Method and equipment for double-ultrasonic synergistic in-situ auxiliary electric arc additive manufacturing of large metal component

Abstract

The invention discloses a method and equipment for double-ultrasonic cooperative in-situ auxiliary electric arc additive manufacturing of a large metal component, an electric arc additive manufacturing system and an ultrasonic vibration auxiliary electric arc additive manufacturing system. The ultrasonic vibration auxiliary electric arc additive manufacturing system comprises two ultrasonic impact guns, an optical sensor, a temperature sensor and a calculation control system. The optical sensor collects optical characteristics of the deposition channel and the molten pool and converts the optical characteristics into electric signals to be transmitted to the calculation control system, and the temperature sensor is used for monitoring and collecting temperature information of the deposition channel and transmitting the temperature information to the calculation control system to draw an isotherm; the calculation control system adjusts the distance between the ultrasonic impact gun and the center of the molten pool according to the isotherm and the optical characteristics of the optical sensor mobile phone, and the ultrasonic power is adjusted; one of the ultrasonic peening guns applies ultrasound from the component side edge as materials are added to the component edge. By means of the multi-axis freedom degree and accuracy of the mechanical arm, double-ultrasonic vibration is applied to all positions of a large metal component in the material adding process, and the mechanical property is improved.

Description

Technical Field

[0001] The present invention belongs to the field of arc additive manufacturing, and particularly relates to a method and equipment for double-ultrasonic synergistic in-situ assisted arc additive manufacturing of large metal components. Background Technique

[0002] Arc additive manufacturing technology is used to manufacture dense metal solid components by layer-by-layer surfacing. Since the arc is used as the energy-carrying beam, it has a high heat input and a fast forming speed, and is suitable for low-cost, high-efficiency and rapid forming of large-size complex components. Facing the manufacturing cost and reliability requirements of special metal structures, its structural components are gradually developing towards large-scale, integral and intelligent, so this technology has incomparable efficiency and cost advantages over other additive technologies in the forming of large-size structural components. However, defects such as coarse grains and pores will appear when manufacturing metal components by arc additive manufacturing. Finding a method to solve coarse grains and pores is of great significance for improving the quality of workpieces.

[0003] Research shows that introducing ultrasonic vibration during the arc additive manufacturing process can generate acoustic streaming effect and cavitation effect. The acoustic streaming effect caused by ultrasonic vibration can enhance the stirring and convection of the molten pool, make the temperature and composition distribution of the molten metal uniform, and the cavitation effect can promote the formation of microbubbles in the molten metal, which is helpful for grain growth. Ultrasonic vibration can also break dendrites and coarse grains during the grain growth process, remove inclusion gases, refine the grain structure, reduce tissue defects, and thus improve the mechanical properties of the components.

[0004] The paper with DOI 10.11817 / j.ysxb.1004.0609.2022-43493 proposed a method for using ultrasonic vibration-assisted arc additive manufacturing of 2219 aluminum alloy. The experimental results show that after applying ultrasonic vibration, the proportion of the grain size of the aluminum alloy below 20μm increases from 29.32% to 46.59%, and the average grain size decreases from 36.80μm to 30.19μm. The microhardness of the specimen increases from 79.9HV to 93.8HV, the tensile properties of the specimen in the vertical direction are strengthened to a certain extent, and the yield strength in the horizontal direction also increases. However, the above method belongs to the additive manufacturing of thin-walled components and cannot be directly applied to the additive manufacturing of large metal components. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and equipment for double-ultrasonic synergistic in-situ assisted arc additive manufacturing of large metal components.

[0006] The technical solution for realizing the purpose of the present invention is as follows:

[0007] An equipment for double ultrasonic collaborative in-situ assisted arc additive manufacturing of large metal components, an arc additive manufacturing system and an ultrasonic vibration assisted arc additive system. The ultrasonic vibration assisted arc additive system includes two ultrasonic impact guns, an optical sensor, a temperature sensor and a calculation and control system;

[0008] The optical sensor collects the optical characteristics of the deposition bead and the molten pool and converts them into electrical signals for transmission to the calculation and control system. The temperature sensor is used to monitor and collect the temperature information of the deposition bead and transmit it to the calculation and control system to draw isotherms;

[0009] The calculation and control system adjusts the distance between the ultrasonic impact gun and the center of the molten pool and adjusts the ultrasonic power according to the isotherms and the optical characteristics collected by the optical sensor;

[0010] When additive manufacturing reaches the edge of the component, one of the ultrasonic impact guns applies ultrasonic waves from the side edge of the component.

