Aluminum alloy welding method, aluminum alloy structural part and vehicle

Abstract

The invention discloses an aluminum alloy welding method, an aluminum alloy structural part and a vehicle, and belongs to the technical field of welding. The welding method comprises the steps that a first aluminum alloy and a second aluminum alloy to be connected are provided, and a first to-be-welded area of the first aluminum alloy and a second to-be-welded area of the second aluminum alloy are determined; the first to-be-welded area, the middle metal layer and the second to-be-welded area are sequentially arranged in a stacked mode, and a to-be-welded intermediate is formed; and in the direction from the first to-be-welded area and the second to-be-welded area to the middle metal layer, set pressure is applied to the to-be-welded intermediate, diffusion welding treatment is conducted at the welding temperature, and the welding temperature is higher than the temperature at which the metal aluminum and the metal corresponding to the middle metal layer are subjected to the eutectic reaction. By means of the method, welding of the aluminum alloy can be completed through the eutectic reaction between the aluminum alloy and the middle metal layer, the welding quality is effectively guaranteed, and the welding efficiency and the welding cost are both considered.

Description

Technical Field

[0001] The present application relates to the field of welding technology, and in particular to an aluminum alloy welding method, an aluminum alloy structural part and a vehicle. Background Art

[0002] With the continuous advancement and innovation of technology, vehicle lightweighting has become an important way to achieve vehicle energy conservation and emission reduction, and is also an important trend in the development of the automobile industry. Aluminum alloy has a low density (2.7g / cm 3 It has high strength, good plasticity, corrosion resistance, and excellent thermal and electrical conductivity, making it the first choice for lightweight automotive materials, and its use in vehicles continues to increase.

[0003] In practical applications, aluminum alloys usually need to be connected to the car body by welding. In related technologies, aluminum alloy welding methods include MIG welding (Metal Inert Gas Welding), TIG welding (Tungsten Inert Gas Welding), laser welding, resistance welding and other methods, which can be applied to different scenarios to meet different welding needs.

[0004] However, among the above-mentioned welding methods, MIG welding has high heat input control accuracy and difficulty, and cannot guarantee welding accuracy; TIG welding requires the operator to precisely control the welding process, and cannot guarantee welding accuracy and efficiency; the welding quality of resistance welding is difficult to guarantee; and laser welding is more expensive. Summary of the invention

[0005] The present application provides an aluminum alloy welding method, an aluminum alloy structural part and a vehicle to solve the technical problems existing in the related art. The technical solutions include the following:

[0006] In a first aspect, the present application provides a method for welding aluminum alloys, the welding method comprising: providing a first aluminum alloy and a second aluminum alloy to be connected, determining a first area to be welded of the first aluminum alloy and a second area to be welded of the second aluminum alloy; arranging the first area to be welded, an intermediate metal layer, and the second area to be welded in sequence to form an intermediate body to be welded; applying a set pressure to the intermediate body to be welded along a direction from the first area to be welded and the second area to be welded to the intermediate metal layer and performing diffusion welding at a welding temperature, wherein the welding temperature is greater than the temperature at which a eutectic reaction occurs between metallic aluminum and the metal corresponding to the intermediate metal layer.

[0007] In some possible implementations, the intermediate metal layer is a copper foil, and the thickness of the copper foil is 30 micrometers to 60 micrometers.

[0008] In some possible implementations, the welding temperature is 550°C-570°C.

[0009] In some possible implementations, the intermediate body to be welded is kept warm for 3 min-10 min at the welding temperature.

[0010] In some possible implementations, the set pressure is 1 MPa-4 MPa.

[0011] In some possible implementations, the welding method further includes: when performing diffusion welding on the intermediate body to be welded, heating the intermediate body to be welded to the welding temperature by electromagnetic induction technology; and measuring the temperature of the intermediate body to be welded with an infrared thermometer to monitor the temperature of the intermediate body to be welded.

[0012] In some possible implementations, the first area to be welded, the intermediate metal layer and the second area to be welded are the same in shape and size.

