Aluminum alloy body member hot stamp forming method and system, vehicle

Abstract

The application belongs to the technical field of automobile manufacturing, and discloses an aluminum alloy vehicle body component hot stamping forming method and system and a vehicle. The method comprises the following steps: a three-dimensional finite element model of an aluminum alloy plate to be welded is established, material parameters and welding process parameters are input, stress field distribution in the welding process is simulated, and the position and range of the stress concentration area are determined; according to the position and range of the stress concentration area, the welding point position is laid out according to the welding point arrangement principle, the welding point layout is iteratively optimized based on the stress distribution result obtained by finite element simulation, and the optimized welding point coordinates are output; the welding point coordinates are marked, friction stir welding is carried out according to the preset welding process parameters; and after the blank after welding is subjected to solid solution treatment, hot stamping forming is carried out. The application guides the welding point layout optimization through CAE simulation, so that each welding point avoids the stress concentration area, the stress uniformity of the welding point in the hot stamping process is realized, the risk of welding point cracking is reduced, and the hot stamping formability is improved.

Description

Technical Field

[0001] This application relates to the field of automotive manufacturing technology, and in particular to a hot stamping forming method and system for aluminum alloy body components and a vehicle. Background Technology

[0002] With the increasing prominence of global energy and environmental issues and the continuous upgrading of lightweight development requirements in the automotive industry, the lightweight aluminum alloy industry is experiencing unprecedented rapid development, and market demand continues to rise. As a core load-bearing component of the automotive passenger compartment, the B-pillar is currently primarily constructed using high-strength steel. High-strength 7xxx series aluminum alloy sheets, with their comprehensive properties such as low density, high strength, good formability, and excellent corrosion resistance, are gradually becoming a key candidate material for load-bearing automotive structural components. However, to date, the application of aluminum alloys in mass-produced automotive B-pillars is still in the technological exploration stage, and a mature mass production application solution has not yet been formed. The core reason is that micro-cracks inevitably occur after spot welding of aluminum alloy outer panels and patch panels. During subsequent hot stamping processes, the stress causes these micro-cracks to further expand, even leading to overall component cracking and failure, seriously threatening the structural safety of the entire vehicle body.

[0003] Currently, resistance spot welding is widely used for welding aluminum alloy sheets. However, spot welding of aluminum alloy outer panels and patch panels easily generates significant residual stress and internal microcracks. During subsequent hot stamping, the weld points located in stress concentration zones are subjected to stress, causing these microcracks to propagate further and even leading to overall component failure, seriously threatening the service life and safety of aluminum alloy structural components. Current technological improvements to address weld point cracking during hot stamping of aluminum alloy sheets mainly focus on optimizing welding process parameters and adjusting the welding equipment structure. For example, controlling heat input by adjusting welding current, voltage, and welding speed to reduce residual stress levels; or adjusting the welding angle to ensure proper fit of the sheets during welding. However, none of these improvement approaches fundamentally solve the problem of weld point cracking induced by stress concentration.

[0004] Friction stir spot welding, as a typical solid-state welding technology, can prevent the formation of hot cracks at the source, while avoiding the microcracks present in resistance spot welding and eliminating the adverse effects of microcracks on subsequent hot stamping processes. This provides a feasible approach to solving the problem of weld cracking in structural components such as hot-formed aluminum alloy B-pillars. However, during subsequent hot stamping, the weld points of aluminum alloy sheets joined by this process will be subjected to uneven shear forces, and this uneven stress can still lead to cracking and failure of the parts. Therefore, there is an urgent need to develop a new method to improve the hot stamping formability of products by reducing the risk of weld cracking in hot-formed aluminum alloy sheets, in order to promote the large-scale application of aluminum alloys in the field of automotive safety structural components. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this application is to provide a hot stamping forming method and system for aluminum alloy body components, and a vehicle, to solve the problem of cracking of weld points of aluminum alloy sheets during hot stamping due to uneven stress and stress concentration, thereby improving the hot stamping formability of aluminum alloy sheets such as B-pillars.

[0006] To achieve the above and other related objectives, this application provides a hot stamping forming method and system for aluminum alloy body components, and a vehicle, comprising the following steps: establishing a three-dimensional finite element model of the aluminum alloy sheet to be welded, inputting the material parameters of the aluminum alloy sheet to be welded and preset friction stir spot welding process parameters, simulating the stress field distribution during the welding process, and determining the location and range of stress concentration areas; arranging the weld points according to the location and range of the stress concentration areas and according to preset weld point layout principles; simulating and obtaining the stress distribution results of each weld point during the welding process under the preliminary layout based on the three-dimensional finite element model, iteratively optimizing the weld point layout, and outputting the optimized weld point coordinates; marking the optimized weld point coordinates on the surface of the blank, and performing welding according to the preset friction stir spot welding process parameters; and hot stamping forming the welded blank after solution treatment.

[0007] In this embodiment of the application, the step of simulating and obtaining the stress distribution results of each weld point in the initial layout during the welding process based on the three-dimensional finite element model, and iteratively optimizing the weld point layout, includes: arranging the weld points in areas where the stress value is lower than a preset stress threshold according to the stress distribution results; iteratively adjusting the position of the weld points until the stress value at each weld point is lower than the critical stress value for cracking, and the stress deviation between each weld point does not exceed a preset deviation range.

[0008] In this embodiment of the application, marking the optimized weld point coordinates on the surface of the blank and performing welding according to the preset friction stir spot welding process parameters includes: marking the optimized weld point coordinates on the surface of the blank, selecting a friction stir spot welding device and a stirring head of matching size based on the characteristics of the aluminum alloy sheet to be welded, and performing welding according to the preset friction stir spot welding process parameters; wherein, the characteristics of the aluminum alloy sheet to be welded include the sheet thickness, and a stirring head with a matching shoulder diameter is selected based on the sheet thickness.

[0009] In this embodiment of the application, the material parameters of the aluminum alloy sheet to be welded include at least one of elastic modulus, Poisson's ratio and thermal conductivity; and / or, the welding process parameters of the friction stir spot welding include at least one of the clamping force of the stirring head, rotation speed, pressing speed, pressing depth, pressing dwell time, retraction speed and shoulder pressing amount.

[0010] In this embodiment of the application, the principle of welding point arrangement includes at least one of the following requirements (1) to (4): (1) all welding points avoid the stress concentration area; (2) the distance between the welding point and the edge of the plate is controlled within a first preset distance; (3) the welding points of the splicing blank are symmetrically arranged on both sides of the splicing seam, and the distance from the splicing seam is controlled within a second preset distance; (4) the spacing between adjacent welding points is controlled within a third preset distance.

