Highly corrosion-resistant aluminum alloy and its preparation method and application

Abstract

The application relates to the technical field of aluminum profile manufacturing, and particularly discloses a high-corrosion-resistance aluminum alloy and a preparation method and application thereof. The preparation method comprises the following steps: obtaining an aluminum alloy liquid by melting, deslagging, refining and standing of raw materials; obtaining an aluminum alloy cast bar by casting; homogenizing treatment; the homogenizing treatment is carried out at a temperature of 420 DEG C to 450 DEG C for 10h to 15h; extruding the aluminum alloy cast bar after the homogenizing treatment to obtain an aluminum alloy blank; heating and solid solution treatment; the heating and solid solution treatment is carried out at a temperature of 520 DEG C to 560 DEG C for 1.5h to 4h; carrying out high-temperature cyclic deformation treatment on the aluminum alloy blank after the heating and solid solution treatment; the high-temperature cyclic deformation treatment is carried out at a temperature of 400 DEG C to 500 DEG C; carrying out quenching treatment on the aluminum alloy blank after the high-temperature cyclic deformation treatment; and aging treatment, so that the aluminum alloy product is obtained. By implementing the application, the corrosion resistance and comprehensive mechanical properties of the aluminum alloy can be improved.

Description

Technical Field

[0001] This invention relates to the field of aluminum profile manufacturing technology, and in particular to a high corrosion-resistant aluminum alloy, its preparation method and application. Background Technology

[0002] Al-Mg-Si-Cu alloys, as important lightweight alloy structural materials, have attracted much attention due to their low density and ultra-high strength. However, their corrosion resistance is currently poor, making them unsuitable for applications requiring high corrosion resistance, such as marine vessels and rail transportation. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a high corrosion-resistant aluminum alloy and its preparation method, which can improve the corrosion resistance and mechanical properties of aluminum alloys.

[0004] Another technical problem that the present invention needs to solve is to provide an application of the above-mentioned high corrosion-resistant aluminum alloy.

[0005] To address the aforementioned technical problems, this invention provides a method for preparing a high corrosion-resistant aluminum alloy, comprising: (1) Prepare various raw materials according to the proportions; the raw material formulas by weight percentage are as follows: Mg 0.55%~0.75%, Si 1.8%~2.2%, Cu 0.4%~0.5%, Zr 0.1%~0.2%, Hf 0.2%~0.3%, balance Al; (2) The raw materials are melted, slag removed, refined and allowed to stand to obtain aluminum alloy liquid; (3) Cast the aluminum alloy liquid to obtain an aluminum alloy casting rod; (4) The aluminum alloy casting rod is homogenized; wherein the homogenization temperature is 420℃~450℃ and the homogenization time is 10h~15h. (5) The homogenized aluminum alloy casting rod is extruded to obtain an aluminum alloy billet; (6) The aluminum alloy billet is subjected to heat solution treatment; wherein the temperature of heat solution treatment is 520℃~560℃ and the time of heat solution treatment is 1.5h~4h; (7) The aluminum alloy billet after heat solution treatment is subjected to high-temperature cyclic deformation treatment; wherein the temperature of high-temperature cyclic deformation treatment is 400℃~500℃, and the deformation amount of high-temperature cyclic deformation treatment is ≤0.1%; (8) The aluminum alloy billet after high-temperature cyclic deformation treatment is quenched. (9) The quenched aluminum alloy billet is subjected to aging treatment to obtain the finished aluminum alloy product.

[0006] As an improvement to the above technical solution, Zr+Hf≤0.45wt%; and / or The aluminum alloy product contains dispersed Al3Zr and Si2(Zr,Hf) phases.

[0007] As an improvement to the above technical solution, Zr+Hf is 0.4%~0.45%; and / or The finished aluminum alloy contains dispersed Al3Zr and Si2(Zr,Hf) phases; the Al3Zr phase is granular with a particle size of 20nm~100nm; the Si2(Zr,Hf) phase is nanoribbon-shaped with a length of 10μm~70μm, a width of 60nm~240nm, and a thickness of 10nm~40nm.

