Narrow-gap laser-MIG composite welding device for thick titanium alloy plate and using method of narrow-gap laser-MIG composite welding device

Abstract

The invention discloses a thick plate titanium alloy narrow gap laser-MIG hybrid welding device which is characterized by comprising a hybrid welding head module, a magnetic field regulation and control module, a double-oscillation collaboration module and an integrated protection module. The composite welding head module comprises an MIG welding gun and a laser gun head; the magnetic field regulation and control module comprises a magnetic field generation device arranged on the outer side of the MIG welding gun in a sleeving mode and a magnetic conduction rod stretching into the narrow gap groove, and the end of the magnetic conduction rod is parallel to the horizontal direction and is centered with the front end of the welding wire. According to the narrow-gap laser-MIG hybrid welding device for the thick titanium alloy plate and the using method of the narrow-gap laser-MIG hybrid welding device, an alternating magnetic field is introduced, electric arcs swing periodically and achieve precise cooperation with laser beam oscillation scanning motion, and on the premise that the welding quality is guaranteed, the welding efficiency is greatly improved. Efficient and high-quality welding of the thick plate titanium alloy narrow-gap connector is achieved, and the method has the remarkable advantages of being high in efficiency, low in material consumption, low in defect rate and the like.

Description

Technical Field

[0001] This invention relates to the technical field of metal welding, specifically to a laser-MIG hybrid welding device for narrow gap welding of thick titanium alloy plates and its application method. Background Technology

[0002] In recent years, with the development of major high-end equipment such as aerospace vehicles, special land vehicles, and deep-sea pressure-resistant submersibles towards larger size, lighter weight, and stronger protection, the demand for large, thick-plate titanium alloy components has become increasingly urgent. Welding is a core technology in the manufacture of thick-plate structures. Breakthroughs in reliable and efficient welding technology for large, thick-plate titanium alloy components will contribute to the realization of lightweight design for titanium alloy components.

[0003] Currently, thick titanium alloy plates are mainly welded using arc welding (TIG welding, MIG welding), which requires prefabricated bevels and multi-layer, multi-pass welding. (Refer to...) Figure 1 Currently, there are two main types of bevel designs in the welding field, fundamentally different in angle and gap width, which directly lead to their respective advantages and disadvantages in welding performance, efficiency, and defect control. Among them, the traditional large-angle bevel ( Figure 1 -a) The large operating space makes it easier for the welding torch or welding gun to enter, and the requirements for the size and oscillation of the welding torch are low. The larger angle makes it easier for the arc or laser to irradiate the sidewall, and the risk of sidewall non-fusion is low.

[0004] However, traditional large-angle beveling is inefficient and costly; it requires a large amount of filler metal, necessitating the melting of a large quantity of welding material to fill the wide bevele, and involves numerous welding passes, resulting in time-consuming, labor-intensive, and low production efficiency. In contrast, narrow-gap, small-angle beveling... Figure 1 -b) Fewer welding passes (dashed lines in the diagram represent welding passes), including less filler metal and a smaller bevel cross-sectional area, significantly saving welding wire and materials and reducing costs. Furthermore, lower heat input, less total weld metal, reduced residual stress and deformation, and superior microstructure and properties.

[0005] However, the efficiency of existing narrow-gap TIG welding and laser welding is still insufficient to meet the demand for high-efficiency welding of thick titanium alloy plates. These two technologies also have limitations in weld quality: TIG welding has a large heat input and low welding efficiency; laser welding has a fast cooling rate, which easily leads to porosity defects. Furthermore, narrow-gap welding commonly results in sidewall incomplete fusion.

