A 6-series aluminum alloy part and its hot stamping forming method

Abstract

This invention discloses a 6-series aluminum alloy part and its hot stamping forming method, relating to the field of precision forming and intelligent manufacturing technology of metal materials. The method includes the following steps: a supersaturated solution-treated 6-series aluminum alloy sheet is subjected to a first-stage heat treatment at a first-set heat treatment temperature and a first-set heat treatment time; the heat-treated sheet is then subjected to vibration treatment at a set vibration frequency and a set vibration time; the vibrated sheet is then subjected to heat treatment at a set heating rate and a set forming temperature; the heated sheet is then subjected to stamping deformation, followed by a second-stage heat treatment at a second-set heat treatment temperature and a second-set heat treatment time, resulting in a 6-series aluminum alloy part that meets the target mechanical performance indicators. This invention not only ensures the mechanical properties of the final part but also significantly improves the stability of performance between different production batches.

Description

Technical Field

[0001] This invention relates to the field of precision forming and intelligent manufacturing technology of metal materials, and in particular to a 6-series aluminum alloy part and its hot stamping forming method. Background Technology

[0002] 6-series aluminum alloys (such as 6082 and 6061) are widely used in lightweight structural components in the automotive and aerospace industries due to their excellent specific strength, corrosion resistance, and heat treatability. The traditional "hot stamping-artificial aging" process typically includes the following steps: solution treatment → hot forming → quenching → long-term (usually 4-8 hours) artificial aging to achieve T6 performance. This traditional process has two major technical bottlenecks: First, the supersaturated solution-treated parts undergo natural aging at room temperature after forming, causing unstable performance over time and making long-term storage impossible, severely restricting production scheduling flexibility; second, the artificial aging time required to reach peak performance is too long, significantly reducing production efficiency.

[0003] To address the aforementioned issues, existing technologies have been improved. For example, patent document CN118147590A proposes a technical solution: first, the aluminum alloy sheet undergoes pre-aging treatment to obtain a special microstructure rich in atomic clusters (such as GP regions), followed by a process route of rapid heating, stamping, and short-time aging. This solution shortens the final aging cycle to a certain extent.

[0004] While existing technologies can achieve efficient and precise industrial production to meet diverse and customized performance requirements, the stability of the sheet metal largely depends on the control of the pre-aging process parameters, which is a passive and outcome-based approach. Furthermore, they exhibit poor adaptability (robustness) to different alloy compositions, environmental fluctuations, or production intervals, and the risk of performance drift remains. Summary of the Invention

[0005] Based on the deficiencies of the existing technology, the present invention provides a 6-series aluminum alloy part and its hot stamping forming method, which solves the existing problems.

[0006] The present invention adopts the following technical solution: In a first aspect, the present invention provides a 6-series aluminum alloy part and its hot stamping forming method, comprising the following steps: The supersaturated solid solution state 6-series aluminum alloy plate is subjected to first-stage heat preservation treatment at the first set heat preservation temperature and the first set heat preservation time. The insulated board material is subjected to vibration treatment at a set vibration frequency and a set vibration time. The vibrated sheet material is then subjected to heat treatment at a set heating rate and a set forming temperature. The heated sheet metal is stamped and deformed, and then subjected to a second-stage heat preservation treatment at a second set heat preservation temperature and a second set heat preservation time to obtain 6-series aluminum alloy parts that meet the target mechanical performance indicators.

[0007] Preferably, the first set heat preservation temperature range is 150℃-200℃, the first set heat preservation time range is 20 minutes-100 minutes, the set vibration frequency range is 30-60Hz, the set vibration time range is 10-30 minutes, the set heating rate range is 10℃ / s-50℃ / s, the set molding temperature range is 200℃-550℃, the second set heat preservation temperature range is 160℃-180℃, and the second set heat preservation time range is 20 minutes-60 minutes.

[0008] Preferably, before heat treatment of the vibrated sheet material at a set heating rate and a set forming temperature, the vibrated sheet material is heated to 80℃-120℃ at a rate of 3℃ / s-5℃ / s.