[0013] In some possible implementations, before the stacking arrangement is performed, the first area to be welded, the intermediate metal layer, and the second area to be welded are polished and cleaned.

[0014] In a second aspect, the present application discloses an aluminum alloy structural part, which is prepared by the welding method described in the first aspect of the present application; the aluminum alloy structural part includes: a first aluminum alloy and a second aluminum alloy, and the first aluminum alloy and the second aluminum alloy are welded and connected via an intermediate metal layer.

[0015] In a third aspect, the present application discloses a vehicle, comprising the aluminum alloy structural member described in the second aspect of the present application.

[0016] The beneficial effects of the technical solution provided by this application include at least:

[0017] The technical solution provided in the embodiment of the present application forms an intermediate body to be welded by sequentially stacking a first area to be welded of a first aluminum alloy, an intermediate metal layer, and a second area to be welded of a second aluminum alloy, and through a eutectic reaction between the metals corresponding to the first aluminum alloy / the second aluminum alloy and the intermediate metal layer, the intermediate body to be welded can be diffusion welded at a set pressure and welding temperature, effectively avoiding the decrease in mechanical properties caused by the appearance of an unexpected molten aluminum alloy during the welding process, which is beneficial to improving the welding quality; at the same time, the method only needs to provide a certain pressure and welding temperature, is simple to operate, and is easy to implement repeatedly, and can ensure low welding costs when used on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 Schematic diagram of the aluminum alloy welding method provided in the embodiment of the present application;

[0020] Figure 2 is a schematic diagram of the structure of the intermediate to be welded provided in an embodiment of the present application;

[0021] Figure 3 This is a SEM morphology image of the weld of the aluminum alloy structural member of Example 1 provided in the present application;

[0022] Figure 4 This is a SEM morphology image of the weld of the aluminum alloy structural member of Example 2 provided in the present application;

[0023] Figure 5 This is a SEM morphology image of the weld of the aluminum alloy structural component of Example 3 provided in the present application. DETAILED DESCRIPTION

[0024] Although the current aluminum alloy welding methods can meet specific welding requirements in different application scenarios, they are unable to combine welding accuracy, welding quality and welding cost. The embodiment of the present invention provides an aluminum alloy welding method, which not only accurately controls the welding process and ensures the welding quality, but also has high welding efficiency and low welding cost.

[0025] In a first aspect, the present application discloses a method for welding aluminum alloy. Figure 1 Schematic diagram of the aluminum alloy welding method provided in the embodiment of the present application. Figure 1 The aluminum alloy welding method provided in the embodiment of the present application may include the following steps.

[0026] Step 110, providing a first aluminum alloy and a second aluminum alloy to be connected, and determining a first region to be welded of the first aluminum alloy and a second region to be welded of the second aluminum alloy.

[0027] Optionally, the first aluminum alloy / second aluminum alloy can be, for example, a standardized or non-standardized aluminum alloy material (for example, an aluminum alloy profile, an aluminum alloy sheet, an aluminum alloy pipe, etc.) formed through a certain processing technology and having a certain size and shape; it can also be an aluminum alloy product with a specific size and structure that can meet specific usage requirements (for example, it can be a vehicle shell, power system, structural parts in the interior and exterior decoration system, etc.), and the present application does not impose any restrictions on this.

[0028] The first area to be welded of the first aluminum alloy can, for example, be used to indicate the area on the first aluminum alloy that needs to be connected to the second aluminum alloy; similarly, the second area to be welded of the second aluminum alloy can, for example, be used to indicate the area on the second aluminum alloy that needs to be connected to the first aluminum alloy.

[0029] In some embodiments, the method of providing a first aluminum alloy and a second aluminum alloy to be connected and determining a first welding area of ​​the first aluminum alloy and a second welding area of ​​the second aluminum alloy can be adjusted according to actual application requirements, and the present application does not impose any restrictions on this.

[0030] Step 120 , stacking the first area to be welded, the middle metal layer, and the second area to be welded in sequence to form an intermediate body to be welded.

