Laser center induction GTAW electric arc synchronous phase control additive manufacturing device and method

Abstract

The invention provides a laser center induction GTAW electric arc synchronous phase control additive manufacturing device and method, and belongs to the technical field of additive manufacturing devices. The device comprises a swinging laser head used for emitting a swinging laser heat source; the GTAW arc coaxial welding torch is provided with a plurality of tungsten electrodes arranged on the circumferential inner side of the laser heat source; the wire feeding mechanism is used for clamping a plurality of welding wires and feeding the welding wires into a molten pool or a GTAW electric arc specific position for stable melting; the laser head, the multi-GTAW electric arc coaxial welding torch and the wire feeding mechanism are fixed together and keep moving synchronously. The laser heat source and the multiple tungsten electrodes arranged on the inner side in the circumferential direction of the laser heat source form a composite large heat source, multi-arc stable control is achieved through stable induction of the laser heat source on multiple arcs, multi-wire stable melting and uniform spreading of liquid metal are achieved, high-quality and stable additive manufacturing is achieved, and the manufacturing cost is reduced. The technical problem of traditional manufacturing of large complex components is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing devices, and in particular to a laser center induced GTAW arc synchronous phase controlled additive manufacturing device and a method for additive manufacturing using the additive manufacturing device, wherein the number of GTAW arcs is n, and n≤4. Background Art

[0002] Additive manufacturing technology was developed in the late 1980s. Its principle is similar to calculus. It uses computer-aided design models and a planned path to manufacture solid parts by adding materials layer by layer. Different from traditional subtractive manufacturing technology, its forming process does not require molds or fixtures. It has outstanding characteristics such as high material utilization, short manufacturing cycle, suitable for complex components, and user-customized manufacturing. Since the development of additive manufacturing technology, more than ten different forming technologies have emerged. According to the physical properties and quantity of heat sources, commonly used metal solid additive manufacturing technologies can be divided into single heat source additive manufacturing technologies such as laser additive manufacturing, electron beam additive manufacturing and arc additive manufacturing, as well as composite additive manufacturing technologies with two or more heat sources. Arc additive manufacturing technology has higher deposition efficiency and lower cost, and can realize rapid forming of large-sized parts. It has become a hot topic for the localization of high-end equipment manufacturing in the fields of engineering machinery, rail transportation, aerospace, military industry, etc. Among them, GTAW arc is favored by researchers for its stability, small splashes in the manufacturing process, and low air pollution, but its low efficiency restricts its application in the manufacturing of large-sized components. At present, arc additive manufacturing of large components still uses a single heat source, with low metal deposition efficiency and long production cycle, which greatly limits the promotion and application of GTAW arc additive manufacturing technology in large components.

[0003] In recent years, in order to improve the efficiency of GTAW arc metal deposition, a variety of new GTAW composite heat sources have been derived based on the GTAW arc, including double tungsten electrode GTAW, triple tungsten electrode GTAW, hollow tungsten electrode-laser coaxial composite, laser-GTAW arc composite, laser-double GTAW arc composite, etc., and around the arc characteristics, droplet transition and molten pool morphology change characteristics, the mechanism of weld bead formation, deposition efficiency, and microstructure performance based on heat source energy output, positional relationship, melt state, etc. has been studied. It can be obtained that multi-arc coupling can reduce arc pressure, avoid the formation of undercut and hump welds during high-speed welding, and obtain good weld formation, which is extremely beneficial for composite heat source additive manufacturing. However, the above-mentioned composite heat sources are mostly used in welding forming manufacturing. How to obtain a stable "flat and wide" weld and realize efficient / high-quality additive manufacturing is still a technical problem for the manufacturing of large and complex components.