[0009] Preferably, the step of stamping and deforming the heated sheet metal specifically includes: quickly transferring the sheet metal heated to the forming temperature into a cold mold, stamping and deforming it to obtain the target part shape, and immediately performing pressure holding and quenching.

[0010] Preferably, mechanical performance index values ​​are set, and the process parameters of the first-stage heat preservation treatment, vibration treatment, heating treatment and second-stage heat preservation treatment are iterated within a set range based on a genetic algorithm to obtain the first set heat preservation temperature, the first set heat preservation time, the set vibration frequency, the set vibration time, the set heating rate, the set forming temperature, the second set heat preservation temperature and the second set heat preservation time.

[0011] Preferably, the process parameters for the primary insulation treatment, vibration treatment, heating treatment, and secondary insulation treatment based on the genetic algorithm are iterated within a set range, specifically including the following steps: Define the target mechanical performance indicators of the target part and set the value range of each process parameter as the search space; An initial population containing multiple parameter combinations is randomly generated within the search space, and each individual is uniquely encoded with a set of process parameter combinations; For each set of parameters, obtain its corresponding performance characteristic value and compare it with the target mechanical performance index. Based on the comparison results, generate the corresponding fitness. Based on fitness, selection, crossover, and mutation operations are performed to generate a new generation of population; The above steps are executed iteratively until the convergence condition is met. The parameter combination with the highest fitness is output as the optimal process parameter combination, namely, the first set heat preservation temperature, the first set heat preservation time, the set vibration frequency, the set vibration time, the set heating rate, the set forming temperature, the second set heat preservation temperature, and the second set heat preservation time.

[0012] Preferably, the mechanical properties include tensile strength, yield strength, and elongation.

[0013] Preferably, the mechanical performance evolution simulation module obtains the performance characteristic values ​​corresponding to each set of parameters. The mechanical performance evolution simulation module is used to simulate the virtual process of the evolution of the mechanical performance index of the obtained part with the process steps under different process parameter combinations, and outputs the simulated performance evolution curve; quantifiable performance characteristic values ​​are extracted from the performance evolution curve.

[0014] Preferably, the corresponding fitness is generated through an objective function, which is constructed by the comprehensive deviation between the simulation results and the measured values.

[0015] Secondly, the present invention provides a 6-series aluminum alloy part, which is prepared by the hot stamping forming method described above.

[0016] Compared with the prior art, the above-mentioned at least one technical solution adopted by the present invention can achieve the following beneficial effects: This invention involves vibration treatment of insulated sheet metal, which promotes the uniform distribution of the GP region and β″ phase, and forms a micro-dislocation structure around the precipitated phase. These uniformly distributed dislocations effectively pin vacancies, significantly suppressing the continuous coarsening of the GP region and its premature non-uniform transformation to the β″ phase during room temperature storage. This fundamentally solves the problem of batch-to-batch performance fluctuations caused by natural aging, endowing the sheet metal and semi-finished parts with excellent long-term room temperature storage capability. Vibration treatment results in a more uniform distribution of the initially precipitated phase, providing a uniform and predictable initial microstructure for subsequent heating, forming, and final aging treatments. Therefore, this method not only ensures the mechanical properties of the final parts but also significantly improves the stability and repeatability of performance between different production batches, overcoming the risk of "performance drift" in existing technologies. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a flowchart of a hot stamping forming method for 6-series aluminum alloy parts according to the present invention; Figure 2 This is a schematic diagram of the iterative process of the present invention; Figure 3 This is a schematic diagram of a transmission electron microscope according to an embodiment of the present invention; in, Figure 3 (a): Schematic diagram of transmission electron microscopy. Figure 3 (b): Precipitated phase size distribution diagram. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Current technologies still face the following unresolved technical bottlenecks in achieving efficient and precise industrial production to meet diverse and customized performance requirements: 1. Lack of proactive and robust control methods for the long-term storage stability of sheet metal: The stability of sheet metal mainly relies on the control of the pre-aging process parameters themselves, which is a passive and result-oriented state. There is a lack of proactive, externally applicable physical fields or process methods to further ensure, enhance, and optimize the long-term storage stability of sheet metal. In particular, the adaptability (robustness) to different alloy compositions, environmental fluctuations, or production intervals is poor, and there is still a risk of performance drift.

