Device and method for plasma arc multi-wire powder coaxial additive manufacturing of high-entropy alloy

Abstract

The invention discloses a device and method for manufacturing high-entropy alloy through plasma arc multi-wire powder coaxial additive manufacturing, and belongs to the field of electric arc additive manufacturing. The device comprises a plasma arc multi-wire powder coaxial welding gun. The welding gun comprises a copper nozzle with an ion gas port in the middle, a welding gun shell and a powder feeding shell. Wire feeding ports are formed in the front and rear ends of the ion gas outlet; powder feeding ports are formed in the left and right ends of the ion gas outlet; a shielding gas outlet is formed in the outer side of the copper nozzle; the copper nozzle is located at the bottom end of the multi-wire powder coaxial welding gun and connected with the welding gun shell. A second channel between the ion gas shell and the powder feeding shell is used for injecting powder; through holes are formed in the surfaces of the two sides of the welding gun shell and the powder feeding shell correspondingly and used for feeding welding wires, and the welding wires are fed into the wire feeding opening through the second channel. According to the device, through the double wire feeding systems and the coaxial double powder feeding systems, the proportion of multiple main elements can be accurately controlled, the component uniformity and high quality of the high-entropy alloy are ensured, and the device is suitable for batch production and large-scale application of the high-entropy alloy.

Description

Technical Field

[0001] The present invention belongs to the field of arc additive manufacturing, and in particular relates to a device and method for manufacturing high entropy alloys by coaxial additive manufacturing of multiple wires and powders using a plasma arc. Background Art

[0002] High entropy alloys (HEAs) have attracted extensive attention in many fields due to their unique multi-element composition and excellent performance. Compared with traditional alloy materials, HEAs have excellent high-temperature strength, corrosion resistance, oxidation resistance, good mechanical properties and thermal stability, which makes them have irreplaceable application advantages in extreme environments. However, the existing high-entropy alloy manufacturing methods have problems such as high cost and complex process, and new manufacturing technologies are urgently needed to improve their production efficiency and reduce costs.

[0003] At present, laser powder cladding technology is the main method for additive manufacturing of high entropy alloys, and there are already many related patents, but the cost of laser powder cladding is high, and the efficiency of powder cladding is relatively low, which is difficult to meet the needs of large-scale industrial applications. Therefore, it is particularly important to find a lower-cost and more efficient additive manufacturing method, especially in the field of high entropy alloys.

[0004] Arc additive manufacturing technology has attracted widespread attention for its advantages such as low equipment cost and high deposition efficiency, but it is not suitable for the preparation of high-entropy alloys with complex compositions. In order to solve this problem, a device and method for plasma arc multi-wire powder coaxial additive manufacturing of high-entropy alloys are proposed. This technology innovatively feeds different types of metal powders on the left and right sides of the plasma arc, and different types of welding wires on the front and back sides. Through this multi-wire and multi-powder coaxial supply mode, precise composition control and efficient additive manufacturing of multi-main element high-entropy alloys are achieved. This device and method not only overcome the problems of high cost and low efficiency of traditional laser powder deposition, but also have higher composition control capabilities and material adaptability than traditional single-wire and double-wire arc additive manufacturing, and are particularly suitable for the preparation of high-entropy alloys.

[0005] Fe 40 Ni 40 Cr 10 Mn 10 The alloy has excellent tensile strength and hardness. It has good corrosion resistance, thermal stability and oxidation resistance. At the same time, the alloy maintains good plasticity and toughness while ensuring high strength. It can work for a long time in high temperature environment and is suitable for extreme temperature conditions such as aerospace and energy fields. High content of Fe and Ni has good weldability and is suitable for making welding wire materials, while low content of Cr and Mn is suitable for making powder. Plasma arc multi-wire multi-powder additive manufacturing Fe 40 Ni 40 Cr 10 Mn10 Alloys are more efficient and cost-effective than traditional laser powder additive manufacturing. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a device for plasma arc multi-wire powder coaxial additive manufacturing of high entropy alloys, which includes a plasma arc welding gun, a dual wire feeding system, a coaxial dual powder feeding system, a gas protection system and a control system. The various devices work closely together to ensure an efficient and stable additive manufacturing process.

