A high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method

Abstract

The present application relates to the technical field of metal sheet, and particularly relates to a high-strength aluminum alloy pre-hardening forming-heat treatment fusion high-efficiency precise hot forming manufacturing method, which comprises the following steps: S1, sequentially performing solid solution treatment on an aluminum alloy component at a solid solution temperature, and then performing quenching treatment to obtain a W-state blank; S2, performing pre-aging treatment on the obtained W-state blank at a pre-aging temperature, and cooling to room temperature to obtain a PA-state pre-hardening blank; S3, then performing stamping pre-heat preservation heating on the obtained PA-state pre-hardening blank, and then performing stamping treatment to obtain a warm forming component; S4, performing first-stage aging treatment on the warm forming component obtained by stamping in step S3, and cooling; S5, performing second-stage aging treatment at a temperature lower than that of the first-stage aging treatment, and cooling to obtain an aluminum alloy component. The manufacturing method shortens the overall process time, and more importantly, can obtain an aluminum alloy component with higher strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal plate manufacturing, in particular to a high-strength aluminum alloy pre-hardening forming-heat treatment fusion high-efficiency precise hot forming manufacturing method. BACKGROUND

[0002] Aluminum alloy is increasingly used as a raw material for producing parts in fields such as aerospace and automobiles that have a demand for lightweight due to its lightweight characteristics. However, due to the poor room temperature plasticity of aluminum alloy, negative effects such as fracture and springback easily occur during the forming process, making it impossible to meet the needs of complex structural parts. In view of this, warm forming technology has been developed to avoid this problem. With the increase of the forming temperature of aluminum alloy sheet, part of the strengthening phase in the alloy dissolves, the dislocation density decreases, the internal stress becomes smaller, and the ductility and formability of the aluminum alloy sheet are significantly improved. However, the warm forming technology also brings the problem of dynamic recovery and dislocation annihilation, which easily leads to a decrease in strengthening effect, and usually requires subsequent baking to improve the strength of the parts, but the overall process is time-consuming, low in efficiency, and the strengthening effect of the parts is limited, which is not conducive to industrial production and application.

[0003] Therefore, it is necessary to provide a technical solution to solve the above problems. SUMMARY

[0004] The present application aims to: in view of the deficiencies of the prior art, provide a high-strength aluminum alloy pre-hardening forming-heat treatment fusion high-efficiency precise hot forming manufacturing method to solve the problems of long aging time and still to be improved strengthening effect of the parts when the current warm forming method is combined with the baking process.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0006] A high-strength aluminum alloy pre-hardening forming-heat treatment fusion high-efficiency precise hot forming manufacturing method, comprising the following steps:

[0007] S1, at the solid solution temperature, the aluminum alloy component is sequentially subjected to solid solution treatment, and then quenched to obtain a W-state blank;

[0008] S2, at the pre-aging temperature, the W-state blank obtained in step S1 is subjected to pre-aging treatment, and cooled to room temperature to obtain a PA-state pre-hardening blank;

[0009] S3, then the PA-state pre-hardening blank obtained in step S2 is subjected to heat preservation before stamping, and then subjected to stamping treatment to obtain a warm forming component;

[0010] S4, the warm forming component obtained by stamping in step S3 is subjected to first-stage aging treatment and cooled;

[0011] S5, performing a second aging treatment at a temperature lower than the first aging treatment, and obtaining the aluminum alloy component after cooling.

[0012] Preferably, in step S1, the temperature of the solid solution treatment is 450-570℃, and the treatment time is 0.5-1h; the temperature of the quenching treatment is 14-20℃.

[0013] Preferably, in step S2, the pre-aging temperature is 70-180℃, and the time is 1-24h.

[0014] Preferably, the W-state blank obtained in step S1 is subjected to the pre-aging treatment of step S2 within 1min-10min.

[0015] Preferably, in step S3, the holding temperature is 200-300℃, and the holding time is 30s-5min.

[0016] Preferably, in step S3, the holding treatment is followed by a stamping treatment within 1s-10s.

[0017] Preferably, in step S4, the temperature of the first aging treatment is 160-200℃, and the time is 10-60min.

[0018] Preferably, in step S5, the temperature of the second aging treatment is 130-160℃, and the time is 10-60min.

