Method for welding of die cast aluminium alloys to dissimilar alloys

Abstract

The application relates to the technical field of dissimilar metal welding, in particular to a die-cast aluminum alloy-dissimilar alloy welding method. The die-cast aluminum alloy-dissimilar alloy welding method comprises the following steps: taking die-cast aluminum alloy and dissimilar alloy; the die-cast aluminum alloy and the dissimilar alloy are partially overlapped in an overlapping manner to form a welding joint, thereby obtaining a workpiece to be welded; and the workpiece to be welded is subjected to filling welding, wherein the welding heat source during the filling welding comprises a first laser beam and a second laser beam; the first laser beam irradiates a welding wire, and the second laser beam irradiates the dissimilar alloy; the interval Delta L of the first laser beam and the second laser beam in the welding direction is controlled to be 0.4mm-1mm; the diameter d of the welding wire is controlled to be 0.8mm-2mm; the vertical distance Delta h between the welding wire and the dissimilar alloy is controlled to be 0-d / 2mm; and the vertical distance Delta Z between the welding wire and the second laser beam is controlled to be 0-0.5mm.

Description

Technical Field

[0001] This application relates to the field of dissimilar metal welding technology, specifically to a welding method for die-cast aluminum alloys and dissimilar alloys. Background Technology

[0002] Die-cast aluminum alloys refer to aluminum alloy materials prepared using the "die-casting process." Common die-cast aluminum alloys include ADC12 and A380. These die-cast aluminum alloys have good fluidity and can quickly fill the mold cavity under high pressure to form high-precision, complex-shaped parts. Dissimilar alloys such as 5-series, 6-series, and 7-series aluminum alloys have excellent corrosion resistance and high strength. Joining die-cast aluminum alloys with dissimilar alloys can achieve a synergistic effect of these properties to meet the needs of complex working conditions.

[0003] However, the die-casting process easily introduces air during melt filling, leading to defects such as internal porosity and oxide film in the die-cast aluminum alloy, which weakens its weldability. During the welding of die-cast aluminum alloys and dissimilar alloys, the inherent internal porosity and heat input sensitivity of the die-cast aluminum alloy make it difficult to control keyhole stability, often resulting in defects such as bursting and weld collapse, leading to low weld formation yield. Furthermore, the compositional differences between die-cast aluminum alloys and dissimilar alloys can easily cause the formation of brittle phases in the welding zone, initiating hot cracking, which further reduces weld formation yield. Summary of the Invention

[0004] Based on this, this application provides a welding method for die-cast aluminum alloys and dissimilar alloys. The welding method provided by this application can effectively avoid defects such as porosity and cracks, and can improve the weld formation yield.

[0005] This application provides a welding method for die-cast aluminum alloy and dissimilar alloys, comprising the following steps:

[0006] Take a die-cast aluminum alloy and a dissimilar alloy; partially overlap the die-cast aluminum alloy and the dissimilar alloy to form a welded joint, thereby obtaining a workpiece to be welded;

[0007] The workpiece to be welded is subjected to filler welding, wherein the welding heat source during filler welding includes a first laser beam and a second laser beam; the first laser beam irradiates the welding wire, and the second laser beam irradiates the dissimilar alloy; the distance ΔL between the first laser beam and the second laser beam in the welding direction is controlled to be 0.4mm~1mm; the diameter d of the welding wire is 0.8mm~2mm; the perpendicular distance Δh between the welding wire and the dissimilar alloy is controlled to be 0~d / 2mm; and the perpendicular distance ΔZ between the welding wire and the second laser beam is controlled to be 0~0.5mm.

[0008] In some embodiments, the angle between the first laser beam and the second laser beam in the welding direction is controlled to be 0° to 3°.

[0009] Optionally, the first laser beam and the second laser beam are controlled to be parallel in the welding direction.

[0010] In some embodiments, the step of the first laser beam irradiating the welding wire includes: controlling the first laser beam to irradiate the welding wire with a power of 1.5kW to 2.5kW; and controlling the angle β between the first laser beam and the welding wire in the welding direction to be 65° to 80°.

[0011] In some embodiments, in the step of the first laser beam irradiating the welding wire, the irradiation length ΔH of the first laser beam on the welding wire is controlled to be 0.4 mm to 2 mm.

[0012] In some embodiments, in the step of the first laser beam irradiating the welding wire, the oscillation diameter D of the first laser beam is controlled to be 0.8 mm to 2 mm.

[0013] In some embodiments, in the step of the first laser beam irradiating the welding wire, the oscillation frequency of the first laser beam is controlled to be 100Hz~350Hz.

[0014] In some embodiments, in the step of performing filler welding on the workpiece to be welded...

[0015] Compared to the die-cast aluminum alloy, the dissimilar alloy in the workpiece to be welded is closer to the welding head end of the welding wire; the distance ΔS between the welding wire and the die-cast aluminum alloy is controlled to be 0.4mm~1.86mm.

[0016] In some embodiments, the welding wire is an Al-Mg welding wire.

[0017] In some embodiments, the diameter d of the welding wire is 0.8 mm to 2 mm.

[0018] In some embodiments, the thickness of the die-cast aluminum alloy is 1mm to 3mm.

[0019] In some embodiments, the dissimilar alloy includes one or more of 5-series aluminum alloys, 6-series aluminum alloys, and 7-series aluminum alloys.

[0020] In some embodiments, the thickness of the dissimilar alloy is 1 mm to 3 mm.

