Heat-resistant anodized aluminum alloy and preparation method thereof

Abstract

The invention discloses a heat-resistant anodized aluminum alloy and a preparation method thereof. The aluminum alloy material comprises the following components: less than or equal to 0.2 wt% of Si, 0.3-1.0 wt% of Fe, less than or equal to 0.2 wt% of Al and the balance of Al. Cu < = 0.5 wt%; mn: 0.2 to 1.0 wt%; 0.8 to 1.2 wt% of Mg; 4.5 to 6.0 wt% of Zn; 0.1 wt% to 0.3 wt% of Ag; zr: 0.2 to 0.5 wt%; the total content of the impurities is less than or equal to 0.15 wt%; the tensile strength of the aluminum alloy is larger than 240 MPa, the yield strength is larger than 130 MPa, and the ductility is larger than 5%. According to the invention, the nucleation, growth and structure of a precipitated phase in the alloy aging process are changed by adding Ag, so that a finer, more stable and more uniformly distributed strengthening phase is obtained, and the binding force between Ag atoms and vacancies is very strong; the aluminum alloy product prepared through die casting is subjected to color anodic oxidation, the bright effect can be equal to the anodic oxidation level of a wrought aluminum alloy product, the production efficiency can be remarkably improved, and the production cost of the product is remarkably reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy manufacturing, in particular to a heat-resistant anodized aluminum alloy and a preparation method thereof. BACKGROUND

[0002] Casting aluminum alloy refers to an aluminum alloy that is mainly shaped by a casting process. Specifically, it is to melt aluminum alloy raw materials prepared according to specific requirements into liquid metal, then pour it into a pre-made casting mold, and after cooling, solidification, and cleaning treatment, an aluminum alloy part with a predetermined shape, size, and performance is obtained.

[0003] Disadvantages of the prior art: At present, the production of 3-5mm appearance thin-walled parts of casting aluminum alloy has the advantages of simple process, high production efficiency, and low cost, but the quality of the conventional Al-Si series casting aluminum alloy anodized film cannot meet the requirements of appearance parts; directly using deformed aluminum alloy die-casting products, due to the fluidity of the material, the casting formability is very poor during the die-casting process, and qualified products cannot be die-cast. SUMMARY

[0004] The purpose of the present application is to provide a heat-resistant anodized aluminum alloy and a preparation method thereof to solve the problems raised in the background art.

[0005] To achieve the above purpose, the present application provides the following technical scheme: a heat-resistant anodized aluminum alloy, the aluminum alloy material composition comprises: Si≤0.2wt%, Fe: 0.3-1.0wt%; Cu≤0.5wt%; Mn: 0.2-1.0wt%; Mg: 0.8-1.2wt%; Zn: 4.5-6.0wt%; Ag: 0.1-0.3wt%; Zr: 0.2-0.5wt%; the balance is Al and impurities, the total content of impurities is less than or equal to 0.15wt%; the tensile strength of the aluminum alloy is greater than 240MPa, the yield strength is greater than 130MPa, and the elongation is greater than 5%.

[0006] Preferably, the amount relationship of Ag and Zr is: 0.6<Ag / Zr<1.0; The amount relationship of Mg and Cu is: 3<Mg / Cu<5; The amount relationship of Zn and Mg is: 4<Zn / Mg<6.

[0007] The present application also provides a preparation method of a heat-resistant anodized aluminum alloy, which specifically comprises: S1, preparing raw materials and obtaining an aluminum liquid melt; S2. Inspect whether the composition of the molten aluminum is up to standard; S3. Pour the molten aluminum into the die-casting machine for die casting. When the molten aluminum has cooled down to the set die-casting temperature, start the die casting process. S4. Perform T6 heat treatment on the die-cast aluminum alloy products.

[0008] Preferably, step S1 specifically includes: a1. Weigh out the raw materials according to the corresponding percentages based on the composition of the aluminum alloy material; a2. The preheating furnace is 300℃; a3. Raw materials are added into the melting furnace in sequence, and after being heated and stirred evenly, aluminum melt is obtained.

[0009] Preferably, step S2 specifically includes: b1. Take TP samples from the smelting furnace to test the aluminum liquid composition and determine whether it meets the material design requirements; b2. If there is an element deviation, add the element; if the material design requirements are met, perform GBF rotary degassing refining treatment on the molten aluminum.

[0010] Preferably, in step a3, the furnace temperature is set to 780°C, and electromagnetic stirring is used for a stirring time of 20 minutes.

