Laser welding method for aluminum alloy and glass heterogeneous materials

Abstract

The invention relates to a laser welding method for aluminum alloy and glass heterogeneous materials, and belongs to the technical field of laser. Through research and optimization of laser welding parameters, welding tracks of a plurality of welding seams are designed, and a transverse and vertical crossing mode is adopted to effectively optimize heat distribution and bonding strength of a welding area; the aluminum alloy-glass welding body which is high in welding strength and excellent in sealing effect is successfully prepared in a room-temperature environment without a protective atmosphere by adopting a lap welding form. The process has the characteristics of simple preparation flow, easiness in operation and high efficiency, and has wide application prospects.

Description

Technical Field

[0001] The present invention relates to a laser welding method for heterogeneous materials, aluminum alloy and glass. By optimizing laser welding parameters, a multi-pass weld trajectory is designed, and a horizontal and vertical cross-welding method is adopted to successfully achieve laser welding of aluminum alloy and glass. This method belongs to the field of laser technology. Background Art

[0002] Aluminum alloy-to-glass connectors offer broad application prospects in optoelectronic components, instrumentation, aerospace, composite materials, and other fields due to their high durability, excellent airtightness, strong electrical insulation, excellent corrosion resistance, light weight, and excellent transparency. Aluminum alloy-to-glass connectors play a key role in the manufacture of high-precision components such as optoelectronic devices, sealed connectors, and sensors.

[0003] Currently, the main technologies for joining aluminum alloys to glass include matching seals and brazing seals, but these traditional methods have certain limitations in practical application. For example, the matching seal process requires heating and cooling in a furnace, which is not only time-consuming and has a long production cycle, but the oxide layer on the aluminum alloy surface easily affects its brightness and weld quality, making it unsuitable for conventional production. Traditional high-temperature brazing technology cannot meet the requirements of aluminum alloy-glass joining due to the poor heat resistance of aluminum alloys, which easily melt and soften at high temperatures.

[0004] Laser welding, an advanced welding technology with advantages such as fast welding speed, high precision, and small weld seams, provides a new solution for connecting aluminum alloys to glass. However, the differences in physical and chemical properties between aluminum alloys and glass, such as the mismatch in thermal expansion coefficients between aluminum alloys and glass, and the poor wettability between the two, result in poor bonding between aluminum alloys and glass during laser welding, making it difficult to form a strong welded joint. To improve welding performance, current research focuses on pre-treating the aluminum alloy surface, such as ink impregnation. However, the organic matter in the ink may release hydrogen during welding, causing pores in the weld. In addition, there are methods such as anodizing, micro-arc oxidation, and vapor deposition to form an intermediate layer on the aluminum alloy surface to improve bonding with glass. However, these methods are complex, difficult to prepare, and costly.

[0005] Therefore, in order to solve the problem of difficulty in welding aluminum alloy and glass and the complex and limited welding process, there is an urgent need for a simple, controllable and excellent sealing welding method to achieve efficient and stable connection between aluminum alloy and glass. Summary of the Invention

[0006] To address these issues, the present invention provides a laser welding method for heterogeneous aluminum alloy and glass. This method directly welds the aluminum alloy and glass, avoiding complex surface pretreatment and cumbersome process flows. The welding process is simple and controllable, requiring no shielding gas and can be completed entirely at room temperature. The result is a high-strength, excellently sealed aluminum alloy-glass weld.

[0007] The purpose of the present invention is to provide a laser welding method for aluminum alloy and glass heterogeneous materials, the specific steps are as follows:

[0008] Step 1: Perform simple pretreatment on the aluminum alloy and glass surfaces to be welded;

[0009] Step 2: Set the welding trajectory according to the specific shape and size of the aluminum alloy and glass.

[0010] Step 3: Set laser processing parameters;

[0011] Step 4: According to the set welding trajectory and parameters, calibrate the welding position and complete the laser welding to obtain an aluminum alloy-glass welded body.

[0012] In an embodiment of the present invention, the pretreatment described in step 1 is as follows: the aluminum alloy surface to be welded is polished with 600-mesh, 800-mesh, 1000-mesh, and 1500-mesh sandpaper in sequence to ensure a smooth and flat surface. The polished aluminum alloy surface is then cleaned with anhydrous ethanol and dried. The glass surface to be welded is then cleaned with water and allowed to dry naturally to ensure a clean surface free of impurities.