[0006] Currently, CN119820115A, "Externally Magnetic Field Assisted Laser-MIG Hybrid Welding Method for Duplex Stainless Steel," introduces an alternating magnetic field into laser-MIG hybrid welding. This magnetic field controls the arc morphology, droplet transfer, and molten pool flow, and is applied to duplex stainless steel. However, the high viscosity of the titanium alloy molten pool and the difficulty in bubble escape make it difficult to apply to thick-plate titanium alloys. CN201310039463.4, "Laser-TIG Arc Off-Axial Hybrid Welding Method and Apparatus with Externally High-Frequency Magnetic Field," discloses a high-frequency magnetic field that enhances molten pool flow and refines grains, thus helping to improve weld formation. However, it uses a TIG arc and only relies on a single magnetic field for control, therefore it cannot solve the matching problem between MIG droplet transfer and narrow gap space.

[0007] Although narrow-gap laser-MIG hybrid welding has high cladding efficiency and fast welding speed, problems such as porosity and sidewall incomplete fusion still exist in the welding of thick titanium alloy plates. Therefore, this application provides a new solution. Summary of the Invention

[0008] This application provides a laser-MIG hybrid welding device for narrow gap welds of thick titanium alloys and its method of use. By introducing an alternating magnetic field, the electric arc is made to oscillate periodically and achieve precise coordination with the oscillating scanning motion of the laser beam. Under the premise of ensuring welding quality, this application realizes efficient and high-quality welding of narrow gap joints of thick titanium alloys, with significant advantages such as high efficiency, low material consumption and low defect rate.

[0009] This application provides a narrow-gap laser-MIG hybrid welding device for thick titanium alloy plates, comprising a hybrid welding head module, a magnetic field control module, a dual-oscillation coordination module, and an integrated protection module. The hybrid welding head module includes a MIG welding torch and a laser torch head. The magnetic field control module includes a magnetic field generating device sleeved on the outside of the MIG welding torch and a magnetic guide rod extending into the narrow-gap groove, the end of which is parallel to the horizontal direction and centered with the welding wire tip. The dual-oscillation coordination module includes an excitation power supply connected to the magnetic field generating device and a laser connected to the laser torch head. The laser torch head controls the laser beam to perform a Z-shaped oscillation scan. The excitation power supply is an alternating current; the excitation frequency of the excitation power supply is coupled to the oscillation frequency of the laser beam. The integrated protection module includes a gas protection shield, which has a groove for accommodating the magnetic guide rod.

[0010] By adopting the above technical solution, this application introduces an external alternating magnetic field to actively regulate the periodic oscillation of the electric arc, enabling it to precisely sweep the side walls of the narrow gap bevel, thereby optimizing the energy distribution within the bevel. Simultaneously, the oscillating electric arc and oscillating laser are coordinated to achieve precise coupling of the electric arc and laser as dual heat sources, effectively solving the problem of incomplete fusion of the side walls in narrow gap welding. Furthermore, the synergistic effect of magnetic field electromagnetic stirring and laser beam stirring enhances the flow of the molten pool, promotes bubble escape, and significantly reduces the porosity tendency in titanium alloy welding. In this application, the excitation frequency and oscillation frequency are integer multiples of each other, achieving periodic superposition of energy, which in turn multiplies the molten pool disturbance frequency, increases the bubble escape velocity, and reduces the occurrence of porosity in thick titanium alloy plates.

[0011] Preferably, the MIG welding torch axis forms an angle β of 55°–58° with the horizontal direction, the laser gun head axis forms an angle α of 12°–15° with the vertical direction, and the two axes are fixed at an angle γ of 45°.

[0012] By adopting the above technical solution, the tilt angle combination allows the laser beam to guide the molten pool first, and the electric arc to fill the wire later, avoiding heat source interference in the narrow gap, improving the consistency of the melt depth, and helping to accurately control the arc oscillation amplitude.

[0013] Preferably, in the magnetic field control module, the magnetic field generating device includes a magnetic head housing, a magnetic core, and an excitation coil; both the magnetic head housing and the magnetic core are made of non-magnetic materials; the excitation coil is wound around the outside of the magnetic core and placed inside the magnetic head housing; the number of turns of the excitation coil ranges from 5 to 400 turns.