[0011] In this embodiment of the application, after the hot stamping forming step, the process further includes: after the hot stamping is completed, the workpiece is cleaned, dried, cut, and aged; after the aging treatment is completed, it is cooled to room temperature and tested.

[0012] In this embodiment of the application, a two-stage artificial aging process is used to age the workpiece, including: performing a two-stage artificial aging process on the workpiece after cutting, wherein the first-stage aging temperature is set at 125℃~135℃ and the holding time is 4h~6h; the second-stage aging temperature is set at 160℃~170℃ and the holding time is 10h~12h.

[0013] In this embodiment of the application, the aluminum alloy body component includes the A-pillar and / or B-pillar of the automobile; and / or, the aluminum alloy sheet to be welded is a 7xxx series aluminum alloy sheet.

[0014] This application also provides a hot stamping forming system for aluminum alloy body components, including: The weld point layout optimization unit is used to establish a three-dimensional finite element model of the aluminum alloy sheet to be welded, input the material parameters of the aluminum alloy sheet to be welded and the preset friction stir spot welding process parameters, simulate the stress field distribution during the welding process, determine the location and range of the stress concentration area, and, based on the location and range of the stress concentration area, arrange the weld points according to the preset weld point layout principle; based on the three-dimensional finite element model, simulate and obtain the stress distribution results of each weld point during the welding process under the initial layout, iteratively optimize the weld point layout, and output the optimized weld point coordinates; The welding unit is used to mark the optimized weld point coordinates on the surface of the blank and to perform welding according to the preset friction stir spot welding process parameters; The solution treatment unit is used to treat the welded blanks with a solution. The hot stamping unit is used to hot stamp and form the blank after solution treatment.

[0015] This application also provides a vehicle comprising an aluminum alloy body component manufactured using the hot stamping forming method for aluminum alloy body components as described above.

[0016] The beneficial effects of this application are: In this embodiment, the stress field distribution during the welding process is simulated using CAE finite element method to accurately determine the location and range of stress concentration areas. Based on this, the weld point layout of friction stir spot welding is optimized, ensuring that all weld points avoid stress concentration areas. Simultaneously, by coordinating the control of the distance between weld points and the edge of the sheet metal and the splice seam, as well as the spacing between adjacent weld points, the uniformity of stress on each weld point during hot stamping is achieved. Compared to related technologies that control welding quality solely by adjusting welding process parameters, this application, starting from the dimension of weld point spatial layout and combining CAE simulation prediction, fundamentally improves the problem of uneven stress on weld points, reduces the risk of weld point cracking during hot stamping, and enhances the hot stamping formability of aluminum alloy body components. This provides strong support for the large-scale application of aluminum alloys in automotive safety structural components. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] In the attached diagram: Figure 1 This is a schematic diagram of a three-dimensional model of the hot-formed aluminum alloy B-pillar outer panel provided in the embodiments of this application.

[0019] Figure 2 This is a schematic diagram of CAE simulation analysis of the hot-formed aluminum alloy B-pillar outer panel provided in the embodiments of this application.

[0020] Figure 3 This is a schematic diagram showing the distribution of the weld point layout scheme 1 for friction stir spot welding of the hot-formed aluminum alloy B-pillar outer panel provided in the embodiments of this application.

[0021] Figure 4 This is a schematic diagram of the weld point layout scheme two for friction stir spot welding of the hot-formed aluminum alloy B-pillar outer panel provided in the embodiments of this application.

[0022] Figure 5 This is a schematic diagram of the weld point layout scheme three for friction stir spot welding of the hot-formed aluminum alloy B-pillar outer panel provided in the embodiments of this application.

[0023] Figure 6 This is a schematic diagram of the weld point layout scheme four for friction stir spot welding of the hot-formed aluminum alloy B-pillar outer panel provided in the embodiments of this application.

[0024] Figure 7 This is a schematic diagram of the physical structure of the hot-formed aluminum alloy B-pillar outer panel prepared according to Scheme 3 provided in this application embodiment.

[0025] Figure 8 A flowchart illustrating the hot stamping forming method for aluminum alloy body components provided in this application embodiment. Detailed Implementation

[0026] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0027] In this application, unless otherwise stated, the term "multiple" means two or more.

[0028] The character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0029] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0030] Before describing the various embodiments, some technical terms used in this application will be explained in a unified manner. CAE (Computer Aided Engineering) refers to the technology of using computers to perform finite element modeling, numerical simulation, and analysis of engineering structures. In this application, CAE finite element simulation is used to simulate and calculate the stress field distribution during the welding process. Friction stir spot welding is a type of solid-state welding technology. It involves inserting a high-speed rotating stirring head into the plate to be welded, relying on the probe to stir the base material to induce plastic flow, and the shoulder friction to generate heat and soften the base material to achieve solid-state connection. The base material does not melt during the welding process.

[0031] In this application, the stress concentration region refers to a localized area, determined by CAE finite element simulation, where the stress value during welding is significantly higher than that of the surrounding area. This area is a high-risk region for crack initiation during hot stamping. The splice seam is the joint formed when the B-pillar outer panel and the patch panel are spliced ​​together, and the edge of the panel is the outer edge of the B-pillar outer panel or the patch panel. The first preset distance, the second preset distance, and the third preset distance refer to the preset value ranges for the distance from the weld point to the edge of the panel, the distance from the weld point to the splice seam, and the spacing between adjacent weld points, respectively. The specific values ​​of each preset distance will be illustrated with examples in the following embodiments.

[0032] First, the technical background of this application will be explained in conjunction with the application scenario. See [link / reference] Figure 1 and Figure 7 In automotive body structures, the B-pillar is a core load-bearing component connecting the roof and the bottom of the vehicle, bearing the loads of side collisions. To reduce overall vehicle weight while maintaining the local strength of the B-pillar, patch panels are typically added to key areas of the outer B-pillar panel as local reinforcement. When manufacturing B-pillars using high-strength 7xxx series aluminum alloy, the process generally involves: first, spot welding the outer B-pillar panel and the patch panel together to form a single, integral blank; then, heating and hot-stamping the blank to obtain a B-pillar component that combines a complex surface with localized reinforcement.

