Coaxial powder feeding MIG wire powder composite additive manufacturing device and method

Abstract

The invention discloses a coaxial powder feeding MIG wire powder composite additive manufacturing device and method, and belongs to the field of electric arc additive manufacturing. The device comprises an MIG wire powder composite welding gun for coaxial powder feeding; the composite welding gun comprises a wire powder coaxial copper nozzle with a wire feeding port in the middle, an ion gas shell and a powder feeding shell. Powder feeding ports are formed in the left end and the right end of the wire feeding port. The wire powder coaxial copper nozzle is located at the bottom end of the plasma arc 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 feeding powder; the MIG electrode comprises a welding wire tube used for arranging a welding wire, and one end of the welding wire is sent out through a wire feeding port. A slotting sleeve is arranged on the outer side of a welding wire tube of an MIG electrode of the composite welding gun and located on the inner side of an ion gas shell. According to the device, the welding wire and the powder can synchronously enter the molten pool, so that the problem of component regulation and control in multi-component alloy additive manufacturing is effectively solved, and the utilization efficiency of the powder is improved.

Description

Technical Field

[0001] The present invention belongs to the field of arc additive manufacturing, and in particular relates to a MIG wire powder composite additive manufacturing device and method with coaxial powder feeding. Background Art

[0002] MIG additive manufacturing technology has the advantages of high efficiency, low cost and wide application range, so it is widely used in the manufacturing process of metal structural parts. However, the traditional MIG process mainly relies on welding wire as the material source. In the additive manufacturing of multi-component alloys, the use of a single welding wire limits the precise control of material composition. Especially for the manufacture of multi-component alloys, it is difficult to achieve dynamic control and uniform distribution of multiple elements by welding wire alone, which affects the performance of the final product. Therefore, to achieve precise additive manufacturing of multi-component alloys, the main existing method is to use laser powder cladding technology. However, although laser powder cladding can achieve precise control of complex components, its equipment cost is high, energy consumption is large, and the molten pool size is small, which limits production efficiency. At the same time, the laser additive manufacturing process has high requirements on the reflectivity and absorptivity of the material, especially for highly reflective materials such as aluminum and copper, the melting efficiency is low and the application is limited.

[0003] In order to solve the above problems, in recent years, powder addition technology has been introduced into the traditional MIG arc additive manufacturing process, and the manufacture of multi-component alloys can be achieved through the composite use of welding wire and powder. This method can not only retain the advantages of high efficiency and low cost of the MIG process, but also realize the regulation of composition to a certain extent. However, the traditional off-axis powder feeding strategy is to place a powder feeding device on the side of the MIG welding gun, and the powder is fed into the MIG arc from the side of the welding gun. However, due to the light weight of the powder, under the strong blowing force of the MIG arc shielding gas, the powder is difficult to be stably fed into the molten pool and is easily blown away, resulting in low powder utilization and material waste. Therefore, it is of great practical significance to develop a coaxial powder feeding MIG wire powder composite additive manufacturing device and method that can stably feed powder and ensure that the powder effectively enters the molten pool. This technical solution can not only improve the utilization efficiency of the powder, but also realize the precise control and efficient manufacturing of complex multi-component alloys through the synergistic effect of welding wire and powder. Summary of the invention

[0004] The present invention aims to solve the problems of difficult material composition control and low powder utilization rate in the existing MIG additive manufacturing technology, and provides a MIG wire-powder composite plasma arc welding gun with coaxial powder feeding and an additive manufacturing device and method. The device adds a coaxial powder feeding system to the traditional MIG welding gun, which can realize the simultaneous feeding of welding wire and powder, thereby effectively solving the composition control problem in multi-component alloy additive manufacturing and improving the utilization efficiency of powder.

[0005] The present invention provides a MIG wire powder composite welding gun with coaxial powder feeding, comprising a MIG electrode, a wire powder coaxial copper nozzle, an ion gas shell, a powder feeding shell, and a welding gun shell; a wire feeding port is provided in the middle of the wire powder coaxial copper nozzle, and a first powder feeding port and a second powder feeding port are arranged at the left and right ends of the wire feeding port; the wire powder coaxial copper nozzle is located at the bottom end of the plasma arc welding gun and is connected to the welding gun shell; a powder feeding shell (13) is nested inside the welding gun shell (14), and a third channel between the powder feeding shell (13) and the welding gun shell (14) is used for injecting protective gas; a wire feeding port is nested inside the powder feeding shell An ion gas shell is provided, and a second channel between the ion gas shell and the powder feeding 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 on the wire-powder coaxial copper nozzle; the first channel inside the ion gas shell is used to inject ion gas; the ion gas shell and the powder feeding shell are internal hollow structures for injecting cooling water; the MIG electrode includes a welding wire tube for arranging welding wire, and one end of the welding wire is sent out through the wire feeding port; a slotted sleeve is provided on the outside of the welding wire tube of the MIG electrode, and the slotted sleeve is located on the inside of the ion gas shell.