[0011] Furthermore, the ultrasonic vibration assisted arc additive system further includes an ultrasonic vibration control device and two six-axis robots; the ultrasonic vibration control device adjusts the frequency, vibration amplitude and energy output of the ultrasonic impact gun, and the ultrasonic impact gun is linked with the six-axis robot to control the movement of the ultrasonic impact gun through the six-axis robot.

[0012] Furthermore, the arc additive manufacturing system includes a CMT welding equipment system, a wire feeding system, a six-axis robotic arm, a shielding gas, a welding torch, a substrate and a workbench.

[0013] Furthermore, the optical sensor is a surface profiler, and the temperature sensor uses an infrared temperature monitor.

[0014] A method for double ultrasonic collaborative in-situ assisted arc additive manufacturing of large metal components using the above equipment, including the following steps:

[0015] Step (1): Pretreat the substrate, fix the substrate, install the wire, and introduce the shielding gas;

[0016] Step (2): Turn on the power of the CMT welding equipment system and set the welding process parameters;

[0017] Step (3): Turn on the welding six-axis robotic arm, set the initial position, tilt angle, travel path and travel speed of the welding torch, and keep the welding torch perpendicular to the substrate;

[0018] Step (4): Turn on the power of the ultrasonic six-axis robot and set the vibration frequency, travel path and travel speed of the ultrasonic impact gun;

[0019] Step (5): Set the initial position and operation path of the six-axis robot. If the initial position is the edge of the component, one of the ultrasonic impact guns is applied to the component from the side;

[0020] Step (6): Ignite the arc, and the welding torch performs arc additive manufacturing along a predetermined path. At the same time, control the ultrasonic impact gun to perform ultrasonic vibration on the deposition pass;

[0021] Step (7): The optical sensor collects the image of the previous deposition pass in front of the ultrasonic impact gun and transmits it to the calculation and control system. The calculation and control system reconstructs the surface contour information based on the image, and performs shape analysis according to the reconstructed contour information to complete the measurement of length, width, and height parameters, as well as the analysis of the concave and convex features of the surface;

[0022] Step (8): The temperature sensor collects the temperature information of the deposition pass, and the calculation and control system draws the isotherm. According to the isotherm and the surface information in step (7), adjust the parameters of the ultrasonic impact gun;

[0023] Step (9): After the formation of one deposition pass is completed, the welding torch extinguishes the arc. The welding torch is positioned at the starting point of the next pass, and the ultrasonic impact gun moves to the starting point to standby. At the same time, determine whether it is the edge part of the component. If so, move one ultrasonic impact gun to act on the side of the component;

[0024] Step (10): Repeat the above steps (6) to (8) until the first layer of additive manufacturing is completed and the arc is extinguished; the welding torch is lifted by a height equal to the thickness of the previous layer of deposition pass at the arc extinguishing point of the previous layer, and the ultrasonic impact gun moves to the starting point of the next layer of deposition pass to standby; repeat the above steps until the additive manufacturing of the large metal component is completed.

[0025] Furthermore, the width of each deposition pass is 10±1 mm, and the height that the welding torch is lifted each time after each layer of additive manufacturing is completed is 2±0.2 mm; the distance between the ultrasonic impact gun and the welding torch remains constant and is not greater than 10 mm, and the walking speeds of the ultrasonic impact gun and the welding torch should be kept consistent.

[0026] Furthermore, the optical sensor and the temperature sensor are arranged on the six-axis robot of the ultrasonic vibration assisted arc additive manufacturing system.

[0027] Furthermore, the ultrasonic vibration frequency is set at 20 kHz, and the initial power is 1000 W.

[0028] Furthermore, in step (8), the adjustment of the distance between the two ultrasonic impact guns in the adjustment of the parameters of the ultrasonic impact gun is determined according to the following formula:

[0029]

[0030] In the formula, d is the distance between the two guns, n is the standing wave order, c is the sound speed in the material, f ultra is the ultrasonic frequency, λ is the process adjustment coefficient, S is the equivalent diameter of the molten pool, P 0 is the initial power;

[0031] The actual ultrasonic power is greater than the minimum effective power and less than the maximum safe power:

[0032] The minimum effective power is:

[0033] Wherein, P min is the minimum effective power, that is, the lowest ultrasonic power required to trigger the cavitation effect, ρ is the melt density, c is the sound velocity in the melt, R 0 is the initial bubble radius, γ is the melt surface tension, f is the actual working frequency, f 0 is the reference benchmark frequency;

[0034] The maximum safe power is:

[0035] Wherein, k1 is the safety factor, T m is the melting point of the material, T 0 is the ambient temperature, δ is the thickness of the heat affected zone, v is the deposition rate, S is the equivalent diameter of the molten pool;

[0036] The actual ultrasonic power is:

[0037] Wherein, P is the actual ultrasonic power in the molten pool, T c is the temperature at the center of the molten pool, k2 is the conduction loss coefficient, β is the melting energy consumption coefficient, and η is the coupling coefficient.