[0021] In some embodiments, the width of the welded joint is greater than 20 mm.

[0022] In some embodiments, the oscillation diameter of the second laser beam is controlled to be 0~0.1mm.

[0023] In some embodiments, the wire feeding speed of the welding wire is controlled to be 1m / min to 2m / min.

[0024] In some embodiments, the welding speed is 1.5 m / min to 2.2 m / min during the filler welding step of the workpiece to be welded.

[0025] In some embodiments, prior to the step of partially overlapping the die-cast aluminum alloy and the dissimilar alloy to form a welded joint, the method further includes:

[0026] The die-cast aluminum alloy and the dissimilar alloy are subjected to surface cleaning.

[0027] The welding method for die-cast aluminum alloys and dissimilar alloys provided in this application has at least the following beneficial effects:

[0028] In the filler welding step of the workpiece to be welded in this application, the first laser beam irradiates the welding wire to ensure that the welding wire is fully melted, and the second laser beam directionally heats the dissimilar alloy to regulate and control the heat input distribution. Furthermore, the distance between the first laser beam and the second laser beam in the welding direction is controlled to be 0.4mm~1mm. At this time, the two beams work together to effectively avoid local overheating caused by excessive energy superposition and the high-energy keyhole of the first laser beam and the second laser beam acting on the die-cast aluminum alloy, thereby effectively preventing the phenomenon of bursting. By controlling the vertical distance between the welding wire and the second laser beam to be 0~0.5mm and the vertical distance between the welding wire and the dissimilar alloy to be 0~d / 2mm, the first laser beam, the second laser beam, the welding wire, the die-cast aluminum alloy, and the dissimilar alloy work together. The welding wire heat can melt the die-cast aluminum alloy, and the second laser beam can directionally heat the dissimilar alloy to form a micro-melt pool on the surface of the dissimilar alloy. The molten die-cast aluminum alloy droplets and the molten dissimilar alloy droplets can further improve the wettability with the welding wire droplets, thereby improving the yield of the molten metal filling the welding area and improving the welding efficiency, thus achieving high-quality and stable welding of die-cast aluminum alloy and dissimilar alloy.

[0029] Therefore, the welding method provided in this application alleviates the sensitivity of die-cast aluminum alloys to heat input, effectively avoiding defects such as bursting and cracking, and improving the yield of die-cast aluminum alloy-dissimilar alloy weld formation. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0031] Figure 1 A schematic diagram of the welding method for die-cast aluminum alloy-dissimilar alloy provided in this application;

[0032] Figure 2 The image shows the surface morphology of the weld seam of the die-cast aluminum alloy-dissimilar alloy welded joint prepared in Example 1.

[0033] Figure 3 The image shows the surface morphology of the weld seam of the die-cast aluminum alloy-dissimilar alloy welded joint prepared in Example 2.

[0034] Figure 4 The surface morphology of the weld seam of the die-cast aluminum alloy-dissimilar alloy welded joint prepared for Comparative Example 1 is shown.

[0035] Explanation of reference numerals in the attached figures

[0036] 10. Die-cast aluminum alloy; 20. Dissimilar alloy; 30. First laser beam; 40. Second laser beam; 50. Welding wire. Detailed Implementation

[0037] The welding method for die-cast aluminum alloy 10 and dissimilar alloy 20 of this application is further described in detail below with reference to specific embodiments. This application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0038] It should be understood that the terminology used in this application is merely for describing particular embodiments and is not intended to limit the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application.

[0039] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art described herein. While only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0040] In this article, "one or more" refers to any one, two or more of the listed items.

[0041] In this application, terms such as "first aspect," "second aspect," "third aspect," "fourth aspect," and "fifth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," "fourth," and "fifth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0042] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0043] Furthermore, for numerical ranges in this application, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0044] Unless otherwise specified, the percentage content mentioned in this application refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures.

[0045] Unless otherwise specified, all percentage concentrations mentioned in this application refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0046] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows for temperature fluctuations within the precision range controlled by the instrument.

[0047] See Figure 1 This application provides a welding method for die-cast aluminum alloy and dissimilar alloy, comprising the following steps:

[0048] S11: Take die-cast aluminum alloy 10 and dissimilar alloy 20; partially overlap die-cast aluminum alloy 10 and dissimilar alloy 20 to form a welding joint, and obtain the workpiece to be welded.

[0049] S12: Perform filler welding on the workpiece to be welded.

[0050] like Figure 1 As shown, in this application, "welding direction" corresponds to the Y-axis. The Z-axis corresponds to the thickness direction of the die-cast aluminum alloy 10 and / or dissimilar alloy 20. In this application, "vertical distance" corresponds to the distance interval along the Z-axis.

[0051] In some examples, prior to the step of partially overlapping the die-cast aluminum alloy 10 and the dissimilar alloy 20 to form a welded joint, the method further includes:

[0052] Surface cleaning was performed on die-cast aluminum alloy 10 and dissimilar alloy 20.

[0053] Understandably, the methods for surface cleaning of the die-cast aluminum alloy 10 and the dissimilar alloy 20 include, but are not limited to, mechanical methods or organic solvent cleaning methods. Further, the method for surface cleaning of the die-cast aluminum alloy 10 is a mechanical method. The method for surface cleaning of the dissimilar alloy 20 is an organic solvent cleaning method. Organic solvents include, but are not limited to, acetone.