[0014] By adopting the above technical solution, non-magnetic materials block the leakage of magnetic field, and magnetic lines of force act on the welding area through the magnetic rod, which reduces the energy consumption of arc control and improves welding stability; and the number of turns of the excitation coil meets the requirements of strong magnetic field for thick plates, which helps to achieve efficient and high-quality welding.

[0015] Preferably, in the magnetic field control module, the magnetic guide rod is made of a magnetically conductive material, the magnetic guide rod is mechanically connected to the magnetic head housing, and the length of the magnetic guide rod is adapted to the narrow gap bevel depth; the center line of the magnetic guide rod is parallel to the welding direction.

[0016] By adopting the above technical solution, the constraint ensures that the maximum gradient of the magnetic field acts on the root of the electric arc, eliminating the blind zone of sidewall fusion.

[0017] Preferably, the excitation frequency fm of the excitation power supply is 50–200Hz; the oscillation frequency fL of the laser beam is 100–200Hz, satisfying fL=n×fm, where n is a positive integer.

[0018] On the other hand, this application discloses a method of using a narrow-gap laser-MIG composite welding device for thick titanium alloy plates, including the following steps: S1: Select filler wire material according to the titanium alloy grade and thickness; process the workpiece to be welded with a blunt edge bevel with steps; mechanically grind or laser clean the bevel of the workpiece to be welded and the area around the welding area, and fix it to the welding worktable using a clamp; S2: Align the lens of the high-speed camera with the bevel gap of the titanium alloy test plate horizontally, and maintain a distance of 0.5 to 0.8 m from the composite welding head module; S3: Adjust the robotic arm so that the MIG welding gun in the composite welding head module forms an angle β with the horizontal direction, and the laser gun head forms an angle α with the vertical direction. S4. Fix the included angle γ of the axis; move the robotic arm so that the end of the magnetic rod in the magnetic field generator is parallel to the horizontal direction and the welding direction, and aligned with the front end of the welding wire; connect the gas shielding shroud and the MIG welding torch through the clamp, and embed the magnetic rod into the groove at the front end of the gas shielding shroud; S5. Synchronously start the magnetic field generator and laser oscillation scanning and control parameters, then the high-speed camera monitors the arc oscillation trajectory in real time, and adjusts the excitation frequency so that the arc amplitude covers the bevel sidewall; first, perform the root pass welding, using laser welding to weld the blunt edge bevel, then perform the fill pass welding, using a composite welding head module; after the fill pass welding is completed, clean the weld bead, then adjust the main parameters, repeat the fill pass welding until the weld is filled, and the welding is completed.

[0019] Preferably, in step S1, the shape of the blunt edge bevel includes a blunt edge V-shaped bevel and a blunt edge U-shaped bevel.

[0020] Preferably, in step S1, the thickness of the workpiece to be welded is in the range of 15 to 100 mm. The workpiece to be welded is pre-made by mechanical processing, and the bevel is a blunt edge U-shaped bevel with a blunt edge of 6-8 mm and a U-shaped bevel angle of 3° to 15°.

[0021] Preferably, in step S5, the welding uses a high-power single laser welding to perform deep penetration welding on the blunt edge of the U-shaped groove, with single-sided welding and double-sided forming; the welding laser power is 5-7kW, the welding speed is 1-1.5m / min, the shielding gas flow rate is 18-20L / min, the shielding gas type is argon with a purity of 99.99%, and the defocusing amount is 0-5mm.

[0022] Preferably, in step S5, the filler welding adopts magnetron-controlled narrow-gap oscillating laser-MIG hybrid welding, with a laser power of 1 to 3.5 kW, a laser oscillation mode of "Z", a laser oscillation frequency of 100 to 200 Hz, a laser oscillation amplitude of 1 to 4 mm, a welding speed of 0.8 to 1 m / min, a welding current of 150 to 300 A, an excitation current of 5 to 35 A, an excitation frequency of 50 to 200 Hz, and a shielding gas of 99.99% purity argon.