[0008] As an improvement to the above technical solution, in step (9), the aging treatment temperature is 160℃~190℃ and the aging treatment time is 0.5h~2h.

[0009] As an improvement to the above technical solution, in step (4), the homogenization temperature is 430℃~445℃, and the homogenization time is 11h~13h; and / or In step (6), the temperature for the solution treatment is 530℃~550℃, and the treatment time is 1.5h~3h; and / or In step (7), the temperature of the high-temperature cyclic deformation treatment is 440℃~480℃, and the deformation amount of the high-temperature cyclic treatment is 0.05%~0.08%.

[0010] As an improvement to the above technical solution, in step (4), the homogenization temperature is 440℃ and the homogenization time is 12h; and / or In step (6), the temperature for the solution treatment is 540°C, and the treatment time is 2 hours; and / or In step (7), the temperature of the high-temperature cyclic deformation treatment is 450℃, and the deformation amount of the high-temperature cyclic treatment is 0.06%.

[0011] As an improvement to the above technical solution, in step (5), the extrusion temperature is 510℃~520℃, the extrusion ratio is ≥25, and the extrusion speed is 1m / min~5m / min.

[0012] As an improvement to the above technical solution, the wall thickness of the finished aluminum alloy product is 3mm~5mm.

[0013] Accordingly, the present invention also discloses a high corrosion-resistant aluminum alloy, which is prepared by the above-described preparation method.

[0014] Accordingly, the present invention also discloses the application of the above-mentioned high corrosion-resistant aluminum alloy in the preparation of marine vessels, rail transportation, aircraft, and new energy vehicles.

[0015] Implementing this invention has the following beneficial effects: In one embodiment of the present invention, trace elements Zr and Hf are introduced into the high corrosion-resistant aluminum alloy for synergistic regulation. Homogenization treatment at a specific temperature and time allows the formation of the Al3Zr phase, which inhibits recrystallization, during homogenization. These particles can suppress dynamic recrystallization during the alloy's extrusion deformation process. Furthermore, by employing heating solution treatment at a specific temperature and time, and high-temperature cyclic deformation treatment at a specific temperature, fatigue damage can be effectively avoided, generating a large number of vacancies and sustainable dislocations, promoting the formation of the high-temperature dispersed phase (Si2(Zr, Hf) phase). This results in uniform corrosion-resistant grain boundaries after aging treatment, significantly improving the corrosion resistance of the aluminum alloy. Simultaneously, the synergistic effect of the Al3Zr combined with the Si2(Zr, Hf) phase provides excellent strengthening, also giving the aluminum alloy superior mechanical properties. Attached Figure Description

[0016] Figure 1 This is a flowchart of a method for preparing a high corrosion-resistant aluminum alloy according to an embodiment of the present invention; Figure 2 This is a TEM image of the Al3Zr phase in an aluminum alloy after homogenization treatment in one embodiment of the present invention. Figure 3 This is a three-dimensional distribution diagram of the Si2(Zr,Hf) dispersed phase in a high corrosion-resistant aluminum alloy according to an embodiment of the present invention. Detailed Implementation

[0017] To facilitate understanding of the present invention, it will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to make the disclosure of the present invention more thorough and complete.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments or examples only and is not intended to limit the invention. The optional range of the term "and / or" as used herein includes any one of two or more of the related listed items, as well as any and all combinations of the related listed items, including any two related listed items, any more related listed items, or a combination of all related listed items.

[0019] The following embodiments are provided for the purpose of illustrating various embodiments of the present invention and are not intended to limit the invention in any way. Those skilled in the art will understand that variations and other uses thereof, as defined in the claims, are included within the spirit and scope of the invention.

[0020] In this invention, terms such as "first aspect" and "second aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features.

[0021] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0022] Unless otherwise specified, the percentage content involved in this invention refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures.