[0054] The die-cast aluminum alloy 10 and dissimilar alloy 20 are surface-cleaned to remove the oxide layer or oil. This reduces the problem of oxide layer or oil being drawn into the molten pool during welding, which hinders fusion and provides a clean surface for subsequent welding, ensuring the metallurgical bonding quality of the weld.

[0055] In some examples, in step S11, the thickness t1 of the die-cast aluminum alloy 10 is 1 mm to 3 mm. For example, the thickness t1 of the die-cast aluminum alloy 10 includes, but is not limited to, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 2.8 mm, or 3 mm, or any two of the above values ​​as endpoints. As a further example, the die-cast aluminum alloy 10 is an Al-Si die-cast aluminum alloy.

[0056] In some of these examples, in step S11, the dissimilar alloy 20 includes one or more of 5-series aluminum alloys, 6-series aluminum alloys, and 7-series aluminum alloys.

[0057] In some examples, in step S11, the thickness t2 of the dissimilar alloy 20 is 1 mm to 3 mm. For example, the thickness t2 of the dissimilar alloy 20 includes, but is not limited to, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 2.8 mm or 3 mm, or any two of the above point values ​​as endpoint values.

[0058] In some of these examples, in step S11, the width of the weld joint is greater than 20 mm.

[0059] In this application, "width of welded joint" refers to the dimension of the weld in the overlapping area perpendicular to the welding direction. For example, the width of welded joint includes, but is not limited to, 25mm, 35mm, 40mm, 55mm, 75mm, 95mm, 100mm, 200mm or 300mm, or any two of the above point values ​​as endpoint values ​​within the range.

[0060] In some examples, in step S11, the dissimilar alloy 20 is placed below the die-cast aluminum alloy 10, partially overlapping to form a weld joint, thus preparing the workpiece to be welded. At this time, in step S12, the dissimilar alloy 20 in the workpiece to be welded is close to the welding tip of the welding wire 50. Understandably, to prevent movement of the workpiece to be welded, a welding clamp can be used to fix it in place.

[0061] In some examples, in step S12, the welding heat source during filler welding includes a first laser beam 30 and a second laser beam 40. The first laser beam 30 irradiates the welding wire 50, and the second laser beam 40 irradiates the dissimilar alloy 20.

[0062] In some examples, the angle between the first laser beam 30 and the second laser beam 40 in the welding direction is controlled to be 0° to 3°. Optionally, the first laser beam 30 and the second laser beam 40 are controlled to be parallel in the welding direction.

[0063] In some examples, the oscillation diameter of the second laser beam 40 is controlled to be 0~0.1mm. Optionally, the oscillation diameter of the second laser beam 40 is controlled to be 0mm.

[0064] See Figure 1 Figure (b) shows the first laser beam 30 irradiating the welding wire 50. In some examples, during the step of the first laser beam 30 irradiating the welding wire 50, the oscillation diameter D of the first laser beam 30 is controlled to be 0.8 mm to 2 mm. For example, the oscillation diameter D of the first laser beam 30 includes, but is not limited to, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, or 2 mm, or any two of the above values ​​as endpoints. As a further example, the oscillation trajectory of the first laser beam 30 is one of "0", "∞", and "8".

[0065] Understandably, the first laser beam 30 is in the welding direction, i.e. Figure 1 The included angle along the Y-axis is 0°~3°. Further, the first laser beam 30 and the second laser beam 40 are in the welding direction, i.e. Figure 1 The Y-axis is parallel upwards. At this time, the second laser beam 40 does not oscillate, and its oscillation center is parallel to that of the first laser beam 30 in the Y-axis direction, that is, the second laser beam only moves with the welding direction.

[0066] By controlling the angle between the two laser beams, the oscillation parameters, and the oscillation plane, the welding wire 50 can be fully melted and the dissimilar alloy 20 can be moderately heated, reducing excessive heat input to the die-cast aluminum alloy 10 and improving the stability of the molten pool and the quality of the weld formation.

[0067] In some examples, during the step of the first laser beam 30 irradiating the welding wire 50, the oscillation frequency of the first laser beam 30 is controlled to be between 100Hz and 350Hz. For example, the oscillation frequency of the first laser beam 30 includes, but is not limited to, 100Hz, 110Hz, 130Hz, 140Hz, 160Hz, 180Hz, 200Hz, 220Hz, 240Hz, 260Hz, 280Hz, 300Hz, 320Hz, or 350Hz, or any two of the above values ​​as endpoints. High-frequency oscillation allows the laser energy of the first laser beam 30 to act more uniformly on the welding wire 50 and its surrounding area, improving the uniformity of the welding wire 50's melting and the fluidity of the molten pool.

[0068] In some examples, the welding wire 50 is an Al-Mg welding wire. The diameter d of the welding wire 50 is 0.8 mm to 2 mm. The diameter d of the welding wire 50 includes, but is not limited to, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm or 2 mm, or any two of the above values ​​as endpoint values.

[0069] In some examples, the distance ΔL between the first laser beam 30 and the second laser beam 40 in the welding direction is controlled to be 0.4 mm to 1 mm. For example, the distance ΔL between the first laser beam 30 and the second laser beam 40 in the welding direction includes, but is not limited to, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm, or any two of the above point values ​​as endpoint values ​​within the range.