[0006] Furthermore, the slotted sleeve is made of a non-conductive and high-temperature resistant material; the angle between the slots of the slotted sleeve is 120°, and the slot width is 2 mm.

[0007] Furthermore, the MIG electrode also includes a conductive nozzle; the welding wire tube is arranged in the middle of the conductive nozzle, and the welding wire in the welding wire tube extends from the conductive nozzle into the wire feeding port of the wire powder coaxial copper nozzle.

[0008] Furthermore, the wire feeding port diameter of the wire-powder coaxial copper nozzle is 4-5 mm, the first powder feeding port and the second powder feeding port diameter are 1.2-2 mm; the distance between the wire feeding port and the first powder feeding port and the second powder feeding port is 1-3 mm.

[0009] Furthermore, the angle between the welding wire and the powder ejection direction is 15° to 20°.

[0010] The present invention also provides a MIG silk powder composite additive manufacturing device with coaxial powder feeding, comprising the above-mentioned MIG silk powder composite welding gun with coaxial powder feeding, a MIG power supply, and a current and voltage control system; the positive electrode of the fixed MIG power supply is connected to the welding wire, and the negative electrode is connected to the substrate through the current and voltage control system; the ion gas shell and the powder feeding shell are connected to a cooling water mechanism; the first channel of the MIG silk powder composite welding gun is connected to the ion gas supply system; the second channel of the MIG silk powder composite welding gun is connected to the powder feeding mechanism; the third channel of the MIG silk powder composite welding gun is connected to the protective gas system; a wire feeding mechanism is arranged on the outside of the MIG silk powder composite welding gun, and the wire feeding mechanism is located at the top of the welding wire.

[0011] Furthermore, the distance between the wire powder coaxial copper nozzle of the plasma arc welding gun and the upper surface of the substrate is 4 to 6 mm.

[0012] The present invention also provides a MIG silk powder composite additive manufacturing method with coaxial powder feeding, comprising the following steps:

[0013] Step 1: fix the pre-treated substrate on the additive manufacturing workbench and connect the above-mentioned coaxial powder feeding MIG silk powder composite additive manufacturing device; the coaxial powder feeding MIG silk powder composite welding gun is installed above the substrate;

[0014] Step 2: Select appropriate welding wire and powder material according to the requirements of the target parts; load the welding wire into the wire feeding mechanism and the powder material into the powder feeding mechanism;

[0015] Step 3: According to the geometric structure and material composition distribution of the target part, the process parameters of the MIG silk powder composite additive manufacturing device with coaxial powder feeding are set;

[0016] 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 plasma arc welding gun; turn on the wire feeding mechanism and the powder feeding mechanism at the same time, and the welding wire and powder are transported synchronously; the proportion of alloy elements in the deposition layer is controlled by adjusting the wire feeding speed and the powder feeding speed, and the welding wire and powder are melted synchronously and deposited on the substrate to build the target part layer by layer.

[0017] Furthermore, the diameter of the welding wire is 1.2-1.6 mm, and the welding wire is a metal wire; the particle size of the powder is 50-200 μm, and the powder is a metal powder.

[0018] Furthermore, in step 3, the welding process parameters are set according to actual conditions, the welding current is 120-180A, the welding voltage is 18-24V; the wire feeding speed is 4-7m / min, and the powder feeding speed is 2-10g / min; the powder feeding argon gas flow rate is 10-15L / 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 5-10L / min.

[0019] The beneficial effects of the present invention are:

[0020] The present invention uses a coaxial powder feeding system, so that powder and welding wire can be fed into the molten pool synchronously, avoiding the problem of powder being blown away due to airflow interference in traditional side-axis powder feeding, thereby effectively improving the utilization rate of powder; this not only reduces material waste, but also improves the efficiency of resource utilization in the production process.

