailed steps of the wire alignment step (S150) may include an IR image capture step (S151), an IR image analysis step (S152), a reference alignment range determination step (S153), and a 3-axis stage drive correction step (S155).

[0180] In the IR image capturing step (S151), the wire IR camera (190) (mounted in a viewport) captures the left and right wires of the apex approach section in real time as infrared images. Position and temperature information of the wires is acquired non-contactually even in high temperature and vacuum environments.

[0181] In the IR image analysis step (S152), when the image acquired by the image acquisition unit (510) is transmitted to the image analysis unit (530), the analysis unit extracts the edge / center line of the wire and calculates the position deviation (ΔX, ΔY, ΔZ) from the reference coordinate system (apex reference line, plasma jet axis). The alignment status can be determined by applying noise removal, binarization, contour tracking, and a correction matrix (calibration).

[0182] The reference alignment range determination step (S153) terminates S150 and continues to the next process (“Yes”) if the calculated position deviation is within the preset reference alignment position range. If it is outside the range (“No”), it branches to the correction command step S155.

[0183] In the 3-axis stage correction drive step (S155), the stage drive control unit (550) calculates a control amount corresponding to the direction and magnitude of the error and transmits it to the wire alignment stage (175) (3-axis).

[0184] The wire alignment stage (175) corrects the X / Y offset and adjusts the gap and intersection angle along the Z axis to realign the intersection point (apex) of the two wires coaxially with the plasma jet axis.

[0185] After calibration, the loop is repeated by returning to S151 until alignment is confirmed to be complete, thereby maintaining an automatic wire alignment state at all times without opening the chamber during production.

[0186] The wire alignment process applied to the method for manufacturing metal spherical powder according to the embodiment of the present invention can achieve the following effects.

[0187] 1) Maximization of arc / plasma stability: Apex-plasma axis alignment is continuously maintained, so the discharge impedance and thermal field become constant, and spatter, spark, and arc instability are significantly reduced.

[0188] 2) Improvement in powder quality: As the reproducibility of droplet size and flight trajectory increases, the particle size distribution becomes narrower, sphericity is increased, satellite powder generation is reduced, and oxygen content is lowered simultaneously.

[0189] 3) Improvement in continuous operation and economy: Downtime and vacuum re-establishment time are reduced by not opening the chamber for alignment correction, gas / power consumption is reduced, and quality variation is reduced, thereby improving yield.

[0190] 4) Improved safety and work efficiency: Manual adjustment in high temperature and vacuum environments is unnecessary, increasing worker safety, and automatic correction improves ease of operation.

[0192] Although various preferred embodiments of the present invention have been described above with some examples, the descriptions of various embodiments described in the "Specific details for carrying out the invention" section are merely illustrative, and those skilled in the art to which the present invention pertains will understand that the present invention can be modified in various ways or equivalent embodiments can be carried out based on the above description.

[0193] In addition, since the present invention can be implemented in various other forms, the present invention is not limited by the description above. The above description is provided merely to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the present invention, and it should be understood that the present invention is defined only by each claim of the claims. Explanation of the symbols

[0195] 100: Wire feeder 110: Wire 120: Straightener 123: Cleaning device 125: Heating device 130: Spool 140: Arc discharge cable port 150: Inert gas inlet 160: Vacuum pump connection 170: Wire feed chamber vacuum pump 175: Wire alignment stage 180: Wire feed chamber 190: IR camera 200: Plasma module 215: Zoom-magnifying nozzle 300: Main chamber 410: Main chamber vacuum pump 420: Cyclone 430: Filter 440: Pressure maintaining valve 500: Wire alignment unit 510: Image acquisition unit 530: Image analysis unit 550: Stage drive control unit