[0033] However, in the aforementioned process route of welding followed by hot stamping, the reliability of the weld points has become a key factor restricting the industrial application of 7xxx series aluminum alloy B-pillars. In related technologies, resistance spot welding is often used for welding aluminum alloy sheets. After the aluminum alloy outer plate and patch plate are connected by resistance spot welding, significant residual stress and internal microcrack defects are easily generated. During the subsequent hot stamping process, the weld points located in stress concentration areas are subjected to stress, leading to further propagation of microcracks and even causing overall cracking and failure of the part, seriously affecting the service life and safety of the aluminum alloy structural components.

[0034] To address the aforementioned weld cracking issue, improvements in related technologies primarily focus on optimizing welding process parameters and adjusting the structure of the welding equipment. For example, controlling heat input by adjusting welding current, voltage, and welding speed can reduce residual stress levels; or adjusting the welding angle can ensure the fit of the plates during welding. However, these improvement paths all revolve around adjusting the welding process itself and do not address the root cause of uneven stress on the weld joints during the hot stamping stage. While friction stir spot welding, as a typical solid-state welding technology, can improve the problem of microcrack formation at the welding mechanism level, aluminum alloy plates joined using this process will still experience uneven shear forces at each weld joint during subsequent hot stamping. This uneven stress can still lead to cracking and failure of the parts. In other words, even if the weld joint itself does not have initial microcracks, the risk of cracking still exists if the weld joint falls into a high-stress area during hot stamping or if the stress distribution between weld joints is severely unbalanced.

[0035] Based on the above analysis, it can be seen that the root cause of weld cracking during the hot stamping process of 7xxx series aluminum alloy B-pillars includes two aspects: First, the inherent fusion welding mechanism of the resistance spot welding process inevitably generates welding micro-cracks, providing an initial defect source for subsequent cracking; Second, even if the initial micro-cracks are eliminated through solid-state welding, the spatial position of the weld point during hot stamping determines the magnitude of the shear force it bears. If the weld point position is not optimized, the stress on each weld point will be uneven, and the shear force on some weld points will exceed the cracking threshold, still leading to part cracking and failure. The difficulty in solving this problem lies in the fact that the stress field distribution inside the blank during hot stamping is highly complex. Arranging weld points uniformly based on experience is blind, while determining the weld point layout through repeated trial and error in physical prototype manufacturing is a complex process with high trial and error costs. This application addresses the aforementioned issues by proposing to predict the stress field distribution during the welding process using CAE finite element simulation. Based on this prediction, the weld point locations are optimized and iteratively adjusted before welding, ensuring that all weld points spatially avoid stress concentration areas. This physically homogenizes the shear force distribution during hot stamping, thereby reducing the risk of weld point cracking and improving hot stamping formability.

[0036] Further analysis from a technical perspective reveals that the breakthrough of the solution provided in this application lies in shifting the approach to solving the weld cracking problem from "welding process control" to "simulation-driven optimization of weld spatial layout." In related technologies, adjusting welding parameters can only improve the initial quality of the weld joint, but cannot change the stress state of the weld point in the subsequent hot stamping stress field. However, this application, by inputting material parameters and welding process parameters for CAE finite element simulation, can identify the location and range of stress concentration areas before actual welding, and use this as a constraint to iteratively optimize the weld layout, ensuring that each weld point is in a region with low stress levels and a relatively gentle distribution. As a result, the shear force borne by the weld point during hot stamping is homogenized, and each weld point does not exceed the cracking critical value, thus improving the problems of weld deformation, detachment, and overall part cracking from the root cause of cracking. Simultaneously, simulation-driven layout optimization replaces physical trial and error with numerical calculations, simplifying the process development process and saving trial production costs.

[0037] The hot stamping forming method for aluminum alloy body components provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0038] See Figure 8This application provides a hot stamping forming method for aluminum alloy body components. The method includes: establishing a three-dimensional finite element model of the aluminum alloy sheet to be welded; inputting the material parameters of the aluminum alloy sheet to be welded and preset friction stir spot welding process parameters; simulating the stress field distribution during the welding process; determining the location and range of stress concentration areas; arranging the weld points according to preset weld point layout principles based on the location and range of stress concentration areas; simulating the stress distribution results of each weld point during the welding process under the preliminary layout based on the three-dimensional finite element model; iteratively optimizing the weld point layout; outputting the optimized weld point coordinates; marking the optimized weld point coordinates on the surface of the blank; performing welding according to preset friction stir spot welding process parameters; and hot stamping forming the welded blank after solution treatment.

[0039] In this embodiment, aluminum alloy body components include, but are not limited to, the A-pillar and B-pillar of a car. The following description uses a 7xxx series high-strength aluminum alloy B-pillar as an example. The material parameters of the aluminum alloy sheet to be welded include at least one of elastic modulus, Poisson's ratio, and thermal conductivity. For example, the elastic modulus is 70 GPa, the Poisson's ratio is 0.33, and the thermal conductivity is 130 W / (m·K). The friction stir spot welding process parameters include at least one of the following: clamping force of the stirring head, rotation speed, pressing speed, pressing depth, pressing dwell time, retraction speed, and shoulder pressing amount. For example, the clamping force is 5000 N~6000 N, the stirring head rotation speed is 2000 r / min~3000 r / min, and the pressing speed is 1 mm / s~3 mm / s.

[0040] First, a three-dimensional finite element model of the aluminum alloy sheet to be welded is established. Specifically, in this embodiment, the aluminum alloy sheet to be welded is the outer panel of the B-pillar and the patch panel, both of which are made of 7xxx series high-strength aluminum alloy, with a thickness of 2.5mm to 6mm. A three-dimensional finite element model of the above-mentioned sheet is established using CAE finite element analysis software. The material parameters of the aluminum alloy sheet to be welded (elastic modulus 70GPa, Poisson's ratio 0.33, thermal conductivity 130W / (m·K)) and the preset friction stir spot welding process parameters (clamping force 5000N~6000N, stirring head rotation speed 2000r / min~3000r / min, pressing speed 1mm / s~3mm / s) are input into the model to simulate the stress field distribution during the welding process and determine the location and range of the stress concentration area.

[0041] See Figure 2CAE finite element simulation can accurately reflect the stress field distribution during the welding process. By calculating the strain and displacement values ​​of each node in the model, the location and range of stress concentration areas can be identified. Stress concentration areas are high-risk regions for crack initiation during subsequent hot stamping. If the weld point falls into this area, it will experience significantly higher shear forces than other areas during hot stamping, significantly increasing the probability of cracking. Understandably, material parameters such as elastic modulus, Poisson's ratio, and thermal conductivity jointly determine the accuracy of the model's description of the mechanical response and heat transfer behavior of the sheet metal, while welding process parameters determine the accuracy of the model's description of welding heat input and mechanical loads. The combined input of these two types of parameters results in a good match between the simulation results and the actual welding and hot stamping processes.

