Device and method for wire arc additive manufacturing of magnesium and aluminum dissimilar metals

Abstract

A device for wire arc additive manufacturing of magnesium and aluminum dissimilar metals, the device comprising a TIG welding gun (1) and an MIG welding gun (2) which cooperate with each other, wherein three wire-feeding mechanisms (3) are provided at one end of the MIG welding gun, and welding wires in the three wire-feeding mechanisms are sequentially arranged between the TIG welding gun and the MIG welding gun. During use, the welding wires close to the TIG welding gun and the MIG welding gun are connected to a welding power supply, and the welding wire in the middle is not connected to the welding power supply; and the MIG welding gun is in direct-current reverse connection, and the TIG welding gun is in direct-current positive connection. The position of the TIG welding gun and the position of the MIG welding gun are adjusted, such that an aluminum alloy bead (12) is located on an aluminum substrate (10), a magnesium alloy bead (14) is located on a magnesium substrate (11), and a zinc alloy bead (13) is located between the aluminum alloy bead and the magnesium alloy bead and located on the magnesium substrate. By means of the device, welding of a magnesium-aluminum dissimilar metal joint can be completed in one step, and the welding efficiency is high; and the generation of intermetallic compounds between magnesium and aluminum can be avoided, the formation of a hump bead is inhibited, and the forming quality is improved. The present invention further relates to a method for wire arc additive manufacturing of magnesium and aluminum dissimilar metals.

Description

Device and method for arc addition of magnesium and aluminum dissimilar metals Technical Field

[0001] The present invention relates to the technical field of arc material addition, and in particular to a device and method for arc material addition of magnesium and aluminum dissimilar metals. Background Art

[0002] With the development of science and technology, energy conservation and environmental protection have become issues that need to be considered in the new era of industry. Lightweight materials such as magnesium alloys and aluminum alloys can reduce energy consumption and have been widely used in aerospace, transportation and other fields. Magnesium alloy is currently the lightest metal engineering structural material in the world, with high specific strength and specific stiffness, good electromagnetic shielding performance, and good damping and vibration reduction effects. Aluminum alloy, as a lighter metal material, also has the advantages of low density, high specific strength and specific stiffness. At the same time, aluminum alloy has good creep resistance, excellent thermal and electrical conductivity, and strong corrosion resistance. Connecting magnesium alloy and aluminum alloy can simultaneously bring out their respective advantages, so that they can be applied to some occasions with special requirements.

[0003] Arc additive manufacturing, as an additive manufacturing technology with higher degrees of freedom and deposition efficiency, can be used for additive manufacturing of magnesium-aluminum alloys. The following difficulties exist in the welding of magnesium-aluminum dissimilar metals:

[0004] (1) Due to the many differences in physical and chemical properties of magnesium and aluminum alloys, there will be many defects in the middle when welding magnesium and aluminum dissimilar metals, resulting in poor mechanical properties of the welded joint, which is difficult to meet existing application requirements;

[0005] (2) The solubility of magnesium and aluminum in liquid state is low. Due to their different lattice types, magnesium has a close-packed hexagonal structure and aluminum has a face-centered cubic structure, so they are not easy to combine;

[0006] (3) The chemical properties of magnesium and aluminum are relatively active, and they easily react with oxygen to form magnesium oxide and aluminum oxide, which affects the metal connection. At the same time, when magnesium and aluminum dissimilar metals are welded, intermetallic compounds such as Mg2Al3 and Mg17Al12 will form in the weld area, reducing the strength of the weld joint;

[0007] (4) The linear expansion coefficients of both metals are large, which will produce welding residual stress, leading to defects such as welding deformation and cracking. The high thermal conductivity will also make it difficult for the shielding gas to escape in time during welding, forming pores in the weld joint;

[0008] These factors have brought a lot of resistance to the welding of magnesium and aluminum dissimilar metals, and defects in welded joints have become the main problem that needs to be solved.

[0009] Summary of the Invention

[0010] In order to effectively connect magnesium and aluminum, the present invention provides a device and method for arc addition of magnesium and aluminum dissimilar metals. The present invention adds a zinc interlayer as an intermediate layer between magnesium and aluminum through arc addition, thereby preventing the two metals from fusing to form Mg2Al3 and Mg 17 Al 12 Such intermetallic compounds can effectively connect magnesium and aluminum and improve the mechanical properties of the welded joint.