[0021] 2. Lack of Intelligent Process Parameter Determination Methods: While the scheme provides a broad range of parameters for each process stage, it offers no systematic solution for quickly and automatically determining a globally optimal combination of process parameters covering multiple coupled stages such as pre-aging, heating, and secondary aging, based on a specific, differentiated end-performance indicator (e.g., "tensile strength ≥ 320 MPa and elongation ≥ 16%). Process development still heavily relies on the experience of technical personnel and cumbersome trial-and-error methods, resulting in lengthy R&D cycles, high costs, and difficulty in guaranteeing optimal or consistent performance. Due to the lack of quantitative optimization methods for the synergistic effects between multi-stage parameters, fixed or experience-based process parameters often fail to accurately meet performance targets when faced with new performance goals, different material batches, or part shapes, posing challenges to process adaptability and repeatability. This makes it difficult to meet the core requirements of modern industry for "precision manufacturing," "flexible production," and rapid response to market demands.

[0022] The core of this invention consists of three mutually supportive and logically rigorous components: customized process methods, intelligent parameter optimization methods, and the final high-performance product. These three form a complete technological closed loop.

[0023] A customized hot stamping forming method for high-strength and high-toughness 6-series aluminum alloy parts. This method is a multi-step, orderly, and causally related complete process flow, referring to... Figure 1 This includes the following five steps performed sequentially: Step 1: Primary insulation treatment (to achieve customized initial microstructure construction).

[0024] After conventional solution treatment and quenching, the supersaturated solution-treated 6-series aluminum alloy plate is placed in an environment of 150-200℃ for heat treatment for 20-100 minutes. The core purpose of this step is to induce solute atoms such as magnesium and silicon to precipitate from the supersaturated solid solution, forming GP regions and β″ phases of specific size, density, and distribution. The GP regions can be referred to as solute atom-rich regions, and the β″ phase is a metastable strengthening phase. This lays a predetermined and customized initial microstructure foundation for all subsequent steps. The first heat treatment temperature and the first heat treatment time are the first set of key optimizable and customizable variables in this process.

[0025] Step 2: Vibration stabilization treatment (to achieve active and reliable long-term storage stability).

[0026] The sheet metal treated in step 1 is placed on a specialized vibration device, and mechanical vibration at a specific frequency and duration is applied. Vibration frequency and vibration time are the second set of optimizable parameters. The vibration frequency is set within the range of 30Hz-60Hz, and the vibration time is set within the range of 10 minutes-30 minutes. This step is not intended to promote nucleation; its core role and the decisive technical effect it produces are:

[0027] This promotes a better uniform distribution of the GP region and β″ phase precipitated in step 1 within the aluminum matrix, reducing segregation; It induces the formation of a high-density, uniformly distributed microdislocation structure around the precipitate phase and in the matrix; The key effect is that these introduced, uniformly distributed micro-dislocations effectively pin vacancies, significantly inhibiting the continued coarsening (i.e., natural aging) of the GP region and its premature non-uniform transformation to the β″ phase during subsequent room temperature storage or transportation. This proactively endows the sheet material with excellent long-term room temperature storage stability (e.g., over 180 days), fundamentally solving the performance inconsistency problem caused by material scheduling, inventory, and batch management in industrial production.

[0028] Step 3: Controllable two-stage heating (to achieve rapid prototyping and preservation of microstructure).

[0029] First, the vibratory sheet is heated to 80-120°C (preferably about 100°C) at a relatively slow rate of 3-5°C / s to achieve uniform preheating of the sheet, providing the necessary activation energy for atomic diffusion while avoiding the dissolution of the existing precipitate phase.