[0042] Secondly, based on the location and extent of the stress concentration area, the weld points are arranged according to the pre-defined weld point layout principles. (See also...) Figure 1 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The welding point arrangement principle includes at least one of the following requirements (1) to (4): (1) All welding points should avoid stress concentration areas; (2) The distance between the welding point and the edge of the plate should be controlled within the first preset distance, and the first preset distance is recommended to be 12mm~15mm; (3) The welding points of the splicing blanks should be symmetrically arranged on both sides of the splicing seam, and the distance from the splicing seam should be controlled within the second preset distance, and the second preset distance is recommended to be 12mm~18mm; (4) The spacing between adjacent welding points should be controlled within the third preset distance, and the third preset distance is recommended to be 50mm~100mm.

[0043] In the above principles for weld point placement, the splice seam / sheet edge is an important spatial reference for weld point layout. If the weld point is too close to the sheet edge or splice seam, the edge effect will cause the weld point to fall into an area of ​​increased local stress, which will crack during hot stamping due to uneven shear force. If the weld point is too far away, it will affect the reinforcement effect of the patch plate on the local reinforcement area of ​​the B-pillar outer panel, resulting in insufficient local strength. By limiting the distance between the weld point and the sheet edge, the splice seam, and the spacing between adjacent weld points within a specific range, it is possible to place each weld point in a position with a relatively gentle stress distribution while ensuring the reinforcement effect.

[0044] It is understandable that, in the above principles for welding point arrangement, requirements (1) to (4) can be partially or fully met according to the specific working conditions. In order to achieve better results, the above four requirements are met simultaneously in this embodiment. In addition, the specific values ​​of the first preset distance, the second preset distance and the third preset distance can be adjusted within a reasonable range according to the component type, plate thickness and stress field distribution. The aforementioned 12mm~15mm, 12mm~18mm and 50mm~100mm are only exemplary values ​​for B-column components.

[0045] Furthermore, based on the three-dimensional finite element model, the stress distribution results of each weld point during the welding process under the initial layout are obtained through simulation. The weld point layout is iteratively optimized, and the optimized weld point coordinates are output. Specifically, according to the stress distribution results, the weld points are arranged in areas where the stress value is lower than a preset stress threshold. The weld point positions are iteratively adjusted until the stress value at each weld point is lower than the critical stress value for cracking, and the stress deviation between each weld point does not exceed a preset deviation range. In this embodiment, through CAE simulation iterative optimization, the shear force on each weld point is made uniform while ensuring that all weld points avoid stress concentration areas, and finally the optimized weld point coordinates are output.

[0046] Subsequently, optimized weld point coordinates are marked on the surface of the blank, and welding is performed according to the preset friction stir spot welding process parameters. Specifically, optimized weld point coordinates are first marked on the surface of the blank so that the welding robot can accurately identify the weld point positions; then, based on the characteristics of the aluminum alloy sheet to be welded, a friction stir spot welding device and a stirring head of matching size are selected, and welding is performed according to the preset friction stir spot welding process parameters. The characteristics of the aluminum alloy sheet to be welded include the sheet thickness, and a stirring head with a matching shoulder diameter can be selected based on the sheet thickness. For example, the aluminum alloy sheet used to make the B-pillar has a thickness of 2mm to 6mm, and the diameter of the stirring head shoulder is 5mm to 10mm. The main welding parameters for friction stir spot welding are: clamping force of 5000N to 6000N, stirring head rotation speed of 2000r / min to 3000r / min, pressing speed of 1mm / s to 3mm / s, pressing depth of 1mm to 3mm, pressing dwell time of 0s to 5s, retraction speed of 1mm / s to 3mm / s, and shoulder pressing amount controlled at 0.1mm to 0.3mm.

[0047] The welding process is carried out by a welding robot that drives a stirring head to complete the welding one by one according to preset coordinates (i.e., optimized weld point coordinates): the stirring head rotates and presses down, the probe agitates the aluminum alloy sheet base material to induce plastic flow, and the friction of the shaft shoulder generates heat to soften the base material, achieving solid-state bonding; after reaching the preset dwell time, the stirring head quickly retracts, completing the welding of a single weld point. After all weld points are completed, the slight burrs on the surface of the friction stir weld points are ground off to ensure a smooth joint surface. Compared with fusion welding processes such as resistance spot welding, friction stir spot welding is a typical solid-state welding technology. The base material does not melt during the welding process, which improves the problem of microcrack formation in welding from the welding mechanism, while avoiding defects such as hot cracks and porosity caused by melting and solidification processes in resistance spot welding.

[0048] Finally, the welded billet undergoes solution treatment and is then hot-stamped. Specifically, the welded aluminum alloy billet is transferred to a heating furnace for solution treatment, which fully dissolves the strengthening phases in the 7xxx series aluminum alloy to obtain a supersaturated solid solution, ensuring good formability of the billet. The billet is then quickly transferred to a pre-cooled hot-stamping die with a cooling system, and the die is closed for stamping and quenching. During hot stamping, the billet exhibits good plasticity at high temperatures, allowing for the formation of complex shapes within the die cavity. Simultaneously, in-die quenching preserves the supersaturated solid solution, providing a microstructure basis for subsequent age hardening.

[0049] In this embodiment, CAE finite element simulation of the welding stress field distribution guides the optimization of weld point layout, ensuring that each friction stir weld point avoids stress concentration areas. This physically homogenizes the shear force distribution during hot stamping, significantly reducing the risk of weld point cracking and improving the hot stamping formability of the aluminum alloy B-pillar plate. Compared to related technologies that control heat input by adjusting parameters such as welding current, voltage, and welding speed, or ensure sheet fit by adjusting welding angles, this embodiment's method, starting from the spatial layout of weld points and combining CAE simulation prediction, achieves uniform stress on weld points, effectively improving the cracking problem caused by stress concentration. Specifically, CAE simulation provides the stress field basis for weld point layout, the weld point arrangement principle transforms this basis into executable spatial constraints, iterative optimization ensures uniform stress on weld point coordinates while satisfying constraints, solid-state welding provides high-quality joints without initial microcracks for splicing blanks, and solution treatment and in-mold quenching ensure the plasticity of the blank during forming and the microstructure after forming.

