A low-power laser welding and cold welding composite welding process for aluminum alloy welding

Abstract

The present invention proposes a low-power laser welding and cold welding composite welding process for aluminum alloy welding, which relates to the field of welding technology. The low-power laser welding and cold welding composite welding process for aluminum alloy welding includes the following steps: surface treatment: cleaning the surface of the plate, removing impurities on the surface of the plate, and obtaining the plate to be welded; assembly before welding: assembling the plate to be welded into a preset welding area; welding process: determining the welding position of the plate to be welded, and using laser pilot welding and cold welding to perform welding processes simultaneously, wherein the position of the laser is located in front of the cold welding current. The present invention effectively reduces heat input, greatly reduces the burnout of low-boiling point alloy elements, is beneficial to actual production applications, and is easy to automate. The low-power laser welding cold welding method proposed in the present invention achieves high-quality and high-strength connections.

Description

Technical Field

[0001] The present invention relates to the technical field of welding, and in particular to a low-power laser welding and cold welding composite welding process for aluminum alloy welding. Background Art

[0002] Aluminum alloys are now widely used in the automotive industry. Demand for aluminum alloys is steadily increasing due to their low density, high strength, excellent plasticity, electrical and thermal conductivity, and corrosion resistance. Aluminum alloys are also widely used in aerospace and shipbuilding.

[0003] At present, scholars at home and abroad have conducted research on various welding methods such as laser welding and composite welding, and have achieved good welding results. Laser welding has high welding speed, precision, reliability and quality, but aluminum alloy has a low absorption rate for lasers, and a large amount of laser light will be reflected by the aluminum alloy. Therefore, in actual production, high-energy-density laser beams or composite welding methods are often used to achieve aluminum alloy welding connections. As a result, low-boiling-point alloying elements are severely heated, welding strength is reduced, and the weld penetration depth is small. Cold welding, on the other hand, has low heat input, which facilitates precise control of heat input, but the weld penetration depth is small and the weld width is too large.

[0004] The inventors found in their research that the prior art has at least the following shortcomings:

[0005] Excessive welding heat input and a large welding heat-affected zone result in reduced strength. Summary of the Invention

[0006] The purpose of the present invention is to provide a low-power laser welding and cold welding composite welding process for aluminum alloy welding, which solves the shortcomings of the existing technology. It can adopt a laser welding and cold welding composite welding method to effectively improve the welding penetration and enhance the mechanical properties of the weld while ensuring low heat input. The design is reasonable and practical.

[0007] The embodiment of the present invention is achieved as follows:

[0008] The present invention provides a low-power laser welding and cold welding hybrid welding process for aluminum alloy welding, comprising the following steps:

[0009] Surface treatment: clean the surface of the plate, remove impurities on the surface of the plate, and obtain the plate to be welded;

[0010] Assembly before welding: assembling the plates to be welded into the preset welding area;

[0011] Welding process: determining the welding position of the plate to be welded, and simultaneously performing the welding process by laser pilot welding and cold welding, wherein the position of the laser is located in front of the cold welding current.

[0012] This low-power laser welding and cold welding hybrid process for aluminum alloy welding effectively reduces heat input and significantly minimizes burnout of low-boiling-point alloying elements, facilitating practical production applications and facilitating automation. Furthermore, the hybrid laser and cold welding method effectively increases weld penetration and enhances the mechanical properties of the weld seam while maintaining low heat input, resulting in a rational and practical design.

[0013] In some embodiments of the present invention, the steps of the welding process include:

[0014] In laser pilot welding, the welding speed is 1.9 to 2.1 mm / s, the defocus rate is 0 mm, and the welding power is 350 W to 400 W.

[0015] In some embodiments of the present invention, the step of welding further includes:

[0016] In cold welding, the cold welding current is 75 to 85 A, the cold welding interval time is 35 ms to 45 ms, and the welding time is 25 ms to 35 ms.

[0017] Cold welding is a process (method) that uses mechanical force, molecular force, or electricity to diffuse the welding material onto the surface of the equipment. It has the following processing advantages: 1. Repair defects in a variety of materials. 2. The weld is strong and can withstand turning, milling, planing, grinding and other processes without falling off, and can withstand pressure. 3. Low-temperature welding. The weld is strong and low-temperature welding can achieve an effect with almost no deformation. 4. There will be no cracks, annealing, or quenching. 5. The weld scar is exquisite and the material consumption is small. 6. Even if you encounter a tricky welding position, don't worry, the machine is lightweight and can be repaired flexibly. 7. The operation is simple and safe, and inexperienced workers can get started directly.