[0038] An arc additive manufacturing large metal component is prepared by the above method.

[0039] Compared with the prior art, the remarkable advantages of the present invention are as follows:

[0040] Due to the existence of temperature gradient and thermal stress, components manufactured by arc additive manufacturing often have problems such as uneven grain size, pores, inclusions and other microstructural defects, and deformation caused by excessive residual stress; introducing ultrasonic vibration during arc additive manufacturing can generate acoustic streaming effect and cavitation effect. The acoustic streaming effect caused by ultrasonic vibration can enhance the stirring and convection of the molten pool, making the temperature and composition distribution of the molten metal uniform. The cavitation effect can promote the formation of microbubbles in the molten metal, which is helpful for grain growth. Ultrasonic vibration can also break dendritic crystals and coarse grains during grain growth, remove inclusion gases, refine the grain structure, reduce microstructural defects, and thus improve the mechanical properties of the component.

[0041] The present invention uses two six-axis robots to control the movement of the ultrasonic impact gun. The two six-axis robots are coordinated by a central controller, which can apply ultrasonic vibration to the top of the metal component and can also apply ultrasonic vibration from the side of the component when adding material to the edge of the component, ensuring the full-position application of double ultrasonic vibration; at the same time, it can also realize the application of ultrasonic impact at different angles and along different routes.

[0042] The present invention has high adaptability and rigor. By using an infrared monitor to monitor the temperature of the molten pool and simultaneously changing the distance between the ultrasonic impact gun and the center of the molten pool and the ultrasonic frequency in real time, it can ensure that the entire molten pool is subjected to ultrasonic action on the premise of protecting the molten pool from being contaminated. Description of the Drawings

[0043] Figure 1 It is a schematic diagram of the overall equipment for large metal component additive manufacturing by double ultrasonic impact synergistic in-situ assisted arc.

[0044] Figure 2 It is a schematic diagram of large metal component additive manufacturing by double ultrasonic impact synergistic in-situ assisted side arc.

[0045] Description of the reference numerals:

[0046] 1 - CMT welding equipment control system, 2 - wire feeding system, 3 - six-axis robotic arm, 4 - shielding gas, 5 - welding gun, 6 - substrate, 7 - workbench, 8 - ultrasonic impact gun, 9 - ultrasonic vibration control device, 10 - six-axis robot, 11 - sensor, 12 - calculation control system. Detailed Embodiment

[0047] The present invention will be further described in detail below with reference to the drawings.

[0048] An equipment for additive manufacturing of large metal components by double ultrasonic synergistic in-situ assisted arc includes an arc additive manufacturing system and an ultrasonic vibration assisted arc additive manufacturing system:

[0049] The arc additive manufacturing system includes: CMT welding equipment system, wire feeding system, six-axis robotic arm, shielding gas, welding gun, substrate, workbench;

[0050] The ultrasonic vibration assisted arc additive manufacturing system includes: ultrasonic impact gun, ultrasonic vibration control device, two six-axis robots, optical sensor, temperature sensor, computer system;

[0051] The ultrasonic impact gun is linked with the six-axis robot, and the movement of the ultrasonic impact gun is controlled by the six-axis robot.

[0052] The ultrasonic vibration control device adjusts the frequency, vibration amplitude and energy output of the ultrasonic impact gun;

[0053] The optical sensor collects the optical characteristics of the deposition bead and the molten pool and converts them into electrical signals for transmission to the computer system; the computer system receives the data from the optical sensor, analyzes and processes them through image processing algorithms, formulates corresponding decisions and feeds them back to the six-axis robotic arm to timely adjust the position of the ultrasonic impact gun;

[0054] The temperature sensor is used to monitor and collect the temperature information of the deposition path, and transmit it to the computer system for data processing, conversion and temperature field modeling. Isothermal lines are drawn based on the temperature field data. When multi-layer and multi-pass welding is carried out, due to the residual heat of the upper layer welding, the welding molten pool will continue to become larger. Based on this, the distance between the ultrasonic impact gun and the center of the molten pool is adjusted according to the drawn isothermal lines, and the computer appropriately adjusts the ultrasonic power according to the size of the distance between the ultrasonic impact gun and the center of the molten pool, so as to achieve a good effect of grain refinement throughout the additive manufacturing process.