[0019] Preferably, after the second aging treatment, a third aging treatment is further included, and the temperature of the third aging treatment is lower than that of the second aging treatment.

[0020] Preferably, the temperature of the second aging treatment is 140-160℃, and the temperature of the third aging treatment is 130-140℃.

[0021] The present application has the following beneficial effects: the preparation method provided by the present application, after solid solution quenching treatment, first performs a pre-aging treatment to obtain a pre-hardened blank in PA state, then performs a holding stamping treatment to obtain a warm forming component, and then directly performs at least two aging treatments, which integrates the pre-hardening forming and the heat treatment in one period of time. Compared with the conventional method which requires a heat treatment of up to several hours after warm forming, the present application not only shortens the overall process time and improves the efficiency, but more importantly, can make the strength of the aluminum alloy component not lower than T6 state or even exceed T6 state, while also obtaining good plasticity and ductility, reducing the risk of fracture and springback, and improving the dynamic recovery and dislocation annihilation problems caused by conventional warm forming. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The present application is a roadmap for the preparation method. DETAILED DESCRIPTION

[0023] In order to make the technical solutions and advantages of the present application clearer, the present application and its beneficial effects are described in further detail below, but the embodiments of the present application are not limited thereto.

[0024] The manufacturing method of the present application is preferably suitable for 2000 series, 6000 series and 7000 series aluminum alloys. Among them, the 2000 series refers to the aluminum-copper series, with a copper content of 3% to 5%, including but not limited to 2014, 2024, 2A16, 2A14; the 6000 series refers to the aluminum-magnesium-silicon alloy series, including but not limited to 6061, 6063; the 7000 series refers to the aluminum-zinc alloy series, including but not limited to 7072, 7055, 7050.

[0025] The present application provides a high-strength aluminum alloy pre-hardening forming-heat treatment fusion high-efficiency precise hot forming manufacturing method, comprising the following steps:

[0026] S1, sequentially performing solid solution treatment on the aluminum alloy component at a solid solution temperature, and then performing quenching treatment to obtain a W-state blank;

[0027] S2, performing pre-aging treatment on the W-state blank obtained in step S1 at a pre-aging temperature, and cooling to room temperature to obtain a PA-state pre-hardened blank;

[0028] S3, then performing stamping pre-heat preservation heating on the PA-state pre-hardened blank obtained in step S2, and then performing stamping treatment to obtain a warm forming component;

[0029] S4, performing first-stage aging treatment on the warm forming component obtained by stamping in step S3, and cooling;

[0030] S5, then performing second-stage aging treatment at a temperature lower than that of the first-stage aging treatment, and obtaining the aluminum alloy component after cooling.

[0031] Among them, heating is performed before stamping, the plate becomes soft after heating, which facilitates subsequent stamping forming, and helps to increase the plasticity of the part. At the same time, the present application also performs pre-aging treatment before heat preservation, and the pre-aging treatment temperature is lower than the heat preservation temperature. On the one hand, it can ensure the subsequent stamping forming effect, and on the other hand, it can improve the hardness of the plate by pre-hardening, which can alleviate the problem of low strength caused by subsequent warm forming treatment, and lay a foundation for subsequent heat baking treatment.

[0032] The pre-aging treatment method provided by this invention, compared to the method of long-term room temperature natural aging, can obtain a PA-state pre-hardened billet, while room temperature natural aging mainly yields a T4-state billet. The inventors have found through experiments that the PA state has good compatibility with subsequent gradient temperature aging treatment, resulting in aluminum alloy components with higher strength. Furthermore, compared to T6-state aluminum alloy components obtained through high-temperature long-term aging treatment, the method of combining pre-hardening with multi-stage aging in this invention ultimately produces components with superior strength.

[0033] The "W state" mentioned in this invention refers to the billet obtained after heat-treatable aluminum alloy sheet is solution-hardened in a high-temperature box-type resistance furnace. The "PA state" refers to the billet obtained after solution-hardened billet is placed in an aging furnace for a short period (e.g., 1-10 minutes) for pre-aging treatment. The "T4 state" refers to the billet obtained by placing solution-hardened billet at room temperature and aging it naturally for more than 96 hours. The "T6 state" refers to the component obtained by placing solution-hardened billet in an aging furnace for a long period (e.g., 6-24 hours) of aging treatment.