[0011] The present invention adopts the following technical solution: a device for arc additive manufacturing of magnesium and aluminum dissimilar metals, comprising a TIG welding gun and a MIG welding gun used in conjunction with each other, the end of the MIG welding gun having three wire feeding mechanisms, and the welding wires in the three wire feeding mechanisms are arranged in sequence between the TIG welding gun and the MIG welding gun.

[0012] It further comprises: a first sliding sleeve is slidably mounted on the TIG welding gun; the first sliding sleeve is fixedly connected to an arcuate guide rail; a second sliding sleeve is slidably mounted on the arcuate guide rail; and the MIG welding gun is rotatably mounted on the second sliding sleeve.

[0013] The first sliding sleeve is equipped with a first positioning screw for positioning the first sliding sleeve on the TIG welding gun; the second sliding sleeve is equipped with a second positioning screw for positioning the second sliding sleeve on the arc guide rail; the second sliding sleeve is also equipped with a third positioning screw for positioning the MIG welding gun on the second sliding sleeve.

[0014] The welding wires in the three wire feeding mechanisms are distributed in an equilateral triangle; the welding wires close to the TIG welding gun and the welding wire close to the MIG welding gun are connected to the welding power supply, and the welding wire in the middle is not connected to the welding power supply; the MIG welding gun adopts DC reverse connection, and the TIG welding gun adopts DC forward connection.

[0015] The welding wires in the three wire feeding mechanisms are respectively aluminum alloy welding wire, magnesium alloy welding wire and zinc alloy welding wire;

[0016] During welding, the welding ends of the aluminum substrate and the magnesium substrate are butted, the aluminum alloy welding wire is located on the aluminum substrate, the magnesium alloy welding wire is located on the magnesium substrate, and the zinc alloy welding wire is located between the aluminum alloy welding wire and the magnesium alloy welding wire and on the magnesium substrate.

[0017] A method for arc material addition of magnesium and aluminum dissimilar metals, comprising the following steps:

[0018] Step S1: installing the magnesium alloy welding wire, the aluminum alloy welding wire, and the zinc alloy welding wire to three wire feeding mechanisms respectively;

[0019] Step S2: pre-treating the aluminum substrate and the magnesium substrate, and splicing the welding ends of the aluminum substrate and the magnesium substrate together;

[0020] Step S3: adjusting the positions of the TIG welding gun and the MIG welding gun so that after welding, the aluminum alloy weld bead is located on the aluminum substrate, the magnesium alloy weld bead is located on the magnesium substrate, and the zinc alloy weld bead is located between the aluminum alloy weld bead and the magnesium alloy weld bead and on the magnesium substrate;

[0021] Step S4 controls the TIG welding gun and the MIG welding gun to move along the weld to complete the additive magnesium-zinc-aluminum operation.

[0022] It is further provided that: in the step S2, pre-treating the aluminum substrate and the magnesium substrate includes: using chemical reagents to remove the oxide film on the aluminum substrate and the magnesium substrate, splicing the aluminum substrate and the magnesium substrate together, and then cleaning the surfaces of the aluminum substrate and the magnesium substrate with acetone.

[0023] The beneficial effects of the present invention are:

[0024] (1) The device has a simple structure and is easy to operate. The device and method can complete the welding of magnesium-aluminum dissimilar metal joints in one go, with high welding efficiency;

[0025] (2) By adding a zinc intermediate layer between magnesium and aluminum, direct contact between the two metals can be avoided, thereby avoiding the formation of intermetallic compounds between magnesium and aluminum, and significantly improving the performance of the welded joint;

[0026] (3) The melting points of zinc, magnesium and aluminum are quite different. The use of composite welding can improve the heat input environment at the joint, while suppressing the formation of hump welds and improving the forming quality.

[0027] (4) Reverse DC connection of the MIG welding gun can remove cathode spots around the weld and the effects of surface oxides. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] FIG1 is a schematic structural diagram of a device for arc additive manufacturing of magnesium and aluminum dissimilar metals in a first embodiment of the present invention.

[0030] FIG2 is a schematic diagram of welding wire distribution in the first embodiment of the present invention.

[0031] FIG3 is a schematic diagram of the operation of a method for arc additive manufacturing of magnesium and aluminum dissimilar metals in a second embodiment of the present invention.