[0004] The composite heat source additive manufacturing process is a complex multi-physical field coupling process, involving complex metallurgical processes such as the interaction between the composite heat source and the melt, energy absorption and conversion, heat / mass transfer, and melt dynamics changes. The process parameters and boundary conditions have strong time-varying disturbances, involving multiple variables such as composite heat source coupling parameters, melt material feeding parameters, and related spatial position parameters. Among them, the composite heat source coupling parameters are the key factors for achieving efficient, high-quality, and customized forming of large and complex components. In recent years, relevant scholars have proposed laser-induced arc additive manufacturing technology, which is still based on a single arc. There are relatively many multi-heat source welding devices and technologies proposed for the welding field (such as a magnetic field-assisted multi-stage argon arc and laser center-coupled eutectic pool welding device disclosed in the patent with application number CN202110642113.1). The device aims to increase the welding penetration and realize one-time single-sided welding and double-sided forming of medium and thick plates. Three identical GTAW torches equipped with independent welding power supplies are evenly distributed around the laser welding head at an angle of 120 degrees to achieve central eutectic pool coupling welding. However, welding and additive manufacturing belong to two different technical fields, and the weld bead shapes they pursue are completely different, so they are not suitable for additive manufacturing.

[0005] In summary, existing additive manufacturing methods all use a single heat source or only a single low-power laser off-axis induced single arc composite heat source, which has the problems of low deposition efficiency and limited manufacturing of large parts. Summary of the invention

[0006] In view of this, in order to solve the technical problems of low deposition efficiency and limited manufacturing of large parts in the existing additive manufacturing, which are the single heat source or only a single low-power laser off-axis induced single arc composite heat source. On the one hand, the present invention provides a laser center-induced n GTAW arcs (n≤4) synchronous phase-controlled additive manufacturing device, which forms a composite large heat source by using a laser heat source and multiple tungsten electrodes arranged on the inner side of the laser heat source, and realizes stable control of multiple arcs through the stable induction of multiple arcs by the laser heat source, realizes stable melting of multiple wires and uniform spreading of liquid metal, realizes high-quality and stable additive manufacturing, and solves the traditional manufacturing technology problems of large and complex components.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A laser center induced GTAW arc synchronous phase control additive manufacturing device, comprising:

[0009] An oscillating laser head for emitting an oscillating laser heat source;

[0010] A GTAW arc coaxial welding torch having a plurality of tungsten electrodes and used for providing a GTAW arc, which is arranged on the circumferential inner side of the laser heat source;

[0011] A wire feeding mechanism, which is used to clamp a plurality of welding wires and feed the welding wires into a molten pool or a specific position of a GTAW arc for stable melting, and is arranged on the circumferential outer side of the laser heat source;

[0012] Among them, there are n GTAW arcs, n≤4;

[0013] The laser head, the GTAW arc coaxial welding torch and the wire feeding mechanism are fixed together to keep the three moving synchronously;

[0014] A plurality of the tungsten electrodes and a plurality of the welding wires are alternately and evenly arranged around the laser heat source along the circumferential direction, and a gap is formed between two adjacent tungsten electrodes. At least one welding wire can be arranged in any gap.

[0015] The coordinated control of the swing parameters of the laser heat source combined with the pulse parameters of the GTAW arc can stabilize the laser heat source at the center, guide multiple GTAW arcs, and induce multiple GTAW arcs to burn stably according to the swing law of the laser heat source.

[0016] Preferably, it also includes an annular housing with a water cooling channel arranged inside, a welding control cabinet and a laser controller;

[0017] Wherein, the laser head, the GTAW arc coaxial welding torch and the wire feeding mechanism are coaxially located inside the annular shell and fixedly connected to the annular shell;

[0018] The welding control cabinet is used to control the GTAW arc coaxial welding torch to start the arc, and control the wire feeding mechanism to feed the wire;

[0019] The laser controller is used to control the laser head to emit a laser beam as a laser heat source.

[0020] Preferably, the plurality of tungsten electrodes are arranged obliquely relative to the laser heat source, the plurality of tungsten electrodes are located on the same conical surface, and the central axis of the conical surface is coaxial with the laser heat source.

[0021] Preferably, the phase difference between the n GTAW arcs can be set through a control panel according to requirements.

[0022] Preferably, the swing parameters include a swing path, a swing frequency and a swing amplitude.

[0023] Preferably, the laser heat source sets the swing amplitude according to the position and spot size of the GTAW arc, so as to control the degree of effect on n GTAW arcs.

[0024] Preferably, the GTAW arc is a DC GTAW arc or a DC pulse GTAW arc.