[0007] The present invention provides a plasma arc multi-wire powder coaxial welding gun, comprising a tungsten electrode, a sleeve, a multi-wire powder coaxial copper nozzle, an ion gas shell, a powder feeding shell and a welding gun shell; an ion gas port is arranged in the middle of the multi-wire powder coaxial copper nozzle, a first wire feeding port and a second wire feeding port are arranged at the front end and the rear end of the ion gas outlet, and a first powder feeding port and a second powder feeding port are arranged at the left end and the right end of the ion gas outlet; the first wire feeding port, the second wire feeding port, the first powder feeding port and the second powder feeding port are evenly arranged around the ion gas outlet; a shielding gas outlet is arranged on the outer side of the multi-wire powder coaxial copper nozzle, and the shielding gas outlet is located between the multi-wire powder coaxial copper nozzle and the welding gun shell; the multi-wire powder coaxial copper nozzle is located at the bottom end of the multi-wire powder coaxial welding gun and is connected to the welding gun shell; a powder feeding port is nested inside the welding gun shell. The outer shell of the welding gun is provided with a third channel between the powder feeding outer shell and the welding gun outer shell for injecting shielding gas; the ion gas outer shell is nested inside the powder feeding outer shell, and the second channel between the ion gas outer shell and the powder feeding outer shell is used to inject the first powder and the second powder, and the first powder and the second powder are respectively sent out through the first powder feeding port and the second powder feeding port of the multi-wire powder coaxial copper nozzle; the first channel inside the ion gas outer shell is used to inject ion gas; the ion gas outer shell is an internal hollow structure for injecting cooling water; a sleeve is arranged on the outer side of the tungsten electrode, and the sleeve is located in the ion gas outer shell; through holes are respectively provided on the two side surfaces of the welding gun outer shell and the powder feeding outer shell, and the through holes are used to feed the first welding wire and the second welding wire, and the first welding wire and the second welding wire are respectively fed into the first wire feeding port and the second wire feeding port through the second channel.

[0008] Furthermore, the sleeve is made of a non-conductive and high temperature resistant material.

[0009] Furthermore, the second channel of the multi-wire powder coaxial welding gun is provided with a partition for separating the first powder, the second powder, the first welding wire and the second welding wire; the channels for conveying the first powder, the second powder, the first welding wire and the second welding wire are independent of each other.

[0010] Furthermore, the diameter of the ion gas outlet of the multi-wire powder coaxial copper nozzle is 5 to 7 mm, the diameter of the first wire feeding port and the second wire feeding port is 2 to 3 mm, the diameter of the first powder feeding port and the second powder feeding port is 2 to 3 mm, and the distance between the first wire feeding port and the second wire feeding port is 15 to 20 mm; the distance between the first powder feeding port and the second powder feeding port is 15 to 20 mm.

[0011] Furthermore, the angle between the first welding wire and the second welding wire sent out of the first wire feeding port and the second wire feeding port and the tungsten electrode is 45° to 60°; the angle between the powder and the tungsten electrode is 45° to 60°.

[0012] The present invention further provides an additive manufacturing device for a plasma arc multi-wire powder coaxial welding gun, comprising the above-mentioned plasma arc multi-wire powder coaxial welding gun and a multi-wire powder coaxial welding power supply; the positive electrode of the multi-wire powder coaxial welding power supply is connected to the tungsten electrode, and the negative electrode is connected to the substrate; the ion gas shell is connected to the cooling water mechanism; the first channel of the multi-wire powder coaxial welding gun is connected to the ion gas supply system; a first powder feeding mechanism is arranged on the top surface of one end of the multi-wire powder coaxial welding gun, and a second powder feeding mechanism is arranged on the top surface of the other end, and the first powder feeding mechanism and the second powder feeding mechanism are connected to the second channel; the third channel of the wire powder coaxial welding gun is connected to the protective gas system; a first wire feeding mechanism is arranged at one end of the multi-wire powder coaxial welding gun, which is located at the top of the first welding wire; a second wire feeding mechanism is arranged at the other end of the multi-wire powder coaxial welding gun, which is located at the top of the second welding wire; the first welding wire and the second welding wire pass through the welding gun shell and the powder feeding shell from the outside to the inside, enter the second channel, and are sent out through the first wire feeding port and the second wire feeding port.