[0018] In some embodiments of the present invention, the step of welding further includes:

[0019] During the welding process, the melting zone and the heat-affected zone are protected by inert gas, wherein the flow rate of the inert gas is 5L / min to 10L / min.

[0020] During welding, the shielding gas is both the protective medium for the welding area and the gas medium for generating the arc. Gas welding and cutting are mainly completed by relying on the high-temperature flame generated by the concentrated heat generated by gas combustion. Therefore, the properties of the gas (such as physical and chemical properties) not only affect the protection effect, but also affect the ignition of the arc and the stability of the welding and cutting processes.

[0021] In some embodiments of the present invention, the inert gas includes one or a combination of CO2, Ar, He, O2, N2 and H2.

[0022] During welding, the shielding gas is both the protective medium for the welding area and the gas medium for generating the arc. Gas welding and cutting are mainly completed by relying on the high-temperature flame generated by the concentrated heat generated by gas combustion. Therefore, the properties of the gas (such as physical and chemical properties) not only affect the protection effect, but also affect the ignition of the arc and the stability of the welding and cutting processes.

[0023] In some embodiments of the present invention, the surface treatment step includes:

[0024] Steel brush scrubbing: Use a steel brush to scrub the plate at a preset angle;

[0025] Ultrasonic cleaning: the scrubbed plate is placed in an acetone solution and cleaned using ultrasonic waves;

[0026] Drying treatment: Let it dry.

[0027] Ultrasonic cleaning has at least the following advantages: 1) Batch cleaning of multiple workpieces: Ultrasonic cleaning machines are particularly suitable for workpieces with complex shapes and structures; no matter how complex the shape of the workpiece is, put it in the cleaning liquid, and the ultrasonic cleaning effect can reach any place that can be exposed to the liquid; 2) Thoroughly clean the dead corners of the workpiece: Ultrasonic cleaning machines have a significant cleaning effect on workpieces that cannot be completely and effectively cleaned by manual and other cleaning methods. They can thoroughly meet the cleaning requirements and remove stains in the dead corners of complex workpieces; 3) Multifunctional cleaning: Ultrasonic cleaning machines can combine different solvents to achieve different effects and meet different supporting production processes, such as degreasing, rust removal, dust removal, wax removal, chip removal, phosphating, passivation, ceramicization, electroplating, etc.; 4) Reduce manpower: The use of ultrasonic cleaning machines can realize fully automatic cleaning and drying of workpieces, Only one operator is required at each loading and unloading end of the workpiece cleaning, which greatly reduces the number of personnel and cleaning time required for manual cleaning; 5) Reduce labor intensity: Manual cleaning: The cleaning environment is relatively harsh, the physical labor is heavy, and complex mechanical parts require a long time to clean; Ultrasonic cleaning: Low labor intensity, clean and orderly cleaning environment, automatic and efficient cleaning of complex parts; 6) Reduce pollution: Ultrasonic cleaning can effectively reduce pollution, reduce the damage of toxic solvents to humans, and is environmentally friendly and efficient; 7) Reduce operating time: Compared with manual cleaning, the cleaning time of ultrasonic cleaning machine is reduced to one-fourth of manual cleaning; 8) Energy saving and environmental protection: Ultrasonic cleaning is equipped with a circulating filtration system, which can realize the circulating filtration and repeated use of cleaning solvents, which is of great significance for saving water resources, cleaning solvent costs, and improving the company's environmental protection image.

[0028] In some embodiments of the present invention, the preset angle is 45 degrees.

[0029] Setting the preset angle to 45 degrees makes it easier to use a steel brush to scrub the plate, making it easier to remove the oxide scale on the surface of the plate and improving the cleanliness of the plate.

[0030] In some embodiments of the present invention, the surface treatment step includes:

[0031] The impurities include oxide scale and oil stains.

[0032] In some embodiments of the present invention, the steps of pre-welding assembly include:

[0033] The plates to be welded are assembled into a preset welding area by splicing, and after ensuring that two adjacent plates abut against each other, the plates are butted together using a welding fixture.

[0034] In some embodiments of the present invention, the plate is an aluminum plate or an aluminum alloy plate.

[0035] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0036] 1) The present invention effectively reduces heat input and greatly reduces the burnout of low-boiling-point alloy elements, is beneficial to actual production applications, and is easy to automate.

