A method for laser-arc hybrid welding of 6mm thick aluminum alloy and welded joint
By optimizing the laser-arc hybrid welding parameters, the problems of porosity, softening, and poor formability in the welding of 5083 aluminum alloy were solved, achieving full penetration and uniform microstructure in 6mm thick aluminum alloy, improving the performance and formability of the welded joint, and providing reproducible process guidance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TONGFANG JIANGXIN SHIPBUILDING CO LTD
- Filing Date
- 2026-04-24
- Publication Date
- 2026-06-12
AI Technical Summary
In the existing technology, the traditional welding methods for 5083 aluminum alloy have problems such as low welding efficiency, large heat input, and easy generation of porosity, deformation and softening of weld joints. In particular, for 6mm thick aluminum alloys, there is a lack of clear, systematic and reproducible optimization process parameters.
A laser-arc hybrid welding method for 6mm thick aluminum alloy is adopted. By optimizing the combination of parameters such as laser power (1550W to 1750W, preferably 1700W), welding current (135A to 145A, preferably 140A), welding speed (0.3m/min to 0.4m/min), and shielding gas flow rate (13-18 L/min), the best synergistic effect of laser and arc energy is achieved, resulting in a welded joint with full penetration, excellent shape, and uniform microstructure.
It achieved full penetration of 6mm thick aluminum alloy sheet, with uniform weld formation, significantly reduced porosity, and obtained welded joints with reasonable hardness gradient and uniform microstructure. It improved the comprehensive mechanical properties of the welded joints and provided clear process parameter guidance, avoiding blind spots.
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Figure CN122184604A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metal material welding technology, and in particular to a laser-arc composite welding method and welded joint for 6mm thick aluminum alloy. Background Technology
[0002] 5083 aluminum alloy, as an Al-Mg based non-heat-treatable strengthening alloy, is widely used in aerospace, automotive manufacturing, rail transportation, and shipbuilding due to its low density, high specific strength, and excellent corrosion resistance. In these applications, welding is a key technology for manufacturing aluminum alloy structural components. However, traditional welding methods for aluminum alloys, such as tungsten inert gas (TIG) welding and metal inert gas (MIG) welding, suffer from low welding efficiency, high heat input, and susceptibility to porosity, deformation, and softening in the weld joint, thus limiting its high-performance applications.
[0003] Laser-arc hybrid welding technology combines the advantages of high energy density and deep penetration of laser welding with the high deposition rate and strong bridging ability of arc welding, and is considered an advanced technology that can effectively solve traditional welding problems of aluminum alloys. However, for 5083 aluminum alloys of a specific thickness (e.g., 6mm), different combinations of process parameters such as laser power, arc current, and welding speed have a complex and significant impact on the final macroscopic morphology, microstructure, and mechanical properties of the welded joint. Currently, there is a lack of clear, systematic, and reproducible technical guidance on how to optimize laser-arc hybrid welding process parameters to obtain high-quality joints with good shape, uniform microstructure, and reasonable hardness matching for 6mm thick 5083 aluminum alloys.
[0004] To address these issues, we propose a laser-arc hybrid welding method for 6mm thick aluminum alloys and a welded joint thereof. Summary of the Invention
[0005] The purpose of this invention is to provide a laser-arc hybrid welding method and welded joint for 6mm thick aluminum alloy, in order to solve the problems of porosity, joint softening, and poor weld formation that are easily encountered in the welding of existing 5083 aluminum alloys. In particular, it aims to obtain a welding process and corresponding high-quality joint that can achieve full penetration of 6mm plate, excellent weld formation, uniform microstructure and reasonable joint hardness distribution.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] A laser-arc hybrid welding method and welded joint for 6mm thick aluminum alloy.
[0008] In a first aspect, the present invention provides a laser-arc hybrid welding method for 6mm thick aluminum alloy, used for butt welding of 6mm thick 5083 aluminum alloy plates, the method comprising the following steps:
[0009] S1. Prepare welding materials: Use 6mm thick 5083 aluminum alloy as the base material and ER-5183 aluminum-magnesium alloy welding wire as the filler material. The diameter of the welding wire is 1.2mm.
[0010] S2. Determine welding process parameters:
[0011] Laser power: 1550W to 1750W, preferably 1700W;
[0012] Welding current: 135A to 145A, preferably 140A;
[0013] Welding speed: 0.3 m / min to 0.4 m / min, preferably 0.35 m / min;
[0014] The protective gas is pure Ar, and the gas flow rate is 13-18 L / min;
[0015] The angle between the laser and the electric arc is 45° to 55°, and the filament distance is 2.0-3.0 mm.