[0030] Subsequently, the preheated sheet metal is immediately transferred to an infrared heating device and rapidly heated to a predetermined forming temperature of 200-550°C at a high rate of 10°C / s-50°C / s. The rapid heating rate and the final forming temperature are the third set of optimizable parameters. The purpose of optimizing this parameter combination is to maximize the preservation of the excellent microstructure created in steps 1 and 2, rich in GP region / β″ phase and specific dislocation structures, by precisely controlling the exposure time in the high-temperature zone, thus ensuring the final performance.

[0031] Step 4: Hot stamping and pressure holding quenching (near-net-shape forming and microstructure freezing of parts).

[0032] The sheet metal, heated to the forming temperature, is rapidly transferred to a cold mold for stamping deformation to obtain the target part shape, followed immediately by pressure holding and quenching. The resulting part retains a large number of GP zones, β″ phases, and uniform atomic clusters in its microstructure, thus exhibiting excellent room temperature storage stability and providing the possibility of production process interruption.

[0033] Step 5: Secondary thermal insulation treatment (to achieve rapid and synergistic enhancement of mechanical properties).

[0034] The formed part obtained in step 4 is placed in an environment of 160-180℃ for a second heat treatment, with a heat treatment time of 20-60 minutes. The heat treatment temperature and heat treatment time are the fourth set of optimizable parameters. Since all the previous steps have jointly constructed a uniform, fine, and high-energy microstructure, this short heat treatment can promote the rapid and uniform transformation, coarsening, and growth of the strengthening phase (mainly the β″ phase), thereby enabling the mechanical properties of the part to reach and exceed the peak level of traditional long-time T6 aging in a very short time, while achieving an excellent match between high strength and high toughness.

[0035] A smart reverse optimization method for determining the above process parameters.

[0036] This invention creatively proposes an optimization method. Its core idea is to treat the complex, multi-step coupled physical process as a holistic system, using the specific performance indicators of the final part as the sole driving objective, and directly searching for the optimal solution in the system's parameter space through an intelligent iterative algorithm. This method is particularly suitable for scenarios where the mechanistic model is complex or difficult to establish precisely. Figure 2 This includes the following steps:

[0037] S1: Optimize the search space definition for the objective and parameters.

[0038] Clearly input one or more specific, quantifiable mechanical performance indicators of the target part (e.g., tensile strength ≥320MPa, elongation ≥12%).

[0039] Based on physical feasibility, equipment capabilities, and process knowledge, a search space is set for all four sets of optimizable parameters defined in the aforementioned forming method (i.e., the parameters in steps 1, 2, 3, and 5), that is, the minimum and maximum values ​​that can be adjusted are defined for each parameter (e.g., primary insulation temperature: [lower limit 150℃, upper limit 200℃]).

[0040] S2: The core engine for iterative optimization based on genetic algorithms.

[0041] S21: Initialize the population: Within the defined search space, an initial population of N individuals is generated using a random method. Each individual uniquely encodes a complete set of process parameters (covering all optimizable parameters from steps 1-5).

[0042] S22: Performance Feedback Acquisition and Evaluation: This is a crucial step driving optimization. For each individual in the current population (i.e., each set of parameters), perform the following operations to obtain its performance evaluation:

[0043] Parameter input: Input the complete set of process parameters encoded for this individual into a preset performance evaluation interface.

[0044] Performance Evolution Simulation and Feature Extraction: This interface calls a mechanical property evolution simulation module. Based on a simplified characterization of key physical phenomena in the above process (such as precipitation, dissolution, transformation of precipitates and dislocation effects), this module simulates the virtual process of the evolution of key mechanical properties (such as tensile strength) of the part with process steps under a specific combination of parameters, and outputs the simulated performance evolution curve.

[0045] Quantitative comparison: Extract quantifiable feature values ​​from the simulated performance evolution curves, such as the simulated peak intensity after secondary insulation treatment, the simulated time point when the intensity reaches a certain percentage (kinetic characteristics), etc. Directly quantify and compare these extracted feature values ​​with the specific performance targets set in S1.