[0070] Understandably, such as Figure 1 As shown in (c), the welding direction is the Y-axis. The distance ΔL between the first laser beam 30 and the second laser beam 40 in the welding direction is 0.4mm~1mm, and the oscillation diameter D of the first laser beam 30 in the plane constructed by the X-axis and Z-axis is 0.8mm~2mm. Further, the distance ΔL between the first laser beam 30 and the second laser beam 40 in the welding direction is D / 2. At this time, the two beams work together to ensure that the oscillation coverage area of ​​the first laser beam 30 and the action area of ​​the second laser beam 40 are precisely connected, which avoids excessive energy superposition leading to local overheating, and ensures that the molten metal of the welding wire 50 and the heated area of ​​the dissimilar alloy 20 are fully fused. At the same time, it ensures that the welding energy is evenly distributed in the overlapping area, reduces incomplete fusion defects, and improves the consistency of weld formation.

[0071] In some examples, the vertical distance Δh between the welding wire 50 and the dissimilar alloy 20 is controlled to be between 0 and d / 2 mm, where d is the diameter of the welding wire 50. Limiting the vertical distance Δh between the welding wire 50 and the dissimilar alloy 20 to between 0 mm and d / 2 mm ensures that the molten droplets formed after the welding wire 50 melts can fall into the welding area on the side of the dissimilar alloy 20. This avoids both droplet splashing and incomplete fusion due to excessive distance and premature contact and short circuits caused by excessively close distance, thus ensuring the stability of the molten wire filling and the metallurgical bonding quality of the weld.

[0072] In some examples, the vertical distance ΔZ between the welding wire 50 and the second laser beam 40 is controlled to be 0~0.5mm. Further, the vertical distance ΔZ between the welding wire 50 and the second laser beam 40 is 0 to Δh / 2mm. Δh is the vertical distance between the welding wire 50 and the dissimilar alloy 20. Limiting the vertical distance ΔZ between the welding wire 50 and the second laser beam 40 to the above range allows the energy of the second laser beam 40 to be precisely applied to the critical area between the welding wire 50 and the dissimilar alloy 20. This ensures that the welding wire 50 is fully melted and the molten metal smoothly transitions to the dissimilar alloy 20 side, while avoiding excessive energy affecting the die-cast aluminum alloy 10, thus improving the stability of the molten pool and the quality of the weld joint.

[0073] In some examples, the step of the first laser beam 30 irradiating the welding wire 50 includes: controlling the first laser beam 30 to irradiate the welding wire 50 with a power of 1.5kW to 2.5kW. The angle β between the first laser beam 30 and the welding wire 50 in the welding direction is controlled to be 65° to 80°. For example, the power of the first laser beam 30 includes, but is not limited to, 1.5kW, 1.8kW, 2kW, 2.1kW, 2.2kW, or 2.5kW, or any two of the above values ​​as endpoints. The angle β between the first laser beam 30 and the welding wire 50 in the welding direction includes, but is not limited to, 65°, 70°, 75°, or 80°, or any two of the above values ​​as endpoints.

[0074] In some examples, during the step of the first laser beam 30 irradiating the welding wire 50, the irradiation length ΔH of the first laser beam 30 on the welding wire 50 is controlled to be 0.4 mm to 2 mm. Further, the lower limit of ΔH is d / 2 mm or D / 2 mm. D is the oscillation diameter of the first laser beam 30. d is the diameter of the welding wire 50. When D > d, the lower limit of ΔH is D / 2 mm. When D < d, the lower limit of ΔH is d / 2 mm. Further, the upper limit of ΔH is 2 - Δh. Δh is the perpendicular distance between the welding wire 50 and the dissimilar alloy 20. The upper limit of ΔH is 2 - Δh. Here, "2" is based on the fact that the maximum conventional diameter of the aluminum alloy welding wire is d = 4 mm, and Δh ≤ d / 2, so the laser beam irradiation position is limited to half the maximum welding wire diameter (2 mm) to ensure that the laser spot fully covers the end of the welding wire.

[0075] In some of these examples, the step of performing filler welding on the workpiece to be welded is described in [reference]. Figure 1 Figure (d) shows that, compared to the die-cast aluminum alloy 10, the dissimilar alloy 20 in the workpiece to be welded is closer to the welding head end of the welding wire 50; the distance ΔS between the welding wire 50 and the die-cast aluminum alloy 10 is controlled to be 0.4mm~1.86mm. For example, the distance ΔS between the welding wire 50 and the die-cast aluminum alloy 10 includes, but is not limited to, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, or 1.86mm, or any two of the above values ​​as endpoint values ​​within a range. Further, the lower limit of ΔS is d / 2mm or D / 2mm. D is the oscillation diameter of the first laser beam 30. d is the diameter of the welding wire 50. When D > d, the lower limit of ΔS is D / 2mm. When D < d, the lower limit of ΔS is d / 2mm. Furthermore, to ensure that the symmetry and effective thickness of the weld meet national standards after welding, the distance between the beam and the side edge is limited. The upper limit of △S is 1.5mm + 0.12 × the thickness t1 of the die-cast aluminum alloy 10 or 1.5mm + 0.12 × the thickness t2 of the dissimilar alloy 20. When t1 > t2, the upper limit of △S is 1.5mm + 0.12 × the thickness t2 of the dissimilar alloy 20. When t1 < t2, the upper limit of △S is 1.5mm + 0.12 × the thickness t1 of the die-cast aluminum alloy 10.

[0076] In some of these examples, the power of the second laser beam 40 is 0.4kW to 1.2kW.

[0077] In some examples, the wire feed speed of the welding wire 50 is controlled to be 1 m / min to 2 m / min. For example, the wire feed speed of the welding wire 50 includes, but is not limited to, 1 m / min, 1.2 m / min, 1.4 m / min, 1.6 m / min, 1.8 m / min or 2 m / min, or any two of the above values ​​as endpoints.