[0016] S3. Welding: Under the stated process parameters, the base material is welded using a laser-arc hybrid welding device.
[0017] Under these optimized parameters (laser power 1700W, welding current 140A, welding speed 0.35m / min), the best synergistic effect of laser and arc energy can be achieved, resulting in welds with excellent penetration, good formability, and optimal macroscopic morphology. At this point, the weld penetration depth can reach 6mm (full penetration), the weld front is uniformly formed, the back is fully penetrated, and there are no obvious surface defects.
[0018] Secondly, the present invention provides an aluminum alloy laser-arc composite welding joint prepared by the above method.
[0019] The hardness of the welded joint exhibits a gradient decreasing trend from the base metal to the weld center, gradually decreasing from approximately 91 HV in the base metal to approximately 63 HV in the weld center. Simultaneously, the hardness distribution characteristics of the weld cross-section are: upper weld (mainly affected by the electric arc heat-affected zone) hardness > middle weld hardness > lower weld (mainly affected by the laser heat-affected zone), indicating that the hardness distribution characteristics are caused by the difference in heat input between the electric arc zone and the laser zone. Microstructurally, under these parameters, the joint exhibits good grain refinement. The upper, middle, and lower weld zones are mainly composed of fine equiaxed grains, with the second phase (mainly the β phase of Mg2Al3) dispersed in fine dots. This avoids grain coarsening and excessive aggregation and growth of the second phase caused by excessive heat input, resulting in a relatively uniform joint structure, which is beneficial for improving the overall mechanical properties of the joint.
[0020] Thirdly, the present invention provides a method for determining process parameters of a welding method, comprising the following experimental steps:
[0021] a. Set up multiple sets of welding parameters with different laser power, welding current and welding speed, and conduct laser-arc hybrid welding tests on 6mm thick 5083 aluminum alloy.
[0022] b. Observe the macroscopic morphology of the welded specimens, measure the penetration depth, penetration width and reinforcement height, evaluate the weld formability, and screen out the parameter combination that can achieve full penetration and excellent form.
[0023] c. Perform microstructure observation and microhardness testing on the welded joints under the selected parameter combinations, and select parameters with uniform structure and reasonable hardness gradient as the optimal process parameters.
[0024] Compared with the prior art, the beneficial effects of the present invention are:
[0025] 1. Resolves the contradiction between penetration and deformation: By optimizing the combination of laser power and welding speed, the method of this invention ensures full penetration of 6mm plates while controlling the total amount of welding heat input, effectively avoiding excessive weld collapse or increased softening of the heat-affected zone due to excessive heat input, as well as incomplete penetration due to insufficient heat.
[0026] 2. Effectively suppresses porosity defects: By selecting a higher welding current (such as 140A), the arc energy and the fluidity and existence time of the molten pool are enhanced, which is conducive to the full escape of gases such as hydrogen generated during the welding process before the molten pool solidifies, and significantly reduces the porosity in the weld.
[0027] 3. Excellent weld formation and microstructure properties were achieved: The specific parameter combination of this invention (1700W, 140A, 0.35m / min) enables the optimal energy ratio and synergistic effect of laser and electric arc, resulting in a weld macromorphology with clear fusion lines, moderate reinforcement height, and uniform formation. Simultaneously, this parameter range is conducive to the formation of fine, uniform weld microstructure and a reasonable hardness gradient distribution, thereby improving the overall performance of the welded joint.
[0028] Clear process parameters and strong guidance: This invention clearly provides the core process parameter range and optimal values applicable to laser-arc hybrid welding of 6mm thick 5083 aluminum alloy, providing a clear and reproducible technical path for actual industrial production and avoiding the blindness of process development. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the welding process according to an embodiment of the present invention.
[0030] Figure 2 This is a schematic diagram of cutting and sampling a welding specimen.
[0031] Figure 3 This is a schematic diagram of the hardness test points for the welded sample.
[0032] Figures 4 to 11 The diagram shows the macroscopic morphology and dimensional changes of the weld cross-section under different laser powers, welding currents, and welding speeds.
[0033] Figures 12 to 47 Typical microstructures and scanning electron microscope (SEM) images of different regions of the weld (upper / middle / lower part of the weld zone, and upper / middle / lower part of the fusion line) are shown under the preferred parameters (1700W, 140A, 0.35m / min) and other comparative parameters, demonstrating the superiority of the microstructure under the preferred parameters.
[0034] Figure 48 (b)(c)(d) show the microhardness distribution curves of the welded joint along the thickness direction (upper, middle, lower) under the preferred parameters.