[0046] S23: Fitness Calculation: Based on the quantization comparison results in S22, the fitness of the individual is calculated using a predefined objective function. The objective function measures the overall deviation between the simulation results and the target (e.g., objective function value = |simulated peak intensity - target intensity| + ...). α *|Simulated feature time - target time|, where α(These are weighting coefficients). The smaller the objective function value, the better the combination of parameters, and the higher its fitness.

[0047] S24: Evolutionary Iteration and Convergence Judgment: Check whether the fitness of the best individual in the current population meets the preset convergence conditions (e.g., the objective function value of the best individual is less than a certain tolerance threshold ε, or the optimization iteration has reached the preset maximum number of generations, or the fitness improvement of the best individual over multiple generations is negligible).

[0048] If the convergence condition is met, the optimization loop terminates and proceeds to S3.

[0049] If the convergence condition is not met, the core operations of the genetic algorithm are executed to generate a new population with greater potential: selection (selecting some high-quality individuals as parents based on fitness), crossover (randomly exchanging and mixing some parameters of individuals from different parents to explore new parameter combinations), and mutation (randomly perturbing some parameters of individuals with a small probability to maintain population diversity and avoid getting trapped in local optima). These operations generate a new generation of the population, and then return to S22 to start a new round of "evaluation-evolution" cycle.

[0050] Step 3: Output optimal process parameters.

[0051] When the iterative optimization process meets the convergence condition, it outputs the complete set of process parameters corresponding to the individual with the highest fitness in the current population. These process parameters are the optimal customized process formula found for the performance target set in S1, namely, the first set holding temperature, the first set holding time, the set vibration frequency, the set vibration time, the set heating rate, the set forming temperature, the second set holding temperature, and the second set holding time. They can be directly used to guide the mass production of the target part. High-performance 6-series aluminum alloy parts are obtained. The 6-series aluminum alloy thin-walled parts are prepared by applying the optimal parameter combination determined by the above-mentioned intelligent reverse optimization method and strictly implementing the above-mentioned customized hot stamping forming method.

[0052] The solution process utilizes a closed-loop iterative framework for model computation and parameter optimization, built collaboratively with MATLAB and ISIGHT software. First, a system of differential equations is established in MATLAB to simulate the evolution of mechanical properties and microstructure based on given model constants. Then, in ISIGHT, upper and lower limits for optimizable parameters are set to form a search space, generating an initial population of candidate parameters. Each candidate parameter set is evaluated using MATLAB's mechanical property evolution simulation, extracting characteristic values ​​such as peak aging intensity and dynamic inflection points from the simulation curves, and comparing them quantitatively with experimental data. The deviation between predicted and measured values ​​is quantified using an objective function. If the convergence condition is met, the optimal parameter combination is obtained; otherwise, ISIGHT performs fitness evaluation, generating a new population through crossover and mutation operations to continue iterating until convergence.

[0053] The prepared 6-series aluminum alloy parts have excellent mechanical properties: their tensile strength and yield strength are not less than 110% of the peak performance of the corresponding grade in the traditional T6 state, while their elongation is not less than 120% of the corresponding peak value in the traditional T6 state, achieving an excellent synergy of high strength and high toughness, namely "high strength and high toughness".

[0054] The prepared 6-series aluminum alloy parts have an ideal microstructure: the strengthening phase is mainly composed of uniformly distributed and size-concentrated β″ phase, which is the microstructure basis for obtaining the above-mentioned excellent comprehensive properties.

[0055] The prepared 6-series aluminum alloy parts have flexible process applicability: throughout the entire production process, the intermediate sheet material after step B and the semi-finished parts after step D can be stored at room temperature for a long time (e.g., 180 days) and maintain stable performance (specifically, the Vickers hardness change is less than 1%). This provides great convenience and fundamental guarantee for production planning, logistics inventory and quality control.