[0023] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0024] 1. This invention introduces an external alternating magnetic field to actively regulate the periodic oscillation of the electric arc, enabling it to precisely sweep across the two side walls of the narrow gap groove, thereby optimizing the energy distribution within the groove; at the same time, the oscillating electric arc and the oscillating laser are coordinated to achieve precise coupling of the electric arc and the laser as dual heat sources, effectively solving the problem of incomplete fusion of the side walls in narrow gap welding; by controlling the electric arc with an external magnetic field and stabilizing the keyhole with the oscillating laser, dynamic and stable high-efficiency narrow gap welding is achieved.

[0025] 2. This invention enhances the flow of the molten pool and promotes the escape of bubbles through the synergistic effect of magnetic field electromagnetic stirring and laser beam stirring, thus significantly reducing the tendency of titanium alloy welding to produce porosity.

[0026] 3. This invention utilizes the stirring effect of coupled dual fields to break dendrites, promote nucleation, refine grains, and reduce α' martensite, thereby improving the uniformity of weld structure and mechanical properties.

[0027] 4. This invention uses a magnetic field generating device and a wide-range adjustable excitation power supply, which can quickly optimize key parameters such as magnetic field strength and frequency, and is simple and flexible to operate. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the narrow gap in the thick titanium alloy plate in this application;

[0030] Figure 2 This is a schematic diagram of the structure of a magnetron-controlled narrow-gap oscillating laser-MIG composite welding device for thick-plate titanium alloys provided by the present invention.

[0031] Figure 3 This is a schematic diagram showing the relative positions of the MIG welding torch and the laser torch head provided by the present invention;

[0032] Figure 4 This is a schematic diagram of the structure and arrangement of the MIG welding torch, magnetic field generating device and excitation power supply provided by the present invention;

[0033] Figure 5 This is a schematic diagram of arc oscillation and oscillating laser under the action of an alternating magnetic field provided by the present invention.

[0034] Explanation of reference numerals in the attached drawings: 1. MIG welding torch; 2. Laser torch head; 3. Magnetic field generator; 4. Welding wire; 5. Laser beam; 6. Electric arc; 7. Workpiece to be welded; 8. Welding worktable; 12. Gas protective cover; 14. High-speed camera; 31. Magnetic head housing; 32. Magnetic core; 33. Excitation coil; 34. Magnetic guide rod. Detailed Implementation

[0035] This application provides a method for using a laser-MIG hybrid welding apparatus for narrow gap welds of thick titanium alloys. By introducing an alternating magnetic field, the electric arc is made to oscillate periodically, and this oscillation is precisely coordinated with the laser beam's scanning motion. This actively optimizes the energy distribution of the narrow gap sidewalls, effectively solving the problem of poor sidewall fusion. Simultaneously, the stirring effect of the coupled magnetic field (electromagnetic stirring) and the laser (beam stirring) on ​​the molten pool achieves synergistic control of the molten pool flow field, significantly promoting bubble escape and suppressing porosity defects. This invention achieves highly efficient and high-quality welding of narrow gap joints in thick titanium alloys while ensuring welding quality, exhibiting significant advantages such as high efficiency, low material consumption, and low defect rate.

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or server that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or modules not explicitly listed or inherent to such processes, methods, products, or devices.

[0038] This embodiment provides a laser-MIG composite welding device for narrow gap welding of thick titanium alloy plates. Specifically, the laser-MIG composite welding device includes a composite welding head module, a magnetic field control module, a dual oscillation coordination module, and an integrated protection module.

[0039] like Figure 2As shown, the composite welding head module includes a MIG welding torch 1 and a laser torch 2. Specifically, the MIG welding torch provides an arc 6 heat source to melt the welding wire 4 and fill the bevel. The arc 6 oscillates periodically under an alternating magnetic field, while the laser torch 2 emits an oscillating laser beam 5 that penetrates the blunt edge of the bevel and stabilizes the molten pool through a zigzag scanning of the beam.