[0031] Figure 2 Schematic diagram of the structure of the intermediate to be welded provided in the embodiment of the present application. Figure 2 The intermediate body to be welded provided in the embodiment of the present application may include a first area to be welded 201 , a second area to be welded 202 and an intermediate metal layer 203 .

[0032] Schematically, the intermediate body to be welded may be, for example, a stacked body formed by sequentially stacking the first area to be welded 201, the second area to be welded 202, and the intermediate metal layer 203. The arrangement order of the first area to be welded 201, the second area to be welded 202, and the intermediate metal layer 203 in the intermediate body to be welded may be, for example, the first area to be welded 201, the intermediate metal layer 203, and the second area to be welded 202 in a stacking order from top to bottom, or the second area to be welded 202, the intermediate metal layer 203, and the first area to be welded 201 in a stacking order, and the present application does not impose any limitation on this.

[0033] Step 130, applying a set pressure to the intermediate body to be welded along the direction from the first welding area and the second welding area to the intermediate metal layer and performing diffusion welding at a welding temperature, wherein the welding temperature is greater than the temperature at which the metal aluminum and the metal corresponding to the intermediate metal layer undergo a eutectic reaction.

[0034] The pressure is set to be sufficient to exhaust the air inside the intermediate body to be welded, so that the first area to be welded, the intermediate metal layer and the second area to be welded can be in close contact.

[0035] The eutectic reaction between the metal aluminum and the intermediate metal layer can make the metal aluminum and the metal corresponding to the intermediate metal layer undergo liquid phase transformation under the set pressure and welding temperature, and form a eutectic structure through atomic diffusion, thereby realizing the welding process of the first aluminum alloy, the intermediate layer metal, and the second aluminum alloy. Among them, when the welding temperature is greater than the temperature (548.2℃) at which the metal aluminum and the metal corresponding to the intermediate metal layer undergo eutectic reaction, the atoms near the contact surface between the first area to be welded / the second area to be welded and the intermediate metal layer can have better diffusivity. The appropriate welding temperature is selected according to the material of the intermediate metal layer.

[0036] In some embodiments, the intermediate metal layer may be, for example, a copper foil, and the thickness of the copper foil may be 30 microns to 60 microns, for example, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, 55 microns, 60 microns, etc., or other values ​​within the above range, and the present application does not impose any limitation on this.

[0037] In some embodiments, the purity of the copper foil may be greater than 99.99%, for example, may include 99.999%, 99.9999%, 99.99999%, etc., or other values ​​within the above range.

[0038] Considering that the metal may undergo microstructural changes in the molten state, thus affecting the welding quality. In view of this, the upper limit of the welding temperature can be determined according to the melting points of the metals corresponding to the first aluminum alloy / second aluminum alloy and the intermediate metal layer. For example, when the intermediate metal layer in the intermediate to be welded is copper foil (melting point is 1083.4°C), the upper limit of the welding temperature can be determined according to the melting point (660°C) of the first aluminum alloy / second aluminum alloy with a lower melting point, and the eutectic reaction temperature of the intermediate metal layer copper foil and aluminum alloy is considered to determine the appropriate welding temperature range.

[0039] In some embodiments, when the intermediate to be welded is subjected to diffusion welding, the welding temperature of the diffusion welding may be 550°C-570°C, for example, 550°C, 555°C, 560°C, 565°C, 570°C, or other values ​​within the above range, and the present application does not impose any restrictions on this. By strictly controlling the range of the welding temperature, the embodiment of the present application can ensure the diffusivity of atoms on the contact surface between the first area to be welded and the intermediate metal layer, and the contact surface between the second area to be welded and the intermediate metal layer; secondly, it can avoid the generation of undesirable molten metal during the welding process to ensure the welding quality.

[0040] In some embodiments, when diffusion welding is performed on the intermediate to be welded, in order to improve the welding quality, the intermediate to be welded can be kept warm for 3 minutes to 10 minutes. The keeping time can include, for example, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, etc., or other values ​​within the above range. The present application does not impose any limitation on this.