[0078] In some examples, during the filler welding step of the workpiece to be welded, the welding speed is 1.5 m / min to 2.2 m / min. For example, the welding speed includes, but is not limited to, 1.5 m / min, 1.6 m / min, 1.7 m / min, 1.8 m / min, 1.9 m / min, 2 m / min, 2.1 m / min or 2.2 m / min, or any two of the above values ​​as endpoints.

[0079] This application describes a filler welding process for the workpiece to be welded. A first laser beam 30 irradiates the welding wire 50 to ensure its complete melting, while a second laser beam 40 directionally heats the dissimilar alloy 20, controlling the heat input distribution. Further defining the positional relationship, wire feed rate, and welding speed of the first laser beam 30, the second laser beam 40, and the welding wire 50 allows for precise positional matching to leverage the synergistic energy of the two laser beams. This avoids excessive energy superposition leading to localized overheating of the die-cast aluminum alloy 10, and ensures that the molten metal from the welding wire 50 fills the welding area promptly and sufficiently by matching the wire feed rate with the welding speed. Simultaneously, it controls the heat input to the die-cast aluminum alloy 10 to reduce the risk of internal porosity expansion, optimizes the wettability of the molten droplets and the dissimilar alloy 20, and suppresses cracking caused by brittle phase formation due to compositional differences.

[0080] Therefore, the welding method provided in this application alleviates the sensitivity of die-cast aluminum alloy 10 to heat input, effectively avoiding defects such as porosity and cracks, and improving the weld formation yield. Furthermore, the welding method provided in this application can increase the one-time welding formation yield of die-cast aluminum alloy 10 and dissimilar alloy 20 from 50% of the traditional method to over 80%.

[0081] The following detailed embodiments illustrate this application in more detail. It should also be understood that the following embodiments are for further explanation only and should not be construed as limiting the scope of protection of this application. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of this application fall within the scope of protection of this application. The specific process parameters, etc., in the following embodiments are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the range based on the description herein, and are not necessarily limited to the specific values ​​in the embodiments below.

[0082] Example 1

[0083] See the process diagram for welding methods of die-cast aluminum alloys and dissimilar alloys. Figure 1 .

[0084] (1) Surface cleaning of die-cast aluminum alloy 10 and dissimilar alloy 20:

[0085] Take an Al-Si high-pressure die-cast aluminum alloy sheet (die-cast aluminum alloy 10) with dimensions of 300mm × 150mm × 3mm, i.e., a thickness t1 of 3mm; remove the oxide layer from the area to be welded using a mechanical method. Take a 6-series aluminum alloy sheet (dissimilar alloy 20) with dimensions of 300mm × 150mm × 3mm, i.e., a thickness t2 of 3mm; remove surface oil stains with acetone, and allow it to dry before use.

[0086] (2) Preparation of the workpiece to be welded:

[0087] A 6-series aluminum alloy sheet is placed below an Al-Si high-pressure die-cast aluminum alloy sheet, and the sheets are partially overlapped to form a welded joint, which is then fixed with a welding clamp. The width of the welded joint is greater than 20 mm. The workpiece to be welded is obtained by placing the 6-series aluminum alloy sheet below the Al-Si high-pressure die-cast aluminum alloy sheet, with the dissimilar alloy 20 close to the welding tip of the welding wire 50.

[0088] (3) Perform filler welding on the workpiece to be welded:

[0089] Laser welding was performed using IPG-6000W and CWX-3000W fiber lasers. The IPG-6000W fiber laser emitted a first laser beam 30, and the CWX-3000W emitted a second laser beam 40. The welding wire 50 was ER5183 with a diameter d of 1.2mm. The second laser beam 40 was directed at 0.6kW to the 6-series aluminum alloy sheet, while the first laser beam 30 was directed at 2kW to the welding wire 50. The angle β between the first laser beam 30 and the welding wire 50 in the welding direction was controlled to be 65°. The first and second laser beams 30 and 40 were kept parallel in the welding direction, and the second laser beam 40 was kept stationary. The distance ΔL between the first and second laser beams 30 and 40 in the welding direction was controlled to be 0.8mm. The oscillation diameter D of the first laser beam 30 was 1.6mm, the oscillation frequency of the first laser beam 30 was 250Hz, and the wire feed speed of the welding wire 50 was 1.5m / min.

[0090] Further adjustments were made to the positions of the first laser beam 30, the second laser beam 40, the welding wire 50, and the workpiece to be welded during the welding process. The vertical distance Δh between the welding wire 50 and the dissimilar alloy 20 was controlled to be 0~0.6mm; the vertical distance ΔZ between the welding wire 50 and the second laser beam 40 was controlled to be 0~0.3mm; the distance ΔS between the welding wire 50 and the side of the Al-Si high-pressure die-cast aluminum alloy sheet was controlled to be 0.8mm~1.74mm; and the irradiation length ΔH of the first laser beam 30 on the welding wire 50 was controlled to be 0.8mm~1.4mm. The welding speed throughout the process was 1.8m / min.

[0091] (4) Welding samples were made on the high-pressure die-cast Al-Si alloy dissimilar joints using the above process, the weld formation quality was observed, and the weld formation yield of 10 welds under the same process parameters was statistically analyzed.

[0092] Example 2

[0093] See the process diagram for welding methods of die-cast aluminum alloys and dissimilar alloys. Figure 1 .