[0025] On the other hand, the present invention also provides a method for manufacturing the above laser center induced GTAW arc synchronous phase controlled additive manufacturing device, comprising the following steps:

[0026] Step 1), select a substrate according to the size of the target metal structure, pre-treat the surface of the substrate, place it on a workbench, and clamp it with a fixture;

[0027] Step 2) establishing a three-dimensional model of the target metal structure, slicing and layering the three-dimensional model, and obtaining a processing path for additive manufacturing;

[0028] Step 3) Select welding wire and set the process parameters for additive manufacturing;

[0029] Step 4), the laser head is perpendicular to the substrate, and a plurality of tungsten electrodes are evenly distributed around the laser heat source, and then welding wires are arranged between any intervals of the tungsten electrodes;

[0030] Step 5), melting the welding wire fed into the molten pool according to the process parameters set in step 3) and spreading it on the substrate, and performing additive manufacturing according to the processing path in step 2) to obtain a target metal structure;

[0031] Step 6) Separate the substrate from the target metal structure by mechanical cutting.

[0032] The laser center induced n GTAW arcs (n≤4) synchronous phase control additive manufacturing device provided by the present invention adopts a laser heat source and multiple tungsten electrodes arranged on the inner side of the laser heat source to form a symmetrical composite heat source, and realizes stable control of multiple arcs through the stable induction of multiple arcs by the laser heat source, realizes stable melting of multiple wires and uniform spreading of liquid metal, realizes high-quality and stable additive manufacturing, and solves the traditional manufacturing technology problems of large and complex components. Compared with the existing technology, it has the following beneficial effects:

[0033] (1) The present invention adopts a laser center-induced GTAW arc synchronous phase control additive scheme, wherein there are n GTAW arcs, n≤4, and different multi-heat source matching modes can be obtained by setting the position parameters between the n GTAW arcs, the laser heat source and the n GTAW arcs, and utilizing the interaction between the arcs under different heat source spacings and the attraction and induction effect of the laser on the multiple arcs. For example, when the heat source spacing is small, the n GTAW arcs are coupled around the central laser beam to form a large heat source with one energy peak; when the heat source spacing is centered, the n GTAW arcs are combined around the central laser beam to form a large heat source with n+1 energy peaks and partial coupling; when the heat source spacing is large, the n GTAW arcs are combined around the central laser beam to form multiple heat sources with n+1 energy peaks and no coupling. The energy distribution and density of different heat source modes are different, which directly affects the heat / mass transfer, solution interaction and dynamic changes, resulting in different weld sizes. Any heat source matching mode can be selected according to application requirements.

[0034] (2) The phase difference of adjacent GTAW arcs is set by the control box, and the laser swing parameters are set by the swing laser setting software to achieve the different induction degrees and effective heat input of the center of n GTAW arcs with different wave periods (positive and negative half-waves, peaks and troughs) of the swing laser, resulting in differences in weld bead size. Therefore, the phase matching control of the composite heat source can be achieved by setting the phase difference and laser swing parameters to obtain beautiful weld bead formation.

[0035] (3) In addition, by combining the settings of n GTAW arc pulse parameters, including pulse current, basic current, pulse width, pulse interval time, pulse period and other parameters, the regular induction of pulse arc by swinging laser can be achieved. The use of pulse current can also reduce welding heat input, thereby reducing the deformation of additive samples and improving manufacturing accuracy.

[0036] (4) The wire feeding mechanism of the present invention is equipped with a three-dimensional steering head, which can realize three-dimensional adjustment of n welding wires (n≤4), and can feed the welding wire to any position of the molten pool using the molten pool hot fuse, or can be selected to feed the welding wire to any position of the electric arc using the arc hot fuse, thereby changing the transition form of the welding wire molten droplet to obtain an ideal weld formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the present invention;

[0038] In the figure, 1. oscillating laser head; 2. laser heat source; 3. GTAW arc coaxial welding torch; 4. tungsten electrode; 5. welding wire; 6. wire feeding mechanism; 7. molten pool; 8. annular shell. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "top / bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] like Figure 1 As shown, the present invention provides a laser center induced GTAW arc arc synchronous phase control additive manufacturing device, comprising:

[0043] An oscillating laser head 1, which is used to emit an oscillating laser heat source 2, the oscillating laser head 1 is preferably located at the center of the device, and can be preferably supported by a support column, wherein the material of the support column is preferably Q235 steel;

[0044] A GTAW arc coaxial welding torch 3, which has a plurality of tungsten electrodes 4 and is used to provide a GTAW arc, is arranged on the circumferential inner side of the laser heat source 2 to form a composite large heat source, and a GTAW arc at a specific position can be selected according to actual needs. The number of GTAW arc coaxial welding torches 3 is preferably n (n≤4), which is used to form n GTAW arcs (n≤4), and there are correspondingly n GTAW arc coaxial welding torches 3, n≤4;

[0045] A wire feeding mechanism 6, which is used to clamp a plurality of welding wires 5 and feed the welding wires 5 into a molten pool 7 or a specific position of a GTAW arc for stable melting, and is arranged on the circumferential outer side of the laser heat source 2, wherein the number of wire feeding mechanisms 6 is preferably n (n≤4);

[0046] Wherein, the GTAW arc coaxial welding torch 3 and the extended line of the normal line of the formed circular ring intersect on the extended line of the laser beam;

[0047] The laser head, n GTAW arc coaxial welding torches 3 and the wire feeding mechanism 6 are fixed together to keep the three moving synchronously;

[0048] A plurality of tungsten electrodes 4 and a plurality of welding wires 5 are alternately and evenly arranged around the laser heat source 2 along the circumferential direction, and a gap is formed between two adjacent tungsten electrodes 4. At least one welding wire 5 can be arranged in any gap.

[0049] The swing parameters of the laser heat source 2 combined with the regulation of the pulse parameters of the GTAW arc can achieve the stability of the laser heat source 2 in the center, guide multiple GTAW arcs, and induce multiple GTAW arcs to burn stably according to the swing law of the laser heat source 2. The swing parameters of the laser heat source 2 preferably include a swing path, a swing frequency, and a swing amplitude. Preferably, the laser heat source sets the swing amplitude according to the position and spot size of the GTAW arc to control the degree of action on n GTAW arcs. The GTAW arc is preferably a DC GTAW arc or a DC pulsed GTAW arc. By setting the swing parameters (swing path, swing frequency, swing amplitude) of the laser heat source 2 and combining with the regulation of the GTAW arc pulse parameters, the laser can be stabilized in the center, multiple arcs can be guided, and n GTAW arcs (n≤4) can be induced to burn stably according to the swing law of the laser heat source 2. On the one hand, it is preferred to set the swing amplitude of the laser heat source 2 according to the positional relationship of n GTAW (n≤4) to control the weld melting width, and utilize the arc stabilization and attraction effect of the laser heat source 2 on the GTAW arc in the center to maintain the stability of the large molten pool 7; on the other hand, the swing parameters of the laser heat source 2 can set the power, swing path, swing amplitude and swing frequency of the laser heat source 2, which is beneficial to the control of the coupling mode of the laser heat source 2 and the GTAW arc, and realize precise control of the weld forming effect.

[0050] The present invention realizes multi-arc distribution state control and adjustment of the feeding position of multiple welding wires 5 through the induction of the central laser heat source 2 and the synchronous phase regulation of n GTAW arcs (n≤4), so as to realize laser-multi-arc-multi-wire eutectic pool 7, and through the adjustment of the swing parameters of the laser heat source 2, not only the wire feeding speed of each welding wire 5 can be increased, the deposition efficiency can be improved, but also a "wide and shallow" stable single weld bead forming which is conducive to additive manufacturing can be obtained, thereby realizing mold-free, high-degree-of-freedom, customized forming of large and complex structural parts.

[0051] When the distance between n GTAW (n≤4) and laser heat source 2 is small, the energy of laser heat source 2 almost completely acts on n GTAW (n≤4), and the energy density is superimposed on each other. At this time, it can be coupled into a large heat source with energy peak value. At this time, the energy density and energy utilization rate are high, the fuse effect is the best, and a large fusion depth and large fusion width weld can be obtained;

[0052] When the distance between n GTAW (n≤4) and laser heat source 2 is moderate, the laser energy partially acts on n GTAW (n≤4), forming a composite large heat source with n+1 energy peaks. The energy density is relatively dispersed but has intersections. At this time, the energy density and energy utilization are moderate, and a weld with moderate penetration depth and width can be obtained.