[0041] In some embodiments, when the intermediate to be welded is subjected to diffusion welding, the set pressure of the diffusion welding can be 1MPa-4MPa, for example, it can include 1MPa, 1.5MPa, 2MPa, 2.5MPa, 3MPa, 3.5MPa, 4MPa, etc., or other values ​​within the above range, and the present application does not impose any limitation on this.

[0042] In some embodiments, the welding method provided by the embodiment of the present application may also include: when the intermediate to be welded is subjected to diffusion welding, the intermediate to be welded is heated to the welding temperature by electromagnetic induction technology; the intermediate to be welded is subjected to temperature measurement by an infrared thermometer to monitor the temperature of the intermediate to be welded. Through the above method, the embodiment of the present application can monitor the temperature of the intermediate to be welded in real time by an infrared thermometer to avoid the negative impact of inappropriate welding temperature on welding quality; on the other hand, the welding temperature and holding time during the welding process can be accurately controlled by adjusting the parameters of the electromagnetic induction technology, thereby ensuring welding quality.

[0043] In some embodiments, a method for heating an intermediate body to be welded to a set temperature by electromagnetic induction technology may include, for example: providing an induction coil; passing an alternating current into the induction coil; placing the intermediate body to be welded in a magnetic field generated around the induction coil to heat the intermediate body to be welded to a set temperature.

[0044] For example, a diffusion welding heating device is used to perform the above diffusion welding, wherein the diffusion welding device may include an induction coil and a control program, the control program may control the induction coil to pass an alternating current to start heating, or control the induction coil to stop heating by eliminating the alternating current, and the control program may also set the welding temperature (for example, by changing the frequency of the alternating current in the induction coil to adjust the temperature of the induction coil when heating) and the insulation time. The specific operation of the diffusion welding heating device for the above diffusion welding may be: placing the intermediate body to be welded at the center of the induction coil, applying a set pressure to the intermediate body to be welded along the direction from the first area to be welded and the second area to be welded in the intermediate body to be welded to the intermediate metal layer with a pressure block to exhaust the air inside the intermediate body to be welded; setting the welding temperature and insulation time of the diffusion welding through the control program; performing real-time infrared temperature measurement on the intermediate body to be welded formed by the first area to be welded, the intermediate metal layer and the second area to be welded, and then starting the control program to heat the intermediate body to the welding temperature, and then the control program enters the insulation state, and when the insulation ends, the control program is closed, and the induction coil no longer generates temperature.

[0045] In some embodiments, in order to ensure the welding quality and avoid the heat generated during the diffusion welding of the intermediate to be welded from affecting other areas on the first aluminum alloy and / or the second aluminum alloy to be connected, the shapes and sizes of the first area to be welded, the intermediate metal layer and the second area to be welded can be the same.

[0046] In some embodiments, in order to avoid the influence of impurities that may exist on the first area to be welded, the second area to be welded and the intermediate metal layer on the welding quality, before the stacking arrangement of the first area to be welded, the intermediate metal layer and the second area to be welded, the first area to be welded, the intermediate metal layer and the second area to be welded can be polished and cleaned to make the contact surface between the first area to be welded and the intermediate metal layer, and the contact surface between the second area to be welded and the intermediate metal layer smooth and clean.

[0047] In some embodiments, the method of grinding and cleaning the first area to be welded, the intermediate metal layer, and the second area to be welded may include, for example: grinding the first area to be welded, the intermediate metal layer, and the second area to be welded with sandpaper; and cleaning the ground first area to be welded, the intermediate metal layer, and the second area to be welded with alcohol. The roughness of the sandpaper may be adjusted according to actual application conditions, and this application does not limit this.

[0048] The technical solution provided in the embodiment of the present application forms an intermediate body to be welded by sequentially stacking a first area to be welded of a first aluminum alloy, an intermediate metal layer, and a second area to be welded of a second aluminum alloy, and through a eutectic reaction between the metals corresponding to the first aluminum alloy / the second aluminum alloy and the intermediate metal layer, the intermediate body to be welded can be diffusion welded at a set pressure and welding temperature, effectively avoiding the decrease in mechanical properties caused by the appearance of an unexpected molten aluminum alloy during the welding process, which is beneficial to improving the welding quality; at the same time, the method only needs to provide a certain pressure and welding temperature, is simple to operate, and is easy to implement repeatedly, and can ensure low welding costs when used on a large scale.