[0056] This invention represents a leap from "experience-based trial and error" to "intelligent and precise customization": through a unique "intelligent reverse optimization method," it establishes an automated and rapid mapping channel from "any given performance index" to "a complete set of optimal process parameters." This completely overturns the traditional process development model that relies on expert experience and tedious experimental trial and error, and is expected to shorten the process development cycle of new products from months or weeks to days or even hours, while flexibly and accurately responding to diverse and rapidly changing market demands.

[0057] This leap forward significantly enhances the stability and controllability of the entire production process: The innovative introduction of "vibration stabilization treatment," a proactive physical field control step, actively constructs a reinforced barrier to suppress natural aging at the microscopic level, ensuring long-term storage stability from raw material sheets to semi-finished parts. This greatly liberates the production process, laying a key technological foundation for lean manufacturing, flexible manufacturing, and supply chain optimization, and solving a core pain point hindering the large-scale industrial application of this advanced technology.

[0058] The final performance of the parts was achieved beyond the conventional level: through global collaborative optimization of the entire process and multiple parameters, it was ensured that the microstructure followed the optimal or near-optimal path in each process evolution, so that the final short-time secondary heat preservation treatment could maximize the material potential and obtain parts with comprehensive performance that surpassed the traditional long-time T6 aging, significantly improving the added value and market competitiveness of the products.

[0059] A robust, composite technological barrier has been constructed: the forming method and optimization method of this invention are not simply superimposed, but rather an interdependent and deeply coupled organic whole. The forming method is the sole physical carrier and implementation object for the optimization method to function, while the optimization method is the core "brain" and navigation system that enables the forming method to achieve its ultimate performance. The two are closely integrated to form a complete, efficient, and robust technological system that is difficult for competitors to circumvent through simple modifications or substitutions.

[0060] Example Take the manufacture of a structural component using 6082 aluminum alloy as an example.

[0061] Optimization target setting: This part requires both high structural strength and a certain impact energy absorption capacity. Its target mechanical properties are set as follows: tensile strength ≥320MPa, elongation ≥12%. This target aims to improve the level of lightweighting while ensuring safety.

[0062] Implement intelligent reverse optimization methods to determine optimal process parameters: Step O1: Set Rm_target=320MPa, A_target=16%. Based on equipment capabilities and prior process knowledge, define the search space for each optimizable parameter as follows:

[0063] First-level insulation temperature: [170, 190]℃, first-level insulation time: [30, 60]min.

[0064] Vibration frequency: [40,60]Hz, vibration time: [10,20]min.

[0065] Rapid heating rate: [20,25]℃ / s, final forming temperature: [420,460]℃.

[0066] Secondary insulation temperature: [170, 175]℃, secondary insulation time: [30, 40]min.

[0067] Step O2: A standard genetic algorithm was used as the optimization engine, with a population size of 100 and a maximum number of iterations of 50. The "Simulation Estimation Feedback" mode was selected, and the mechanical performance evolution simulation module was built based on the Arrhenius-type kinetic formula and the precipitation enhancement empirical model. The algorithm converged after 38 iterations, with the convergence criterion being that the fitness change of the best individual was less than 0.1% for 10 consecutive generations.

[0068] Step O3: The algorithm outputs the parameter combination corresponding to the current optimal individual, denoted as "customized formula P". A specific numerical example is shown below:

[0069] Level 1 insulation: Insulate at 185℃ for 45 minutes.

[0070] Vibration treatment: Vibrate at a frequency of 50Hz for 15 minutes.

[0071] Rapid heating: Heats to 350°C at a rate of 23°C / s.

[0072] Level 2 insulation: Insulate at 172℃ for 35 minutes.

[0073] The simulation predicts the performance of this formulation as follows: Rm_pred = 322 MPa, A_pred = 16.5%.

[0074] Perform the hot stamping process according to "customized formula P".

[0075] Preliminary preparation: Commercial T6 state 6082 aluminum alloy sheet is selected. It is first subjected to standard solution treatment (540℃ ± 5℃, heat preservation for 30 minutes) and then water quenched to room temperature to obtain supersaturated solution state sheet material.

[0076] Step 1: Place the sheet material into an air-circulating oven preheated to 185°C and hold it at that temperature for 45 minutes.