[0050] Based on the above technical solutions, in some embodiments, the steps for iteratively optimizing the solder joint layout are further explained.

[0051] Specifically, based on the stress distribution results of each weld point during the welding process under the initial layout obtained by simulation using the three-dimensional finite element model, the weld point layout is iteratively optimized, including: First, according to the stress distribution results, the weld points are arranged in areas where the stress value is lower than a preset stress threshold, so that the stress level at the location of the weld point is within a safe range, reducing the probability of the weld point falling into a high-stress area. The preset stress threshold can be set according to the yield strength of 7xxx series aluminum alloy materials and the allowable stress under hot stamping conditions, for example, it can be set to 60%~80% of the material's yield strength.

[0052] Secondly, the weld joint positions are iteratively adjusted until the stress value at each weld joint is lower than the critical stress value for cracking, and the stress deviation between weld joints does not exceed a preset deviation range, thereby achieving uniform stress distribution at the weld joints. The critical stress value for cracking is the minimum stress value that will cause the weld joint to crack, which can be determined experimentally or estimated based on the fracture toughness of the material. The preset deviation range is used to limit the uniformity of stress distribution between weld joints; for example, it can be set to within ±10% of the average stress value of each weld joint.

[0053] The aforementioned iterative optimization process is essentially a closed-loop process consisting of simulation, adjustment, and re-simulation. Through continuous iterative calculations, it gradually approximates a solder joint layout scheme with more balanced stress. This process ensures that the final output solder joint coordinates theoretically meet the requirement of uniform stress distribution, thus improving the stress concentration problem caused by improper solder joint placement. Furthermore, this iterative optimization method does not impose prior restrictions on the number and location of solder joints, allowing for flexible adjustment based on the actual stress field distribution, demonstrating good adaptability and versatility.

[0054] Based on the above technical solution, in some embodiments, the subsequent processes after the hot stamping forming step are further described. In this embodiment, after the hot stamping forming step, the process further includes: after hot stamping, cleaning, drying, cutting, and aging treatment of the workpiece; after aging treatment, cooling to room temperature and performing testing.

[0055] For example, the cleaning and drying process is as follows: After hot stamping, the workpiece is removed and first, the oxide scale residue and mold release agent residue on the surface are blown off by high-pressure air. Then, it is placed in an alkaline cleaning tank for ultrasonic cleaning to thoroughly remove stamping oil stains and oxide residues from the workpiece surface. After cleaning, it is rinsed with deionized water and then dried with hot air to reduce the probability of workpiece corrosion caused by residual moisture. The above cleaning process can effectively remove contaminants such as oxide scale, mold release agent, and oil stains remaining on the workpiece surface during hot stamping, keeping the workpiece surface clean and providing a good surface condition for subsequent cutting and aging treatment.

[0056] Laser cutting can be used for the cutting process, and the specific procedure is as follows: After drying, the workpiece is transferred to the laser cutting equipment. After positioning with special tooling, edge trimming and hole drilling are performed according to design requirements: First, the process allowance reserved for hot stamping is removed, and then the door hinge mounting holes, seat belt mounting holes, wire harness through holes, and other process structures are processed in sequence. During the cutting process, the laser power and cutting speed are controlled to keep the processing accuracy within ±0.1mm, meeting the accuracy requirements of subsequent vehicle assembly. Using laser cutting equipment for edge trimming and hole drilling is a non-contact processing method with no mechanical cutting force, which improves the problem of secondary micro-cracks and residual stress introduced at the edges of stamped parts by traditional mechanical stamping, ensuring the quality of the cut edges. High-strength aluminum alloys are relatively sensitive to notches. Non-contact laser cutting, combined with the aforementioned non-destructive forming process, helps to ensure the reliability of the final B-pillar product for vehicle assembly.

[0057] The aging process can be carried out using a two-stage artificial aging process, the specific process is as follows: After the workpiece is cut, a two-stage artificial aging process is carried out. The first stage aging temperature is set at 125℃~135℃ and the holding time is 4h~6h; the second stage aging temperature is set at 160℃~170℃ and the holding time is 10h~12h, so that the supersaturated solid solution aluminum matrix is ​​filled with the precipitation of nano-scale strengthening phase.

[0058] After aging, the workpiece is cooled to room temperature in the furnace and then removed for final inspection: first, visual inspection is performed to confirm that the weld joints are free of cracks, then ultrasonic testing is used to confirm that there are no pores or cracks inside the weld joints, and finally, after the dimensional accuracy is checked to meet the requirements, the hot-formed high-strength 7xxx series aluminum alloy B-pillar is obtained.

[0059] In this embodiment, a complete post-processing procedure, including cleaning, drying, cutting, aging treatment, and testing, ensures that the surface quality, dimensional accuracy, and mechanical properties of the B-pillar product meet the requirements, providing a reliable structural component for subsequent vehicle assembly. This post-processing procedure, along with the aforementioned weld point layout optimization, friction stir spot welding, solution treatment, and hot stamping processes, forms a complete process chain from raw materials to finished product.

[0060] Based on the above technical solutions, in some embodiments, the types of aluminum alloy body components and the grades of aluminum alloy sheets are further explained.

[0061] In this embodiment, aluminum alloy body components include, but are not limited to, the A-pillar and B-pillar of a car. These body structural components are all critical load-bearing parts for automotive collision safety, requiring high material strength and formability. The method in this embodiment uses CAE finite element simulation of welding stress field distribution to guide the optimization of weld point layout, effectively reducing the risk of weld point cracking during hot stamping. It is applicable to the manufacturing of the aforementioned various body structural components. This embodiment uses the B-pillar as an example for illustration; those skilled in the art will understand that this method is also applicable to the manufacturing of other body structural components such as the A-pillar.

[0062] In this embodiment, the aluminum alloy sheet to be welded is a 7xxx series aluminum alloy sheet. 7xxx series aluminum alloys are aluminum-based alloys with zinc as the main alloying element. They possess comprehensive properties such as low density, high specific strength, good formability, and excellent corrosion resistance, making them a key candidate material for load-bearing components in automotive structures. In a specific example, the mass percentage of each component in the high-strength 7xxx series aluminum alloy is as follows: Zn: 5.1%~6.1%; Mg: 2.1%~2.9%; Cu: 1.0%~2.0%; Cr: 0.18%~0.28%; Mn: 0.1%~0.3%; Si: 0.2%~0.4%; Fe: less than 0.2%; Ti: 0.05%~0.1%; Zr: 0.01%~0.03%; Sc: 0.03%~0.05%; other individual elements not exceeding 0.05%, the total amount of other impurity elements not exceeding 0.15%, and the balance being Al.