[0023] Unless otherwise specified, all percentage concentrations mentioned in this invention refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0024] Unless otherwise specified, the temperature parameters in this invention can be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows temperature fluctuations within the precision range controlled by the instrument.

[0025] As a first aspect of the present invention, the present invention provides a method for preparing a high corrosion-resistant aluminum alloy, which includes the following steps: S1: Prepare all raw materials according to the proportions; S2: The raw materials are melted, slag removed, refined and allowed to stand to obtain aluminum alloy liquid; S3: Cast the molten aluminum alloy to obtain an aluminum alloy casting rod; S4: Homogenize the aluminum alloy casting rod. S5: Extrude the homogenized aluminum alloy casting rod to obtain an aluminum alloy billet; S6: The aluminum alloy billet is subjected to heat solution treatment; S7: The aluminum alloy billet after heat solution treatment is subjected to high-temperature cyclic deformation treatment. S8: The aluminum alloy billet after high-temperature cyclic deformation is quenched. S9: The quenched aluminum alloy billet is subjected to aging treatment to obtain the finished aluminum alloy product.

[0026] The raw material formula of the high corrosion-resistant aluminum alloy of the present invention, by weight percentage, is as follows: Si 0.55%~0.75%, Mg 1.8%~2.2%, Cu 0.4%~0.5%, Zr 0.1%~0.2%, Hf 0.2%~0.3%, with the balance being Al.

[0027] In step S4, the homogenization treatment temperature is 420℃~450℃, and the homogenization treatment time is 10h~15h. In step S6, the solution treatment temperature is 520℃~560℃, and the solution treatment time is 1.5h~4h. In step S7, the high-temperature cyclic deformation treatment temperature is 400℃~500℃, and the deformation amount of the high-temperature cyclic deformation treatment is ≤0.1%.

[0028] This invention introduces trace elements Zr and Hf for synergistic regulation, and through homogenization treatment at a specific temperature and time, the Al3Zr phase, which inhibits recrystallization, forms during homogenization. These particles suppress dynamic recrystallization during alloy extrusion deformation. Furthermore, by employing heating solution treatment at specific temperatures and times, and high-temperature cyclic deformation treatment at specific temperatures, fatigue damage is effectively avoided, generating a large number of vacancies and sustainable dislocations, promoting the formation of a high-temperature dispersed phase (Si2(Zr, Hf) phase). This results in uniform corrosion-resistant grain boundaries after aging treatment, significantly improving the corrosion resistance of the aluminum alloy. Simultaneously, the synergistic effect of the Al3Zr combined with the Si2(Zr, Hf) phase provides excellent strengthening, also giving the aluminum alloy superior mechanical properties.

[0029] Specifically, in step S1, in the raw material formulation of the high corrosion-resistant aluminum alloy, Si and Mg can form a strengthening phase—Mg2Si phase—to optimize mechanical properties. However, excessive Si and Mg can easily form coarse, uneven Mg2Si phases, which will reduce the plasticity and corrosion resistance of the aluminum alloy. For example, the amount of Mg used is 0.58wt%, 0.61wt%, 0.64wt%, 0.67wt%, 0.71wt%, or 0.74wt%, but is not limited thereto. Preferably, it is 0.55%~0.65%, more preferably 0.58%~0.62%. The amount of Si used is 1.85wt%, 1.9wt%, 1.95wt%, 2.0wt%, 2.05wt%, 2.1wt%, or 2.15wt%, but is not limited thereto; preferably, the amount of Si used is 1.9%~2.2%. More preferably, it is 2%~2.2%.

[0030] Specifically, in step S1, in the raw material formulation of the high corrosion-resistant aluminum alloy, Cu can significantly improve the strength and heat resistance of the alloy, but excessive Cu can easily lead to grain boundary segregation and reduce corrosion resistance. For example, the amount of Cu used is 0.42wt%, 0.44wt%, 0.46wt%, or 0.48wt%, but is not limited thereto. Preferably, the amount of Cu used is 0.42%~0.48%, more preferably 0.45%~0.48%.