[0040] Combination Figure 4 The magnetic field control module includes a magnetic field generating device 3 sleeved on the outside of the MIG welding torch 1 and a magnetic guide rod 34 extending into the narrow gap groove.

[0041] Furthermore, in the magnetic field control module, the magnetic field generating device 3 includes a magnetic head housing 31, a magnetic core 32, and an excitation coil 33. Both the magnetic head housing 31 and the magnetic core 32 are made of non-magnetic materials. The excitation coil 33 is wound around the outside of the magnetic core 32 and placed inside the magnetic head housing 31. It is worth noting that the number of turns of the excitation coil 33 ranges from 5 to 400 turns.

[0042] In addition, the magnetic guide rod 34 is made of magnetically conductive material. One end of the magnetic guide rod 34 is fixed to the magnetic head housing 31, and the other end of the magnetic guide rod 34 extends into the narrow gap bevel, with the length of the magnetic guide rod 34 adapted to the depth of the narrow gap bevel. Furthermore, the end of the magnetic guide rod 34 is parallel to the horizontal direction and centered with the front end of the welding wire 4.

[0043] In addition, the dual-oscillation coordination module includes an excitation power supply connected to the magnetic field generator 3 and a laser (not shown in the figure) connected to the laser gun head 2. Then, the laser beam 5 is used to perform Z-shaped oscillation scanning through the laser gun head 2.

[0044] In addition, the integrated protection module includes a gas protection cover 12, which has a groove for accommodating the magnetic rod 34.

[0045] Reference Figure 2 The laser-MIG hybrid welding device also includes a welding worktable 8, and before the workpiece 7 to be welded is subjected to magnetron narrow gap laser-MIG hybrid welding, a clamp should be used to fix the workpiece 7 to be welded on the welding worktable 8.

[0046] In addition, the laser-MIG hybrid welding device also includes a high-speed camera 14, which is set on one side of the MIG welding torch. The lens of the high-speed camera 14 is positioned opposite to the bevel gap of the workpiece 7 to be welded. The lens of the high-speed camera 14 is horizontal with the workpiece 7 to be welded, and the distance between the lens of the high-speed camera 14 and the laser-MIG hybrid welding module is 0.5m. The high-speed camera 14 is equipped with a clamp, and the welding process can be synchronously acquired by adjusting its position. In addition, the high-speed camera 14 is connected to a computer.

[0047] In addition, the workpiece 7 to be welded is made of titanium alloy, and there is no limitation on the grade of titanium alloy. The thickness of the workpiece 7 to be welded ranges from 15 to 100 mm. The workpiece 7 to be welded is pre-formed by machining. The bevel type is a blunt edge U-shaped bevel. The blunt edge of the bevel is set to 6-8 mm. The blunt edge meets the front and back forming requirements of high-power single laser-MIG welding root pass. The U-shaped bevel angle is 3° to 15°. The root radius of the U-shaped bevel is determined according to the actual plate thickness and the narrow gap bevel angle, and there is no special limitation.

[0048] The MIG welding torch 1 and the laser torch head 2 are assembled into a laser-MIG composite welding head; such as Figure 3 As shown, the angle γ formed by the axes of the MIG welding torch 1 and the laser gun head 2 is 45°. The robotic arm is adjusted so that the angle β between the axis of the MIG welding torch 1 and the horizontal direction is 55°, and the angle α between the axis of the laser gun head 2 and the vertical direction is 12°.

[0049] The workpiece 7 to be welded and the MIG welding torch 1 are respectively connected to the positive and negative terminals of the MIG welding power source to introduce the arc 6 heat source and welding wire 4 into the narrow gap bevel of the workpiece 7 to be welded; the laser torch head 2 is a galvanometer laser torch head 2. Specifically, the laser is a fiber laser; the laser torch head 2 is connected to the laser through a flexible optical fiber to emit a periodically oscillating laser beam 5 into the narrow gap bevel of the workpiece 7 to be welded.