[0053] When the distance between n GTAW (n≤4) and the laser heat source 2 is large, n+1 independent heat sources can be formed, and the energy density is relatively independent. At this time, the energy density and energy utilization rate are small, and a weld with small penetration depth and small penetration width can be obtained; therefore, the heat source mode can be set according to different application requirements to obtain the expected weld size.

[0054] The wire feeding mechanism 6 can simultaneously clamp n welding wires 5 and feed them into the molten pool 7 or a specific position of the GTAW arc to stably melt and spread on the substrate; the n welding wires 5 can be arbitrarily distributed along the circumference of the above-mentioned symmetrical composite heat source according to actual needs. Through the adjustment of n wire feeding mechanisms 6, combined with the multi-heat source energy setting, different fuse positions of any welding wire 5 can be achieved. The welding wire 5 can be adjusted to the front of the welding direction to achieve front wire feeding, and can also be adjusted to the rear of the welding direction to achieve rear wire feeding. The end of the welding wire 5 can be sent to the inside of the molten pool 7 to pass through the heat fuse of the molten pool 7, and can also be sent to the arc column area to pass through the arc heat fuse. Fuses at different positions can obtain different forming effects, and this can be selected according to actual needs;

[0055] The energy output of the swinging laser heat source 2 and n GTAW (n≤4) arcs can be controlled by setting the pulse parameters (pulse current, pulse period) of the GTAW arc and the arc phase. On the one hand, the peak current Im, peak time tm, base current Ij, and base time tj of any GTAW arc can be adjusted as needed, so that the n GTAW (n≤4) arcs are still in a synchronous pulse mode; on the other hand, through the phase setting between the n GTAW (n≤4), a phase difference can be made between adjacent arcs. Combined with the parameter setting of the swinging laser, the swinging laser heat source 2 can act on a specific phase of the arc, thereby realizing personalized regulation of n+1 independent heat sources.

[0056] In the present invention, it also includes an annular housing 8 with a water cooling channel arranged inside, a welding control cabinet, a laser controller and a multi-heat source multi-wire composite integrated welding gun;

[0057] The multi-heat source multi-wire composite integrated welding gun designs and integrates water, electricity, gas, light, wire and other modules to achieve stability and reliability of the cooling system, protection system, wire feeding system and laser and arc under long-term service conditions of the composite welding gun;

[0058] The welding machine control system comprises a welding machine control box and a welding control cabinet, and the welding control box is operated to control the n GTAW arc coaxial welding torches 3 to start the arc, and to control the wire feeding mechanism 6 to feed the wire;

[0059] The laser head, n GTAW arc coaxial welding torches 3 and the wire feeding mechanism 6 are coaxially located inside the annular housing 8, fixed together, keep synchronous movement, and are fixedly connected to the annular housing 8;

[0060] The welding control cabinet is used to control the n GTAW arc coaxial welding torches 3 to start the arc, and control the wire feeding mechanism 6 to feed the wire;

[0061] The laser controller is used to control the laser head to emit a laser beam as a laser heat source 2 .

[0062] In the present invention, the multiple tungsten electrodes 4 are tilted relative to the laser heat source 2, the ends of the multiple tungsten electrodes 4 are located on the same conical surface, and the central axis of the conical surface is coaxial with the laser heat source 2, thereby forming a symmetrical composite large heat source. Preferably, a glass shield made of high-temperature resistant glass is set at the position where the composite large heat source is formed, for protection, heat insulation and reduction of heat radiation. Preferably, the n GTAW arcs can set the phase difference between different arcs through the control panel according to the needs. Specifically, taking four tungsten electrodes 4 as an example, the four tungsten electrodes 4 are tilted relative to the laser heat source 2, the four tungsten electrodes 4 are located on the same conical surface, the central axis of the conical surface is coaxial with the laser heat source 2, and there is a gap between every two tungsten electrodes 4, so that four gaps are formed, and a welding wire 5 is set in each of at least two gaps, such as, a welding wire 5 is set between every two tungsten electrodes 4 (a total of 4 welding wires 5, the welding wire 5 is preferably located in the middle of the two tungsten electrodes 4). The molten pool 7 generated by the laser heat source 2 and the four tungsten electrodes 4 realizes the melting of the four welding wires 5; thus, each welding wire 5 has a corresponding heat source, which can increase the wire feeding speed of the welding wire 5, thereby improving the additive efficiency, and each welding wire 5 is heated evenly, which can realize high-quality and stable additive manufacturing.