[0049] The present application also provides an aluminum alloy structural part, which is prepared by the welding method described in the first aspect of the present application. The aluminum alloy structural part may include, for example, a first aluminum alloy and a second aluminum alloy. The first aluminum alloy and the second aluminum alloy may be welded and connected via an intermediate metal layer.

[0050] In some embodiments, the Vickers hardness of the weld of the aluminum alloy structural member provided in the embodiment of the present application may be greater than 90.2Hv, for example, 90.2Hv, 91.2Hv, 92.2Hv, 93.3Hv, 94.2Hv, 95.2Hv, 96.2Hv, 97.2Hv, 98.2Hv, 99.2Hv, etc. The shear strength of the weld of the aluminum alloy structural member may be greater than 96.4MPa, for example, 96.4MPa, 97.4MPa, 98.4MPa, 99.4MPa, etc., or other values ​​within the above range, and the present application does not impose any limitation on this.

[0051] The weld of the aluminum alloy structural part can be used to indicate, for example, a first area to be welded of the first aluminum alloy, a second area to be welded of the second aluminum alloy, and a bonding area formed by the intermediate metal layer. The aluminum alloy structural part provided by the embodiment of the present application not only has good mechanical properties, but also is simple to prepare and easy to repeat, and has broad prospects in many fields, especially in automotive alloys.

[0052] The third aspect of the present application discloses a vehicle, which includes the aluminum alloy structural parts described in the second aspect of the present application. In some embodiments, the aluminum alloy structural parts in the vehicle may include, for example, body structural parts, engine structural parts, chassis structural parts, wheel structural parts, etc., and the present application does not impose any restrictions on this. The aluminum alloy structural parts used in the vehicle provided in the embodiment of the present application not only have excellent mechanical properties, but also the welding method thereof is simple to operate and easy to repeat, which can meet the vehicle's demand for lightweight while reducing production costs.

[0053] The exemplary embodiments of the present invention will be described in more detail below. Although the exemplary embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. In the embodiment, if specific techniques or conditions are not indicated, the techniques or conditions described in the document in this area or the product instructions are carried out. The reagents used or the instruments that are not indicated by the manufacturer are all conventional products that can be obtained commercially.

[0054] Example 1

[0055] Example 1 provides an aluminum alloy structural part obtained based on a novel preparation method. The aluminum alloy structural part is prepared by the following preparation method:

[0056] Step 1: Provide a first aluminum alloy, a second aluminum alloy and an intermediate metal layer copper foil (50 μm), and determine a first area to be welded of the first aluminum alloy and a second area to be welded of the second aluminum alloy.

[0057] Step 2: Use 220-grit sandpaper to grind the first area to be welded, the middle metal layer copper foil and the second area to be welded. After grinding off the oxide scale, use alcohol to clean the surface of the first area to be welded, the middle metal layer copper foil and the second area to be welded.

[0058] Step 3: The first area to be welded, the intermediate metal layer copper foil and the second area to be welded after polishing and cleaning are stacked in sequence to form an intermediate body to be welded.

[0059] Step 4: Use a diffusion welding heating device to perform diffusion welding on the intermediate to be welded, which includes: applying a pressure of 2MPa to the intermediate to be welded along the direction from the first area to be welded and the second area to be welded to the copper foil of the intermediate metal layer. Place the intermediate to be welded in the center of the induction coil into which the alternating current is passed and heat it to 550℃ and keep it warm for 5 minutes. During this process, the temperature of the intermediate to be welded is monitored by an infrared thermometer to keep the intermediate to be welded at the welding temperature.

[0060] Step 5: After diffusion welding is completed, the intermediate to be welded is cooled to room temperature to obtain an aluminum alloy structural part, in which the first aluminum alloy and the second aluminum alloy are connected by copper foil welding.