[0063] In this embodiment, the above method is applied to the manufacturing of 7xxx series aluminum alloy body structural parts, which effectively improves the problem of weld cracking in aluminum alloy sheets during hot stamping, improves the hot stamping formability of aluminum alloy B-pillar sheets, and provides technical support for the large-scale application of aluminum alloys in the field of automotive safety structural parts.

[0064] Those skilled in the art will understand that any equivalent method that can achieve the same function in the foregoing embodiments, such as replacing the CAE finite element analysis software with other numerical analysis tools with stress field coupling simulation capabilities, or applying this method to other body structural components such as the A-pillar, are all within the scope of this application.

[0065] After describing the various embodiments of the method, the following describes the hot stamping forming system for aluminum alloy body components provided in the embodiments of this application.

[0066] This application provides a hot stamping forming system for aluminum alloy body components. The system includes a weld point layout optimization unit, a welding unit, a solution treatment unit, and a hot stamping unit.

[0067] The weld point layout optimization unit is used to establish a three-dimensional finite element model of the aluminum alloy sheet to be welded, input the material parameters of the aluminum alloy sheet to be welded and the preset friction stir spot welding process parameters, simulate the stress field distribution during the welding process, determine the location and range of the stress concentration area, and, based on the location and range of the stress concentration area, arrange the weld points according to the preset weld point layout principle; based on the three-dimensional finite element model, simulate and obtain the stress distribution results of each weld point during the welding process under the initial layout, iteratively optimize the weld point layout, and output the optimized weld point coordinates.

[0068] Specifically, the solder joint layout optimization unit may include a CAE finite element analysis module and a solder joint layout optimization module. The CAE finite element analysis module is used to establish a three-dimensional finite element model and simulate the stress field distribution; the solder joint layout optimization module is used to optimize the solder joint layout according to the stress field distribution results and a preset solder joint arrangement principle. The implementation process of the solder joint layout optimization unit is consistent with the implementation process of establishing the model, determining the stress concentration area, and iteratively optimizing the solder joint layout in the aforementioned method embodiments. Through the solder joint layout optimization unit, the optimization design of the solder joint layout can be automatically completed, and the optimized solder joint coordinates can be output, providing accurate solder joint position information for the welding unit.

[0069] The welding unit is used to mark optimized weld point coordinates on the surface of the blank and to perform welding according to preset friction stir spot welding process parameters. Specifically, the welding unit may include a welding robot and a friction stir spot welding device. The welding robot marks the weld point positions on the surface of the blank according to the weld point coordinates output by the weld point layout optimization unit, and drives the stirring head to complete the welding of each weld point one by one according to the preset friction stir spot welding process parameters. The implementation process of the welding unit is consistent with the implementation process of the welding steps in the aforementioned method embodiments. Through the welding unit, friction stir spot welding can be accurately completed according to the optimized weld point coordinates, ensuring accurate weld point position and reliable welding quality.

[0070] The solution treatment unit is used to perform solution treatment on the welded billet. Specifically, the solution treatment unit may include a heating furnace to heat the welded aluminum alloy billet to the solution temperature, so that the strengthening phase in the 7xxx series aluminum alloy is fully dissolved to obtain a supersaturated solid solution, ensuring that the billet has good formability. The implementation process of the solution treatment unit is consistent with the implementation process of the solution treatment steps in the aforementioned method embodiments.

[0071] The hot stamping unit is used to hot stamp and form the solution-treated blank. Specifically, the hot stamping unit may include a pre-cooled hot stamping die with a cooling system and stamping equipment. The solution-treated blank is quickly transferred to the pre-cooled hot stamping die, and the die is closed for stamping and forming. The implementation process of the hot stamping unit is consistent with the implementation process of the hot stamping forming step in the aforementioned method embodiments. Through the hot stamping unit, the blank can be formed at high temperature, and the in-die quenching allows the supersaturated solid solution to be retained, providing a microstructure basis for subsequent aging strengthening.

[0072] The system provided in this embodiment realizes an integrated process for hot stamping forming of aluminum alloy body components, fundamentally improving the problem of weld cracking during hot stamping and enhancing the hot stamping formability of aluminum alloy body components. Specifically, the weld layout optimization unit uses CAE finite element simulation to predict the location and range of stress concentration areas and optimizes the weld layout accordingly, ensuring that each weld avoids stress concentration areas and achieving uniform stress distribution on the welds; the welding unit performs friction stir spot welding according to the optimized weld coordinates, ensuring welding quality; the solution treatment unit and the hot stamping unit ensure the plasticity of the blank during forming and the mechanical properties after forming.

[0073] In some embodiments, this application also provides a vehicle comprising an aluminum alloy body component manufactured using the hot stamping forming method for aluminum alloy body components provided in the foregoing embodiments. The aluminum alloy body component includes the A-pillar, B-pillar, etc., of a vehicle, and may also be other body structural components suitable for manufacture using aluminum alloys (such as 7xxx series aluminum alloys).

[0074] In some embodiments, this application also provides an electronic device including one or more processors and storage devices.

[0075] The processor can be a Central Processing Unit (CPU), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), or a Field Programmable Gate Array (FPGA), etc., used to execute one or more programs stored in the storage device. The storage device can be a Read-Only Memory (ROM), Random Access Memory (RAM), Flash memory, etc., used to store one or more programs. When one or more programs are executed by one or more processors, the electronic device enables the hot stamping forming method for aluminum alloy body components as provided in the foregoing embodiments.

[0076] Specifically, when the processor executes the program in the storage device, it can implement the function of the solder joint layout optimization unit, that is, to establish a three-dimensional finite element model of the aluminum alloy sheet to be welded, input material parameters and welding process parameters, simulate the stress field distribution during the welding process, and determine the location and range of stress concentration areas; based on the location and range of stress concentration areas, the solder joint positions are arranged according to the preset solder joint layout principles; based on the three-dimensional finite element model, the stress distribution results of each solder joint during the welding process under the initial layout are simulated and obtained, the solder joint layout is iteratively optimized, and the optimized solder joint coordinates are output. At the same time, the processor can also control the welding unit, solution treatment unit, and hot stamping unit to realize an integrated process of welding, solution treatment, and hot stamping forming.

[0077] In this embodiment, the automated operation of the aforementioned hot stamping forming system for aluminum alloy body components is achieved through electronic devices, providing hardware support and an intelligent control platform for the hot stamping forming of aluminum alloy body components. Operators can input material parameters and welding process parameters through electronic devices, which automatically complete the optimization of weld point layout and control of hot stamping forming, improving production efficiency and quality stability.