[0055] The six-axis robotic arm can control the application direction of the ultrasonic impact gun in all positions. When additive manufacturing reaches the edge of the component, an ultrasonic impact gun can be adjusted to apply ultrasonic waves from the edge of the structure to ensure that the entire structure can be subjected to double ultrasonic impacts.

[0056] The CMT welding equipment system controls the process parameters during additive manufacturing. The six-axis robotic arm is connected to the welding gun and is used to control the movement of the welding gun, including the walking speed and path. The substrate provides support and stability for the metal thin-walled component, and also plays a role in heat conduction and dissipation.

[0057] The optical sensor is a surface profiler.

[0058] The temperature sensor is an infrared temperature monitor.

[0059] A method for additive manufacturing of large metal components assisted by dual ultrasonic waves in-situ and synergistically according to the above equipment is as follows:

[0060] Step 1: Clean the surface of the substrate, remove the oxide layer and oil, fix the substrate, install the wire, and introduce the shielding gas;

[0061] Step 2: Turn on the power of the CMT welding machine and set process parameters such as welding process, wire feeding speed, additive voltage, additive current, and wire diameter;

[0062] Step 3: Turn on the power of the welding robot, set the initial position, tilt angle, walking path, and walking speed of the welding gun, and keep the welding gun perpendicular to the substrate;

[0063] Step 4: Turn on the power of the ultrasonic-assisted robot and set the vibration frequency, walking path, and walking speed of the ultrasonic impact gun;

[0064] Step 5: Calibrate the optical sensor and the temperature sensor, run the computer system, and execute the control task through the PLC;

[0065] Step 6: Set the initial position and operation path of the six-axis robot (if the initial position is the edge of the structure, an ultrasonic impact gun will act on the structure from the side);

[0066] Step 7: Ignite the arc, the welding gun performs arc addition along a predetermined path, and the robotic arm controls the ultrasonic impact gun to perform ultrasonic vibration on the deposition path;

[0067] Step 8: The optical sensor works to collect the quality and morphology data of the deposition path in front of the ultrasonic impact gun head and transmits it to the computer system for analysis and processing. The computer system evaluates the quality of the deposition path and feeds back the decision to the robotic arm. At the same time, the optical sensor determines the morphology of the molten pool, and the robotic arm makes corresponding height and distance adjustments to the ultrasonic impact gun.

[0068] Step 9: The temperature sensor is used to monitor and collect the temperature information of the deposition path, and the isotherm diagram is drawn through the linkage computer system. The distance between the ultrasonic impact gun and the center of the molten pool is adjusted according to the isotherm diagram, and the ultrasonic frequency is adjusted accordingly;

[0069] Step 10: After the formation of a deposition path is completed, the welding gun extinguishes the arc, and the welding gun is positioned to the arc starting point of the next path, and the ultrasonic impact gun moves to the arc starting point to wait (at the same time, it is determined whether the next path is the edge of the structure, if so, an impact gun is moved to the side of the component to act);

[0070] Step 11: Repeat steps 7 to 10 until the first layer of material addition is completed and the arc is extinguished. The welding gun is raised to the same height as the thickness of the previous deposition path at the arc extinguishing point of the previous layer, and the ultrasonic impact gun is moved to the arc starting point of the next deposition path and waits.

[0071] Step 12: Repeat steps 7 to 11 until the large metal component is added, and then turn off the arc additive manufacturing system and the ultrasonic vibration auxiliary system.

[0072] During the additive manufacturing process, the energy of ultrasonic vibration is transferred to the molten pool through the deposition channel.

[0073] The width of each deposition path is 10 mm, and the welding gun is raised 2 mm each time.

[0074] The robotic arms in the ultrasonic vibration-assisted additive system are two robotic arms equipped with sensors and data acquisition equipment, which collect and analyze data from the additive process in real time and adjust the position of the ultrasonic impact gun in a timely manner.

[0075] The ultrasonic vibration frequency was set at 20kHz and the initial power was 1000W.