[0032] Explanation of the accompanying symbols: 1. TIG welding gun; 2. MIG welding gun; 3. Wire feeding mechanism; 4. First sliding sleeve; 5. Arc guide rail; 6. Second sliding sleeve; 7. First positioning screw; 8. Second positioning screw; 9. Third positioning screw; 10. Aluminum substrate; 11. Magnesium substrate; 12. Aluminum alloy weld; 13. Zinc alloy weld; 14. Magnesium alloy weld. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] Example 1

[0035] As shown in Figures 1 and 2 , a device for arc additive manufacturing of dissimilar metals including magnesium and aluminum includes a TIG welding gun 1 and a MIG welding gun 2 that work in conjunction with each other. The end of the MIG welding gun 2 has three independent wire feeders 3, with the welding wires in the three wire feeders 3 arranged sequentially between the TIG welding gun 1 and the MIG welding gun 2.

[0036] The TIG welding gun 1 and the MIG welding gun 2 are connected using an adjustable structure, ensuring both adjustable relative positions and synchronization between the two guns. Specifically, a first sleeve 4 is slidably mounted on the TIG welding gun 1, and a first positioning screw 7 is mounted on the first sleeve 4 for positioning the first sleeve 4 on the TIG welding gun 1. The first sleeve 4 is fixedly connected to an arcuate guide rail 5, and a second sleeve 6 is slidably mounted on the arcuate guide rail 5, and a second positioning screw 8 is mounted on the second sleeve 6 for positioning the second sleeve 6 on the arcuate guide rail 5. The MIG welding gun 2 is rotatably mounted on the second sleeve 6, and a third positioning screw 9 is mounted on the second sleeve 6 for positioning the MIG welding gun 2 on the second sleeve 6. The MIG welding gun 2 can slide along the arcuate guide rail 5 to adjust the wire feed angle, and can also tilt and rotate to change the distance between the welding wire and the tungsten electrode of the TIG welding gun 1. The height of the welding wire can be adjusted by sliding the TIG welding gun 1 and the arcuate guide rail 5 up and down.

[0037] As shown in Figure 2 , the welding wires in the three wire feed mechanisms 3 in this embodiment are arranged in an equilateral triangle and can be positioned using a guide block with three holes. Each wire is independently controlled by the wire feed mechanism 3, allowing for separate feeding. The wire closest to the TIG welding gun 1 and the wire closest to the MIG welding gun 2 are connected to the welding power source; the wire in the middle is not connected to the welding power source and is used only for wire feeding.

[0038] In this embodiment, the three wire feed mechanisms 3 each contain an aluminum alloy wire, a magnesium alloy wire, and a zinc alloy wire. During welding, the MIG welding gun 2 uses reverse DC connection, while the TIG welding gun 1 uses forward DC connection. The welding ends of the aluminum substrate 10 and the magnesium substrate 11 are butted together. The aluminum alloy wire is positioned on the aluminum substrate 10, the magnesium alloy wire is positioned on the magnesium substrate 11, and the zinc alloy wire is positioned between the aluminum and magnesium alloy wires and on the magnesium substrate 11. During welding, the zinc alloy wire is positioned farther from the TIG welding gun 1 than the magnesium alloy wire in the welding direction.

[0039] Example 2

[0040] As shown in FIG3 , based on the above-mentioned embodiment 1, a method for arc adding magnesium and aluminum dissimilar metals includes the following steps:

[0041] Step S1: Select magnesium alloy welding wire, aluminum alloy welding wire, and zinc alloy welding wire suitable for material addition, and install the magnesium alloy welding wire, aluminum alloy welding wire, and zinc alloy welding wire to three wire feeding mechanisms 3 respectively;

[0042] Step S2: using chemical reagents to remove the oxide film on the aluminum substrate 10 and the magnesium substrate 11, splicing the aluminum substrate 10 and the magnesium substrate 11 together by welding their ends, and then cleaning the surfaces of the aluminum substrate 10 and the magnesium substrate 11 with acetone;

[0043] Step S3: Adjust the positions of the TIG welding gun 1 and the MIG welding gun 2 so that after welding, the aluminum alloy weld bead 12 is located on the aluminum substrate 10, the magnesium alloy weld bead 14 is located on the magnesium substrate 11, and the zinc alloy weld bead 13 is located between the aluminum alloy weld bead 12 and the magnesium alloy weld bead 14 and on the magnesium substrate 11.

[0044] Step S4 controls the TIG welding gun 1 and the MIG welding gun 2 to move along the weld to complete the additive magnesium-zinc-aluminum operation.