[0078] In some embodiments, this application also provides a computer-readable storage medium storing a computer program that, when executed by a computer's processor, causes the computer to perform the hot stamping forming method for aluminum alloy body components provided in the foregoing embodiments.

[0079] Computer-readable storage media can be any medium capable of storing program code, such as a USB flash drive, external hard drive, read-only memory, random access memory, magnetic disk, or optical disk. When executed by a computer processor, the computer program stored on the storage medium can perform the function of a weld point layout optimization unit. This involves establishing a three-dimensional finite element model of the aluminum alloy sheet to be welded, inputting material parameters and welding process parameters, simulating the stress field distribution during welding, and determining the location and range of stress concentration areas. Based on the location and range of stress concentration areas, the program arranges the weld points according to a preset weld point layout principle. Based on the three-dimensional finite element model, it simulates and obtains the stress distribution results of each weld point during the welding process under the initial layout, iteratively optimizes the weld point layout, and outputs the optimized weld point coordinates. Simultaneously, the computer program can also control the welding unit, solution treatment unit, and hot stamping unit, realizing an integrated process of welding, solution treatment, and hot stamping.

[0080] In this embodiment, the software program of the aforementioned aluminum alloy body component hot stamping forming system can be conveniently deployed to various computer devices via a computer-readable storage medium, facilitating the promotion and portability of the system. Users only need to install the computer program in the storage medium onto their computer to realize the functions of the aluminum alloy body component hot stamping forming system, without the need to redevelop the software, thus reducing the system deployment cost and technical threshold.

[0081] The following combination Figures 1 to 7 Taking the actual production of 7xxx series high-strength aluminum alloy B-pillars as an example, a complete application example of the technical solution of this application is illustrated. This application example sequentially goes through the cutting process, the blank welding process, the hot stamping forming process, the cleaning and drying process, the laser cutting process, and the artificial aging process.

[0082] Step 1: Take a 2.5mm thick 7075 aluminum alloy sheet as the outer panel and patch panel of the B-pillar.

[0083] Step 2: Cut the outer B-pillar panel and patch panel to be welded according to the design dimensions, and then perform mechanical grinding to fully remove the oxide film, oil, dust and other impurities on the surface of the panel, so that the surface cleanliness meets the requirements of solid phase welding.

[0084] Step 3: A 3D model of the aluminum alloy sheet to be welded is established using CAE finite element analysis software. Material parameters (elastic modulus 70 GPa, Poisson's ratio 0.33, thermal conductivity 130 W / (m·K)) and welding process parameters (clamping force 5000 N~6000 N, stirring head rotation speed 2000 r / min~3000 r / min, pressing speed 1 mm / s~3 mm / s) are input to simulate the stress field distribution during welding, determine the location and range of stress concentration areas, and the simulation results are as follows: Figure 2 As shown.

[0085] Step 4: In the blank welding process, the weld point distribution is iteratively optimized based on the CAE simulation stress field results, following these principles: all weld points avoid stress concentration areas; the distance between the weld point and the edge of the plate is controlled at 12mm~15mm; weld points for inner and outer spliced ​​blanks are symmetrically arranged on both sides of the splice seam, with the distance from the splice seam controlled at 12mm~18mm; the spacing between adjacent weld points is controlled at 50mm~100mm. After the weld point positions are determined, the coordinates of each weld point are marked on the blank surface.

[0086] Step 5: Select a friction stir spot welding machine with a stirring head shoulder diameter of 6mm. Set the main process parameters as follows: clamping force 5000N~6000N, rotation speed 2000r / min~3000r / min, pressing speed 1mm / s~3mm / s, pressing depth 1mm~3mm, pressing dwell time 0s~5s, retraction speed 1mm / s~3mm / s, and shoulder pressing amount controlled at 0.1mm~0.3mm. The welding robot drives the stirring head to perform point-by-point welding according to the preset coordinates. After welding, grind away the burrs to ensure a flat spliced ​​surface.

[0087] Step Six: In the hot stamping process, the welded spliced ​​blanks are transferred to a heating furnace for solution treatment, so that the reinforcing phase is fully dissolved to form a supersaturated solid solution; then they are quickly transferred to a pre-cooled hot stamping die with a cooling system for die closing, stamping and quenching to obtain a crack-free and well-formed B-pillar outer panel semi-finished product.

[0088] Step 7: In the cleaning and drying process, after the molded workpiece is taken out, the surface oxide scale residue and mold release agent are first blown off with high-pressure air, and then it is placed in an alkaline cleaning tank for ultrasonic cleaning. After that, it is rinsed with deionized water and dried with hot air to prevent surface corrosion.

[0089] Step 8: In the laser cutting process, the dried workpiece is placed in a special tooling fixture for positioning. The hot stamping process allowance is removed by laser cutting equipment, and the process structures such as door hinge mounting holes, seat belt mounting holes, and wire harness through holes are processed. The processing accuracy is controlled within ±0.1mm.

[0090] Step Nine: In the aging process, the cut B-pillar workpiece undergoes two-stage artificial aging: the first stage aging temperature is 125℃~135℃, held for 4h~6h; the second stage aging temperature is 160℃~170℃, held for 10h~12h. After aging, it is cooled to room temperature in the furnace and then subjected to final inspection: first, a visual inspection is performed to confirm that the weld joints are free of cracks; then, ultrasonic testing is used to confirm that there are no pores or cracks inside the weld joints; finally, after the dimensional accuracy is checked and found to meet the requirements, the hot-formed high-strength 7xxx series aluminum alloy B-pillar is obtained.

[0091] Table 1. Comparison of stress on solder joints in CAE simulation under different solder joint layout schemes.