[0034] In some embodiments, the pre-aging treatment temperature is 70–180°C, and the time is 1–24 hours. Specifically, it can be 70–100°C, 100–120°C, 120–140°C, 140–160°C, or 160–180°C, and the pre-aging time can be 1–5 hours, 5–10 hours, 10–15 hours, 15–20 hours, or 20–24 hours. Adjusting the pre-aging treatment temperature according to the specific composition of the aluminum alloy component can yield a pre-hardened blank that is more favorable for subsequent processing steps. Through experimental research, the inventors have found that the pre-aging treatment temperature for 2000 series aluminum alloy components is 70–180°C, for 6000 series it is 80–160°C, and for 7000 series it is 80–120°C.

[0035] Preferably, the W-state billet obtained in step S1 is subjected to pre-aging treatment in step S2 within 1 to 10 minutes. Rapid pre-aging treatment of the W-state billet obtained after solution quenching is beneficial for obtaining a PA-state pre-hardened billet. Subsequent gradient aging treatment in the PA state results in aluminum alloy components with higher strength.

[0036] The pre-pressing insulation temperature is controlled at 200–300℃, with an insulation time of 30 seconds to 5 minutes. Specifically, it can be 200–220℃, 220–240℃, 240–260℃, 260–280℃, or 280–300℃, with an insulation time of 30 seconds to 1 minute, 1–3 minutes, or 3–5 minutes. The insulation temperature is adjusted according to the specific composition of the aluminum alloy component. Generally, the insulation temperature is higher than the pre-aging temperature, matching the pre-hardening temperature. For 2000 series aluminum alloy components, the insulation temperature is 210–300℃; for 6000 series, it is 220–280℃; and for 7000 series, it is 200–250℃.

[0037] In addition, after heat preservation treatment, the blank is transferred to stamping treatment within 1 to 10 seconds, which quickly transfers the softened blank to the stamping die, avoiding the room temperature from lowering the blank temperature, which is more conducive to increasing the plasticity of the part.

[0038] The stamping pressure and time can refer to the conventional stamping conditions. After stamping, the mold can be closed and pressure held for a certain period of time to further ensure the forming accuracy and at the same time suppress springback.

[0039] Furthermore, since the aforementioned pre-aging treatment has been carried out to regulate the hardness of the sheet material before warm forming, the inventors have discovered that, with at least two stages of aging treatment at different temperatures, compared to the conventional long-duration single-stage baking method, the two aging treatments of the present invention can be completed in a shorter time, effectively shortening the overall process time. Moreover, the aluminum alloy components obtained have a better strengthening effect, solving the problems of dynamic recovery and dislocation annihilation caused by warm forming technology.

[0040] Preferably, the temperature for the first-stage aging treatment is 160–200℃, and the time is 10–60 minutes. The baking temperature is adjusted according to the specific composition of the aluminum alloy component. Specifically, the first-stage aging treatment temperature for 2000 series aluminum alloy components is 160–180℃, for 6000 series it is 180–200℃, and for 7000 series it is 170–190℃.

[0041] After the first-stage aging treatment, a relatively lower second-stage aging treatment temperature is adjusted based on the first-stage temperature. Through two gradient temperature baking processes, the hardness of the component is strengthened multiple times, resulting in an aluminum alloy component with a hardness exceeding that obtained by conventional manufacturing methods. Specifically, the second-stage aging treatment temperature can be 130–160℃, and the time can be 10–60 minutes. Corresponding to the second-stage aging treatment temperature for different aluminum alloy components, the temperature for 2000 series is 130–150℃, the temperature for 6000 series is 150–170℃, and the temperature for 7000 series is 140–160℃.

[0042] For 2000 series aluminum alloy components, the first-stage aging treatment mainly forms the θ phase that has not been sheared by dislocations, while the second-stage aging treatment mainly forms the GPII region that has been sheared by dislocations, as well as some θ phase that has not been sheared by dislocations. This results in a mixed microstructure with good uniformity and a combination of soft and hard phases, thus obtaining high-strength aluminum alloy components.