[0011] Preferably, in step S4, the T6 heat treatment is performed with the following parameters: solution temperature set to 420-450℃, holding time set to 3-5h, cooling water temperature set to 65-85℃, quenching time set to 5-10s, aging temperature set to 125-165℃, holding time set to 3-10h, and finally, natural cooling.

[0012] Preferably, in step S3, the die-casting mold temperature is set to 250°C, and the ultra-low filling molding process and oxygen-filled die-casting process are used to make the filling speed of the aluminum liquid at the inner interface 0.1 m / s and the mold generate an Al2O3 film, respectively.

[0013] Preferably, in step S3, the scoop used in the die-casting process is immersed in molten aluminum, the scoop is made of ceramic material, and zinc oxide is sprayed on its surface.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention relates to a heat-resistant anodized aluminum alloy and its preparation method. By adding Ag, the nucleation, growth, and structure of precipitated phases during the alloy's aging process are altered, resulting in finer, more stable, and more uniformly distributed strengthening phases. Ag atoms have a very strong binding force with vacancies. During the quenching process after solution treatment, Ag can effectively "capture" supersaturated vacancies, forming Ag-vacancy clusters. These Ag-vacancy clusters, in turn, have a strong attraction for solute atoms such as Cu and Mg, becoming traps for solute atom enrichment. The addition of Ag can effectively suppress the creep rate of the alloy under high temperature and stress. Color anodizing of aluminum alloy products prepared by die casting can achieve a brightness level comparable to that of wrought aluminum alloy products, significantly improving production efficiency and reducing product production costs. Attached Figure Description

[0015] Fig. 1 The present invention relates to a heat-resistant anodized aluminum alloy product; Fig. 2 The present invention relates to a heat-resistant anodized aluminum alloy product. Detailed Implementation

[0016] 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.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integrated connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a number" means two or more, unless otherwise explicitly specified.

[0020] Example 1 Please see Figs. 1-2 As shown, the present invention provides a heat-resistant anodized aluminum alloy technical solution: the aluminum alloy material composition includes: Si: 0.15wt%, Fe: 0.5wt%; Cu: 0.5wt%; Mn: 0.5wt%; Mg: 1.0wt%; Zn: 5.2wt%; Ag: 0.23wt%; Zr: 0.23wt%; the balance is Al and impurities, the total impurity content is less than or equal to 0.15wt%; wherein, Ag / Zr is 1.0, Mg / Cu is 5.0, and Zn / Mg is 5.2.

[0021] Adding Ag to aluminum alloys can ensure their fluidity and mechanical properties, as well as provide them with good anodizing and high-temperature resistance. Adding Zr, which refines grain size, can comprehensively improve the mechanical properties of aluminum alloys and optimize the anodizing effect.

[0022] This invention also provides a method for preparing a heat-resistant anodized aluminum alloy, the method specifically including: S1. Prepare raw materials and produce molten aluminum; a1. Weigh out the raw materials according to the corresponding percentages based on the composition of the aluminum alloy material; a2. The preheating furnace is 300℃; a3. The raw materials are put into the melting furnace in sequence. After being melted and stirred evenly, aluminum melt is obtained. The temperature of the melting furnace is set to 780℃, and electromagnetic stirring is used. The stirring time is set to 20 minutes to ensure that the various elements in the melting furnace are evenly distributed. S2. Inspect whether the composition of the molten aluminum is up to standard; b1. Take TP samples from the smelting furnace to test the aluminum liquid composition and determine whether it meets the material design requirements; b2. If there is an element deviation, the element shall be added; if the material design requirements are met, the molten aluminum shall be subjected to GBF rotary degassing refining treatment. S3. Pour the molten aluminum into the die-casting machine. Once the molten aluminum has cooled to the set die-casting temperature, die-casting begins. The die-casting mold temperature is set to 250℃ to improve the mold temperature field and enhance the fluidity of the molten aluminum. Ultra-low filling molding and oxygen-filled die-casting processes are employed to achieve a filling speed of 0.1 m / s at the inner joint and to generate an Al2O3 film in the mold, reducing air entrapment in the die-casting parts. The scoop used during die-casting is immersed in the molten aluminum. The scoop is made of ceramic and coated with zinc oxide to reduce heat loss from the molten aluminum. During die-casting, the mold filling and venting systems are optimized, increasing the filling volume of the gating system and shortening the filling time to improve filling quality. Spot cooling devices are added to areas of localized thickness to accelerate cooling, ensuring a consistent temperature field in the casting and reducing shrinkage.