[0031] Specifically, in step S1, Zr and Hf are introduced in the raw material formulation of the high corrosion-resistant aluminum alloy in a composite additive form, which plays a synergistic role in strengthening and improving corrosion resistance. For example, the amount of Zr used is 0.12wt%, 0.14wt%, 0.16wt%, or 0.18wt%, but is not limited thereto. Preferably, the amount of Zr used is 0.12%~0.2%, more preferably 0.15%~0.18%. For example, the amount of Hf used is 0.22wt%, 0.24wt%, 0.26wt%, or 0.28wt%, but is not limited thereto. Preferably, the amount of Hf used is 0.22%~0.28%, more preferably 0.24%~0.26%.

[0032] It should be noted that in the high corrosion-resistant aluminum alloy of the present invention, unavoidable impurities may be introduced due to the purity of raw materials, etc., and the content of these unavoidable impurities is ≤0.15wt%.

[0033] Preferably, in some embodiments, the total content of Zr and Hf is ≤0.45wt% to avoid excessive precipitation affecting processing performance. More preferably, the total content of Zr and Hf is controlled between 0.4wt% and 0.45wt% to ensure uniform distribution of dispersed precipitates, balancing strength improvement and plasticity maintenance.

[0034] Specifically, in step S2, various raw materials are melted and stirred at 720℃~750℃, then a slag remover is added to remove slag, and then refined at 730℃~740℃ for 20min~40min, and then allowed to stand at 725℃~735℃ for 30min~50min to obtain aluminum alloy liquid.

[0035] Specifically, in step S3, the molten aluminum alloy is cast at 700℃~720℃ at a casting speed of 40mm / min~60mm / min. After casting, it is cooled by water at a temperature of 20℃~40℃ and a cooling rate of 15℃ / s~25℃ / s.

[0036] Specifically, in step S4, the coarse primary phase formed during the remelt casting process is homogenized to form a dispersed Al3Zr phase (see [reference]). Figure 2This process inhibits dynamic recrystallization of the alloy during subsequent extrusion. Exemplarily, the homogenization treatment temperature is 425°C, 430°C, 435°C, 440°C, or 445°C, but is not limited to these. The homogenization treatment time (i.e., the holding time at the highest temperature) is 11h, 12h, 13h, 14h, or 15h, but is not limited to these. Preferably, in some embodiments, the homogenization treatment temperature is 430°C to 445°C, and the homogenization treatment time is 11h to 13h. More preferably, the homogenization treatment temperature is 440°C, and the homogenization treatment time is 12h.

[0037] Specifically, in step S4, after homogenization, the mixture is cooled to room temperature. Cooling can be achieved through air cooling or water mist cooling, but is not limited to these methods.

[0038] Specifically, in step S5, the extrusion temperature is 510℃~520℃, the extrusion ratio is ≥25, and the extrusion speed is 0.5m / min~5m / min. The wall thickness of the blank obtained after extrusion is 3mm~5mm.

[0039] Specifically, in step S6, the heat solution treatment can form a Si2(Zr, Hf) phase in the aluminum alloy billet, thereby enhancing its corrosion resistance and mechanical properties. Exemplarily, the heat solution treatment temperature is 535°C, 540°C, 545°C, 550°C, or 555°C, but is not limited to these. Exemplarily, the heat solution treatment time (i.e., the holding time at the highest temperature) is 1.8h, 2.1h, 2.5h, 2.8h, 3.2h, 3.5h, or 3.9h, but is not limited to these. Preferably, in some embodiments, the heat solution treatment temperature is 530°C to 550°C, and the heat solution treatment time is 1.5h to 3h. More preferably, the heat solution treatment temperature is 540°C, and the heat solution treatment time is 2h; and / or Specifically, in step S7, the high-temperature cycling treatment refers to directly subjecting the aluminum alloy billet to high-temperature cyclic tensile and compressive deformation after the solution treatment. Through high-temperature cycling treatment, grain refinement and optimization of the distribution of strengthening phases can be achieved, thereby eliminating residual stress and improving the corrosion resistance and mechanical properties of the aluminum alloy. Since cooling inevitably occurs during the transfer of the aluminum alloy billet after solution treatment, the temperature of the aluminum alloy billet drops to 400℃~500℃ during the high-temperature cyclic deformation treatment.