[0043] For 6000 series aluminum alloy components, the first-stage aging treatment mainly forms the β” phase that has not been sheared by dislocations, while the second-stage aging treatment mainly forms the GPII, Initialβ”, Preβ” phase that has been sheared by dislocations, as well as some β” phases that have not been sheared by dislocations. This results in a mixed microstructure with good uniformity and a combination of soft and hard phases, thus obtaining high-strength aluminum alloy components.

[0044] For 7000 series aluminum alloy components, the first-stage aging treatment mainly forms the η' phase that has not been sheared by dislocations, while the second-stage aging treatment mainly forms the GPII region that has been sheared by dislocations, as well as some η' phase that has not been sheared by dislocations. This results in a mixed microstructure with good uniformity and a combination of soft and hard phases, thus obtaining high-strength aluminum alloy components.

[0045] Furthermore, the inventors have discovered that employing a gradient three-stage aging treatment, i.e., adding a third stage of aging treatment after the second stage, results in better strengthening of aluminum alloy components, with higher tensile strength and yield strength after forming. Specifically, the temperature of the third stage aging treatment is lower than that of the second stage. The third stage aging treatment temperature is 130–140°C, while the corresponding second stage aging treatment temperature is preferably 140–160°C.

[0046] In some embodiments, in step S1, the solution treatment temperature is 450–570°C, and the treatment time is 0.5–1 hour. Specifically, the solution treatment temperature for different aluminum alloy components can be selected according to the actual material. For example, the solution treatment temperature for 2000 series aluminum alloy components is 490–540°C, for 6000 series aluminum alloy components it is 500–570°C, and for 7000 series aluminum alloy components it is 450–520°C.

[0047] In some embodiments, the quenching temperature in step S1 is 14–20°C. The quenching medium can be water. Preferably, the solution treatment is followed by quenching within 15 seconds.

[0048] The present invention and its beneficial effects will be further described in detail below with reference to specific embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0049] Example 1

[0050] Using 2A14 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0051] 1) Heat-treatable 2A14 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 520℃ for 50 minutes.

[0052] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0053] 3) Within 5 minutes, put the quenched W-state billet into an aging furnace, heat it to 160℃ for pre-aging treatment for 12 hours, and then cool it at room temperature to obtain the PA-state pre-hardened billet.

[0054] 4) The PA-state pre-hardened blank is then transferred to the hot stamping production line for pre-stamping heat preservation heating at 280°C for 1 minute. Then, it is quickly transferred to the stamping die within 7 seconds for die closing and stamping. After cooling, the part is formed.

[0055] 4) The stamped warm-formed component is heated to 160°C for the first stage of aging treatment for 30 minutes. The component has an θ phase that has not been cut by dislocations. After the treatment is completed, it is cooled to room temperature.

[0056] 5) Then, a second aging treatment is carried out within 10 minutes at a temperature of 140℃ for 30 minutes. After the treatment is completed, the component is cooled to room temperature. The component finally obtains a GPII region that has been cut by dislocations and a θ phase that has not been cut by dislocations, forming a mixed structure of soft and hard bonding, thus completing the preparation of the 2A14 aluminum alloy component.

[0057] Example 2

[0058] Unlike Example 1, this example also includes a third-level aging process, the steps of which are as follows:

[0059] The components after the second-stage aging treatment were subjected to the third-stage aging within 10 minutes. The aging temperature was 130℃ and the holding time was 30 minutes. After the third-stage aging treatment, the components were cooled to room temperature to obtain the final 2A14 aluminum alloy components.

[0060] The rest is the same as in Example 1, and will not be repeated here.

[0061] Example 3

[0062] Using 6061 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0063] 1) Heat-treatable 6061 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 570℃ for 30 minutes.

[0064] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0065] 3) Within 5 minutes, put the quenched W-state billet into an aging furnace, heat it to 120°C for pre-aging treatment for 12 hours, and then cool it at room temperature to obtain the PA-state pre-hardened billet.

[0066] 4) The PA-state pre-hardened blank is then transferred to the hot stamping production line for pre-stamping heat preservation heating at 250°C for 1 minute. Then, it is quickly transferred to the stamping die within 7 seconds for die closing and stamping. After cooling, the part is formed.

[0067] 4) The stamped warm-formed component is heated to 180°C for the first stage of aging treatment for 30 minutes. The component has a β” phase that has not been cut by dislocations. After the treatment is completed, it is cooled to room temperature.