[0050] The magnetic head housing 31 in the magnetic field generating device 3 is made of aluminum alloy. In this embodiment, the excitation coil 33 has 400 turns, the magnetic core 32 is made of aluminum alloy, and the magnetic rod 34 is made of magnetically conductive pure iron.

[0051] like Figure 4 As shown, the excitation coil 33 is wound around the outside of the magnetic core 32 and placed inside the magnetic head housing 31. The magnetic guide rod 34 is mechanically fixed to the magnetic head housing 31. The size of the magnetic guide rod 34 is based on the standard that it can be inserted into the narrow gap bevel of the workpiece 7 to be welded, and there is no specific size limit. The end of the magnetic guide rod 34 is parallel to the horizontal direction and is aligned with the end of the welding wire 4.

[0052] The magnetic field generating device 3 is mounted on the outside of the MIG welding torch 1. The magnetic core 32 is concentrically interference-fitted with the torch handle of the MIG welding torch 1 and is fixed with set screws.

[0053] Connect the two terminals on the magnetic field generator 3 to the positive and negative terminals of the excitation power supply using wires, such as... Figure 4 As shown.

[0054] The excitation power supply outputs alternating current, which generates an alternating magnetic field through the magnetic field generator 3. The magnetic rod 34 is introduced into the welding area within the narrow gap groove.

[0055] Within the narrow bevel of the workpiece 7 to be welded, the alternating magnetic field causes the electric arc 6 to oscillate periodically. The oscillation frequency of the electric arc 6 is the same as or a multiple of the oscillation frequency of the laser beam 5 (achieving arc-light coupling), thus optimizing the energy distribution within the bevel. Figure 5 As shown, the stirring effect of the magnetic field and laser beam 5 intensifies the flow of the weld pool.

[0056] The gas shield shroud 12 and the MIG welding torch 1 are fixed by the clamp on the shroud. After clamping, the magnetic rod 34 is embedded in the groove at the front end of the gas shield shroud 12. The gas inlet of the gas shield shroud 12 is connected to the outlet of the argon cylinder by a gas guide tube to achieve synchronous inert gas protection during the welding process.

[0057] On the other hand, embodiments of the present invention also disclose a magnetically controlled narrow-gap oscillating laser-MIG hybrid welding method for thick plate titanium alloys, comprising the following steps:

[0058] Step 1: Select national standard TC4 titanium alloy for material, thickness 30mm, and filler material selection. TC4 titanium alloy welding wire.

[0059] Step 2: Machin the 30mm thick titanium alloy test plate into a blunt-edged U-shaped bevel. The blunt edge of the bevel is set to 8mm, the U-shaped bevel angle is 6°, and the root radius of the U-shaped bevel is 3mm. This bevel design will significantly reduce the filling area and greatly improve welding efficiency.

[0060] Step 3: Before welding, mechanically grind or laser clean the bevel and surrounding welding area to remove surface oil and oxide film. After cleaning, use a clamp to fix the test plate on the welding worktable.

[0061] Step 4: Set up a high-speed camera on one side of the laser-MIG composite welding head, align the lens of the high-speed camera with the bevel gap of the titanium alloy test plate horizontally, and the distance between the lens of the high-speed camera and the laser-MIG composite welding head is 0.5 to 0.8 m, and connect it to the computer.

[0062] Step 5: Since the test plate thickness is >16mm, the MIG welding torch nozzle needs to be replaced with a special slender nozzle for narrow gap welding. After replacement, adjust the position and posture of the laser-MIG composite welding head to ensure that the MIG welding torch axis forms an angle β of 55° with the horizontal direction and the laser torch head axis forms an angle α of 12° with the vertical direction.

[0063] Step 6: Move the robotic arm to extend the magnetic rod in the magnetic field generator into the narrow gap bevel, with the end of the magnetic rod parallel to the horizontal direction and the welding direction, and aligned with the front end of the welding wire; connect the gas shielding shroud and the MIG welding torch through the clamp, and embed the magnetic rod into the groove at the front end of the gas shielding shroud; check the operating status of the shielding gas and welding equipment.