[0040] More specifically, after heat solution treatment, high-temperature cyclic deformation treatment is directly performed, and the total deformation is controlled to be ≤0.1%. Preferably, in some embodiments, the temperature of the high-temperature cyclic deformation treatment is 440℃~480℃, and the deformation amount of the high-temperature cyclic deformation treatment is 0.05%~0.08%. More preferably, the temperature of the high-temperature cyclic deformation treatment is 450℃, and the deformation amount of the high-temperature cyclic deformation treatment is 0.06%.

[0041] Specifically, in step S8, the quenching treatment can be achieved through forced air cooling, water mist cooling, or water-cooling, but is not limited to these methods. Preferably, in some embodiments, quenching is performed using water-cooling. Quenching effectively preserves the dislocations and grain structures obtained from high-temperature solution treatment and high-temperature cyclic deformation treatment, thereby improving the various properties of the aluminum alloy.

[0042] Specifically, in step S9, the aging treatment can be natural aging or artificial aging, but is not limited to these. Preferably, in some embodiments, the aging treatment temperature is 160℃~190℃, and the aging treatment time is 0.5h~2h. This invention effectively shortens the aging treatment time and improves production efficiency through the control of the aluminum alloy formula and the synergy of homogenization treatment, heating solution treatment, and high-temperature cyclic deformation treatment.

[0043] The aluminum alloy product prepared by the above preparation method contains dispersed Al3Zr and Si2(Zr,Hf) phases; the Al3Zr phase is granular with a particle size of 20nm~100nm; the Si2(Zr,Hf) phase is nanoribbon-like with a length of 10μm~70μm, a width of 60nm~240nm, and a thickness of 10nm~40nm (see reference). Figure 3 ).

[0044] Accordingly, as a second aspect of the present invention, the present invention provides a high corrosion-resistant aluminum alloy, which is prepared by the above-described preparation method.

[0045] Accordingly, as a third aspect of the present invention, the present invention provides the application of the above-mentioned high corrosion-resistant aluminum alloy in the manufacture of marine vessels, rail transportation, aircraft, and new energy vehicles.

[0046] The present invention is further illustrated below with specific embodiments: Example 1 This embodiment provides a method for preparing a high corrosion-resistant aluminum alloy, which includes the following steps: (1) Prepare various raw materials according to the proportions; the raw material formulas by weight percentage are as follows: Mg 0.6%, Si 1.9%, Cu 0.42%, Zr 0.18%, Hf 0.21%, balance Al; (2) The raw materials are melted, slag removed, refined and allowed to stand to obtain aluminum alloy liquid; (3) Cast the aluminum alloy liquid to obtain an aluminum alloy casting rod; (4) The aluminum alloy casting rod is homogenized; the homogenization temperature is 435℃ and the homogenization time is 14h.

[0047] (5) The homogenized aluminum alloy casting rod is extruded to obtain an aluminum alloy billet; The extrusion temperature was 510℃ and the extrusion speed was 3.5m / min.

[0048] (6) The aluminum alloy billet is subjected to heat solution treatment; wherein the temperature of heat solution treatment is 550℃ and the time of heat solution treatment is 1.5h; (7) The aluminum alloy billet after heat solution treatment is subjected to high-temperature cyclic deformation treatment; Specifically, after heat solution treatment, the material is directly subjected to high-temperature cyclic deformation treatment at 470℃, and the deformation amount is controlled to be 0.05%.