[0037] 2) The low-power laser cold welding method proposed in the present invention realizes high-quality and high-strength connections, and can achieve the effect of "1+1>2". Under lower heat input, a larger penetration depth is obtained, and the tensile strength can reach 92MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 A flow chart of a low-power laser welding and cold welding composite welding process for aluminum alloy welding provided by an embodiment of the present invention;

[0040] Figure 2 Metallographic micrograph of the heat-affected zone of the weld seam during cold welding of aluminum plate composite welding;

[0041] Figure 3 Metallographic micrograph of the heat-affected zone of the weld during laser welding of aluminum composite plates;

[0042] Figure 4 This is a metallographic micrograph of the heat-affected zone of the laser-welded aluminum plate.

[0043] Figure 5 This is a metallographic micrograph of the heat-affected zone of the weld of the aluminum plate cold welding;

[0044] Figure 6 Schematic diagram of the device for the low-power laser welding and cold welding composite welding process for aluminum alloy welding provided in this embodiment. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0047] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0048] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "inner," etc. appear to indicate an orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings, or are the orientation or positional relationship in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," etc. are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0049] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0050] Example 1

[0051] Please refer to Figure 1 and Figure 6 , Figure 1 This is a flow chart of a low-power laser welding and cold welding composite welding process for aluminum alloy welding provided by an embodiment of the present invention. Figure 6 Schematic diagram of the device for the low-power laser welding and cold welding composite welding process for aluminum alloy welding provided in this embodiment.

[0052] The present invention provides a low-power laser welding and cold welding hybrid welding process for aluminum alloy welding, comprising the following steps:

[0053] S100 surface treatment: clean the surface of 6061 aluminum alloy plate, remove impurities on the surface of 6061 aluminum alloy plate, and obtain 6061 aluminum alloy plate to be welded;

[0054] S200 pre-welding assembly: Assemble the 6061 aluminum alloy plate to be welded into the preset welding area;

[0055] S300 welding process: Determine the welding position of the 6061 aluminum alloy plate to be welded, and use laser pilot welding and cold welding to perform welding processes simultaneously, wherein the laser is positioned in front of the cold welding current.

[0056] This low-power laser welding and cold welding hybrid process for aluminum alloy welding effectively reduces heat input and significantly minimizes burnout of low-boiling-point alloying elements, facilitating practical production applications and facilitating automation. Furthermore, the hybrid laser and cold welding method effectively increases weld penetration and enhances the mechanical properties of the weld seam while maintaining low heat input, resulting in a rational and practical design.

[0057] In this embodiment, the steps of the welding process include: in laser pilot welding, the welding speed is 1.9 mm / s, the defocus rate is 0 mm, and the welding power is 350 W.

[0058] In the cold welding process, the cold welding current is 75A, the cold welding interval is 35ms, and the welding time is 25ms. During the welding process, the molten zone and the heat-affected zone are protected by inert gas, wherein the flow rate of the inert gas is 5L / min to 10L / min.

[0059] At the same time, the steps in surface treatment include:

[0060] Steel brush scrubbing: Use a steel brush to scrub the plate at a preset angle;

[0061] Ultrasonic cleaning: Place the scrubbed plate into an acetone solution and clean it with ultrasonic waves;

[0062] Drying treatment: Let it dry.

[0063] In this embodiment, the surface treatment steps include:

[0064] Impurities include scale and oil.

[0065] At the same time, the steps of pre-welding assembly include:

[0066] The plates to be welded are assembled into the preset welding area by splicing, and after ensuring that the two adjacent plates are in contact with each other, the plates are butted together using a welding fixture.

[0067] That is to say, the 6061 aluminum alloy plates are assembled in the welding area by mechanical devices. The assembly method is splicing without leaving any gaps, and the parent materials are accurately connected by welding fixtures.

[0068] In this embodiment, the specification of the 6061 aluminum alloy plate is 60*60*1.5 (mm).

[0069] Example 2

[0070] Please refer to Figure 1 and Figure 6 , Figure 1 This is a flow chart of a low-power laser welding and cold welding composite welding process for aluminum alloy welding provided by an embodiment of the present invention. Figure 6 Schematic diagram of the device for the low-power laser welding and cold welding composite welding process for aluminum alloy welding provided in this embodiment.