[0021] The present invention can accurately adjust the feeding speed and ratio of welding wire and powder according to welding requirements, ensure the uniform distribution of elements in the molten pool, accurately control the composition of multi-component alloys, and meet the manufacturing requirements of complex alloys such as high entropy alloys. By optimizing material input, it is ensured that the alloy properties of the final product meet the design requirements. Accurately control alloy composition:

[0022] Compared with laser powder cladding technology, the MIG welding gun of the present invention includes a coaxial powder feeding system to improve powder utilization, and the structure of the present invention is relatively simple, and the additive manufacturing of multi-component alloys can be achieved without expensive laser equipment, which greatly reduces the investment cost of production equipment. Compared with variable polarity TIG and plasma wire powder cladding, the present invention not only has low equipment cost, but also has a simple process and high deposition efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the MIG silk powder composite additive manufacturing device with coaxial powder feeding;

[0024] Figure 2 This is a physical picture of the MIG wire powder composite welding gun with coaxial powder feeding.

[0025] 1-Cooling water tank, 2-Wire feeder, 3-Welding wire, 4-Ion gas, 5-Argon powder feeding, 6-Shielding gas, 7-MIG power supply, 8-Slotted ceramic sleeve, 9-Conductive nozzle, 10-Powder, 11-Arc, 12-Ion gas housing, 13-Powder feeding gas housing, 14-Welding gun housing, 15-Current and voltage control system, 16-Baseboard. DETAILED DESCRIPTION

[0026] 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.

[0027] In view of the difficulties in controlling material composition and low powder utilization in existing MIG additive manufacturing technologies, the present invention provides a MIG wire-powder composite additive manufacturing device and method with coaxial powder feeding. By adding a coaxial powder feeding system to a traditional MIG welding gun, the device can simultaneously feed the welding wire and powder, thereby effectively solving the problem of composition control in multi-component alloy additive manufacturing and improving the utilization efficiency of the powder. The device of the present invention includes components such as a MIG welding gun, a coaxial powder feeding system, a welding wire feeding system, a gas protection system, and a control system. Each system works in coordination to ensure that the welding wire and powder are evenly fed into the molten pool during the additive manufacturing process, thereby achieving precise control of the composition.

[0028] The design of the coaxial powder feeding system ensures that the powder and the welding wire can enter the molten pool synchronously, avoiding the problem of the powder being blown away by the airflow during the feeding process. By adjusting the speed and ratio of powder feeding and wire feeding, dynamic regulation of different elemental components can be achieved according to process requirements, which is suitable for the manufacture of multi-element alloys such as high entropy alloys and gradient materials. At the same time, the gas protection system around the welding gun can effectively prevent the molten pool from reacting adversely with the surrounding air during the additive manufacturing process, avoid oxidation or impurities, thereby ensuring the purity and quality of the additively manufactured parts.

[0029] The method of the present invention is suitable for efficient additive manufacturing of complex multi-component metal materials, using MIG welding wire as the main material source, and realizing precise control of multiple alloy elements through coaxially fed powder. In actual operation, through intelligent control of the wire feeding and powder feeding system, the input amount of welding wire and powder can be accurately adjusted to ensure the uniform distribution of each component in the molten pool, meet the requirements of different material ratios, and finally produce a multi-component alloy component that meets the design requirements. The present invention effectively improves the flexibility and applicability of MIG additive manufacturing, and can realize efficient and precise multi-element alloy additive manufacturing without increasing the complexity of the equipment.

[0030] The present invention discloses a MIG silk powder composite additive manufacturing method with coaxial powder feeding, which can be achieved by the following steps:

[0031] Step 1: Assemble and debug the MIG silk powder composite additive manufacturing device with coaxial powder feeding, including connecting the MIG silk powder composite welding gun, coaxial powder feeding system, wire feeding system, gas protection system and control system to ensure the normal operation of each component.

[0032] Step 2: Select welding wire and powder materials according to design requirements. Load the welding wire into the wire feeder and the powder material into the coaxial powder feeding system to ensure that the powder particle size is suitable for the equipment requirements and meets the material composition design requirements.

[0033] Step 3: According to the required alloy composition ratio, set the wire feeding speed, powder feeding amount, welding current and voltage and other parameters. Set the welding trajectory, speed and process parameters in the control system to ensure that the wire and powder are fed into the molten pool synchronously.

[0034] Step 4: Start the gas protection system, turn on argon or other protective gas, and ensure that the welding area is not in contact with the air to prevent the molten pool from reacting with oxygen or nitrogen, and to avoid material oxidation or impurities from mixing in.

[0035] Step 5: Start the MIG wire powder composite welding gun, and turn on the wire feeding system and coaxial powder feeding system at the same time. The welding wire and powder melt under the high temperature of the arc to form a molten pool. By precisely controlling the movement of the welding gun and the material feeding speed, the material is deposited layer by layer to complete additive manufacturing.