[0077] Step 2: After removing the item, immediately place it on a vibration platform, set the vibration frequency to 50Hz, and perform vibration treatment for 15 minutes.

[0078] Step 3: After vibration, the sheet material is fed into the preheating furnace and heated to 100°C at a rate of 5°C / s and kept at a uniform temperature for 2 minutes. Then, it is quickly transferred to the infrared radiation heating equipment and heated at a set rate of 23°C / s. The heating is monitored with an infrared thermometer and stopped immediately when the center temperature of the sheet material reaches 450°C.

[0079] Step 4: Within 3 seconds after heating ends, transfer the sheet metal to a mold at a temperature of approximately 80°C and stamp it at a punch speed of 300 mm / s. After forming, hold the pressure for 10 seconds to achieve full quenching.

[0080] Step 5: Place the formed part into an aging furnace at 172℃ and hold it at that temperature for 35 minutes.

[0081] After the parts are removed from the furnace, they are air-cooled to room temperature to obtain the final product.

[0082] Final mechanical property testing of parts: Standard room temperature tensile tests (according to GB / T 228.1) were conducted on three batches of parts (3 pieces per batch) produced according to "customized formula P". The results are shown in Table 1 below: Table 1 Standard room temperature tensile test of three batches of parts The measured average tensile strength and elongation both met and slightly exceeded the set targets of Rm≥320MPa and A≥16%, and the data had a small standard deviation and good repeatability, proving that the "customized formula P" is effective and the process is stable.

[0083] Storage stability verification: The sheet metal samples after vibration treatment in step 2 and the control samples after only treatment in step 1 (without vibration) were stored in a dry environment at room temperature (25±2℃), and their Vickers hardness (HV5) was tested periodically. The results are shown in Table 2 below: Table 2 Comparison Untreated aluminum alloys have small GP regions, uneven partitioning, and large activity space. When stored under natural conditions, they are prone to the storage effect, that is, the GP regions grow and prematurely transform into metastable strengthening phases. The macroscopic manifestation is a slight increase in hardness. However, after hot stamping and secondary aging, due to the premature transformation into metastable strengthening phases, the precipitation size difference is large and the distribution is uneven, and it cannot reach the T6 state.

[0084] Vibration stabilization treatment resulted in a hardness decrease of less than 3% in the sheet material after 30 days of storage, while the untreated sheet material experienced a hardness decrease of up to 17.5%. This conclusively demonstrates that step 2 plays a decisive role in achieving long-term storage stability.

[0085] Microstructural characterization: The final part was sampled and observed using a transmission electron microscope (TEM). The images are as follows: Figure 3 As shown, numerous fine, uniformly sized (average about 20 nm) rod-shaped β″ phases are evenly distributed within the aluminum matrix, with no obvious precipitate-free zones. This is direct microscopic evidence that the part achieves high strength and good elongation.

[0086] This invention provides an innovative hot stamping forming process that includes an active physical field stabilization step, which can stably and repeatedly produce 6-series aluminum alloy parts with comprehensive mechanical properties (especially the synergy of strength and toughness) that surpass the traditional T6 state level, and whose intermediate states (sheet metal and semi-finished products) can be reliably stored for a long time.

[0087] This invention provides a set of intelligent parameter optimization methods that are deeply coupled and work collaboratively with the above-mentioned specific processes. It can automatically and efficiently deduce the complete set of optimal process parameters that are precisely matched to any given specific part performance index, and truly realize "performance-driven manufacturing" from "performance index input" to "optimal process output".

[0088] This invention provides high-performance 6-series aluminum alloy parts that possess both excellent mechanical properties and good processability, prepared by the above-described methods and processes.