[0064] Step 7: For the root pass welding, a high-power single laser welder is used to perform deep penetration welding on the blunt edge of the U-shaped bevel, with single-sided welding and double-sided forming. The laser power for the root pass welding is 5-7kW, the welding speed is 1-1.5m / min, the shielding gas flow rate is 18-20L / min, the shielding gas type is 99.99% pure argon, and the defocusing amount is 0-5mm.

[0065] Step 8: The filler welding adopts magnetron-controlled narrow gap oscillating laser-MIG hybrid welding, with laser power of 1 to 3.5 kW, laser oscillation mode of "Z" shape, laser oscillation frequency of 100 to 200 Hz, laser oscillation amplitude of 1 to 4 mm, welding speed of 0.8 to 1 m / min, welding current of 150 to 300 A, excitation current of 5 to 35 A, excitation frequency of 50 to 200 Hz, and shielding gas of 99.99% purity argon.

[0066] Specifically, the excitation power supply is an alternating current with an excitation frequency fm of 50–200Hz; the laser oscillation frequency fL is 100–200Hz, satisfying fL=n×fm (n is a positive integer).

[0067] Step 9: After each layer is filled, clean the weld bead. Move the laser-MIG composite welding head upward to the standard pre-welding position. Adjust the welding parameters and excitation parameters according to the welding process captured by the high-speed camera to prepare for welding the next layer. Finally, the cover welding can increase the oscillation amplitude of the arc and laser beam to avoid undercut defects on the weld surface.

[0068] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims can be performed in a different order than that shown in the embodiments and still achieve the desired result. Additionally, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0069] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0070] This specification and accompanying drawings are merely illustrative examples of this application and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Therefore, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A laser-MIG hybrid welding device for narrow gap welding of thick titanium alloy plates, characterized in that, It includes a composite welding head module, a magnetic field control module, a dual oscillation coordination module, and an integrated protection module; The composite welding head module includes a MIG welding gun (1) and a laser gun head (2); The magnetic field control module includes a magnetic field generating device (3) sleeved on the outside of the MIG welding torch (1) and a magnetic guide rod (34) extending into the narrow gap groove. The end of the magnetic guide rod (34) is parallel to the horizontal direction and is centered with the front end of the welding wire (4). The dual-oscillation coordination module includes an excitation power supply connected to the magnetic field generator (3) and a laser connected to the laser gun head (2); the laser gun head (2) controls the laser beam (5) to perform Z-shaped oscillation scanning; the excitation power supply is an alternating current; the excitation frequency of the excitation power supply is coupled with the oscillation frequency of the laser beam (5); The integrated protection module includes a gas protection cover (12), which has a groove for accommodating a magnetic rod (34).

2. The laser-MIG hybrid welding apparatus for narrow gap thick titanium alloys as described in claim 1, characterized in that, The MIG welding torch (1) forms an angle β of 55°–58° with the horizontal direction, and the laser gun head (2) forms an angle α of 12°–15° with the vertical direction. The fixed angle γ between the two axes is 45°.

3. The laser-MIG hybrid welding apparatus for narrow gap thick titanium alloys as described in claim 1, characterized in that, In the magnetic field control module, the magnetic field generating device (3) includes a magnetic head housing (31), a magnetic core (32), and an excitation coil (33); the magnetic head housing (31) and the magnetic core (32) are both made of non-magnetic materials; the excitation coil (33) is wound around the outside of the magnetic core (32) and placed inside the magnetic head housing (31); the number of turns of the excitation coil (33) ranges from 5 to 400 turns.

4. The laser-MIG hybrid welding apparatus for narrow gap thick titanium alloys as described in claim 3, characterized in that, In the magnetic field control module, the magnetic rod (34) is made of magnetic material. The magnetic rod (34) is mechanically connected to the magnetic head shell (31), and the length of the magnetic rod (34) is adapted to the narrow gap bevel depth. The center line of the magnetic rod (34) is parallel to the welding direction.