[0071] The present invention provides a low-power laser welding and cold welding hybrid welding process for aluminum alloy welding, comprising the following steps:

[0072] S100 surface treatment: clean the surface of 6061 aluminum alloy plate, remove impurities on the surface of 6061 aluminum alloy plate, and obtain 6061 aluminum alloy plate to be welded;

[0073] S200 pre-welding assembly: Assemble the 6061 aluminum alloy plate to be welded into the preset welding area;

[0074] S300 welding process: Determine the welding position of the 6061 aluminum alloy plate to be welded, and use laser pilot welding and cold welding to perform welding processes simultaneously, wherein the laser is positioned in front of the cold welding current.

[0075] This low-power laser welding and cold welding hybrid process for aluminum alloy welding effectively reduces heat input and significantly minimizes burnout of low-boiling-point alloying elements, facilitating practical production applications and facilitating automation. Furthermore, the hybrid laser and cold welding method effectively increases weld penetration and enhances the mechanical properties of the weld seam while maintaining low heat input, resulting in a rational and practical design.

[0076] In this embodiment, the steps of the welding process include: in laser pilot welding, the welding speed is 2.0 mm / s, the defocus rate is 0 mm, and the welding power is 375 W.

[0077] In cold welding, the cold welding current is 80A, the cold welding interval is 40ms, and the welding time is 30ms. During the welding process, inert gas is used to protect the melting zone and the heat-affected zone, wherein the flow rate of the inert gas is 5L / min to 10L / min.

[0078] At the same time, the steps in surface treatment include:

[0079] Steel brush scrubbing: Use a steel brush to scrub the plate at a preset angle;

[0080] Ultrasonic cleaning: Place the scrubbed plate into an acetone solution and clean it with ultrasonic waves;

[0081] Drying treatment: Let it dry.

[0082] In this embodiment, the surface treatment steps include:

[0083] Impurities include scale and oil.

[0084] At the same time, the steps of pre-welding assembly include:

[0085] The plates to be welded are assembled into the preset welding area by splicing, and after ensuring that the two adjacent plates are in contact with each other, the plates are butted together using a welding fixture.

[0086] In this embodiment, the specification of the 6061 aluminum alloy plate is 60*60*1.5 (mm).

[0087] Example 3

[0088] Please refer to Figure 1 and Figure 6 , Figure 1 This is a flow chart of a low-power laser welding and cold welding composite welding process for aluminum alloy welding provided by an embodiment of the present invention. Figure 6 Schematic diagram of the device for the low-power laser welding and cold welding composite welding process for aluminum alloy welding provided in this embodiment.

[0089] The present invention provides a low-power laser welding and cold welding hybrid welding process for aluminum alloy welding, comprising the following steps:

[0090] S100 surface treatment: clean the surface of 6061 aluminum alloy plate, remove impurities on the surface of 6061 aluminum alloy plate, and obtain 6061 aluminum alloy plate to be welded;

[0091] S200 pre-welding assembly: Assemble the 6061 aluminum alloy plate to be welded into the preset welding area;

[0092] S300 welding process: Determine the welding position of the 6061 aluminum alloy plate to be welded, and use laser pilot welding and cold welding to perform welding processes simultaneously, wherein the laser is positioned in front of the cold welding current.

[0093] This low-power laser welding and cold welding hybrid process for aluminum alloy welding effectively reduces heat input and significantly minimizes burnout of low-boiling-point alloying elements, facilitating practical production applications and facilitating automation. Furthermore, the hybrid laser and cold welding method effectively increases weld penetration and enhances the mechanical properties of the weld seam while maintaining low heat input, resulting in a rational and practical design.

[0094] In this embodiment, the steps of the welding process include: in laser pilot welding, the welding speed is 2.1 mm / s, the defocus rate is 0 mm, and the welding power is 400 W.

[0095] In the cold welding process, the cold welding current is 85A, the cold welding interval is 45ms, and the welding time is 35ms. During the welding process, the molten zone and the heat-affected zone are protected by inert gas, wherein the flow rate of the inert gas is 5L / min to 10L / min.

[0096] At the same time, the steps in surface treatment include:

[0097] Steel brush scrubbing: Use a steel brush to scrub the plate at a preset angle;

[0098] Ultrasonic cleaning: Place the scrubbed plate into an acetone solution and clean it with ultrasonic waves;

[0099] Drying treatment: Let it dry.

[0100] In this embodiment, the surface treatment steps include:

[0101] Impurities include scale and oil.

[0102] At the same time, the steps of pre-welding assembly include:

[0103] The plates to be welded are assembled into the preset welding area by splicing, and after ensuring that the two adjacent plates are in contact with each other, the plates are butted together using a welding fixture.

[0104] In this embodiment, the specification of the 6061 aluminum alloy plate is 60*60*1.5 (mm).