[0068] 5) Then, a second aging treatment is carried out within 10 minutes at a temperature of 150℃ for 30 minutes. After the treatment is completed, the component is cooled to room temperature. The component finally obtains GPII, Initialβ”, Preβ” phases that have been dislocated and some β” phases that have not been dislocated, forming a mixed structure of soft and hard bonding, thus completing the preparation of the 6061 aluminum alloy component.

[0069] Example 4

[0070] Unlike Example 3, this example also includes a third-level aging process, the steps of which are as follows:

[0071] The components after the second-stage aging treatment were subjected to the third-stage aging within 10 minutes. The aging temperature was 130℃ and the holding time was 30 minutes. After the third-stage aging treatment, the components were cooled to room temperature to obtain the final 6061 aluminum alloy components.

[0072] The rest is the same as in Example 3, and will not be repeated here.

[0073] Example 5

[0074] Using 7055 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0075] 1) Heat-treatable 7055 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 450℃ for 60 minutes.

[0076] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0077] 3) Within 5 minutes, put the quenched W-state billet into an aging furnace, heat it to 85°C for pre-aging treatment for 12 hours, and then cool it at room temperature to obtain the PA-state pre-hardened billet.

[0078] 4) The PA-state pre-hardened blank is then transferred to the hot stamping production line for pre-stamping heat preservation heating at a temperature of 220°C for 1 minute. Then, it is quickly transferred to the stamping die within 7 seconds for die closing and stamping. After cooling, the part is formed.

[0079] 4) The stamped warm-formed component is heated to 170°C for the first stage of aging treatment for 30 minutes. The component has an η' phase that has not been cut by dislocations. After the treatment is completed, it is cooled to room temperature.

[0080] 5) Then, a second-stage aging treatment is carried out within 10 minutes. The treatment temperature is 150℃ and the time is 30 minutes. After the treatment is completed, it is cooled to room temperature. The component finally obtains a GPII region that has been cut by dislocations and some η' phase that has not been cut by dislocations, forming a mixed structure of soft and hard bonding, thus completing the preparation of the 7075 aluminum alloy component.

[0081] Example 6

[0082] Unlike Example 5, this example also includes a third-level aging process, the steps of which are as follows:

[0083] The components after the second-stage aging treatment were subjected to the third-stage aging within 10 minutes. The aging temperature was 130℃ and the holding time was 30 minutes. After the third-stage aging treatment, the components were cooled to room temperature to obtain the final 6061 aluminum alloy components.

[0084] The rest is the same as in Example 5, and will not be repeated here.

[0085] Example 7

[0086] Unlike Example 3, this example also includes a third-level aging process, the steps of which are as follows:

[0087] Within 10 minutes, the component after the second-stage aging treatment is subjected to the third-stage aging treatment at a temperature of 150℃, the same as the second-stage aging treatment temperature, with a holding time of 30 minutes. After the third-stage aging treatment, it is cooled to room temperature to obtain the final 6061 aluminum alloy component.

[0088] The rest is the same as in Example 3, and will not be repeated here.

[0089] Example 8

[0090] Using 2A14 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0091] 1) Heat-treatable 2A14 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 520℃ for 50 minutes.

[0092] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0093] 3) Within 5 minutes, put the quenched W-state billet into an aging furnace, heat it to 180°C for pre-aging treatment for 1 hour, and then cool it at room temperature to obtain the PA-state pre-hardened billet.

[0094] 4) The PA-state pre-hardened blank is then transferred to the hot stamping production line for pre-stamping heat preservation heating at 300℃ for 30s. Then, it is quickly transferred to the stamping die within 7s for die closing and stamping. After cooling, the part is formed.

[0095] 4) The stamped warm-formed component is heated to 200°C for the first stage of aging treatment for 20 minutes. The component has an θ phase that has not been cut by dislocations. After the treatment is completed, it is cooled to room temperature.

[0096] 5) Then, a second-stage aging treatment is carried out within 10 minutes. The treatment temperature is 160℃ and the time is 10 minutes. After the treatment is completed, it is cooled to room temperature. The component finally obtains a GPII region that has been cut by dislocations and a θ phase that has not been cut by dislocations, forming a mixed structure of soft and hard bonding, thus completing the preparation of the 2A14 aluminum alloy component.