[0061] Example 2

[0062] Example 2 provides an aluminum alloy structural part obtained based on a new preparation method, and the aluminum alloy structural part is prepared by the following preparation method:

[0063] Step 1: Provide a first aluminum alloy, a second aluminum alloy and an intermediate metal layer copper foil (50 μm), and determine a first area to be welded of the first aluminum alloy and a second area to be welded of the second aluminum alloy.

[0064] Step 2: Use 220-grit sandpaper to grind the first area to be welded, the middle metal layer copper foil and the second area to be welded. After grinding off the oxide scale, use alcohol to clean the surface of the first area to be welded, the middle metal layer copper foil and the second area to be welded.

[0065] Step 3: The first area to be welded, the intermediate metal layer copper foil and the second area to be welded after polishing and cleaning are stacked in sequence to form an intermediate body to be welded.

[0066] Step 4: Use a diffusion welding heating device to perform diffusion welding on the intermediate to be welded, which includes: applying a pressure of 2MPa to the intermediate to be welded along the direction from the first area to be welded and the second area to be welded to the copper foil of the intermediate metal layer. Place the intermediate to be welded in the center of the induction coil with alternating current and heat it to 555℃ and keep it warm for 5 minutes. During this process, use an infrared thermometer to monitor the temperature of the intermediate to be welded so that the intermediate to be welded is kept at the welding temperature.

[0067] Step 5: After diffusion welding is completed, the intermediate to be welded is cooled to room temperature to obtain an aluminum alloy structural part, in which the first aluminum alloy and the second aluminum alloy are connected by copper foil welding.

[0068] Example 3

[0069] Example 3 provides an aluminum alloy structural part obtained based on a novel preparation method. The aluminum alloy structural part is prepared by the following preparation method:

[0070] Step 1: Provide a first aluminum alloy, a second aluminum alloy and an intermediate metal layer copper foil (50 μm), and determine a first area to be welded of the first aluminum alloy and a second area to be welded of the second aluminum alloy.

[0071] Step 2: Use 220-grit sandpaper to grind the first area to be welded, the middle metal layer copper foil and the second area to be welded. After grinding off the oxide scale, use alcohol to clean the surface of the first area to be welded, the middle metal layer copper foil and the second area to be welded.

[0072] Step 3: The first area to be welded, the intermediate metal layer copper foil and the second area to be welded after polishing and cleaning are stacked in sequence to form an intermediate body to be welded.

[0073] Step 4: Perform diffusion welding on the intermediate to be welded using a diffusion welding heating device, which includes: applying a pressure of 2MPa to the intermediate to be welded along the direction from the first area to be welded and the second area to be welded to the copper foil of the intermediate metal layer. The intermediate to be welded is placed in the center of the induction coil into which an alternating current is passed and heated to 560°C and kept warm for 5 minutes. During this process, the temperature of the intermediate to be welded is monitored by an infrared thermometer so that the intermediate to be welded is kept at the welding temperature.

[0074] Step 5: After diffusion welding is completed, the intermediate to be welded is cooled to room temperature to obtain an aluminum alloy structural part, in which the first aluminum alloy and the second aluminum alloy are connected by copper foil welding.

[0075] Test Case

[0076] The aluminum alloy structural parts of the above-mentioned Examples 1-3 were tested, and the operation process was as follows: the aluminum alloy structural parts were cut to obtain a cubic sample (10 mm×10 mm×10 mm) centered on the weld of the aluminum alloy structural part. The cubic samples were ground and polished in turn with sandpapers of 400 mesh, 800 mesh, 1000 mesh, 1500 mesh, 2000 mesh, and 3000 mesh, and then the ground and polished cubic samples were metallographically etched with Keller reagent.

[0077] The surface of the cube sample after metallographic corrosion was scanned and observed by SEM (Scanning Electron Microscope), and the Vickers hardness and shear strength of the weld were tested. The test results are shown in Table 1.

[0078] Figure 3 This is the SEM morphology of the weld of the aluminum alloy structural component in Example 1. Figure 4 This is the SEM morphology of the weld of the aluminum alloy structural component of Example 2. Figure 5 This is the SEM morphology of the weld of the aluminum alloy structural component of Example 3.