[0013] In an embodiment of the present invention, the welding trajectory designed in step 2 is a multi-pass weld, which is welded in a horizontal and vertical cross manner. First, the welding is scanned line by line in the X-axis direction, and then the welding is scanned line by line in the Y-axis direction. Adjacent welding lines are parallel and have equal spacing.

[0014] In an embodiment of the present invention, the laser used in step three is a 1064nm fiber laser, and the main welding parameters are: laser power of 2 to 20W, laser frequency of 2 to 20Khz, laser welding speed of 200 to 1200mm / s, focal length range of -0.5mm to 0.5mm, and weld line spacing of 0.1 to 0.5mm.

[0015] In an embodiment of the present invention, the welding connection method adopted in step 4 is lap welding, specifically, the glass is covered on the upper surface of the aluminum alloy for welding.

[0016] In an embodiment of the present invention, in step four, according to the set welding trajectory and parameters, in a room temperature environment without a protective atmosphere, the laser generated by the laser is focused through the glass to the upper surface of the aluminum alloy, generating heat to melt the aluminum alloy and glass near the contact surface, and finally obtaining an aluminum alloy-glass welded body.

[0017] The advantages of the present invention are:

[0018] (1) The present invention directly welds aluminum alloy and glass using a laser welding method. The entire welding process is carried out at room temperature without a protective atmosphere, achieving good welding results. Compared with matching sealing, laser welding has a shorter production cycle and higher welding precision. At the same time, laser welding avoids the limitations of traditional high-temperature brazing, where excessive temperatures have an adverse effect on aluminum alloys.

[0019] (2) By optimizing the welding trajectory and improving the welding parameters, the present invention successfully achieves direct welding of aluminum alloy to glass with only simple sandpaper pre-grinding of the aluminum alloy surface. Compared with the complex pretreatment methods commonly used in existing research, such as anodizing, micro-arc oxidation, and vapor deposition, the welding method of the present invention is simple and easy to control, does not require strict process control, and can directly weld aluminum alloy to glass, producing an aluminum alloy-glass welded body with high weld strength and excellent sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of laser welding trajectory

[0021] Figure 2 Schematic diagram of aluminum alloy-glass laser welding

[0022] Explanation of reference numerals: 1-laser beam, 2-glass, 3-aluminum alloy, 4-welding platform DETAILED DESCRIPTION

[0023] In the embodiment, the aluminum alloy used is 6061 aluminum alloy with a thickness of 4 mm, and the glass is K9 glass with a size of 10 mm×10 mm×1 mm. Various processes and methods not described in detail are conventional methods well known in the art.

[0024] Example 1

[0025] Step 1: Grind the surface of the 6061 aluminum alloy to be welded with 600 mesh, 800 mesh, 1000 mesh, and 1500 mesh sandpaper in turn to ensure that the surface is flat and smooth; clean the polished aluminum alloy surface with anhydrous ethanol and dry it; for the K9 glass surface to be welded, clean it with clean water and dry it naturally to ensure that the surface is clean and free of impurities.

[0026] Step 2: According to the specific shape and size of the 6061 aluminum alloy and K9 glass to be welded, set the shape of the welding track as follows: Figure 1 As shown, the specific size is 8mm×8mm.

[0027] Step 3: Set the laser processing parameters; use a 1064nm fiber laser, and the welding parameters are as follows: laser power is 14W, laser frequency is 3Khz, laser welding speed is 400mm / s, and weld line spacing is 0.1mm.

[0028] Step 4: Place the aluminum alloy surface facing up, the glass on top, and the aluminum alloy on the bottom, overlapping each other, on a welding platform. Align the welding position according to the set welding trajectory and parameters, and complete the welding in room temperature air. This results in a 6061 aluminum alloy-K9 glass weld.

[0029] After testing, a shear test was conducted on the 6061 aluminum alloy-K9 glass welded body, and the sealing strength was measured to be 21.38Mpa.

[0030] Example 2

[0031] Step 1: According to the specific shape and size of the 6061 aluminum alloy and K9 glass to be welded, set the shape of the welding track as follows: Figure 1 As shown, the specific size is 8mm×8mm.

[0032] Step 2: Set the laser processing parameters; use a 1064nm fiber laser, and the welding parameters are as follows: laser power is 14W, laser frequency is 3Khz, laser welding speed is 400mm / s, and weld line spacing is 0.1mm.