[0036] Example 1

[0037] This example is based on the coaxial powder feeding MIG wire powder composite additive manufacturing Al-6.5Zn-2.4Mg-1.6Cu-10Ag multi-element alloy as the research object, and commercial Al-6.5Zn-2.4Mg-1.6Cu alloy welding wire and Ag powder are selected as filler materials. Figure 1As shown, the wire feeder 2 feeds the welding wire into the welding gun, the diameter of the welding wire is 1.2 mm, the conductive nozzle 9 is used to fix the welding wire, and the ceramic sleeve 8 is between the conductive nozzle 9 and the ion gas housing 12, which plays a fixing role to ensure the stability of the wire feeding structure. It is worth noting that the ceramic sleeve 8 is slotted to ensure that the ion gas 4 is stably fed into the arc 11.

[0038] The welding current range is 120-180A, the welding voltage range is 18-24V, the wire feeding speed is controlled to 6m / min, and the wire feeding mass is 19.4g / min. According to the mass ratio of Al-6.5Zn-2.4Mg-1.6Cu alloy welding wire and Ag powder in Al-6.5Zn-2.4Mg-1.6Cu-20Ag alloy is 4:1, it can be calculated that the matching Ag powder feeding speed is 4.8g / min. The ratio of wire feeding speed and powder feeding speed is fixed, which can ensure the acquisition of Al-6.5Zn-2.4Mg-1.6Cu-10Ag multi-element alloy. It is adjusted in real time according to the specific welding conditions. The arc length is controlled at 2-4mm, the distance between the conductive nozzle 9 and the substrate 16 is 8-10mm, and the welding wire and the powder ejection direction clamp are 15-20° to ensure that the powder is stably fed into the arc area. The argon powder feeder 5 feeds Ag powder into the molten pool at an angle of 15 to 20 degrees through the coaxial powder feeding system. The powder feeding speed is controlled at 1 to 2 g / min, the powder feeding gas flow rate is 10 to 15 L / min, the ion gas flow rate is 0.5 to 1 L / min, and the shielding gas flow rate is 5 to 10 L / min, ensuring that the powder can stably enter the molten pool without being blown away by the shielding gas 6 or the ion gas 4. All of them are controlled by an independent gas regulating system to provide sufficient protection to prevent material oxidation or impurities from entering the molten pool during welding.

[0039] To ensure that the temperature of the welding area is controllable, the cooling water in the cooling water tank 1 cools the welding gun through the internal pipeline, and the cooling temperature is controlled between 20 and 40°C to ensure that the temperature is stable during welding and to avoid overheating of the equipment affecting the welding quality. During welding, the welding gun housing 14 and the powder feeding gas housing 13 accurately locate the conveying path of the powder and the shielding gas 6. The position of the powder feeding outlet relative to the welding wire is optimized, and the relative distance between the powder feeding and the welding wire is 1 to 3 mm to ensure that the welding wire and the powder are fully mixed in the molten pool.

[0040] In order to improve the accuracy of material ratio and the final alloy performance, the welding current and voltage are monitored and adjusted in real time through the current and voltage control system 15 during the welding process to ensure a stable and uniform welding process and avoid uneven melting of materials caused by current fluctuations.

[0041] Finally, through this device and process, Al-Zn-Mg-Cu-Ag multi-alloy components that met the design requirements were successfully manufactured. The material composition is uniform, the microstructure is dense, and it has excellent mechanical properties and corrosion resistance.

[0042] The actual picture of the welding gun device and internal structure is as follows Figure 2 As shown, the overall structure of the welding gun, the internal MIG electrode, the insulating slotted ceramic sleeve that fixes the MIG electrode and isolates the MIG electrode and the copper nozzle, and the conductive copper nozzle for feeding powder and wire are shown. Other structures not shown are integrated inside the welding gun. Figure 2 It is mainly to help understand the schematic diagram of the welding gun device. In addition, the detailed ceramic sleeve slot angle and width are given. Three slots are opened at equal distances to conduct plasma gas. The angles of adjacent slots are 120° (relative to the center) and the slot width is 2mm. The diameter of the wire feed port of the copper nozzle is 4mm, and the diameters of the two powder feed ports are both 2mm. The distance between each powder feed port and the wire feed port is 1.5mm.

[0043] 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.