[0094] (1) Surface cleaning of die-cast aluminum alloy 10 and dissimilar alloy 20:

[0095] Take an Al-Si high-pressure die-cast aluminum alloy sheet (die-cast aluminum alloy 10) with dimensions of 300mm × 150mm × 1mm, i.e., a thickness t1 of 1mm; remove the oxide layer in the area to be welded from the Al-Si high-pressure die-cast aluminum alloy sheet using a mechanical method. Take a 7-series aluminum alloy sheet (dissimilar alloy 20) with dimensions of 300mm × 150mm × 3mm, i.e., a thickness t2 of 3mm; remove surface oil stains with acetone, and allow it to dry before use.

[0096] (2) Preparation of the workpiece to be welded:

[0097] A 7-series aluminum alloy sheet is placed below an Al-Si high-pressure die-cast aluminum alloy sheet, and the sheets are partially overlapped to form a welded joint, which is then fixed with a welding clamp. The width of the welded joint is greater than 20 mm. The workpiece to be welded is obtained by placing the 7-series aluminum alloy sheet below the Al-Si high-pressure die-cast aluminum alloy sheet, with the dissimilar alloy 20 close to the welding tip of the welding wire 50.

[0098] (3) Perform filler welding on the workpiece to be welded:

[0099] Laser welding was performed using IPG-6000W and CWX-3000W fiber lasers. The IPG-6000W fiber laser emitted a first laser beam 30, and the CWX-3000W emitted a second laser beam 40. The welding wire 50 was ER5183 with a diameter d of 1.2mm. The second laser beam 40 was directed to irradiate the 6-series aluminum alloy sheet at a power of 0.6kW, while the first laser beam 30 was directed to irradiate the welding wire 50 at a power of 2kW. The angle β between the first laser beam and the welding wire 50 in the welding direction was controlled to be 65°. The first laser beam 30 and the second laser beam 40 were kept parallel in the welding direction, and the second laser beam 40 was kept stationary. The distance ΔL between the first laser beam 30 and the second laser beam 40 in the welding direction was controlled to be 0.8mm. The oscillation diameter D of the first laser beam 30 was controlled to be 1.6mm, the oscillation frequency of the first laser beam 30 was controlled to be 250Hz, and the wire feed speed of the welding wire 50 was controlled to be 1.5m / min.

[0100] Further adjustments were made to the positions of the first laser beam 30, the second laser beam 40, the welding wire 50, and the workpiece to be welded during the welding process. The vertical distance Δh between the welding wire 50 and the dissimilar alloy 20 was controlled to be 0~0.6mm; the vertical distance ΔZ between the welding wire 50 and the second laser beam 40 was controlled to be 0~0.3mm; the distance ΔS between the welding wire 50 and the side of the Al-Si high-pressure die-cast aluminum alloy sheet was controlled to be 0.8mm~1.62mm; and the irradiation length ΔH of the first laser beam 30 on the welding wire 50 was controlled to be 0.8mm~1.4mm. The welding speed throughout the process was 1.8m / min.

[0101] (4) Welding samples were made on the high-pressure die-cast Al-Si alloy dissimilar joints using the above process, the weld formation quality was observed, and the weld formation yield of 10 welds under the same process parameters was statistically analyzed.

[0102] Example 3

[0103] Example 3 is basically the same as Example 1, the main difference being that step (3) in Example 3 is different from that in Example 1. Step (3) in Example 3 is as follows:

[0104] (3) Perform filler welding on the workpiece to be welded:

[0105] Laser welding was performed using IPG-6000W and CWX-3000W fiber lasers. The IPG-6000W fiber laser emitted a first laser beam 30, and the CWX-3000W emitted a second laser beam 40. The welding wire 50 was ER5183 with a diameter d of 1.6mm. The second laser beam 40 was directed at 0.6kW to the 6-series aluminum alloy sheet, while the first laser beam 30 was directed at 2kW to the welding wire 50. The angle β between the first laser beam 30 and the welding wire 50 in the welding direction was controlled to be 65°. The first and second laser beams 30 and 40 were kept parallel in the welding direction, and the second laser beam 40 was kept stationary. The distance ΔL between the first and second laser beams 30 and 40 in the welding direction was controlled to be 0.8mm. The oscillation diameter D of the first laser beam 30 was 1.6mm, the oscillation frequency of the first laser beam 30 was 250Hz, and the wire feed speed of the welding wire 50 was 1.5m / min.

[0106] Further adjustments were made to the positions of the first laser beam 30, the second laser beam 40, the welding wire 50, and the workpiece to be welded during the welding process. The vertical distance Δh between the welding wire 50 and the dissimilar alloy 20 was controlled to be 0~0.8mm; the vertical distance ΔZ between the welding wire 50 and the second laser beam 40 was controlled to be 0~0.4mm; the distance ΔS between the welding wire 50 and the side of the Al-Si high-pressure die-cast aluminum alloy sheet was controlled to be 0.8mm~1.74mm; and the irradiation length ΔH of the first laser beam 30 on the welding wire 50 was controlled to be 0.8mm~1.2mm. The welding speed throughout the process was 1.8m / min.