[0013] The present invention further provides a method for manufacturing a high entropy alloy by coaxial addition of plasma arc multi-wire powder, comprising the following steps:

[0014] Step 1: Fix the pre-treated substrate on the additive manufacturing workbench and connect the plasma arc multi-wire powder coaxial additive manufacturing device; the multi-wire powder coaxial welding gun is installed above the substrate;

[0015] Step 2: According to the required high entropy alloy material composition, appropriate welding wire and powder are selected; the first wire feeding mechanism and the second wire feeding mechanism at both ends of the multi-wire powder coaxial welding gun are respectively loaded with the same or different types of welding wires, and the first powder feeding mechanism and the second powder feeding mechanism are respectively loaded with the same or different types of metal powders;

[0016] Step 3: According to the geometric structure and material composition distribution of the target part, the process parameters of the multi-wire powder coaxial additive manufacturing device are set;

[0017] Step 4: Turn on the ion gas supply system and the shielding gas system to form a stable shielding atmosphere; turn on the cooling water mechanism and start the multi-wire powder coaxial welding gun; start the wire feeding mechanism and the powder feeding mechanism at the same time, and the welding wire in the first wire feeding mechanism and the second wire feeding mechanism at both ends of the multi-wire powder coaxial welding gun is synchronously transported with the powder in the first powder feeding mechanism and the second powder feeding mechanism; the multi-wire powder coaxial welding gun generates a high-temperature plasma arc, and the welding wire and powder are melted at the same time and deposited on the substrate, and the target parts are stacked layer by layer.

[0018] Furthermore, the distance between the wire powder coaxial copper nozzle of the multi-wire powder coaxial welding gun and the upper surface of the substrate is 3 to 4 mm.

[0019] Furthermore, in step 2, the diameter of the welding wire is 0.8 mm; and the particle size of the powder is 10 to 100 μm.

[0020] Furthermore, in step 3, the welding process parameters are set according to actual conditions, the welding current is 150-200A, the welding voltage is 20-25V; the wire feeding speed is 1-4m / min, and the powder feeding speed is 2-10g / min; the powder feeding argon gas flow rate is 5-8L / min, the ion gas flow rate of the ion gas supply system is 0.5-1L / min, and the shielding gas flow rate of the shielding gas system is 10-12L / min.

[0021] The beneficial effects of the present invention are:

[0022] (1) The present invention provides a plasma arc multi-wire powder coaxial welding gun and a device for additive manufacturing of high entropy alloys. By innovatively adopting a multi-wire and multi-powder coaxial supply method, the shortcomings of the existing laser powder cladding technology, such as high cost and low efficiency, are effectively overcome. Compared with traditional single-wire or double-wire arc additive manufacturing, the present invention has stronger material adaptability and composition control capabilities while ensuring efficient melting. Through the dual wire feeding system and the coaxial dual powder feeding system, the ratio of multiple main elements can be accurately controlled to ensure the composition uniformity and high quality of the high entropy alloy, which is particularly suitable for mass production and large-scale application of high entropy alloys.

[0023] (2) The present invention proposes a low-cost plasma arc additive manufacturing method for Fe 40 Ni 40 Cr 10 Mn 10 A new approach to high-entropy alloys that enables precise control of Fe 40 Ni 40 Cr 10 Mn 10The multi-element composition of the alloy ensures uniform alloy composition and sufficient melting, solving the high cost and low efficiency problems in the manufacturing process of high entropy alloys in the existing technology. In addition, this method uses the high temperature effect of the plasma arc and the precise material delivery technology to ensure the excellent properties of the high entropy alloy, such as excellent corrosion resistance, high temperature strength and mechanical properties, greatly enhancing the application potential of high entropy alloys in extreme environments, especially suitable for high-tech fields such as aerospace, energy and military. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of a plasma arc multi-wire powder coaxial additive manufacturing high entropy alloy device;

[0025] Figure 2 It is a plasma arc multi-wire powder coaxial additive manufacturing high entropy alloy Fe 40 Ni 40 Cr 10 Mn 10 Process schematic diagram.

[0026] Wherein: 1-first argon powder feeder, 2-second argon powder feeder, 3-cooling water tank, 4-ion gas, 5-shielding gas, 6-copper nozzle, 7-first powder feeding outlet, 8-second powder feeding outlet, 9-first powder, 10-second powder, 11-welding gun housing, 12-first wire feeder, 13-second wire feeder, 14-first welding wire, 15-second welding wire, 16-tungsten electrode, 17-ceramic sleeve, 18-plasma arc, 19-connecting piece, 20-first wire feeding outlet, 21-second wire feeding outlet, 22-first powder feeding outlet, 23-second powder feeding outlet, 24-shielding gas outlet, 25-welding gun housing, 26-ion gas outlet. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of those skilled in the art, the present invention is further described in detail below with reference to the accompanying drawings and implementation cases, which is intended to help understand the technical solution of the present invention, but does not limit the protection scope of the present invention.