[0105] Comparative Example

[0106] In the comparative example, 6061 aluminum alloy plates were welded by cold welding, laser welding and arc pilot respectively, and the first preset position and the second preset position were tested to obtain the depth of the two places, namely, the depth of the two places, namely the depth of the two places 1 and the depth of the two places 2.

[0107] After averaging the dissolution depth data obtained in Experimental Examples 1 to 3, the dissolution depths at the first preset position and the second preset position in the laser pilot mode are obtained, namely, dissolution depth 1 and dissolution depth 2.

[0108] Finally, we get the following table:

[0109] Table 1 Comparison of penetration depth (unit: mm)

[0110]

[0111] It is worth noting that the metallographic micrograph of the weld can be referred to Figure 2-Figure 5 ,in, Figure 2 Metallographic micrograph of the heat-affected zone of the weld seam during cold welding of aluminum plate composite welding; Figure 3 Metallographic micrograph of the heat-affected zone of the weld during laser welding of aluminum composite plates; Figure 4 This is a metallographic micrograph of the heat-affected zone of the laser-welded aluminum plate. Figure 5 This is a metallographic micrograph of the heat-affected zone of the weld of cold welding of aluminum plates.

[0112] In summary, the embodiments of the present invention provide a low-power laser welding and cold welding composite welding process for aluminum alloy welding. The low-power laser welding and cold welding composite welding process for aluminum alloy welding includes the following steps: surface treatment: cleaning the surface of the plate, removing impurities on the surface of the plate, and obtaining the plate to be welded; pre-welding assembly: assembling the plate to be welded into a preset welding area; welding treatment: determining the welding position of the plate to be welded, and using laser pilot welding and cold welding to perform welding treatment simultaneously, wherein the position of the laser is located in front of the cold welding current. The present invention effectively reduces the heat input, greatly reduces the burnout of low-boiling point alloy elements, is beneficial to actual production applications, and is easy to automate. A low-power laser welding cold welding method proposed in the present invention realizes high-quality and high-strength connections, and can achieve the effect of "1+1>2", as shown in Table 1 for details. Under lower heat input, a larger penetration depth is obtained, and the tensile strength can reach 92MPa.

[0113] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A low-power laser welding and cold welding composite welding process for aluminum alloy welding, characterized in that: The following steps are involved: Surface treatment: cleaning the surface of the plate to remove impurities on the surface of the plate to obtain the plate to be welded, the plate is an aluminum plate or an aluminum alloy plate; Assembly before welding: assembling the plates to be welded into the preset welding area; Welding process: Determine the welding position of the plate to be welded, and use laser pilot welding and cold welding to perform welding processes simultaneously, wherein the position of the laser is located in front of the cold welding current. In laser pilot welding, the welding speed is 1.9~2.1mm / s, the defocus rate is 0mm, and the welding power is 350W~400W. In cold welding, the cold welding current is 75~85A, the cold welding interval time is 35ms~45ms, and the welding time is 25ms~35ms.

2. The low-power laser welding and cold welding composite welding process for aluminum alloy welding according to claim 1 is characterized in that: The welding process also includes: During the welding process, inert gas is used to protect the melting zone and heat-affected zone, wherein the flow rate of the inert gas is 5L / min to 10L / min.

3. The low-power laser welding and cold welding composite welding process for aluminum alloy welding according to claim 2 is characterized in that: The inert gas includes one or a combination of CO2, Ar, He, O2, N2 and H2.

4. The low-power laser welding and cold welding composite welding process for aluminum alloy welding according to claim 1 is characterized in that: The steps in surface treatment include: Steel brush scrubbing: Use a steel brush to scrub the plate at a preset angle; Ultrasonic cleaning: the scrubbed plate is placed in an acetone solution and cleaned using ultrasonic waves; Drying treatment: Let it dry.

5. The low-power laser welding and cold welding composite welding process for aluminum alloy welding according to claim 4 is characterized in that: The preset angle is 45 degrees.

6. The low-power laser welding and cold welding composite welding process for aluminum alloy welding according to claim 4, characterized in that: The steps in surface treatment include: The impurities include oxide scale and oil stains.

7. The low-power laser welding and cold welding composite welding process for aluminum alloy welding according to claim 1 is characterized in that: The steps of pre-welding assembly include: The plates to be welded are assembled into a preset welding area by splicing, and after ensuring that two adjacent plates abut against each other, the plates are butted together using a welding fixture.

Images