[0079] Depend on Figure 3-Figure 5 It can be seen that the welding effect of the welds of the above aluminum alloy structural parts is good, there are no obvious defects in the welds, and only a small amount of impurities exist in the welds at 560°C (Example 3). When the welding temperature is 550°C (Example 1) and 555°C (Example 2), the welding effect is good, no defects are generated, there is no obvious isothermal solidification zone, and the diffusion effect of the copper foil of the middle metal layer to the aluminum alloy parent materials at both ends is good. EDS (Energy Dispersive Spectroscopy, energy dispersive spectroscopy analysis) line scan analysis is performed on the welds of the aluminum alloy structural parts, and it is found that the Cu element corresponding to the middle metal layer diffuses into the aluminum alloy parent material in a relatively gentle manner, which proves that the welding effect is good.

[0080] Table 1

[0081]

[0082] In summary, the mechanical properties such as hardness and shear strength of the welds of the aluminum alloy structural parts in Examples 1-3 are all good. Among them, when the welding temperature is 555°C (Example 2), the mechanical properties of the welds of the aluminum alloy structural parts are the best. It can be seen that the aluminum alloy welding method provided in the embodiments of the present application has simple steps and convenient operation, and the mechanical properties of the welds of the aluminum alloy structural parts obtained are excellent, and the welding accuracy, welding quality, and welding cost are taken into account. It has broad application prospects in vehicle body structures, welding of structural parts in interior and exterior systems, and other use scenarios.

[0083] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. The term "plurality" refers to two or more, unless otherwise clearly defined.

[0084] The above description is only for the purpose of facilitating the technical solution of the present application to be understood by those skilled in the art, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for welding aluminum alloy, characterized in that: The welding method comprises: Providing a first aluminum alloy and a second aluminum alloy to be connected, and determining a first area to be welded of the first aluminum alloy and a second area to be welded of the second aluminum alloy; The first area to be welded, the intermediate metal layer, and the second area to be welded are stacked in sequence to form an intermediate body to be welded; Along the direction from the first area to be welded and the second area to be welded to the intermediate metal layer, a set pressure is applied to the intermediate body to be welded and diffusion welding is performed at a welding temperature, wherein the welding temperature is greater than the temperature at which a eutectic reaction occurs between metal aluminum and the metal corresponding to the intermediate metal layer.

2. The welding method according to claim 1, characterized in that: The intermediate metal layer is a copper foil, and the thickness of the copper foil is 30 micrometers to 60 micrometers.

3. The welding method according to claim 2, characterized in that: The welding temperature is 550°C-570°C.

4. The welding method according to claim 3, characterized in that: At the welding temperature, the intermediate body to be welded is kept warm for 3 minutes to 10 minutes.

5. The welding method according to claim 1, characterized in that: The set pressure is 1MPa-4MPa.

6. The welding method according to any one of claims 1 to 5, characterized in that: The welding method further comprises: When the intermediate body to be welded is subjected to diffusion welding, the intermediate body to be welded is heated to the welding temperature by electromagnetic induction technology; The intermediate body to be welded is subjected to temperature measurement by using an infrared thermometer to monitor the temperature of the intermediate body to be welded.

7. The welding method according to claim 1 is characterized in that: The first area to be welded, the intermediate metal layer and the second area to be welded are the same in shape and size.

8. The welding method according to any one of claims 1 to 7, characterized in that: Before the stacking arrangement is performed, the first area to be welded, the intermediate metal layer and the second area to be welded are polished and cleaned.

9. An aluminum alloy structural part, characterized in that: The aluminum alloy structural part is prepared by the welding method described in claims 1-8; The aluminum alloy structural member comprises: a first aluminum alloy and a second aluminum alloy, wherein the first aluminum alloy and the second aluminum alloy are welded and connected via an intermediate metal layer.

10. A vehicle, characterized in that: The vehicle includes the aluminum alloy structural member according to claim 9.

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