[0023] S4. Perform T6 heat treatment on the die-cast aluminum alloy product. Set the solution temperature to 420-450℃, the holding time to 3-5h, the cooling water temperature to 65-85℃, the quenching time to 5-10s, the aging temperature to 125-165℃, the holding time to 3-10h, and finally allow it to cool naturally.

[0024] The aluminum alloy produced by the above steps has a tensile strength of 248 MPa, a yield strength of 135 MPa, and an elongation of 7.2%.

[0025] Example 2 Please see Figs. 1-2 As shown, the present invention provides a heat-resistant anodized aluminum alloy technical solution: the aluminum alloy material composition includes: Si: 0.12wt%, Fe: 0.65wt%; Cu: 0.3wt%; Mn: 0.6wt%; Mg: 0.9wt%; Zn: 5.0wt%; Ag: 0.18wt%; Zr: 0.22wt%; the balance is Al and impurities, the total impurity content is less than or equal to 0.15wt%; wherein, Ag / Zr is 0.81, Mg / Cu is 3.0, and Zn / Mg is 5.5.

[0026] Adding Ag to aluminum alloys can ensure their fluidity and mechanical properties, as well as provide them with good anodizing and high-temperature resistance. Adding Zr, which refines grain size, can comprehensively improve the mechanical properties of aluminum alloys and optimize the anodizing effect.

[0027] This invention also provides a method for preparing a heat-resistant anodized aluminum alloy, the method specifically including: S1. Prepare raw materials and produce molten aluminum; a1. Weigh out the raw materials according to the corresponding percentages based on the composition of the aluminum alloy material; a2. The preheating furnace is 300℃; a3. The raw materials are put into the melting furnace in sequence. After being melted and stirred evenly, aluminum melt is obtained. The temperature of the melting furnace is set to 780℃, and electromagnetic stirring is used. The stirring time is set to 20 minutes to ensure that the various elements in the melting furnace are evenly distributed. S2. Inspect whether the composition of the molten aluminum is up to standard; b1. Take TP samples from the smelting furnace to test the aluminum liquid composition and determine whether it meets the material design requirements; b2. If there is an element deviation, the element shall be added; if the material design requirements are met, the molten aluminum shall be subjected to GBF rotary degassing refining treatment. S3. Pour the molten aluminum into the die-casting machine. Once the molten aluminum has cooled to the set die-casting temperature, die-casting begins. The die-casting mold temperature is set to 250℃ to improve the mold temperature field and enhance the fluidity of the molten aluminum. Ultra-low filling molding and oxygen-filled die-casting processes are employed to achieve a filling speed of 0.1 m / s at the inner joint and to generate an Al2O3 film in the mold, reducing air entrapment in the die-casting parts. The scoop used during die-casting is immersed in the molten aluminum. The scoop is made of ceramic and coated with zinc oxide to reduce heat loss from the molten aluminum. During die-casting, the mold filling and venting systems are optimized, increasing the filling volume of the gating system and shortening the filling time to improve filling quality. Spot cooling devices are added to areas of localized thickness to accelerate cooling, ensuring a consistent temperature field in the casting and reducing shrinkage.

[0028] S4. Perform T6 heat treatment on the die-cast aluminum alloy product. Set the solution temperature to 420-450℃, the holding time to 3-5h, the cooling water temperature to 65-85℃, the quenching time to 5-10s, the aging temperature to 125-165℃, the holding time to 3-10h, and finally allow it to cool naturally.

[0029] The aluminum alloy produced by the above steps has a tensile strength of 253 MPa, a yield strength of 130 MPa, and an elongation of 6.1%.

[0030] Example 3 Please see Figs. 1-2 As shown, the present invention provides a heat-resistant anodized aluminum alloy technical solution: the aluminum alloy material composition includes: Si: 0.13wt%, Fe: 0.75wt%, Cu: 0.35wt%, Mn: 0.65wt%, Mg: 0.95wt%, Zn: 5.1wt%, Ag: 0.25wt%, Zr: 0.35wt%, with the balance being Al and impurities, the total impurity content being less than or equal to 0.15wt%; wherein, Ag / Zr is 0.71, Mg / Cu is 2.7, and Zn / Mg is 5.3.