[0097] Example 9

[0098] Using 7055 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0099] 1) Heat-treatable 7055 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 450℃ for 60 minutes.

[0100] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0101] 3) Within 5 minutes, put the quenched W-state billet into an aging furnace, heat it to 70°C for pre-aging treatment for 24 hours, and then cool it at room temperature to obtain the PA-state pre-hardened billet.

[0102] 4) The PA-state pre-hardened blank is then transferred to the hot stamping production line for pre-stamping heat preservation heating at 200°C for 5 minutes. Then, it is quickly transferred to the stamping die within 7 seconds for die closing and stamping. After cooling, the part is formed.

[0103] 4) The stamped warm-formed component is heated to 170°C for the first stage of aging treatment for 30 minutes. The component has an η' phase that has not been cut by dislocations. After the treatment is completed, it is cooled to room temperature.

[0104] 5) Then, a second-stage aging treatment is carried out within 10 minutes at a temperature of 130°C for 60 minutes. After the treatment is completed, the component is cooled to room temperature. The component finally obtains a GPII region that has been cut by dislocations and a portion of the η' phase that has not been cut by dislocations, forming a mixed structure of soft and hard bonding, thus completing the preparation of the 7075 aluminum alloy component.

[0105] Comparative Example 1

[0106] Using 2A14 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0107] 1) Heat-treatable 2A14 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 520℃ for 50 minutes.

[0108] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0109] 3) Within 5 minutes, transfer the W-state blank to the hot stamping production line for pre-stamping heat preservation heating at a temperature of 280°C for 1 minute. Then, within 7 seconds, quickly transfer it to the stamping die for die closing and stamping. After cooling, form the component.

[0110] 4) The stamped warm-formed component is heated to 160°C for the first stage of aging treatment for 30 minutes. The component has an θ phase that has not been cut by dislocations (the proportion is lower than that of the θ phase obtained from the PA state). After the treatment is completed, it is cooled to room temperature.

[0111] 5) Then, perform a second-stage aging treatment within 10 minutes at a temperature of 140°C for 30 minutes. After the treatment, cool to room temperature. The component will eventually have a GPII region that has been cut by dislocations and a portion of the θ phase that has not been cut by dislocations (the proportion is lower than that of the θ phase obtained from the PA state), thus completing the preparation of the 2A14 aluminum alloy component.

[0112] Comparative Example 2

[0113] Using 2A14 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0114] 1) Heat-treatable 2A14 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 520℃ for 50 minutes.

[0115] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0116] 3) Place the quenched W-state billet in a room temperature environment and allow it to age naturally for more than 96 hours to obtain the T4-state billet;

[0117] 4) The T4 state blank is then transferred to the hot stamping production line for pre-stamping heat preservation heating at a temperature of 280°C for 1 minute. Then, it is quickly transferred to the stamping die within 7 seconds for die closing and stamping. After cooling, the part is formed.

[0118] 5) The stamped warm-formed component is heated to 160°C for the first stage of aging treatment for 30 minutes. The component has an θ phase (with a ratio between W and PA states) that has not been cut by dislocations. After the treatment is completed, it is cooled to room temperature.

[0119] 5) Then, a second aging treatment is carried out within 10 minutes at a temperature of 140℃ for 30 minutes. After the treatment is completed, the component is cooled to room temperature. The component finally obtains a GPII region that has been dislocated and a portion of the θ phase that has not been dislocated (the proportion is between the W state and the PA state), forming a mixed structure of soft and hard bonding, thus completing the preparation of the 2A14 aluminum alloy component.

[0120] Comparative Example 3

[0121] Using 2A14 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0122] 1) Heat-treatable 2A14 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 520℃ for 50 minutes.

[0123] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0124] 3) Within 5 minutes, transfer the quenched W-state billet to an aging furnace and heat it to 160°C. The aging time is 10 hours to obtain the T6 state aluminum alloy component.

[0125] Comparative Example 4

[0126] Using 6061 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0127] 1) Heat-treatable 6061 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 570℃ for 30 minutes.

[0128] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0129] 3) Within 5 minutes, transfer the quenched W-state blank to the hot stamping production line for pre-stamping heat preservation heating at 250℃ for 1 minute. Then, within 7 seconds, quickly transfer it to the stamping die for die closing and stamping. After cooling, form the component.