[0028] The invention discloses a device for manufacturing high entropy alloy by coaxial plasma arc multi-wire powder additive manufacturing. The plasma arc multi-wire powder coaxial welding gun is the core component of the device, which is responsible for generating a high-temperature plasma arc for melting the welding wire and powder fed in, ensuring that the powder is stably fed into the molten pool and is not blown away by airflow interference. The multi-channel wire feeding system supports the simultaneous feeding of different types of welding wires, and the welding wires are respectively fed on the front and rear sides to ensure that the multi-element component requirements of the high entropy alloy are met. The system is precisely matched with the welding gun, and by adjusting the wire feeding speed and position, the precise control of the element ratio in the molten pool is achieved, ensuring that the multi-main elements are uniformly melted and distributed, and finally obtaining a high entropy alloy that meets the design requirements. The coaxial powder feeding system is designed to coaxially feed different metal powders into the molten pool, and the powder feeding ports on the left and right sides work simultaneously to ensure that the elements in the molten pool are evenly mixed. In order to prevent the powder from being affected by airflow during the transportation process, the system adopts an airflow control device to ensure that the powder is stably fed into the molten pool without being blown away, avoiding waste and loss. The role of the gas protection system is to provide protection for the molten pool during the additive manufacturing process, prevent the high-entropy alloy from reacting with oxygen or nitrogen in the air, and avoid oxidation or impurities. By accurately controlling the gas flow, the gas protection system can provide adequate protection throughout the entire processing process to ensure the purity and quality of the high-entropy alloy. The control system is responsible for automatically adjusting the key parameters of the entire additive manufacturing process, including wire feeding speed, powder feeding amount, plasma arc current voltage and gas flow. The system has a dynamic adjustment function, which can accurately control various parameters according to actual process requirements to ensure the stability and consistency of the entire manufacturing process, and ultimately produce high-entropy alloy components that meet the design requirements.

[0029] The present invention discloses a plasma arc multi-wire powder coaxial additive manufacturing method for high entropy alloy, which specifically comprises the following steps:

[0030] Step 1: Select appropriate welding wire and powder according to the required high entropy alloy material composition. The wire feeders on the left and right sides are respectively loaded with different types of welding wires, and the powder feeding system is loaded with a variety of metal powders. Check the gas protection system to ensure sufficient shielding gas supply to prevent oxidation or other impurities from mixing in.

[0031] Step 2: Start the control system and set the welding parameters, including key parameters such as plasma arc current and voltage, wire feeding speed, powder feeding rate, and gas flow rate. Adjust the temperature and energy of the plasma arc welding gun to make it suitable for melting multi-primary element high entropy alloy materials.

[0032] Step 3: Start the wire feeding and powder feeding devices through the control system to ensure that the multi-channel wire feeding system and the coaxial powder feeding system work simultaneously. Different welding wires are fed into the left and right sides respectively, and different metal powders are synchronously fed into the left and right sides of the powder feeding system. At this time, the plasma arc welding gun generates a high-temperature plasma arc, and the welding wire and powder melt at the same time to form a uniform molten pool.

[0033] Step 4: During the molten pool formation process, adjust the wire feeding speed and powder feeding amount in real time to ensure that the ratio of different elements in the molten pool meets the design requirements.

[0034] Step 5: The gas protection system provides a stable protective atmosphere around the molten pool to prevent oxygen, nitrogen or other impurities in the air from entering the molten pool. By precisely controlling the flow and pressure of the protective gas, the high entropy alloy material in the molten pool is protected from oxidation and the purity of the alloy is maintained. At the same time, the airflow control device ensures that the powder enters the molten pool smoothly without being disturbed by the airflow or blown away.

[0035] Step 6: By controlling the welding torch movement path and welding speed, the high entropy alloy material is deposited layer by layer. The melting and solidification process is maintained uniformly between each layer to ensure the density and strength of the material. This process can be repeated until the component reaches the designed size and shape.