[0049] (8) The aluminum alloy billet after high-temperature cyclic deformation treatment is quenched. (9) The quenched aluminum alloy billet is subjected to aging treatment to obtain the finished aluminum alloy product. The aging treatment temperature is 180℃ and the time is 10h.

[0050] Example 2 This embodiment provides a method for preparing a high corrosion-resistant aluminum alloy, which includes the following steps: (1) Prepare various raw materials according to the proportions; the raw material formulas by weight percentage are as follows: Mg 0.6%, Si 1.9%, Cu 0.42%, Zr 0.14%, Hf 0.29%, balance Al; (2) The raw materials are melted, slag removed, refined and allowed to stand to obtain aluminum alloy liquid; (3) Cast the aluminum alloy liquid to obtain an aluminum alloy casting rod; (4) The aluminum alloy casting rod is homogenized; the homogenization temperature is 435℃ and the homogenization time is 14h.

[0051] (5) The homogenized aluminum alloy casting rod is extruded to obtain an aluminum alloy billet; The extrusion temperature was 510℃ and the extrusion speed was 3.5m / min.

[0052] (6) The aluminum alloy billet is subjected to heat solution treatment; wherein the temperature of heat solution treatment is 550℃ and the time of heat solution treatment is 1.5h; (7) The aluminum alloy billet after heat solution treatment is subjected to high-temperature cyclic deformation treatment; Specifically, after heat solution treatment, the material is directly subjected to high-temperature cyclic deformation treatment at 470℃, and the deformation amount is controlled to be 0.05%.

[0053] (8) The aluminum alloy billet after high-temperature cyclic deformation treatment is quenched. (9) The quenched aluminum alloy billet is subjected to aging treatment to obtain the finished aluminum alloy product.

[0054] Specifically, the aging treatment temperature is 180℃ and the aging treatment time is 1 hour.

[0055] Example 3 This embodiment provides a method for preparing a high corrosion-resistant aluminum alloy, which includes the following steps: (1) Prepare various raw materials according to the proportions; the raw material formulas by weight percentage are as follows: Mg 0.6%, Si 1.9%, Cu 0.42%, Zr 0.14%, Hf 0.29%, balance Al; (2) The raw materials are melted, slag removed, refined and allowed to stand to obtain aluminum alloy liquid; (3) Cast the aluminum alloy liquid to obtain an aluminum alloy casting rod; (4) The aluminum alloy casting rod is homogenized; the homogenization temperature is 440℃ and the homogenization time is 12h.

[0056] (5) The homogenized aluminum alloy casting rod is extruded to obtain an aluminum alloy billet; The extrusion temperature was 510℃ and the extrusion speed was 3.5m / min.

[0057] (6) The aluminum alloy billet is subjected to heat solution treatment; wherein the temperature of heat solution treatment is 550℃ and the time of heat solution treatment is 1.5h; (7) The aluminum alloy billet after heat solution treatment is subjected to high-temperature cyclic deformation treatment; wherein, Specifically, after heat solution treatment, the material is directly subjected to high-temperature cyclic deformation treatment at 470℃, and the deformation amount is controlled to be 0.05%.

[0058] (8) The aluminum alloy billet after high-temperature cyclic deformation treatment is quenched. (9) The quenched aluminum alloy billet is subjected to aging treatment to obtain the finished aluminum alloy product.

[0059] Specifically, the aging treatment temperature is 180℃ and the aging treatment time is 1 hour.

[0060] Example 4 This embodiment provides a method for preparing a high corrosion-resistant aluminum alloy, which includes the following steps: (1) Prepare various raw materials according to the proportions; the raw material formulas by weight percentage are as follows: Mg 0.6%, Si 1.9%, Cu 0.42%, Zr 0.14%, Hf 0.29%, balance Al; (2) The raw materials are melted, slag removed, refined and allowed to stand to obtain aluminum alloy liquid; (3) Cast the aluminum alloy liquid to obtain an aluminum alloy casting rod; (4) The aluminum alloy casting rod is homogenized; the homogenization temperature is 440℃ and the homogenization time is 12h.