5. The laser-MIG hybrid welding apparatus for narrow gap thick titanium alloys as described in claim 1, characterized in that, The excitation frequency fm of the excitation power supply is 50–200Hz; the oscillation frequency fL of the laser beam (5) is 100–200Hz, satisfying fL=n×fm, where n is a positive integer.

6. A method of using the laser-MIG hybrid welding apparatus for narrow gap welding of thick titanium alloy plates as described in any one of claims 1-5, characterized in that, The following steps are included: S1: Select filler wire (4) material according to titanium alloy grade and thickness; process the workpiece (7) to be welded with a blunt edge bevel with steps; mechanically grind or laser clean the bevel of the workpiece (7) to be welded and the area around the welding area, and use a clamp to fix it to the welding worktable (8). S2. Align the lens of the high-speed camera (14) with the gap between the bevel of the titanium alloy test plate horizontally, and maintain a distance of 0.5 to 0.8 m from the composite welding head module; S3. Adjust the robotic arm so that the MIG welding gun (1) in the composite welding head module forms an angle β with the horizontal direction, and the laser gun head (2) forms an angle α with the vertical direction, and the axes of the two are fixed at an angle γ. S4. Move the robotic arm so that the end of the magnetic rod (34) in the magnetic field generating device (3) is parallel to the horizontal direction and the welding direction, and is aligned with the front end of the welding wire (4); connect the gas shield (12) and the MIG welding gun (1) through the clamp, and embed the magnetic rod (34) into the front groove of the gas shield (12). S5. Simultaneously start the magnetic field generator (3) and laser oscillation scanning and control parameters. Then, the high-speed camera (14) monitors the arc (6) swing trajectory in real time and adjusts the excitation frequency so that the arc (6) amplitude covers the bevel sidewall. First, the root pass welding is performed using laser welding to weld the blunt edge bevel. Then, the fill pass welding is performed using a composite welding head module. After the fill pass welding is completed, the weld bead is cleaned, the main parameters are adjusted, and the fill pass welding is repeated until the weld is filled, thus completing the welding process.

7. The method of using the laser-MIG hybrid welding apparatus for narrow gap thick plate titanium alloys as described in claim 6, characterized in that; In step S1, the shape of the blunt edge bevel includes a blunt edge V-shaped bevel and a blunt edge U-shaped bevel.

8. The method of using the laser-MIG hybrid welding apparatus for narrow gap thick titanium alloys as described in claim 6, characterized in that, In step S1, the thickness of the workpiece (7) to be welded is 15 to 100 mm. The workpiece (7) to be welded is pre-made by mechanical processing. The bevel is a blunt edge U-shaped bevel with a blunt edge of 6-8 mm and a U-shaped bevel angle of 3° to 15°.

9. The method of using the laser-MIG hybrid welding apparatus for narrow gap thick titanium alloys as described in claim 6, characterized in that, In step S5, high-power single-laser welding is used to perform deep penetration welding on the blunt edge of the U-shaped groove, with single-sided welding and double-sided forming; the welding laser power is 5-7kW, the welding speed is 1-1.5m / min, the shielding gas flow rate is 18-20L / min, the shielding gas type is 99.99% pure argon, and the defocusing amount is 0-5mm.

10. The method of using the laser-MIG hybrid welding apparatus for narrow gap thick plate titanium alloys as described in claim 6, characterized in that, In step S5, the filler welding adopts magnetron-controlled narrow-gap oscillating laser-MIG hybrid welding, with a laser power of 1 to 3.5 kW, a laser oscillation mode of "Z", a laser oscillation frequency of 100 to 200 Hz, a laser oscillation amplitude of 1 to 4 mm, a welding speed of 0.8 to 1 m / min, a welding current of 150 to 300 A, an excitation current of 5 to 35 A, an excitation frequency of 50 to 200 Hz, and a shielding gas of 99.99% purity argon.

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