[0044] 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 MIG wire powder composite welding gun with coaxial powder feeding, characterized in that: It includes a MIG electrode, a wire powder coaxial copper nozzle, an ion gas housing (12), a powder delivery housing (13), and a welding gun housing (14); A wire feeding port is provided in the middle of the wire-powder coaxial copper nozzle, and a first powder feeding port and a second powder feeding port are arranged at the left and right ends of the wire feeding port; the wire-powder coaxial copper nozzle is located at the bottom end of the plasma arc welding gun and is connected to the welding gun housing (14); A powder delivery housing (13) is nested inside the welding gun housing (14), and a third channel between the powder delivery housing (13) and the welding gun housing (14) is used to inject shielding gas; an ion gas housing (12) is nested inside the powder delivery housing (13), and a second channel between the ion gas housing (12) and the powder delivery housing (13) 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 and a second powder delivery port on the wire powder coaxial copper nozzle; the first channel inside the ion gas housing (12) is used to inject ion gas; the ion gas housing (12) and the powder delivery housing (13) are internal hollow structures for injecting cooling water; The MIG electrode comprises a welding wire tube for arranging welding wire, one end of which is fed out through a wire feeding port; a slotted sleeve is provided on the outside of the MIG electrode, and the slotted sleeve is located on the inside of an ion gas housing (12).

2. The MIG wire powder composite welding gun with coaxial powder feeding according to claim 1, characterized in that: The slotted sleeve is made of non-conductive and high-temperature resistant material; the angle between the slots of the slotted sleeve is 120°, and the slot width is 2mm.

3. The MIG wire powder composite welding gun with coaxial powder feeding according to claim 1, characterized in that: The MIG electrode further comprises a conductive nozzle (9); the welding wire tube is arranged in the middle of the conductive nozzle (9), and the welding wire in the welding wire tube extends from the conductive nozzle (9) into the wire feeding port of the wire-powder coaxial copper nozzle.

4. The MIG wire powder composite welding gun with coaxial powder feeding according to claim 1, characterized in that: The diameter of the wire feeding port of the wire-powder coaxial copper nozzle is 4-5 mm, and the diameters of the first powder feeding port and the second powder feeding port are 1.2-2 mm; the distance between the wire feeding port and the first powder feeding port and the second powder feeding port is 1-3 mm.

5. The MIG wire powder composite welding gun with coaxial powder feeding according to claim 1, characterized in that: The angle between the welding wire and the powder ejection direction is 15° to 20°.

6. An additive manufacturing device using the MIG wire powder composite welding gun with coaxial powder feeding according to any one of claims 1 to 5, characterized in that: It also includes a MIG power supply (7) and a current and voltage control system (15); the positive electrode of the fixed MIG power supply (7) is connected to the welding wire, and the negative electrode is connected to the base plate (16) through the current and voltage control system (15); the ion gas shell (12) and the powder feeding shell (13) are connected to a cooling water mechanism; the first channel of the MIG wire powder composite welding gun is connected to the ion gas supply system; the second channel of the MIG wire powder composite welding gun is connected to the powder feeding mechanism; the third channel of the MIG wire powder composite welding gun is connected to the protective gas system; and a wire feeding mechanism is arranged on the outside of the MIG wire powder composite welding gun, and the wire feeding mechanism is located at the top of the welding wire.

7. The MIG silk powder composite additive manufacturing device with coaxial powder feeding according to claim 6, characterized in that: The distance between the wire powder coaxial copper nozzle of the plasma arc welding gun and the upper surface of the substrate (16) is 4 to 6 mm.

8. A method for manufacturing a MIG silk powder composite additive manufacturing device using the coaxial powder feeding method of claim 6, characterized in that: The following steps are involved: Step 1: fix the pre-treated substrate (16) on the additive manufacturing workbench and connect the above-mentioned coaxial powder feeding MIG silk powder composite additive manufacturing device; the coaxial powder feeding MIG silk powder composite welding gun is installed above the substrate (16); Step 2: Select appropriate welding wire and powder material according to the requirements of the target parts; load the welding wire into the wire feeding mechanism and the powder material into the powder feeding mechanism; Step 3: According to the geometric structure and material composition distribution of the target part, the process parameters of the MIG silk powder composite additive manufacturing device with coaxial powder feeding 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 plasma arc welding gun; turn on the wire feeding mechanism and the powder feeding mechanism at the same time, and the welding wire and powder are transported synchronously; the welding wire and powder are melted synchronously and deposited on the substrate to build the target part layer by layer.

9. The MIG silk powder composite additive manufacturing method with coaxial powder feeding according to claim 8, characterized in that: The diameter of the welding wire is 1.2 mm, and the welding wire is a metal wire; the particle size of the powder is 50-200 mm, and the powder is a metal powder.

10. The MIG silk powder composite additive manufacturing method with coaxial powder feeding according to claim 8, characterized in that: In step 3, the welding process parameters are set according to the actual situation, the welding current is 120-180A, the welding voltage is 18-24V; the wire feeding speed is 4-7m / min, the powder feeding speed is 2-10g / min; the powder feeding argon gas flow rate is 10-15L / 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 5-10L / min.

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