[0036] Example 1

[0037] Combination Figure 1 The structural composition and use method of the plasma arc multi-wire powder coaxial additive manufacturing high entropy alloy device are described. Figure 1 As shown, Fe 40 Ni 40 Cr 10 Mn 10Taking high entropy alloy as an example, the core components of the plasma arc welding gun include the welding gun housing 11, the tungsten electrode 16, the ceramic sleeve 17, the connector 19 and the ion gas outlet 26. The tungsten electrode 16 is a key component for generating the plasma arc 18. The high temperature of the plasma arc 18 melts the Fe wire, Ni wire, Cr powder and Mn powder. The feeding angle of the welding wire is 45-60°, and the feeding angle of the powder is also 45-60°. The wire feeding and powder feeding angles are consistent, so that the welding wire and powder will melt near the tungsten electrode, and thus enter the arc together with the plasma arc, avoiding uneven heat distribution and powder loss caused by the melting of multiple wire powders. The diameters of the wire feeding port and the powder feeding port are both 2-3 mm to ensure stable gas and powder extraction. With the tungsten electrode as the center, the wire feeding ports are symmetrically distributed along the tungsten electrode, and the powder feeding ports are also symmetrically distributed along the tungsten electrode. The distance between the two wire feeding ports is 15-20 mm, and the distance between the two powder feeding ports is the same as the distance between the two wire feeding ports, and the wire feeding port connection line and the powder feeding port connection line are perpendicular to each other. The powder material is introduced through the argon powder feeder at the top of the welding gun. The argon powder feeder provides auxiliary argon to ensure that the powder is not disturbed by the airflow and blown away during the process of feeding into the molten pool. The first powder feeding outlet 7 and the second powder feeding outlet 8 respectively feed Cr powder and Mn powder from the left and right sides of the welding gun. The two powders are fed into the molten pool through precisely controlled airflow to ensure uniform mixing of the elements. The first wire feeder 12 and the second wire feeder 13 are used to transport Fe wire and Ni wire respectively. These two welding wires enter the plasma arc area through the first wire feeding outlet 20 and the second wire feeding outlet 21, and are stacked layer by layer to form a high entropy alloy. The cooperation between the wire feeder and the powder feeding system is precisely adjusted by the control system to ensure that the powder and the welding wire enter the molten pool in proportion, thereby achieving the melting and uniform distribution of different elements. The ion gas 4 enters the welding area through the ion gas outlet 26 to maintain stable burning of the arc, and the shielding gas 5 protects the molten pool from oxidation and impurity contamination through the shielding gas outlet 24. The cooling water tank 3 provides cooling for the welding gun, maintains the stability of the equipment during welding, ensures that the temperature of the welding gun is controlled within a reasonable range, and avoids equipment damage or welding quality problems caused by overheating. The plasma arc 18 adjusts its energy output by controlling the changes in current and voltage to adapt to different metal materials and process requirements, especially in the manufacturing process of high entropy alloys, it is necessary to maintain the stability and uniformity of the plasma arc. The position design of the first powder delivery outlet 22 and the second powder delivery outlet 23 is opposite to the first wire delivery outlet 20 and the second wire delivery outlet 21, so that the powder and the welding wire can be melted at the same time under the action of the plasma arc to form a uniform molten pool, ensuring that each element is fully fused at high temperature. By controlling the speed, ratio of powder delivery and wire delivery and the energy of the plasma arc, precise control of multiple main elements can be achieved to form a high entropy alloy component with uniform composition and dense structure.

[0038] Combination Figure 2 Description Plasma Arc Multi-Wire Powder Coaxial Additive Manufacturing Fe 40 Ni 40 Cr 10 Mn10 The manufacturing steps of high entropy alloy:

[0039] Preparation before welding:

[0040] Select low-cost and low-carbon steel with good thermal conductivity as the substrate 29, ensure that the welding area is clean and pollution-free, and remove possible oxide layers or impurities on the metal surface. Select Fe wire, Ni wire, Cr powder, and Mn powder as filling materials. According to the mass ratio of 4:4:1:1 of the four elements Fe, Ni, Cr, and Mn of the Fe40Ni40Cr10Mn10 alloy to be prepared, taking two wires with a diameter of 1.2mm as an example, set the wire feeding speed of Fe wire to 2m / min, that is, 17.8g / min, the wire feeding speed of Ni wire to 1.77m / min, that is, 17.8g / min, the powder feeding speed of Cr powder to 4.45g / min, and the powder feeding speed of Mn powder to 4.45g / min. Check the plasma welding gun 27 and power supply, specifically including the plasma arc welding machine 28, wire feeding system, powder feeding system, gas protection system, and cooling system, to ensure that all equipment is working properly. Set the current of the plasma arc power supply to 150-200A and the voltage to 20-25V. Set the powder feeding argon gas flow rate to 5-8L / min to ensure the stability of powder feeding into the molten pool and avoid the powder being disturbed by the airflow. Set the welding speed to 2-4mm / s. Adjust the argon shielding gas flow rate to 10-12L / min to ensure that the molten pool is fully protected and avoid oxidation. Set the ion gas flow rate to 0.5-1L / min to stabilize the plasma arc and enhance the melting capacity of the arc.

[0041] Additive Manufacturing Process:

[0042] Turn on the plasma welding machine power, turn on the plasma gas and shielding gas devices, start the plasma arc, and turn on the plasma arc after the arc stabilizes. At the beginning of welding, the welding wire and powder are fed into the molten pool at the preset speed at the same time, and the powder feeding argon gas flow rate is gradually increased from 5L / min until the powder is stably fed and melted at the same position as the Fe wire and Ni wire. The best result is that the melting height of the powder droplet and the welding wire droplet are the same.

[0043] The additive manufacturing method of the present invention realizes precise control and efficient manufacturing of multiple main elements through multi-wire powder coaxial feeding technology, avoids the problems of low powder utilization and high cost in traditional laser powder cladding, and significantly improves the composition uniformity and mechanical properties of the material.

[0044] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0045] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A plasma arc multi-wire powder coaxial welding gun, characterized in that: It comprises a tungsten electrode (16), a sleeve (17), a multi-wire powder coaxial copper nozzle (19), an ion gas housing, a powder delivery housing, and a welding gun housing (11); An ion gas port (26) is provided in the middle of the multi-wire powder coaxial copper nozzle (19); a first wire feeding port (20) and a second wire feeding port (21) are arranged at the front and rear ends of the ion gas outlet (26); a first powder feeding port (22) and a second powder feeding port (23) are arranged at the left and right ends of the ion gas outlet (26); the first wire feeding port (20), the second wire feeding port (21), the first powder feeding port (22), and the second powder feeding port (23) are evenly arranged around the ion gas outlet (26); a protective gas outlet (24) is provided on the outer side of the multi-wire powder coaxial copper nozzle (19); the multi-wire powder coaxial copper nozzle (19) is located at the bottom end of the multi-wire powder coaxial welding gun and is connected to the welding gun housing (11); A powder delivery shell is nested inside the welding gun shell (11), and a third channel between the powder delivery shell and the welding gun shell (11) is used to inject shielding gas; an ion gas shell is nested inside the powder delivery shell, and a second channel between the ion gas shell and the powder delivery shell is used to inject a first powder and a second powder, and the first powder and the second powder are respectively delivered through a first powder delivery port (22) and a second powder delivery port (23) of a multi-wire powder coaxial copper nozzle (19); the first channel inside the ion gas shell is used to inject ion gas; the ion gas shell is an internal hollow structure and is used to inject cooling water; a sleeve (17) is arranged outside the tungsten electrode (16), and the sleeve (17) is located inside the ion gas shell; through holes are respectively provided on both side surfaces of the welding gun shell (11) and the powder delivery shell, and the through holes are used to deliver a first welding wire and a second welding wire, and the first welding wire and the second welding wire are respectively delivered into a first wire delivery port (20) and a second wire delivery port (21) through the second channel.

2. A plasma arc multi-wire powder coaxial welding gun according to claim 1, characterized in that: The sleeve is made of non-conductive and high temperature resistant material.

3. The plasma arc multi-wire powder coaxial welding gun according to claim 1, characterized in that: The second channel of the multi-wire powder coaxial welding gun is provided with a partition for separating the first powder, the second powder, the first welding wire and the second welding wire.

4. The plasma arc multi-wire powder coaxial welding gun according to claim 1, characterized in that: The diameter of the ion gas outlet (26) of the multi-wire powder coaxial copper nozzle (19) is 5 to 7 mm, the diameters of the first wire feeding port (20) and the second wire feeding port (21) are 2 to 3 mm, the diameters of the first powder feeding port (22) and the second powder feeding port (23) are 2 to 3 mm, and the distance between the first wire feeding port (20) and the second wire feeding port (21) is 15 to 20 mm; the distance between the first powder feeding port (22) and the second powder feeding port (23) is 15 to 20 mm.