[0031] Adding Ag to aluminum alloys can ensure their fluidity and mechanical properties, as well as provide them with good anodizing and high-temperature resistance. Adding Zr, which refines grain size, can comprehensively improve the mechanical properties of aluminum alloys and optimize the anodizing effect.

[0032] This invention also provides a method for preparing a heat-resistant anodized aluminum alloy, the method specifically including: S1. Prepare raw materials and produce molten aluminum; a1. Weigh out the raw materials according to the corresponding percentages based on the composition of the aluminum alloy material; a2. The preheating furnace is 300℃; a3. The raw materials are put into the melting furnace in sequence. After being melted and stirred evenly, aluminum melt is obtained. The temperature of the melting furnace is set to 780℃, and electromagnetic stirring is used. The stirring time is set to 20 minutes to ensure that the various elements in the melting furnace are evenly distributed. S2. Inspect whether the composition of the molten aluminum is up to standard; b1. Take TP samples from the smelting furnace to test the aluminum liquid composition and determine whether it meets the material design requirements; b2. If there is an element deviation, the element shall be added; if the material design requirements are met, the molten aluminum shall be subjected to GBF rotary degassing refining treatment. S3. Pour the molten aluminum into the die-casting machine. Once the molten aluminum has cooled to the set die-casting temperature, die-casting begins. The die-casting mold temperature is set to 250℃ to improve the mold temperature field and enhance the fluidity of the molten aluminum. Ultra-low filling molding and oxygen-filled die-casting processes are employed to achieve a filling speed of 0.1 m / s at the inner joint and to generate an Al2O3 film in the mold, reducing air entrapment in the die-casting parts. The scoop used during die-casting is immersed in the molten aluminum. The scoop is made of ceramic and coated with zinc oxide to reduce heat loss from the molten aluminum. During die-casting, the mold filling and venting systems are optimized, increasing the filling volume of the gating system and shortening the filling time to improve filling quality. Spot cooling devices are added to areas of localized thickness to accelerate cooling, ensuring a consistent temperature field in the casting and reducing shrinkage.

[0033] S4. Perform T6 heat treatment on the die-cast aluminum alloy product. Set the solution temperature to 420-450℃, the holding time to 3-5h, the cooling water temperature to 65-85℃, the quenching time to 5-10s, the aging temperature to 125-165℃, the holding time to 3-10h, and finally allow it to cool naturally.

[0034] The aluminum alloy produced by the above steps has a tensile strength of 243 MPa, a yield strength of 133 MPa, and an elongation of 5.8%.

[0035] Comparative Example 1 Another aluminum alloy technical solution is provided: the aluminum alloy material composition includes: Si: 0.1wt%, Fe: 0.9wt%; Cu: 0.25wt%; Mn: 0.6wt%; Mg: 0.85wt%; Zn: 5.0wt%; Zr: 0.35wt%; the balance is Al and impurities.

[0036] Another method for preparing an aluminum alloy is provided, the method specifically including: S1. Prepare raw materials and produce molten aluminum; a1. Weigh out the raw materials according to the corresponding percentages based on the composition of the aluminum alloy material; a2. The preheating furnace is 300℃; a3. The raw materials are put into the melting furnace in sequence. After being melted and stirred evenly, aluminum melt is obtained. The temperature of the melting furnace is set to 780℃, and electromagnetic stirring is used. The stirring time is set to 20 minutes to ensure that the various elements in the melting furnace are evenly distributed. S2. Inspect whether the composition of the molten aluminum is up to standard; b1. Take TP samples from the smelting furnace to test the aluminum liquid composition and determine whether it meets the material design requirements; b2. If there is an element deviation, the element shall be added; if the material design requirements are met, the molten aluminum shall be subjected to GBF rotary degassing refining treatment. S3. Pour the molten aluminum into the die-casting machine. Once the molten aluminum has cooled to the set die-casting temperature, die-casting begins. The die-casting mold temperature is set to 250℃ to improve the mold temperature field and enhance the fluidity of the molten aluminum. Ultra-low filling molding and oxygen-filled die-casting processes are employed to achieve a filling speed of 0.1 m / s at the inner joint and to generate an Al2O3 film in the mold, reducing air entrapment in the die-casting parts. The scoop used during die-casting is immersed in the molten aluminum. The scoop is made of ceramic and coated with zinc oxide to reduce heat loss from the molten aluminum. During die-casting, the mold filling and venting systems are optimized, increasing the filling volume of the gating system and shortening the filling time to improve filling quality. Spot cooling devices are added to areas of localized thickness to accelerate cooling, ensuring a consistent temperature field in the casting and reducing shrinkage.