[0130] 5) The stamped warm-formed component is heated to 180°C for the first stage of aging treatment for 30 minutes. The component has a β” phase that has not been cut by dislocations (the proportion is lower than that of the β” phase obtained from the PA state). After the treatment is completed, it is cooled to room temperature.

[0131] 6) Then, a second-stage aging treatment is carried out within 10 minutes at a temperature of 150°C for 30 minutes. After the treatment is completed, the component is cooled to room temperature. The component finally obtains GPII, Initialβ”, Preβ” phases that have been dislocated and partially undislocated β” phases (the proportion is lower than that of β” phases obtained from the PA state), forming a mixed structure of soft and hard bonding, thus completing the preparation of the 6061 aluminum alloy component.

[0132] Comparative Example 5

[0133] Using 6061 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0134] 1) Heat-treatable 6061 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 570℃ for 30 minutes.

[0135] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0136] 3) Place the quenched W-state billet in a room temperature environment and allow it to age naturally for more than 96 hours to obtain the T4-state billet;

[0137] 4) The T4 state blank is then transferred to the hot stamping production line for pre-stamping heat preservation heating at 250°C for 1 minute. Then, it is quickly transferred to the stamping die within 7 seconds for die closing and stamping. After cooling, the part is formed.

[0138] 5) The stamped warm-formed component is heated to 180°C for the first stage of aging treatment for 30 minutes. The component has a β” phase (with a ratio between W and PA states) that has not been cut by dislocations. After the treatment is completed, it is cooled to room temperature.

[0139] 6) Then, a second-stage aging treatment is carried out within 10 minutes at a temperature of 150°C for 30 minutes. After the treatment is completed, the component is cooled to room temperature. The component finally obtains GPII, Initialβ”, Preβ” phases that have been dislocated and partially undislocated β” phases (the proportion is between W and PA states), forming a mixed structure of soft and hard bonding, thus completing the preparation of the 6061 aluminum alloy component.

[0140] Comparative Example 6

[0141] Using 6061 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0142] 1) Heat-treatable 6061 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 570℃ for 30 minutes.

[0143] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0144] 3) Place the quenched W-state billet in a room temperature environment and allow it to age naturally for more than 96 hours to obtain the T4-state billet;

[0145] 4) The T4 state billet is then transferred to an aging furnace and heated to 175°C for 8 hours to obtain a T6 state aluminum alloy component.

[0146] Comparative Example 7

[0147] Using 7055 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0148] 1) Heat-treatable 7055 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 450℃ for 60 minutes.

[0149] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0150] 3) Within 5 minutes, the quenched W-state blank is transferred to the hot stamping production line for pre-stamping heat preservation heating at 220℃ for 1 minute. Then, within 7 seconds, it is quickly transferred to the stamping die for die closing and stamping. After cooling, the component is formed.

[0151] 4) The stamped warm-formed component is heated to 170°C for the first stage of aging treatment for 30 minutes. The component has an η' phase that has not been cut by dislocations (the proportion is lower than that of the η' phase obtained from the PA state). After the treatment is completed, it is cooled to room temperature.

[0152] 5) Then, a second-stage aging treatment is carried out within 10 minutes at a temperature of 150°C for 30 minutes. After the treatment is completed, the component is cooled to room temperature. The component finally obtains a GPII region that has been dislocated and a portion of the η' phase that has not been dislocated (the proportion is lower than that of the η' phase obtained from the PA state), forming a mixed structure of soft and hard bonding, thus completing the preparation of the 7075 aluminum alloy component.

[0153] Comparative Example 8

[0154] Using 7055 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0155] 1) Heat-treatable 7055 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 450℃ for 60 minutes.

[0156] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0157] 3) Place the quenched W-state billet in a room temperature environment and allow it to age naturally for more than 96 hours to obtain the T4-state billet;

[0158] 4) The T4 state blank is then transferred to the hot stamping production line for pre-stamping heat preservation heating at a temperature of 220°C for 1 minute. Then, it is quickly transferred to the stamping die within 7 seconds for die closing and stamping. After cooling, the part is formed.