5. The plasma arc multi-wire powder coaxial welding gun according to claim 1, characterized in that: The angles at which the first welding wire and the second welding wire are fed out of the first wire feeding port (20) and the second wire feeding port (21) and the tungsten electrode (16) are 45° to 60°; the angles at which the powder and the tungsten electrode (16) are 45° to 60°.

6. A device for additively manufacturing high entropy alloys using the plasma arc multi-wire powder coaxial welding gun according to any one of claims 1 to 5, characterized in that: It also includes a multi-wire powder coaxial welding power source (28); the positive electrode of the multi-wire powder coaxial welding power source (28) is connected to the tungsten electrode (16), and the negative electrode is connected to the substrate (29); the ion gas housing is connected to the cooling water mechanism; the first channel of the multi-wire powder coaxial welding gun is connected to the ion gas supply system; A first powder feeding mechanism is arranged on the top surface of one end of the multi-wire powder coaxial welding gun, and a second powder feeding mechanism is arranged on the top surface of the other end, and the first powder feeding mechanism and the second powder feeding mechanism are connected to the second channel; the third channel of the wire powder coaxial welding gun is connected to the shielding gas system; A first wire feeding mechanism is arranged at one end of the multi-wire powder coaxial welding gun, and is located at the top end of the first welding wire; A second wire feeding mechanism is arranged at the other end of the multi-wire powder coaxial welding gun, located at the top end of the second welding wire; the first welding wire and the second welding wire penetrate the welding gun housing and the powder feeding housing from the outside to the inside, enter the second channel and are fed out through the first wire feeding port (20) and the second wire feeding port (21).

7. A method for manufacturing a high entropy alloy using the plasma arc multi-wire powder coaxial additive manufacturing device according to claim 6, characterized in that: The following steps are involved: Step 1: Fix the pre-treated substrate on the additive manufacturing workbench and connect the plasma arc multi-wire powder coaxial additive manufacturing device; A multi-wire powder coaxial welding gun is mounted above the base plate; Step 2: According to the required high entropy alloy material composition, appropriate welding wire and powder are selected; the first wire feeding mechanism and the second wire feeding mechanism at both ends of the multi-wire powder coaxial welding gun are respectively loaded with the same or different types of welding wires, and the first powder feeding mechanism and the second powder feeding mechanism are respectively loaded with the same or different types of metal powders; Step 3: According to the geometric structure and material composition distribution of the target part, the process parameters of the multi-wire powder coaxial additive manufacturing device are set; Step 4: Turn on the ion gas supply system and the shielding gas system to form a stable shielding atmosphere; turn on the cooling water mechanism and start the multi-wire powder coaxial welding gun; start the wire feeding mechanism and the powder feeding mechanism at the same time, and the welding wires in the first wire feeding mechanism and the second wire feeding mechanism at both ends of the multi-wire powder coaxial welding gun are synchronously transported with the powders in the first powder feeding mechanism and the second powder feeding mechanism; The multi-wire powder coaxial welding gun generates a high-temperature plasma arc. The welding wire and powder are melted at the same time and then deposited on the substrate, stacking the target parts layer by layer.

8. The plasma arc multi-wire powder coaxial additive manufacturing device according to claim 7, characterized in that: The distance between the wire powder coaxial copper nozzle (19) of the multi-wire powder coaxial welding gun and the upper surface of the substrate (29) is 3 to 4 mm.

9. The plasma arc multi-wire powder coaxial additive manufacturing method according to claim 7, characterized in that: In step 2, the diameter of the welding wire is 0.8 mm; the particle size of the powder is 10 to 100 μm.

10. The plasma arc multi-wire powder coaxial additive manufacturing method according to claim 7, characterized in that: In step 3, the welding process parameters are set according to actual conditions, the welding current is 150-200A, the welding voltage is 20-25V; the wire feeding speed is 1-4m / min, the powder feeding speed is 2-10g / min; the powder feeding argon gas flow rate is 5-8L / min, the ion gas flow rate of the ion gas supply system is 0.5-1L / min, and the shielding gas flow rate of the shielding gas system is 10-12L / min.

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