[0035] Figure 49 The front and back morphology and cross-sectional macromorphology of the weld were obtained by fixing the laser power and welding current to 1700W and 140A respectively, and only changing the welding speed (0.35m / min~0.5m / min). Detailed Implementation
[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0037] Please see Figure 1 A laser-arc hybrid welding method for 6mm thick aluminum alloy, which is also a method for optimizing the microstructure and properties of 6mm thick 5083 aluminum alloy laser-arc hybrid welded joints, includes the following steps:
[0038] Provide 6mm thick 5083 aluminum alloy sheets to be welded and matching ER-5183 welding wire; employ a side-axis laser-arc hybrid welding system, combining laser heat source and MIG arc heat source for the butt joint of the aluminum alloy sheets; the key is to determine, through system testing and comprehensive comparative analysis, a set of core process parameters that optimize the synergistic effect of laser and arc energy, specifically:
[0039] The laser power is set to 1700W ± 50W;
[0040] The welding current is set to 140A ± 5A;
[0041] The welding speed is set to 0.35 m / min ± 0.02 m / min.
[0042] As a further limitation of the present invention, the above process is carried out with the following fixed parameters: the laser focal length is 268mm, the shielding gas is pure argon, the gas flow rate is 15 L / min, the lateral distance (optical wire distance) between the laser beam and the arc welding wire axis is 2.5mm, and the angle between the laser beam and the arc is 50°.
[0043] This invention systematically investigated the effects of three core parameters—laser power (P), welding current (I), and welding speed (V)—on the quality of laser-arc hybrid welded joints of 6mm thick 5083 aluminum alloy using experimental methods.
[0044] The experiment used flat plate butt welding, with the base material being a 6mm 5083 aluminum alloy plate and the welding wire being ER-5183 with a diameter of 1.2mm.
[0045] Fixed parameters include: laser focal length 268 mm, filament distance 2.5 mm, laser-arc angle 50°, protective gas is pure Ar, gas flow rate 15 L / min, and the back is suspended.
[0046] Multiple sets of variable parameters are set, and comparisons are performed based on the principle of a single variable.
[0047] Example 1: The Influence of Laser Power
[0048] The welding current was set to I=140A, the welding speed to v=0.35 m / min, and the laser power P was set to 1500W, 1600W, 1650W, 1700W, and 1800W respectively.
[0049] The results show that:
[0050] When P=1500W, the energy is insufficient, the penetration depth is only 3.73mm, and the weld is not fully penetrated, resulting in excess height (protrusion) on the upper surface of the weld.
[0051] When P≥1600W, full penetration (6mm penetration depth) can be achieved.
[0052] As the power increases from 1600W to 1800W, the excess height becomes deeper from a negative value (collapse), and the weld width shows a trend of first slightly decreasing and then increasing.
[0053] Considering factors such as the uniformity of weld formation on both sides and the degree of collapse, under the conditions of 140A and 0.35m / min, a laser power of 1700W performs best and has the optimal weld formation.
[0054] Example 2: The Influence of Welding Current
[0055] The laser power was set to P=1650W, the welding speed to v=0.35 m / min, and the welding currents to I were 120A, 130A, and 140A, respectively.
[0056] The results show that under the specified parameters, all three currents can achieve full penetration. With increasing current, the number of weld pores decreases significantly; at a current of 140A, there are virtually no visible pores in the weld cross-section. Simultaneously, both the upper and lower weld widths increase with increasing current. Therefore, while ensuring sufficient penetration depth, using a welding current of 140A helps to obtain high-quality welds with low porosity and moderate weld width.
[0057] Example 3: The Influence of Welding Speed
[0058] The laser power was set to P=1700W, the welding current to I=140A, and the welding speeds v were 0.35 m / min, 0.4 m / min, 0.45 m / min, and 0.5 m / min, respectively.
[0059] The results show that full penetration can be achieved when v ≤ 0.45 m / min; however, when v = 0.5 m / min, the penetration depth drops sharply to 2.88 mm due to insufficient heat input, resulting in incomplete penetration. As the welding speed increases from 0.35 m / min to 0.45 m / min, the weld collapse (negative reinforcement) intensifies, and the weld width narrows somewhat. At v = 0.5 m / min, due to incomplete penetration, the deposited metal accumulates on the surface, forming a positive reinforcement. In summary, at v = 0.35 m / min, the weld formation is optimal while ensuring full penetration.
[0060] Example 4: Welded joint under preferred parameters
[0061] Based on the system analysis of the above embodiments, the optimal parameter combination is adopted for welding: P=1700W, I=140A, v=0.35m / min, and other parameters are the same as above.