[0076] Ultrasonic vibration can act on the deposition path that has not been completely cooled. The distance between the ultrasonic impact gun and the welding gun should be kept constant and not more than 10 mm, and the travel speed of the ultrasonic impact gun and the welding gun should be kept consistent.

[0077] The surface profiler illuminates the object to be measured through a light source system. The camera captures the image of the surface of the object to be measured, and the captured image is processed and analyzed by an image processing unit. The processing steps include image denoising, edge detection, contour extraction, thermal radiation analysis, and additive defect analysis. The computer system reconstructs the contour information of the object surface based on the processed image. Finally, based on the reconstructed contour information, shape analysis is performed to complete the measurement of length, width, and height parameters, as well as the analysis of the concave and convex features of the surface. At the same time, in combination with the temperature of the molten pool monitored by the temperature sensor, the distance between the two ultrasonic peening guns and the ultrasonic frequency are controlled in real time.

[0078] The infrared temperature monitor monitors the temperature of the molten pool in real time and draws an isothermal line map. At the same time, the computer system adjusts the distance between the ultrasonic peening gun and the center of the molten pool according to the temperature at the center of the molten pool. The specific adjustment scheme is as follows: According to past research, in order to achieve the effect of grain refinement during the additive process, the minimum effective power of ultrasound is:

[0079]

[0080] In the formula, P min : Minimum effective power: The lowest ultrasonic power required to trigger the cavitation effect, ρ: Melt density: The density of molten metal, c: Sound velocity in the melt, R0: Initial bubble radius, γ: Melt surface tension, f: Actual working frequency, f 0 Reference reference frequency;

[0081] The maximum safe power is:

[0082] In the formula, k1: Safety factor, T m : Material melting point, T 0 : Ambient temperature, δ Heat affected zone thickness, v Deposition speed, S: Equivalent diameter of the molten pool;

[0083] Considering the transmission loss, melting loss, and ultrasonic coupling loss of ultrasound in the molten pool, based on the law of conservation of energy, the actual ultrasonic power is:

[0084] In the formula, P: Actual ultrasonic power in the molten pool, Tc: Temperature at the center of the molten pool, k2: Conduction loss coefficient, β: Melting energy consumption coefficient, η: Coupling coefficient;

[0085] Based on the sound field interference theory, the optimization equation for the distance between the two guns is:

[0086] In the formula, d: Distance between the two guns, n: Standing wave order, c: Sound velocity in the material, f ultra : Ultrasonic frequency, λ: Process adjustment coefficient, P 0 : Initial power;

[0087] Based on the above formula, the initial spacing of the two guns is calculated according to the initial power. During the additive manufacturing process, by combining the measurement data of the temperature sensor and the optical sensor, the actual power of the ultrasonic wave during the additive manufacturing process is calculated in real time, and the spacing of the two guns is dynamically adjusted, so as to ensure that the actual power of the ultrasonic wave is greater than the minimum effective power and less than the maximum safe power. Ensure that the ultrasonic wave can act effectively throughout the additive manufacturing process.

Claims

1. A dual ultrasonic coordinated in-situ assisted arc additive equipment for large metal components, characterized in that: An arc additive manufacturing system and an ultrasonic vibration-assisted arc additive manufacturing system, wherein the ultrasonic vibration-assisted arc additive manufacturing system comprises two ultrasonic impact guns (8), an optical sensor, a temperature sensor and a computing control system (12); The optical sensor collects the optical characteristics of the deposition path and the molten pool and converts them into electrical signals for transmission to the computing control system (12). The temperature sensor is used to monitor and collect the temperature information of the deposition path, transmit it to the computing control system (12), and draw isotherms. The computing control system (12) adjusts the distance between the ultrasonic impact gun and the center of the molten pool and the ultrasonic power according to the isothermal line and the optical characteristics of the optical sensor mobile phone; When adding material to the edge of the component, one of the ultrasonic impact guns (8) applies ultrasound from the side edge of the component.

2. The device according to claim 1, characterized in that: The ultrasonic vibration-assisted arc material addition system also includes an ultrasonic vibration control device (9) and two six-axis robots (10); the ultrasonic vibration control device adjusts the frequency, vibration amplitude and energy output of the ultrasonic impact gun, and the ultrasonic impact gun is linked with the six-axis robot (10), and the six-axis robot (10) controls the movement of the ultrasonic impact gun.