[0107] Example 4

[0108] Example 4 is basically the same as Example 1, the main difference being that step (3) in Example 4 is different from that in Example 1. Step (3) in Example 4 is as follows:

[0109] (3) Perform filler welding on the workpiece to be welded:

[0110] Laser welding was performed using IPG-6000W and CWX-3000W fiber lasers. The IPG-6000W fiber laser emitted a first laser beam 30, and the CWX-3000W emitted a second laser beam 40. The welding wire 50 was ER5183 with a diameter d of 1.2mm. The second laser beam 40 was directed at 0.6kW to the 6-series aluminum alloy sheet, while the first laser beam 30 was directed at 2kW to the welding wire 50. The angle β between the first laser beam 30 and the welding wire 50 in the welding direction was controlled to be 65°. The first and second laser beams 30 and 40 were kept parallel in the welding direction, and the second laser beam 40 was kept stationary. The distance ΔL between the first and second laser beams 30 and 40 in the welding direction was controlled to be 0.9mm. The oscillation diameter D of the first laser beam 30 was 1.8mm, the oscillation frequency of the first laser beam 30 was 250Hz, and the wire feed speed of the welding wire 50 was 1.5m / min.

[0111] Further adjustments were made to the positions of the first laser beam 30, the second laser beam 40, the welding wire 50, and the workpiece to be welded during the welding process. The vertical distance Δh between the welding wire 50 and the dissimilar alloy 20 was controlled to be 0~0.6mm; the vertical distance ΔZ between the welding wire 50 and the second laser beam 40 was controlled to be 0~0.3mm; the distance ΔS between the welding wire 50 and the side of the Al-Si high-pressure die-cast aluminum alloy sheet was controlled to be 0.9mm~1.74mm; and the irradiation length ΔH of the first laser beam 30 on the welding wire 50 was controlled to be 0.9mm~1.4mm. The welding speed throughout the process was 1.8m / min.

[0112] (4) Welding samples were made on the high-pressure die-cast Al-Si alloy dissimilar joints using the above process, the weld formation quality was observed, and the weld formation yield of 10 welds under the same process parameters was statistically analyzed.

[0113] Comparative Example 1

[0114] See the process diagram for welding dissimilar die-cast aluminum alloys. Figure 1 .

[0115] (1) Surface cleaning of die-cast aluminum alloy 10 and dissimilar alloy 20:

[0116] Take an Al-Si high-pressure die-cast aluminum alloy sheet (die-cast aluminum alloy 10) with dimensions of 300mm × 150mm × 3mm, i.e., a thickness t1 of 3mm; remove the oxide layer from the area to be welded using a mechanical method. Take a 6-series aluminum alloy sheet (dissimilar alloy 20) with dimensions of 300mm × 150mm × 3mm, i.e., a thickness t2 of 3mm; remove surface oil stains with acetone, and allow it to dry before use.

[0117] (2) Preparation of the workpiece to be welded:

[0118] A 6-series aluminum alloy sheet is placed below an Al-Si high-pressure die-cast aluminum alloy sheet, and the sheets are partially overlapped to form a welded joint, which is then fixed with a welding clamp. The width of the welded joint is greater than 20 mm. The workpiece to be welded is obtained by placing the 6-series aluminum alloy sheet below the Al-Si high-pressure die-cast aluminum alloy sheet, with the dissimilar alloy 20 close to the welding tip of the welding wire 50.

[0119] (3) Perform filler welding on the workpiece to be welded:

[0120] Laser welding was performed using IPG-6000W and CWX-3000W fiber lasers. The IPG-6000W fiber laser emitted a first laser beam 30, and the CWX-3000W emitted a second laser beam 40. The welding wire 50 was ER5183 with a diameter d of 1.2mm. The second laser beam 40 was directed to irradiate the 6-series aluminum alloy sheet at a power of 0.6kW, while the first laser beam 30 was directed to irradiate the welding wire 50 at a power of 2kW. The angle β between the first laser beam 30 and the welding wire 50 in the welding direction was controlled to be 65°. The first laser beam 30 and the second laser beam 40 were kept parallel in the welding direction, and the second laser beam 40 was kept stationary. The distance ΔL between the first laser beam 30 and the second laser beam 40 in the welding direction was controlled to be 0.8mm. The oscillation diameter D of the first laser beam 30 was controlled to be 1.6mm, the oscillation frequency of the first laser beam 30 was controlled to be 250Hz, and the wire feed speed of the welding wire 50 was controlled to be 1.5m / min.

[0121] Further adjustments were made to the positions of the first laser beam 30, the second laser beam 40, the welding wire 50, and the workpiece to be welded during the welding process. The vertical distance Δh between the welding wire 50 and the dissimilar alloy 20 was controlled to be 0.8 mm; the vertical distance ΔZ between the welding wire 50 and the second laser beam 40 was controlled to be 0.4 mm; the distance ΔS between the welding wire 50 and the side edge of the Al-Si high-pressure die-cast aluminum alloy sheet was controlled to be 0.6 mm; and the irradiation length ΔH of the first laser beam 30 on the welding wire 50 was controlled to be 0.6 mm. The welding speed throughout the process was 1.8 m / min. The vertical distance Δh between the welding wire 50 and the dissimilar alloy 20 exceeded the upper limit of d / 2.

[0122] (4) Welding samples were made on the high-pressure die-cast Al-Si alloy dissimilar joints using the above process, the weld formation quality was observed, and the weld formation yield of 10 welds under the same process parameters was statistically analyzed.