[0061] (5) The homogenized aluminum alloy casting rod is extruded to obtain an aluminum alloy billet; The extrusion temperature was 510℃ and the extrusion speed was 3.5m / min.

[0062] (6) The aluminum alloy billet is subjected to heat solution treatment; wherein the temperature of heat solution treatment is 540℃ and the time of heat solution treatment is 2h; (7) The aluminum alloy billet after heat solution treatment is subjected to high-temperature cyclic deformation treatment; Specifically, after heat solution treatment, the material is directly subjected to high-temperature cyclic deformation treatment at 470℃, and the deformation amount is controlled to be 0.05%.

[0063] (8) The aluminum alloy billet after high-temperature cyclic deformation treatment is quenched. (9) The quenched aluminum alloy billet is subjected to aging treatment to obtain the finished aluminum alloy product.

[0064] Specifically, the aging treatment temperature is 180℃ and the aging treatment time is 1 hour.

[0065] Example 5 This embodiment provides a method for preparing a high corrosion-resistant aluminum alloy, which includes the following steps: (1) Prepare various raw materials according to the proportions; the raw material formulas by weight percentage are as follows: Mg 0.6%, Si 1.9%, Cu 0.42%, Zr 0.14%, Hf 0.29%, balance Al; (2) The raw materials are melted, slag removed, refined and allowed to stand to obtain aluminum alloy liquid; (3) Cast the aluminum alloy liquid to obtain an aluminum alloy casting rod; (4) The aluminum alloy casting rod is homogenized; the homogenization temperature is 440℃ and the homogenization time is 12h.

[0066] (5) The homogenized aluminum alloy casting rod is extruded to obtain an aluminum alloy billet; The extrusion temperature was 510℃ and the extrusion speed was 3.5m / min.

[0067] (6) The aluminum alloy billet is subjected to heat solution treatment; wherein the temperature of heat solution treatment is 540℃ and the time of heat solution treatment is 2h; (7) The aluminum alloy billet after heat solution treatment is subjected to high-temperature cyclic deformation treatment; wherein, Specifically, after heat solution treatment, the material is directly subjected to high-temperature cyclic deformation treatment at 450℃, and the deformation amount is controlled to be 0.06%.

[0068] (8) The aluminum alloy billet after high-temperature cyclic deformation treatment is quenched. (9) The quenched aluminum alloy billet is subjected to aging treatment to obtain the finished aluminum alloy product.

[0069] Specifically, the aging treatment temperature is 180℃ and the aging treatment time is 1 hour.

[0070] Comparative Example 1 This comparative example provides a method for preparing an aluminum alloy, which differs from Example 1 in that: In step (1), the raw material formula by weight percentage is as follows: Mg 0.6%, Si 1.9%, Cu 0.42%, Zr 0.22%, Hf 0.18%, balance Al; Everything else is the same as in Example 1.

[0071] Comparative Example 2 This comparative example provides a method for preparing an aluminum alloy, which differs from Example 1 in that: In step (4), the homogenization temperature is 520℃ and the homogenization time is 9h.

[0072] Everything else is the same as in Example 1.

[0073] Comparative Example 3 This comparative example provides a method for preparing an aluminum alloy, which differs from Example 1 in that: Step (6) is not included.

[0074] Everything else is the same as in Example 1.

[0075] Comparative Example 4 This comparative example provides a method for preparing an aluminum alloy, which differs from Example 1 in that: Step (7) is not included.

[0076] Everything else is the same as in Example 1.

[0077] The aluminum alloys obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were tested; the details are as follows: (1) Mechanical properties were determined according to the method of GB / T 6892-2015; (2) The corrosion resistance was determined according to the method of GB / T 10125. The specific test data are shown in the table below:

[0078] The above description is a preferred embodiment of the invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the invention, and these improvements and modifications are also considered to be within the scope of protection of the invention.