[0063] In order to improve the forming effect of the additive wall, the welding wire 5 may not be arranged between the two tungsten electrodes 4; the symmetrical composite large

[0064] heat source; however, no welding wire 5 is arranged between two of the tungsten electrodes 4, that is, only one welding wire 5 is arranged in each of the three intervals. When in use, the end of the interval where the welding wire 5 is not arranged faces backward; not arranging the welding wire 5 at the rear can avoid excessive weld excess height, thereby affecting the flatness of the single weld, and further affecting the forming effect of the additive wall.

[0065] On the other hand, the present invention provides a method for manufacturing the above-mentioned laser center induced GTAW arc synchronous phase control additive manufacturing device, comprising the following steps:

[0066] Step 1), select a substrate according to the size of the target metal structure, pre-treat the surface of the substrate, place it on a workbench, and clamp it with a fixture;

[0067] Step 2) establishing a three-dimensional model of the target metal structure, slicing and layering the three-dimensional model, and obtaining a processing path for additive manufacturing;

[0068] Step 3), select welding wire 5 and set the process parameters of additive manufacturing;

[0069] Step 4), the laser head is perpendicular to the substrate, and a plurality of tungsten electrodes 4 are evenly distributed around the laser heat source 2, and then welding wires 5 are arranged between any intervals of the tungsten electrodes 4;

[0070] Step 5), melting the welding wire 5 fed into the molten pool 7 according to the process parameters set in step 3) and spreading it on the substrate, and performing additive manufacturing according to the processing path in step 2) to obtain a target metal structure;

[0071] Step 6) Separate the substrate from the target metal structure by mechanical cutting.

[0072] The above-mentioned manufacturing method of the present invention is described in detail below in conjunction with specific embodiments.

[0073] Example 1

[0074] The manufacturing method of the laser center induced four GTAW arc synchronous phase control additive manufacturing device is carried out in the following steps:

[0075] Step 1) Mechanically polish the surface of the 30 mm thick steel substrate required for additive manufacturing to remove surface oil stains, dry it for standby use, measure the size of the pre-treated substrate, place it on the workbench, and clamp it with a fixture.

[0076] Step 2) Create a 3D model of the metal part to be processed, obtain the 3D model file, perform slicing processing through slicing software, and obtain the processing path for additive manufacturing.

[0077] Step 3), according to the metal parts to be processed, use ER50-6 welding wire 5, and select argon as the shielding gas 1 according to the type of welding wire 5; the diameter of the welding wire 54 is 1.2 mm, the shielding gas 1 is argon, and the flow rate of the shielding gas is 30 L / min; set the process parameters of additive manufacturing: the swing mode of the laser heat source 23 is circular swing, the swing frequency is 100 Hz, and the laser swing amplitude is 2 mm; the power of the laser heat source 23 is 1000 W, the defocus amount is 5 mm, the distance between the laser heat source 23 and the tungsten electrode 42 is 2 mm, the angle between the laser heat source 23 and the tungsten electrode 42 is 10°, the welding current is 50 A, the wire feeding speed is 4 m / min, and the welding speed is 0.6 m / min.

[0078] Step 4), the laser head is perpendicular to the substrate and fixed with four GTAW arc coaxial welding torches 3 and a wire feeding mechanism 6; four tungsten electrodes 4 are evenly spaced around the laser heat source 2, and then welding wires 5 are arranged between any intervals of the tungsten electrodes 4;

[0079] Step 5), arc starting and wire feeding are performed through the welding control cabinet, and the laser controller controls the laser head to emit a laser beam as a laser heat source 2 for additive manufacturing. The welding wire 5 fed into the molten pool 7 is melted and spread on the substrate according to the process parameters set in step 3), and additive manufacturing is performed according to the processing path in step 2) to obtain the target metal structure, thereby completing the additive manufacturing of the target metal part.