[0045] This invention uses TIG-MIG hybrid welding to simultaneously add magnesium, zinc, and aluminum to a substrate. During welding, zinc prevents direct contact between the two metals, preventing the formation of brittle intermetallic compounds and improving the strength of the dissimilar magnesium-aluminum welded joint. This invention improves the efficiency of dissimilar magnesium-aluminum welding while maintaining the quality of the welded joint, demonstrating its potential for significant production applications.

[0046] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A device for arc material addition of magnesium and aluminum dissimilar metals, characterized in that: The invention comprises a TIG welding gun (1) and a MIG welding gun (2) which are used in conjunction with each other. The end of the MIG welding gun (2) is provided with three wire feeding mechanisms (3). The welding wires in the three wire feeding mechanisms (3) are arranged in sequence between the TIG welding gun (1) and the MIG welding gun (2).

2. The device for arc material addition of magnesium and aluminum dissimilar metals according to claim 1, characterized in that: A first sliding sleeve (4) is slidably mounted on the TIG welding gun (1); the first sliding sleeve (4) is fixedly connected to an arc-shaped guide rail (5); a second sliding sleeve (6) is slidably mounted on the arc-shaped guide rail (5); and the MIG welding gun (2) is rotatably mounted on the second sliding sleeve (6).

3. The device for arc material addition of magnesium and aluminum dissimilar metals according to claim 2, characterized in that: The first sliding sleeve (4) is provided with a first positioning screw (7) for positioning the first sliding sleeve (4) on the TIG welding gun (1); the second sliding sleeve (6) is provided with a second positioning screw (8) for positioning the second sliding sleeve (6) on the arc guide rail (5); and the second sliding sleeve (6) is also provided with a third positioning screw (9) for positioning the MIG welding gun (2) on the second sliding sleeve (6).

4. The device for arc material addition of magnesium and aluminum dissimilar metals according to claim 1, characterized in that: The welding wires in the three wire feeding mechanisms (3) are distributed in an equilateral triangle; the welding wires close to the TIG welding gun (1) and the welding wires close to the MIG welding gun (2) are connected to a welding power source, and the welding wires in the middle are not connected to a welding power source; the MIG welding gun (2) uses a direct current reverse connection, and the TIG welding gun (1) uses a direct current forward connection.

5. The device for arc material addition of magnesium and aluminum dissimilar metals according to claim 4, characterized in that: The welding wires in the three wire feeding mechanisms (3) are respectively aluminum alloy welding wire, magnesium alloy welding wire and zinc alloy welding wire; During welding, the welding end faces of the aluminum substrate (10) and the magnesium substrate (11) are butted, the aluminum alloy welding wire is located on the aluminum substrate (10), the magnesium alloy welding wire is located on the magnesium substrate (11), and the zinc alloy welding wire is located between the aluminum alloy welding wire and the magnesium alloy welding wire and on the magnesium substrate (11).

6. A method for arc material addition of magnesium and aluminum dissimilar metals, using the device for arc material addition of magnesium and aluminum dissimilar metals as claimed in any one of claims 1 to 5, characterized in that: The steps include: Step S1: installing the magnesium alloy welding wire, the aluminum alloy welding wire, and the zinc alloy welding wire to three wire feeding mechanisms (3) respectively; Step S2: pre-treating the aluminum substrate (10) and the magnesium substrate (11), and splicing the aluminum substrate (10) and the magnesium substrate (11) together at their welding ends; Step S3: adjusting the positions of the TIG welding gun (1) and the MIG welding gun (2) so that after welding, the aluminum alloy weld bead (12) is located on the aluminum substrate (10), the magnesium alloy weld bead (14) is located on the magnesium substrate (11), and the zinc alloy weld bead (13) is located between the aluminum alloy weld bead (12) and the magnesium alloy weld bead (14) and on the magnesium substrate (11); Step S4 controls the TIG welding gun (1) and the MIG welding gun (2) to move along the weld to complete the additive magnesium-zinc-aluminum operation.

7. A method for arc material addition of magnesium and aluminum dissimilar metals according to claim 6, characterized in that: In the step S2, pre-treating the aluminum substrate (10) and the magnesium substrate (11) comprises: using a chemical reagent to remove oxide films on the aluminum substrate (10) and the magnesium substrate (11), splicing the aluminum substrate (10) and the magnesium substrate (11) together, and then cleaning the surfaces of the aluminum substrate (10) and the magnesium substrate (11) with acetone.

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