Claims

1. A method for preparing a high corrosion-resistant aluminum alloy, characterized in that, include: (1) Prepare various raw materials according to the proportions; the raw material formulas by weight percentage are as follows: Mg 0.55%~0.75%, Si 1.8%~2.2%, Cu 0.4%~0.5%, Zr 0.1%~0.2%, Hf 0.2%~0.3%, balance Al; (2) The raw materials are melted, slag removed, refined and allowed to stand to obtain aluminum alloy liquid; (3) Cast the aluminum alloy liquid to obtain an aluminum alloy casting rod; (4) The aluminum alloy casting rod is homogenized; wherein the homogenization temperature is 420℃~450℃ and the homogenization time is 10h~15h. (5) The homogenized aluminum alloy casting rod is extruded to obtain an aluminum alloy billet; (6) The aluminum alloy billet is subjected to heat solution treatment; wherein the temperature of heat solution treatment is 520℃~560℃ and the time of heat solution treatment is 1.5h~4h; (7) The aluminum alloy billet after heat solution treatment is subjected to high-temperature cyclic deformation treatment; wherein the temperature of high-temperature cyclic deformation treatment is 400℃~500℃, and the deformation amount of high-temperature cyclic deformation treatment is ≤0.1%; (8) The aluminum alloy billet after high-temperature cyclic deformation treatment is quenched. (9) The quenched aluminum alloy billet is subjected to aging treatment to obtain the finished aluminum alloy product.

2. The method for preparing the high corrosion-resistant aluminum alloy as described in claim 1, characterized in that, Zr+Hf≤0.45wt%; and / or The finished aluminum alloy product contains dispersed Al3Zr and Si2(Zr,Hf) phases.

3. The method for preparing the high corrosion-resistant aluminum alloy as described in claim 1, characterized in that, Zr+Hf is 0.4%~0.45%; and / or The finished aluminum alloy contains dispersed Al3Zr and Si2(Zr,Hf) phases; the Al3Zr phase is granular with a particle size of 20nm~100nm; the Si2(Zr,Hf) phase is nanoribbon-shaped with a length of 10μm~70μm, a width of 60nm~240nm, and a thickness of 10nm~40nm.

4. The method for preparing the high corrosion-resistant aluminum alloy as described in claim 1, characterized in that, In step (9), the aging treatment temperature is 160℃~190℃ and the aging treatment time is 0.5h~2h.

5. The method for preparing the high corrosion-resistant aluminum alloy as described in claim 1, characterized in that, In step (4), the homogenization temperature is 430℃~445℃, and the homogenization time is 11h~13h; and / or In step (6), the temperature for the solution treatment is 530℃~550℃, and the treatment time is 1.5h~3h; and / or In step (7), the temperature of the high-temperature cyclic deformation treatment is 440℃~480℃, and the deformation amount of the high-temperature cyclic treatment is 0.05%~0.08%.

6. The method for preparing the high corrosion-resistant aluminum alloy as described in claim 1, characterized in that, In step (4), the homogenization temperature is 440℃, and the homogenization time is 12h; and / or In step (6), the temperature for the solution treatment is 540°C, and the treatment time is 2 hours; and / or In step (7), the temperature of the high-temperature cyclic deformation treatment is 450℃, and the deformation amount of the high-temperature cyclic treatment is 0.06%.

7. The method for preparing the high corrosion-resistant aluminum alloy as described in claim 1, characterized in that, In step (5), the extrusion temperature is 510℃~520℃, the extrusion ratio is ≥25, and the extrusion speed is 1m / min~5m / min.

8. The method for preparing the high corrosion-resistant aluminum alloy as described in claim 1, characterized in that, The wall thickness of the finished aluminum alloy product is 3mm to 5mm.

9. A high corrosion-resistant aluminum alloy, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the high corrosion-resistant aluminum alloy as described in claim 9 in the manufacture of marine vessels, rail transportation, aircraft, and new energy vehicles.

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