[0062] The resulting welded joint has the following characteristics:
[0063] (1) Macroscopic morphology: The weld penetration depth is 6mm (full penetration), the fish scale pattern on the front is uniform and fine, the back is well formed, the excess height is slightly negative (about -0.65mm), and there are no obvious defects such as undercut, weld beads, or excessive collapse. That is, after welding, the weld front is uniform and continuous with fine fish scale pattern; the back is uniformly penetrated and well formed. Macroscopic metallographic observation of the cross section shows that the weld is fully penetrated with a penetration depth of 6mm, the upper and lower weld widths are uniform (the upper weld width is about 8.39mm and the lower weld width is about 7.76mm), the excess height is slightly concave (-0.65mm), and the formability is optimal.
[0064] (2) Microstructure: The weld zone (upper, middle, and lower parts) and fusion zone have fine grains, mainly equiaxed or fine columnar grains, with no obvious coarse columnar grains. The second phase (β phase) is dispersed in the α-Al matrix as fine dots, with good microstructure uniformity and a narrow heat-affected zone, as observed under a metallographic microscope after Keller's reagent etching. The weld zone has fine grains overall, with the upper part being a mixture of equiaxed and fine columnar grains, and the middle and lower parts being dominated by fine equiaxed grains. The strengthening phase (β phase) is dispersed in fine dots. The fusion line is clear, but the heat-affected zone is narrow, and the base metal microstructure has not undergone severe coarsening.
[0065] (3) Mechanical properties: Microhardness tests were performed on the weld cross-section. The hardness gradually decreased from the base metal (approximately 91 HV) to the weld center (approximately 63 HV). Within the weld zone, the hardness distribution exhibited the characteristic of upper (arc zone) hardness > middle hardness > lower (laser zone) hardness. That is, the Vickers hardness test (load 500g, hold for 15s) results showed that the hardness decreased gradually from the base metal to the weld center, with the base metal having the highest hardness of approximately 91 HV and the weld center having the lowest hardness of approximately 63 HV. The overall hardness distribution showed a trend of "upper part of weld > middle part of weld > lower part of weld".
[0066] Example 5: Welded joints under high efficiency parameters
[0067] When it is necessary to appropriately improve welding efficiency, the following parameters can be used: P=1800W, I=140A, v=0.5m / min.
[0068] At this higher welding speed, full penetration of a 6mm plate can also be achieved by increasing the laser power to 1800W. Although the weld formation is slightly inferior to the optimal parameters, it still meets general quality requirements. This solution can be used in applications where efficiency is a higher priority and weld surface finish requirements are slightly lower.
[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0070] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A laser-arc hybrid welding method for 6mm thick aluminum alloy, used for welding 6mm thick 5083 aluminum alloy plates, characterized in that: Includes the following steps: S1. Prepare welding materials: Use 6mm thick 5083 aluminum alloy as the base material and ER-5183 aluminum-magnesium alloy welding wire as the filler material. S2. Determine the welding process parameters: laser power range is 1550W to 1750W, welding current range is 135A to 145A, and welding speed range is 0.3m / min to 0.4m / min; S3. Under the stated process parameters, the base material is welded using a laser-arc hybrid welding device.
2. The laser-arc hybrid welding method for 6mm thick aluminum alloy according to claim 1, characterized in that: The laser power is 1700W, the welding current is 140A, and the welding speed is 0.35m / min.
3. The laser-arc hybrid welding method for 6mm thick aluminum alloy according to claim 1, characterized in that: The diameter of the welding wire is 1.2 mm.
4. The laser-arc hybrid welding method for 6mm thick aluminum alloy according to claim 1, characterized in that: Argon is used as the shielding gas during the welding process.
5. The laser-arc hybrid welding method for 6mm thick aluminum alloy according to claim 1, characterized in that: The lateral distance between the laser beam and the arc welding wire axis of the laser-arc hybrid welding equipment is 2.5 mm, and the angle between the laser beam and the arc is 50°.
6. A laser-arc hybrid welding joint for aluminum alloys, characterized in that, The welded joint is obtained by welding using the method described in any one of claims 1 to 5.
7. The aluminum alloy laser-arc composite welding joint according to claim 6, characterized in that: The weld penetration depth of the welded joint is 6 mm, and the hardness of the weld cross section decreases gradually from the base material to the weld center.
8. The aluminum alloy laser-arc composite welding joint according to claim 7, characterized in that: The hardness distribution characteristics of the weld section of the welded joint are as follows: the hardness value of the upper part of the weld is greater than that of the middle part of the weld, and the hardness value of the middle part of the weld is greater than that of the lower part of the weld.
9. The aluminum alloy laser-arc composite welding joint according to claim 6, characterized in that: The microstructure of the weld zone and fusion zone of the welded joint is mainly composed of fine equiaxed crystals, with the second phase distributed in a dotted pattern.