Claims

Claim 1 A metal wire supply device used in a metal spherical powder manufacturing apparatus comprises: a wire supply chamber capable of lowering pressure; two spools spaced apart from each other at the top inside the chamber and discharged to the bottom while unwinding a wound wire; a cleaning device for cleaning the surface of a wire supplied from the spools with an organic solvent; a heating device for drying and preheating the cleaned wire; and a wire alignment device installed to support a wire adjacent to an apex and movable in three axes to adjust the wire's approach position to the apex, wherein the cleaning device, the heating device, and the wire alignment device are configured to be performed as a continuous process before the wire reaches the plasma apex, and the wire alignment device is configured to calculate a deviation relative to a reference alignment range using an IR image of the wire captured in real time and to correct the wire position in real time according to the deviation. Claim 2 A metal wire supply device according to claim 1, wherein the wire supply chamber is connected to a rotary pump to lower the internal pressure to 0.01 torr or less. Claim 3 A metal wire feeding device according to claim 1, further comprising a straightener that supplies wires discharged from both spools in a straight line to an apex. Claim 4 A metal wire feeder according to claim 1, characterized in that the organic solvent is one of ethanol, acetone, isopropyl alcohol (IPA), and methyl ethyl ketone (MEK). Claim 5 A wire supply device used in a metal spherical powder manufacturing apparatus comprises: a wire supply chamber capable of lowering pressure; two spools spaced apart from each other at the top inside the chamber and discharged to the bottom while unwinding a wound wire; a cleaning device for cleaning the surface of a wire supplied from the spools with an organic solvent; a heating device for drying and preheating the cleaned wire; and a wire alignment unit that analyzes an image of a wire approaching an apex to determine whether it is located within a preset wire reference alignment range and aligns the position of the wire so as to be located within the reference alignment range, wherein the cleaning device, the heating device, and the wire alignment unit are configured to be performed as a continuous process before the wire reaches the plasma apex, and wherein the wire alignment unit comprises an IR camera mounted in the viewport of the wire supply chamber, an alignment stage that moves the wire in three axes, and a control unit that calculates a wire position deviation from the IR image of the IR camera and controls the operation of the alignment stage, wherein the control unit is configured to calculate a deviation relative to the reference alignment range from the wire image and correct the wire position in real time according to the deviation. Claim 6 delete Claim 7 A metal wire feeding device according to claim 5, further comprising a straightener that supplies wires discharged from both spools in a straight line to the apex. Claim 8 A metal wire feeder according to claim 5, characterized in that the organic solvent is one of ethanol, acetone, isopropyl alcohol (IPA), and methyl ethyl ketone (MEK). Claim 9 delete Claim 10 A metal spherical powder manufacturing apparatus characterized by comprising: a metal wire feeding device of claim 5; a first vacuum pump for reducing the pressure of the wire feeding chamber; a plasma module for spraying a plasma jet toward the apex; a main chamber into which fine metal droplets fall; and a main chamber pressure maintaining device for regulating the pressure of the main chamber. Claim 11 A metal spherical powder manufacturing apparatus according to claim 10, characterized in that the first vacuum pump is a rotary pump and the pressure inside the wire supply chamber is 0.01 torr or less. Claim 12 A metal spherical powder manufacturing apparatus according to claim 10, wherein the wire supply chamber further comprises a straightener that supplies wires discharged from both spools in a straight line to the apex. Claim 13 A metal spherical powder manufacturing apparatus according to claim 10, wherein the main chamber pressure maintaining device comprises a second vacuum pump, a cyclone for primarily removing impurities, a filter for secondarily removing impurities, and a pressure maintaining valve. Claim 14 A metal spherical powder manufacturing apparatus according to claim 13, wherein the pressure maintaining valve maintains the main chamber at a pressure of 200 torr or more and 500 torr or less. Claim 15 A metal spherical powder manufacturing apparatus characterized in that, in item 10, the pressure maintaining valve is a dry pump. Claim 16 A method for manufacturing metal powder using a metal spherical powder manufacturing apparatus of claim 10, comprising: (a) a step of supplying the wire to the apex within the wire supply chamber; (b) a step of spraying a plasma jet by a plasma torch; and (c) a step of reducing the pressure of the main chamber.

Images