3. The device according to claim 2, characterized in that: The arc additive manufacturing system includes a CMT welding equipment system (1), a wire feeding system (2), a six-axis robot arm (3), a shielding gas (4), a welding gun (5), a base plate (6) and a workbench (7).

4. The device according to claim 1, characterized in that: The optical sensor is a surface profile measuring instrument, and the temperature sensor is an infrared temperature monitor.

5. A method for adding large metal components by using the equipment of any one of claims 1 to 4 using dual ultrasonic coordinated in-situ auxiliary arc, characterized in that: The steps include: Step (1): pre-treating the substrate, fixing the substrate, installing the wire, and introducing protective gas; Step (2): Turn on the power of the CMT welding equipment system (1) and set the welding process parameters; Step (3): start the welding six-axis robot arm (3), set the initial position, tilt angle, travel path, and travel speed of the welding gun (5), and keep the welding gun (5) perpendicular to the substrate; Step (4): Turn on the power of the ultrasonic six-axis robot (10), and set the vibration frequency, walking path, and walking speed of the ultrasonic impact gun; Step (5): setting the initial position and running path of the six-axis robot. If the initial position is the edge of the component, one of the ultrasonic impact guns is applied to the component from the side. Step (6): igniting the arc, the welding gun performs arc addition along a predetermined path, and at the same time controlling the ultrasonic impact gun to ultrasonically vibrate the deposition path; Step (7): The optical sensor collects the image of the previous deposition path of the ultrasonic impact gun and transmits it to the computing control system. The computing control system reconstructs the surface contour information based on the image, and performs shape analysis based on the reconstructed contour information to complete the measurement of length, width, and height parameters, as well as the surface concave-convex feature analysis; Step (8): The temperature sensor collects the temperature information of the deposition path, draws the isotherm through the computing control system, and adjusts the parameters of the ultrasonic impact gun according to the isotherm and the surface information of step (7); Step (9): After the formation of a deposition path is completed, the welding gun extinguishes the arc, and the welding gun is positioned to the arc starting position of the next path. The ultrasonic impact gun moves to the arc starting position and waits for operation. At the same time, it is determined whether it is the edge of the component. If so, an ultrasonic impact gun is moved to the side of the component to act; Step (10): Repeat the above steps (6) to (8) until the first layer of material addition is completed and the arc is extinguished; the welding gun is raised to the same height as the thickness of the previous deposition path at the arc extinguishing point of the previous layer, and the ultrasonic impact gun is moved to the arc starting point of the next deposition path and waits; repeat the above steps until the large metal component is added.

6. The method according to claim 5, characterized in that The width of each deposition path is 10±1mm, and the welding gun is raised 2±0.2mm each time after each layer of additive is completed; the distance between the ultrasonic impact gun and the welding gun is kept constant at no more than 10mm, and the moving speeds of the ultrasonic impact gun and the welding gun should be kept consistent.

7. The method according to claim 6, characterized in that The optical sensor and the temperature sensor are arranged on a six-axis robot (10) of an ultrasonic vibration assisted arc material addition system.

8. The method according to claim 7, characterized in that The ultrasonic vibration frequency was set at 20 kHz and the initial power was 1000 W.

9. The method according to claim 8, characterized in that In step (8), the distance between the two ultrasonic impact guns in adjusting the ultrasonic impact gun parameters is determined according to the following formula: In the formula, d is the distance between the two guns, n is the standing wave order, c is the sound velocity in the material, and f is ultra is the ultrasonic frequency, λ is the process adjustment coefficient, S is the equivalent diameter of the molten pool, and P0 is the initial power; The actual ultrasonic power is greater than the minimum effective power and less than the maximum safe power: The minimum effective power is: Where P min is the minimum effective power, i.e., the minimum ultrasonic power required to trigger the cavitation effect, ρ is the melt density, c is the sound velocity in the melt, R0 is the initial bubble radius, γ is the melt surface tension, f is the actual working frequency, and f0 is the reference frequency; The maximum safe power is: In the formula, k1 is the safety factor, T m is the melting point of the material, T0 is the ambient temperature, δ is the thickness of the heat-affected zone, v is the deposition rate, and S is the equivalent diameter of the molten pool; The actual ultrasonic power is: Where, P is the actual ultrasonic power in the molten pool, T c is the center temperature of the molten pool, k2 is the conduction loss coefficient, β is the melting energy consumption coefficient, and η is the coupling coefficient.

10. A large metal component made by arc additive manufacturing, characterized in that: The method is prepared by any one of claims 4 to 9.

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