[0092] Table 2 Welding defects and formability characteristics of hot-formed high-strength 7xxx series aluminum alloy B-pillars with different weld point layout schemes

[0093] See Figures 3 to 6In this example, for the splicing blank of the B-pillar outer panel and the patch panel, step four simulated and compared different weld point layout schemes through the following iterative optimization process, and the stress results are shown in Table 1. Among them, as... Figure 3 As shown, Scheme 1 for solder joint layout has 12 solder joints (1# to 12#). Simulation results show that the maximum stress on the solder joints in Scheme 1 reaches 4953N (solder joint 4#), indicating significant local stress concentration. Based on Scheme 1, the number of solder joints is increased to 13, forming... Figure 4 The second solder joint layout scheme is shown. However, among the 13 solder joints (1# to 13#) in Scheme 2, the maximum stress on a solder joint is 4826N (solder joint 4#), indicating that the local stress peak is still relatively high, and there is still a risk of cracking. Therefore, the solder joint positions are further adjusted: the number of solder joints is increased to 14 based on Scheme 2, forming Solder Joint Layout Scheme 3, as shown below. Figure 5 As shown, Scheme 3 sets the number of solder joints to 14 (1# to 14#), with each solder joint experiencing a force between 3304N and 4744N. The force distribution across the solder joints is relatively uniform, with no obvious points of high stress concentration. Further adjustments to the solder joint positions based on Scheme 3 are made: increasing the number of solder joints to 15, resulting in Scheme 4, as shown... Figure 6 As shown, Scheme 4 sets 15 solder joints (1# to 15#). Solder joint 3# is subjected to a force of 4901N. Although the number of solder joints has increased, the uniformity of force distribution has decreased.

[0094] Additionally, from Table 2 and Figure 7 It is evident that among the four welding point layout schemes, only the welding points of the hot-formed high-strength 7xxx series aluminum alloy B-pillar product corresponding to Scheme 3 are free from cracking, and the product is well formed after hot stamping.

[0095] The above results indicate that the relationship between the number of weld points and the uniformity of stress distribution is not a simple linear one. A higher number of weld points does not necessarily mean more uniform stress distribution; in fact, blindly increasing the number of weld points may lead to an increase in localized stress peaks. Through the iterative optimization process described above, a balanced configuration of the number and location of weld points can be found under specific working conditions, causing the stress on each weld point during hot stamping to converge within a narrower range, thereby reducing stress peaks and improving cracking issues.

[0096] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A method for hot stamping forming of aluminum alloy car body components, characterized in that, include: A three-dimensional finite element model of the aluminum alloy sheet to be welded is established. The material parameters of the aluminum alloy sheet to be welded and the preset friction stir spot welding process parameters are input to simulate the stress field distribution during the welding process and determine the location and range of the stress concentration area. Based on the location and extent of the stress concentration area, the solder joint positions are initially arranged according to the preset solder joint arrangement principle. Based on the three-dimensional finite element model, the stress distribution of each weld point under the initial layout during the welding process is simulated and obtained. The weld point layout is iteratively optimized, and the optimized weld point coordinates are output. Mark the optimized weld point coordinates on the surface of the blank, and perform welding according to the preset friction stir spot welding process parameters; After the welded blanks are solution treated, they are hot stamped into shape.

2. The hot stamping forming method for aluminum alloy car body components according to claim 1, characterized in that, The process of simulating the stress distribution of each weld point during the welding process based on the three-dimensional finite element model to obtain the initial layout, and iteratively optimizing the weld point layout, includes: Based on the stress distribution results, the weld points are arranged in areas where the stress value is lower than the preset stress threshold; the positions of the weld points are iteratively adjusted until the stress value at each weld point is lower than the critical stress value for cracking, and the stress deviation between each weld point does not exceed the preset deviation range.

3. The hot stamping forming method for aluminum alloy car body components according to claim 1, characterized in that, The step of marking the optimized weld point coordinates on the surface of the blank and performing welding according to the preset friction stir spot welding process parameters includes: The optimized weld point coordinates are marked on the surface of the blank. Based on the characteristics of the aluminum alloy sheet to be welded, a friction stir welding device and a stirring head of matching size are selected, and welding is performed according to the preset friction stir welding process parameters.

4. The hot stamping forming method for aluminum alloy body components according to claim 1, characterized in that: The material parameters of the aluminum alloy sheet to be welded include at least one of elastic modulus, Poisson's ratio, and thermal conductivity. And / or, the welding process parameters of the friction stir spot welding include at least one of the following: the clamping force of the stirring head, the rotation speed of the stirring head, the pressing speed, the pressing depth, the pressing dwell time, the retraction speed, and the shoulder pressing amount.

5. The hot stamping forming method for aluminum alloy car body components according to claim 1, characterized in that, The principle for arranging the solder joints includes at least one of the following requirements (1) to (4): (1) All solder joints should avoid the stress concentration area; (2) The distance between the weld point and the edge of the plate is controlled within the first preset distance; (3) The welding points of the splicing blanks are symmetrically arranged on both sides of the splicing seam, and the distance from the splicing seam is controlled within the second preset distance; (4) The distance between adjacent welding points is controlled within the third preset distance.

6. The hot stamping forming method for aluminum alloy car body components according to claim 1, characterized in that, Following the hot stamping process, the process also includes: After hot stamping, the workpiece is cleaned, dried, cut, and aged. After the aging process is completed, the sample is cooled to room temperature before testing.

7. The hot stamping forming method for aluminum alloy body components according to claim 6, characterized in that, The workpiece is aged using a two-stage artificial aging process, which includes: the workpiece after cutting is subjected to a two-stage artificial aging process, the first stage aging temperature is set at 125℃~135℃, and the holding time is 4h~6h; the second stage aging temperature is set at 160℃~170℃, and the holding time is 10h~12h.

8. The hot stamping forming method for aluminum alloy body components according to any one of claims 1 to 7, characterized in that: The aluminum alloy body components include the A-pillar and / or B-pillar of the vehicle; And / or, the aluminum alloy sheet to be welded is a 7xxx series aluminum alloy sheet.

9. A hot stamping forming system for aluminum alloy car body components, characterized in that, include: The weld point layout optimization unit is used to establish a three-dimensional finite element model of the aluminum alloy sheet to be welded, input the material parameters of the aluminum alloy sheet to be welded and the preset friction stir spot welding process parameters, simulate the stress field distribution during the welding process, determine the location and range of the stress concentration area, and lay out the weld point positions according to the location and range of the stress concentration area and the preset weld point layout principle. Based on the three-dimensional finite element model, the stress distribution of each weld point during the welding process under the initial layout is obtained through simulation. The weld point layout is iteratively optimized, and the optimized weld point coordinates are output. The welding unit is used to mark the optimized weld point coordinates on the surface of the blank and to perform welding according to the preset friction stir spot welding process parameters; The solution treatment unit is used to treat the welded blanks with a solution. The hot stamping unit is used to hot stamp and form the blank after solution treatment.

10. A vehicle, characterized in that: The vehicle includes an aluminum alloy body component manufactured using the hot stamping forming method for aluminum alloy body components as described in any one of claims 1 to 8.

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