[0080] Step 6), finally, the substrate is separated from the target metal part by wire cutting.

[0081] The above are only preferred specific implementations of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and improved concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A laser center induced GTAW arc synchronous phase control additive manufacturing device, characterized in that: include: An oscillating laser head for emitting an oscillating laser heat source; A GTAW arc coaxial welding torch having a plurality of tungsten electrodes and used for providing a GTAW arc, which is arranged on the circumferential inner side of the laser heat source; A wire feeding mechanism, which is used to clamp a plurality of welding wires and feed the welding wires into a molten pool or a specific position of a GTAW arc for stable melting, and is arranged on the circumferential outer side of the laser heat source; Among them, there are n GTAW arcs, n≤4; The laser head, the GTAW arc coaxial welding torch and the wire feeding mechanism are fixed together to keep the three moving synchronously; A plurality of the tungsten electrodes and a plurality of the welding wires are alternately and evenly arranged around the laser heat source along the circumferential direction, and a gap is formed between two adjacent tungsten electrodes. At least one welding wire can be arranged in any gap. The coordinated control of the swing parameters of the laser heat source combined with the pulse parameters of the GTAW arc can stabilize the laser heat source at the center, guide multiple GTAW arcs, and induce multiple GTAW arcs to burn stably according to the swing law of the laser heat source.

2. The laser center induced GTAW arc synchronous phase controlled additive manufacturing device according to claim 1, characterized in that: It also includes a ring-shaped housing with a water cooling channel arranged inside, a welding control cabinet and a laser controller; Wherein, the laser head, the GTAW arc coaxial welding torch and the wire feeding mechanism are coaxially located inside the annular shell and fixedly connected to the annular shell; The welding control cabinet is used to control the GTAW arc coaxial welding torch to start the arc, and control the wire feeding mechanism to feed the wire; The laser controller is used to control the laser head to emit a laser beam as a laser heat source.

3. The laser center induced GTAW arc synchronous phase controlled additive manufacturing device according to claim 1, characterized in that: The plurality of tungsten electrodes are arranged obliquely relative to the laser heat source, and the plurality of tungsten electrodes are located on the same conical surface, and the central axis of the conical surface is coaxial with the laser heat source.

4. The laser center induced GTAW arc synchronous phase controlled additive manufacturing device according to claim 1, characterized in that: The phase difference between n GTAW arcs can be set through the control panel according to the needs.

5. The laser center induced GTAW arc synchronous phase controlled additive manufacturing device according to claim 1, characterized in that: The swing parameters include a swing path, a swing frequency and a swing amplitude.

6. The laser center induced GTAW arc synchronous phase controlled additive manufacturing device according to claim 5, characterized in that: The laser heat source sets the swing amplitude according to the position and spot size of the GTAW arc to control the degree of effect on n GTAW arcs.

7. A laser center induced GTAW arc synchronous phase controlled additive manufacturing device according to any one of claims 1 to 6, characterized in that: The GTAW arc is a DC GTAW arc or a DC pulse GTAW arc.

8. A method for manufacturing a laser center induced GTAW arc synchronous phase controlled additive manufacturing device according to any one of claims 1 to 7, characterized in that: The steps include: Step 1), select a substrate according to the size of the target metal structure, pre-treat the surface of the substrate, place it on a workbench, and clamp it with a fixture; Step 2) establishing a three-dimensional model of the target metal structure, slicing and layering the three-dimensional model, and obtaining a processing path for additive manufacturing; Step 3) Select welding wire and set the process parameters for additive manufacturing; Step 4), the laser head is perpendicular to the substrate, and a plurality of tungsten electrodes are evenly distributed around the laser heat source, and then welding wires are arranged between any intervals of the tungsten electrodes; Step 5), melting the welding wire fed into the molten pool according to the process parameters set in step 3) and spreading it on the substrate, and performing additive manufacturing according to the processing path in step 2) to obtain a target metal structure; Step 6) Separate the substrate from the target metal structure by mechanical cutting.

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