[0123] Statistical analysis of the number of defects on the weld surfaces after welding in the examples and comparative examples revealed that in Examples 1 and 2, the high-energy keyhole was not applied to the high-pressure die-cast aluminum alloy 10, and the weld surfaces of Examples 1 and 2 showed no obvious defects. Examples 3 and 4 also significantly reduced the number of defects after welding compared to Comparative Example 1. However, in Comparative Example 1, the tiny molten pools on the dissimilar alloy 20 could not form a good connection with the welding wire 50 droplets, resulting in increased weld surface defects and poor weld formation. The statistical data on the number of defects on the weld surfaces after welding in Examples 1 to 4 and Comparative Example 1 are shown in Table 1.

[0124] Table 1. Statistical data on the number of defects on the weld surface after welding.

[0125]

[0126] The surface morphology of the weld joint in the embodiments and comparative examples is as follows: Figures 2-4 As shown. Figure 2 The surface morphology of the weld seam of the die-cast aluminum alloy 10-dissimilar alloy 20 prepared in Example 1 is shown by... Figure 2 As can be seen, no obvious welding defects were found at the weld in Example 1, and the first-time welding yield was 80%. Figure 3 The surface morphology of the weld seam of the die-cast aluminum alloy 10-dissimilar alloy 20 prepared in Example 2 is shown by... Figure 3 As can be seen, the weld in Example 2 was well formed, and no welding defects such as porosity or cracks were found. Figure 4 This image shows the surface morphology of the weld seam of the die-cast aluminum alloy 10-dissimilar alloy 20 welded joint obtained using the welding method of Comparative Example 1. Figure 4 As can be seen, the weld seam is discontinuous and prone to defects such as bursts and bulges, and the first-pass welding yield is less than 20%. Examples 3 and 4 also achieved better first-pass welding yields. The statistical data of the first-pass welding yields after welding in Examples 1 to 4 and Comparative Example 1 are shown in Table 2.

[0127] Table 2. Statistical data on the first-pass welding yield after welding.

[0128]

[0129] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A welding method for die-cast aluminum alloy and dissimilar alloy, characterized in that, Includes the following steps: Take a die-cast aluminum alloy and a dissimilar alloy; partially overlap the die-cast aluminum alloy and the dissimilar alloy to form a welded joint, thereby obtaining a workpiece to be welded; the dissimilar alloy includes one of 5-series aluminum alloy, 6-series aluminum alloy and 7-series aluminum alloy; The workpiece to be welded is subjected to filler welding; wherein the welding heat source during filler welding includes a first laser beam and a second laser beam; the first laser beam irradiates the welding wire, and the second laser beam irradiates the dissimilar alloy; the distance ΔL between the first laser beam and the second laser beam in the welding direction is controlled to be 0.4mm~1mm; the diameter d of the welding wire is 0.8mm~2mm; the perpendicular distance Δh between the welding wire and the dissimilar alloy is controlled to be 0~d / 2mm; and the perpendicular distance ΔZ between the welding wire and the second laser beam is controlled to be 0~0.5mm. In the step of performing filler welding on the workpiece to be welded, the dissimilar alloy in the workpiece to be welded is closer to the welding head end of the welding wire than the die-cast aluminum alloy; the distance ΔS between the welding wire and the die-cast aluminum alloy is controlled to be 0.4mm~1.86mm.

2. The welding method for die-cast aluminum alloy and dissimilar alloy according to claim 1, characterized in that, The angle between the first laser beam and the second laser beam in the welding direction is controlled to be 0°~3°.

3. The welding method for die-cast aluminum alloy-dissimilar alloy according to claim 2, characterized in that, The first laser beam and the second laser beam are controlled to be parallel in the welding direction.

4. The welding method for die-cast aluminum alloy and dissimilar alloy according to claim 1, characterized in that, The step of irradiating the welding wire with the first laser beam includes: controlling the first laser beam to irradiate the welding wire with a power of 1.5kW to 2.5kW; and controlling the angle β between the first laser beam and the welding wire in the welding direction to be 65° to 80°.

5. The welding method for die-cast aluminum alloy-dissimilar alloy according to claim 4, characterized in that, The step of irradiating the welding wire with the first laser beam has one or more of the following features: (1) Control the irradiation length ΔH of the first laser beam on the welding wire to be 0.4mm~2mm; (2) Control the oscillation diameter D of the first laser beam to be 0.8 mm to 2 mm; (3) Control the oscillation frequency of the first laser beam to 100Hz~350Hz.

6. The welding method for die-cast aluminum alloy-dissimilar alloy according to any one of claims 1 to 5, characterized in that, The welding wire is an Al-Mg welding wire.

7. The welding method for die-cast aluminum alloy-dissimilar alloy according to any one of claims 1 to 5, characterized in that, The thickness of the die-cast aluminum alloy is 1mm to 3mm; And / or, the thickness of the dissimilar alloy is 1mm to 3mm.

8. The welding method for die-cast aluminum alloy-dissimilar alloy according to any one of claims 1 to 5, characterized in that, The width of the welded joint is >20mm; And / or, control the oscillation diameter of the second laser beam to be 0~0.1mm.

9. The welding method for die-cast aluminum alloy-dissimilar alloy according to any one of claims 1 to 5, characterized in that, The wire feeding speed of the welding wire is controlled to be 1m / min to 2m / min; In the step of performing filler welding on the workpiece to be welded, the welding speed is 1.5m / min to 2.2m / min.

10. The welding method for die-cast aluminum alloy-dissimilar alloy according to any one of claims 1 to 5, characterized in that, Before the step of partially overlapping the die-cast aluminum alloy and the dissimilar alloy to form a welded joint, the method further includes: The die-cast aluminum alloy and the dissimilar alloy are subjected to surface cleaning.

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