[0089] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0090] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A hot stamping forming method for 6-series aluminum alloy parts, characterized in that, Includes the following steps: The supersaturated solid solution state 6-series aluminum alloy plate is subjected to first-stage heat preservation treatment at the first set heat preservation temperature and the first set heat preservation time. The insulated board material is subjected to vibration treatment at a set vibration frequency and a set vibration time. The vibrated sheet material is then subjected to heat treatment at a set heating rate and a set forming temperature. The heated sheet metal is stamped and deformed, and then subjected to a second-stage heat preservation treatment at a second set heat preservation temperature and a second set heat preservation time to obtain 6-series aluminum alloy parts that meet the target mechanical performance indicators.

2. The hot stamping forming method for 6-series aluminum alloy parts as described in claim 1, characterized in that, The first set heat preservation temperature range is 150℃-200℃, the first set heat preservation time range is 20 minutes-100 minutes, the set vibration frequency range is 30-60Hz, the set vibration time range is 10-30 minutes, the set heating rate range is 10℃ / s-50℃ / s, the set molding temperature range is 200℃-550℃, the second set heat preservation temperature range is 160℃-180℃, and the second set heat preservation time range is 20 minutes-60 minutes.

3. The hot stamping forming method for 6-series aluminum alloy parts as described in claim 1, characterized in that, Before heat treatment of the vibrated sheet material at a set heating rate and a set forming temperature, the vibrated sheet material is heated to 80℃-120℃ at a rate of 3℃ / s-5℃ / s.

4. The hot stamping forming method for 6-series aluminum alloy parts as described in claim 1, characterized in that, The process of stamping and deforming the heated sheet metal specifically includes: rapidly transferring the sheet metal heated to the forming temperature into a cold mold, stamping and deforming it to obtain the target part shape, and immediately performing pressure holding and quenching.

5. The hot stamping forming method for 6-series aluminum alloy parts as described in claim 1, characterized in that, Mechanical performance index values ​​are set, and the process parameters of the first-stage heat preservation treatment, vibration treatment, heating treatment and the second-stage heat preservation treatment are iterated within the set range based on the genetic algorithm to obtain the first set heat preservation temperature, the first set heat preservation time, the set vibration frequency, the set vibration time, the set heating rate, the set forming temperature, the second set heat preservation temperature and the second set heat preservation time.

6. The hot stamping forming method for 6-series aluminum alloy parts as described in claim 5, characterized in that, The process parameters for the primary heat preservation treatment, vibration treatment, heating treatment, and secondary heat preservation treatment are iterated within a set range based on a genetic algorithm, specifically including the following steps: Define the target mechanical performance indicators of the target part and set the value range of each process parameter as the search space; An initial population containing multiple parameter combinations is randomly generated within the search space, and each individual is uniquely encoded with a set of process parameter combinations; For each set of parameters, obtain its corresponding performance characteristic value and compare it with the target mechanical performance index. Based on the comparison results, generate the corresponding fitness. Based on fitness, selection, crossover, and mutation operations are performed to generate a new generation of population; The above steps are executed iteratively until the convergence condition is met. The parameter combination with the highest fitness is output as the optimal process parameter combination, namely, the first set heat preservation temperature, the first set heat preservation time, the set vibration frequency, the set vibration time, the set heating rate, the set forming temperature, the second set heat preservation temperature, and the second set heat preservation time.

7. The hot stamping forming method for 6-series aluminum alloy parts as described in claim 5, characterized in that, The mechanical properties include tensile strength, yield strength, and elongation.

8. The hot stamping forming method for 6-series aluminum alloy parts as described in claim 5, characterized in that, The mechanical performance evolution simulation module obtains the performance characteristic values ​​corresponding to each set of parameters. The mechanical performance evolution simulation module is used to simulate the virtual process of the evolution of the mechanical performance index of the obtained part with the process steps under different process parameter combinations, and outputs the simulated performance evolution curve; quantifiable performance characteristic values ​​are extracted from the performance evolution curve.

9. The hot stamping forming method for 6-series aluminum alloy parts as described in claim 5, characterized in that, The corresponding fitness is generated by an objective function, which is constructed by the comprehensive deviation between simulation results and measured values.

10. A 6-series aluminum alloy part, characterized in that, It is prepared by the hot stamping forming method according to any one of claims 1 to 9.

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