[0033] Step 3: Place the aluminum alloy surface facing up, the glass on top, and the aluminum alloy on the bottom, overlapping each other and placing them on the welding platform. Align the welding position according to the set welding trajectory and parameters, and complete the welding in room temperature air. This results in a 6061 aluminum alloy-K9 glass weld.

[0034] Tests have shown that the seal strength of a 6061 aluminum alloy-K9 glass weld is 4.98 MPa. Therefore, proper grinding and cleaning can remove some imperfections on the surface to be welded, improve the surface finish, and enhance weld quality.

[0035] Example 3

[0036] Step 1: Grind the surface of the 6061 aluminum alloy to be welded with 600 mesh, 800 mesh, 1000 mesh, and 1500 mesh sandpaper in turn to ensure that the surface is flat and smooth; clean the polished aluminum alloy surface with anhydrous ethanol and dry it; for the K9 glass surface to be welded, clean it with clean water and dry it naturally to ensure that the surface is clean and free of impurities.

[0037] Step 2: According to the specific shape and size of the 6061 aluminum alloy and K9 glass to be welded, set the shape of the welding track as follows: Figure 1 As shown, the specific size is 8mm×8mm.

[0038] Step 3: Set the laser processing parameters; use a 1064nm fiber laser, and the welding parameters are as follows: laser power is 14W, laser frequency is 5Khz, laser welding speed is 400mm / s, and weld line spacing is 0.3mm.

[0039] Step 4: Place the aluminum alloy surface facing up, the glass on top, and the aluminum alloy on the bottom, overlapping each other, on a welding platform. Align the welding position according to the set welding trajectory and parameters, and complete the welding in room temperature air. This results in a 6061 aluminum alloy-K9 glass weld.

[0040] After testing, the sealing strength of the 6061 aluminum alloy-K9 glass welded body is 20.58Mpa.

[0041] The results of the examples demonstrate that the laser welding method for heterogeneous aluminum alloy and glass provided by the present invention, by optimizing the laser welding trajectory and improving welding parameters, employs a simple pretreatment step (requiring only sandpaper to polish and clean the aluminum alloy surface to be welded), and can complete welding at room temperature without a protective atmosphere. The entire process is simple and efficient, and the resulting aluminum alloy-glass welded body exhibits excellent performance and is widely applicable to sealed connectors in optoelectronic components, aerospace, and automotive applications, demonstrating broad application prospects.

Claims

1. A laser welding method for aluminum alloy and glass heterogeneous materials, characterized in that: The specific steps are as follows: Step 1: Grind the aluminum alloy surface to be welded with 600 mesh, 800 mesh, 1000 mesh, and 1500 mesh sandpaper in sequence to ensure that the surface is flat and smooth. Clean the polished aluminum alloy surface with anhydrous ethanol and dry it. Wash the glass surface to be welded with clean water and dry it naturally to ensure that the surface is clean and free of impurities. Step 2: Set the welding trajectory according to the shape and size of the aluminum alloy and glass to be welded. The welding trajectory is designed as multiple welds, using a horizontal and vertical cross-beam method to optimize the heat distribution in the welding area and enhance the bonding strength; Step 3: Set the laser processing parameters, including: laser power of 2 to 20 W, laser frequency of 2 to 20 kHz, laser welding speed of 200 to 1200 mm / s, focal length range of -0.5 mm to 0.5 mm, and weld line spacing of 0.1 to 0.5 mm; Step 4: Place the aluminum alloy surface to be welded facing up, the glass on top and the aluminum alloy on the bottom. Overlap the two and place them on the welding platform. Calibrate the welding position according to the set welding trajectory and parameters, and complete the welding at room temperature to finally obtain an aluminum alloy-glass welded body with high welding strength and excellent sealing effect.

2. The laser welding method of aluminum alloy and glass heterogeneous materials according to claim 1 is characterized in that The welding trajectory is designed as a multi-pass weld, using a horizontal and vertical cross method. First, the welding is scanned line by line in the X-axis direction, and then scanned line by line in the Y-axis direction. Adjacent welding lines are parallel and have equal spacing.

3. The laser welding method of aluminum alloy and glass heterogeneous materials according to claim 1, characterized in that The entire welding process is carried out at room temperature without protective atmosphere.

4. The laser welding method of aluminum alloy and glass heterogeneous materials according to claim 1, characterized in that The aluminum alloy and glass used can be widely used in sealed connectors in optoelectronic components, aerospace and automotive fields.

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