[0159] 5) The stamped warm-formed component is heated to 170°C for the first stage of aging treatment for 30 minutes. The component has an η' phase that has not been cut by dislocations (the proportion is between the W state and the PA state). After the treatment is completed, it is cooled to room temperature.

[0160] 6) Then, a second aging treatment is carried out within 10 minutes at a temperature of 150°C for 30 minutes. After the treatment is completed, the component is cooled to room temperature. The component finally obtains a GPII region that has been dislocated and a portion of the η' phase that has not been dislocated (the proportion is between the W state and the PA state), forming a mixed structure of soft and hard bonding, thus completing the preparation of the 7075 aluminum alloy component.

[0161] Comparative Example 9

[0162] Using 7055 aluminum alloy as the sheet material, a high-strength aluminum alloy pre-hardening forming-heat treatment integrated high-efficiency and precise hot forming manufacturing method includes the following steps:

[0163] 1) Heat-treatable 7055 aluminum alloy components are placed in a high-temperature box-type resistance furnace for solution treatment at a temperature of 450℃ for 60 minutes.

[0164] 2) Then, within 15 seconds, the solution-treated aluminum alloy component is immersed in cold water for quenching to obtain a W-state billet.

[0165] 3) Within 5 minutes, transfer the quenched W-state billet to an aging furnace and heat it to 120°C. The aging time is 24 hours to obtain the T6 state aluminum alloy component.

[0166] Strength tests were conducted on the aluminum alloy components obtained in Examples 1-9 and Comparative Examples 1-9. Tensile specimens were cut and subjected to single tensile tests to test their mechanical properties after forming. The average value of multiple tensile specimens was taken. The test results are shown in Table 1 below.

[0167] Table 1 Strength Test Results

[0168]

[0169] As can be seen from the test results of Examples 1-9 and Comparative Examples 1-9 above, the aluminum alloy components prepared by the method of the present invention integrate pre-hardening forming and heat treatment within a certain period of time, which can greatly shorten the overall process time. Moreover, the obtained aluminum alloy components have higher strength, exceeding that of the T6 state, and the components have good plasticity and ductility. It is evident that the improved method has improved the dynamic recovery and dislocation annihilation problems caused by warm forming.

[0170] As can be seen from the comparison of Examples 1 to 6, the aluminum alloy components obtained are stronger when combined with a three-stage gradient aging treatment. Furthermore, as can be seen from the comparison of Examples 4 and 7, the strength of the aluminum alloy components is further improved when the third-stage aging temperature is lower than the second-stage aging temperature.

[0171] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A high-strength aluminum alloy pre-hardened forming-heat treatment fusion high-efficiency precision hot forming manufacturing method, characterized in that, The method comprises the following steps: S1. sequentially performing solid solution treatment and quenching treatment on the aluminum alloy component at a solid solution temperature to obtain a W-state blank; S2. performing pre-aging treatment on the W-state blank obtained in step S1 at a pre-aging temperature, and cooling to room temperature to obtain a PA-state pre-hardened blank; S3. subsequently performing holding heating before stamping on the PA-state pre-hardened blank obtained in step S2, and then performing stamping treatment to obtain a warm-formed component; S4. performing first-stage aging treatment on the warm-formed component obtained by stamping in step S3, and cooling; S5. performing second-stage aging treatment at a temperature lower than that of the first-stage aging treatment, and further performing third-stage aging treatment at a temperature lower than that of the second-stage aging treatment, and cooling to obtain the aluminum alloy component; The W-state blank obtained in step S1 is subjected to the pre-aging treatment in step S2 within 1 min to 10 min; In step S1, the solid solution temperature is 450-570 DEG C, and the treatment time is 0.5-1 h; the quenching treatment temperature is 14-20 DEG C; In step S2, the pre-aging temperature is 70-180 DEG C, and the time is 1-24 h; In step S3, the holding temperature is 200-300 DEG C, the holding time is 30 s-5 min, and the stamping treatment is performed in a stamping die within 1 s-10 s after the holding treatment; In step S4, the first-stage aging treatment temperature is 160-200 DEG C, and the time is 10-60 min; In step S5, the second-stage aging treatment temperature is 140-160 DEG C; and the third-stage aging treatment temperature is 130-140 DEG C; The aluminum alloy is a 2000 series, 6000 series or 7000 series aluminum alloy.

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