[0037] S4. Perform T6 heat treatment on the die-cast aluminum alloy product. Set the solution temperature to 420-450℃, the holding time to 3-5h, the cooling water temperature to 65-85℃, the quenching time to 5-10s, the aging temperature to 125-165℃, the holding time to 3-10h, and finally allow it to cool naturally.

[0038] The aluminum alloy produced by the above steps has a tensile strength of 225 MPa, a yield strength of 124 MPa, and an elongation of 3.8%.

[0039] Comparing Examples 1, 2, and 3 with Comparative Example 1, it was found that Comparative Example 1, without the addition of Ag, had reduced material performance and decreased gloss after color anodizing. In contrast, the added Ag formed intermetallic compounds that were uniformly dispersed in the aluminum matrix. During the anodizing process, Ag acted as heterogeneous nucleation sites, refining the oxide film. Homogeneous nucleation also helped reduce internal stress during the oxide film production process, resulting in a more uniform and dense oxide film. Ultimately, the product had the best appearance.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heat-resistant anodized aluminum alloy, characterized in that: The aluminum alloy material composition includes: Si ≤ 0.2 wt%, Fe: 0.3-1.0 wt%, Cu ≤ 0.5 wt%, Mn: 0.2-1.0 wt%, Mg: 0.8-1.2 wt%, Zn: 4.5-6.0 wt%, Ag: 0.1-0.3 wt%, Zr: 0.2-0.5 wt%, with the balance being Al and impurities, and the total impurity content being less than or equal to 0.15 wt%. The aluminum alloy has a tensile strength greater than 240 MPa, a yield strength greater than 130 MPa, and an elongation greater than 5%.

2. The heat-resistant anodized aluminum alloy according to claim 1, characterized in that: The quantitative relationship between Ag and Zr is as follows: 0.6 < Ag / Zr < 1.0; The quantitative relationship between Mg and Cu is as follows: 3 < Mg / Cu < 5; The quantitative relationship between Zn and Mg is as follows: 4 < Zn / Mg < 6.

3. The method for preparing a heat-resistant anodized aluminum alloy according to any one of claims 1-2, characterized in that: The preparation method specifically includes: S1. Prepare raw materials and produce molten aluminum; S2. Inspect whether the composition of the molten aluminum is up to standard; S3. Pour the molten aluminum into the die-casting machine for die casting. When the molten aluminum has cooled down to the set die-casting temperature, start the die casting process. S4. Perform T6 heat treatment on the die-cast aluminum alloy products.

4. The method for preparing a heat-resistant anodized aluminum alloy according to claim 3, characterized in that: Step S1 specifically includes: a1. Weigh out the raw materials according to the corresponding percentages based on the composition of the aluminum alloy material; a2. The preheating furnace is 300℃; a3. Raw materials are added into the melting furnace in sequence, and after being heated and stirred evenly, aluminum melt is obtained.

5. The method for preparing a heat-resistant anodized aluminum alloy according to claim 3, characterized in that: Step S2 specifically includes: b1. Take TP samples from the smelting furnace to test the aluminum liquid composition and determine whether it meets the material design requirements; b2. If there is an element deviation, add the element; if the material design requirements are met, perform GBF rotary degassing refining treatment on the molten aluminum.

6. The method for preparing a heat-resistant anodized aluminum alloy according to claim 4, characterized in that: In step a3, the furnace temperature is set to 780℃, and electromagnetic stirring is used for 20 minutes.

7. The method for preparing a heat-resistant anodized aluminum alloy according to claim 3, characterized in that: In step S4, the T6 heat treatment is performed with the following steps: solution temperature set to 420-450℃, holding time set to 3-5h, cooling water temperature set to 65-85℃, quenching time set to 5-10s, aging temperature set to 125-165℃, holding time set to 3-10h, and finally, natural cooling.

8. The method for preparing a heat-resistant anodized aluminum alloy according to claim 3, characterized in that: In step S3, the die-casting mold temperature is set to 250℃, and ultra-low filling molding process and oxygen-filled die-casting process are used to make the filling speed of aluminum liquid at the inner interface 0.1m / s and the mold generate Al2O3 film, respectively.

9. The method for preparing a heat-resistant anodized aluminum alloy according to claim 3, characterized in that: In step S3, the scoop used in the die casting process is immersed in molten aluminum. The scoop is made of ceramic material and coated with zinc oxide.

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