High-strength and high-corrosion-resistance aluminum alloy and treatment method thereof

Abstract

The invention discloses a high-strength and high-corrosion-resistance aluminum alloy and a treatment method thereof, and belongs to the technical field of materials.The aluminum alloy is prepared from, by mass, 5%-7% of Si, 0.5%-0.7% of Mg, 1.3%-1.5% of Cu, smaller than or equal to 0.05% of a single impurity and the balance Al. The treatment method comprises the steps that firstly, the aluminum alloy is subjected to solution aging treatment, and then the aluminum alloy is subjected to heat treatment; and then the treated aluminum alloy is subjected to micro-arc oxidation. The method mainly aims at achieving the purpose of improving the strength and corrosion resistance of the alloy.

Description

Technical Field

[0001] The invention relates to an aluminum alloy with high strength and strong corrosion resistance and a processing method thereof, belonging to the technical field of materials. Background Art

[0002] Aluminum alloy plays an important role in industry as a lightweight, high-strength and corrosion-resistant material. However, traditional aluminum alloys and processing methods have certain limitations in improving their performance. Therefore, designing a new high-strength aluminum alloy and finding a corresponding processing method to improve the strength and corrosion resistance of the aluminum alloy has become one of the current research hotspots. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides an aluminum alloy with high strength and strong corrosion resistance and a processing method thereof, so as to achieve the purpose of improving the strength and corrosion resistance of the alloy.

[0004] The invention provides an aluminum alloy with high strength and strong corrosion resistance and a processing method thereof. The aluminum alloy is prepared from raw materials with the following mass percentages: Si: 5-7%, Mg: 0.5-0.7%, Cu: 1.3-1.5%, other impurities individually ≤0.05%, and the balance is Al.

[0005] Furthermore, the aluminum alloy is prepared from the following raw materials in percentage by mass: Si: 5.5-6.5%, Mg: 0.55-0.65%, Cu: 1.35-1.45%, other impurities are ≤0.05% each, and the balance is Al.

[0006] Furthermore, the aluminum alloy is prepared from the following raw materials in percentage by mass: Si: 5.7-6.3%, Mg: 0.57-0.53%, Cu: 1.37-1.43%, other impurities are ≤0.05% each, and the balance is Al.

[0007] A method for processing an aluminum alloy with high strength and strong corrosion resistance, the specific steps are: S1: Prepare ingredients according to the chemical composition and mass percentage of the aluminum alloy; S2: Use a melting resistance furnace to melt the raw materials at a melting temperature of 680-740°C and keep warm for 30 minutes; S3: Using N2 as refining gas, the completely molten metal liquid is refined by rotary blowing, and the refining temperature should be maintained in the range of 690-730℃; S4: Keep the refined metal liquid warm for 10 minutes, add the modifier and refiner and stir thoroughly for 5 minutes; S5: After the stirring is completed, the temperature is kept at 15 minutes and casting begins. During casting, the temperature of the molten metal is maintained at 700-720°C; S6: performing solution treatment and aging treatment on the ingot; S7: grinding, polishing, degreasing and cleaning the ingot after solution treatment and aging treatment; S8: performing micro-arc oxidation treatment on the ingot.

[0008] Furthermore, the process of the solution treatment in S6 is: the solution temperature is 520-530° C., the solution time is 6-8 hours, and the cooling method is water cooling.

[0009] Furthermore, the aging treatment process in S6 is: the aging temperature is 160-170° C., the aging time is 8-10 hours, and the cooling method is air cooling.

[0010] Furthermore, the process of micro-arc oxidation treatment in S8 is: the solution composition ratio is: 10g / L NaAlO2+1.1g / LNaOH, and the process parameters are: forward voltage is 430V, frequency is 50Hz, duty cycle is 45%, and oxidation time is 30min.

[0011] The above technical scheme is adopted, and the advantages of the present invention are: in the Al-Si-Mg-Cu alloy, the addition of copper as a strengthening element may cause the precipitation of Al2Cu or CuAl2Mg phases with poor electrochemical stability. These phases gather on the grain boundaries to form current concentration, which easily leads to holes in the oxide film, triggering local corrosion, damaging the integrity of the oxide film, and then weakening the effect of micro-arc oxidation, significantly reducing the corrosion resistance of the alloy. By implementing appropriate solid solution aging treatment, large pieces of Al2Cu phase can be dissolved into the matrix to form a nanophase, thereby reducing the impact of local corrosion. Therefore, solid solution aging treatment can effectively improve the effect of subsequent micro-arc oxidation, promote the formation of a uniform oxide film on the surface of the material, and enhance the corrosion resistance of the Al-Si-Mg-Cu alloy. This method combines solid solution aging with micro-arc oxidation, which not only improves the strength of the material, but also enhances its corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is the tensile curve of aluminum alloy; Figure 2 This is a high-resolution TEM morphology of the Al2Cu phase after solution aging; Figure 3 Comparison of polarization curves of aluminum alloy before and after micro-arc oxidation. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0014] The terms "first", "second", etc. (if any) in the specification and claims of the present invention are used to distinguish similar objects, rather than to describe a specific order or sequence. Even if "second" is used to distinguish before a certain technical feature, it does not necessarily indicate that "first" is present. It should be understood that in the present invention, "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. It should be understood that in the present invention, "multiple" refers to two or more. "And / or" is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, X and / or Y can represent: X exists alone, X and Y exist at the same time, and Y exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "Contains X, Y and Z", "Contains X, Y, Z" means that X, Y, and Z are all included, "Contains X, Y or Z" means that one of X, Y, and Z is included, and "Contains X, Y and / or Z" means that any one, any two, or three of X, Y, and Z are included. Example

[0015] The invention provides an aluminum alloy with high strength and strong corrosion resistance and a processing method thereof. The aluminum alloy is prepared from raw materials with the following mass percentages: Si: 5-7%, Mg: 0.5-0.7%, Cu: 1.3-1.5%, other impurities are individually ≤0.05%, and the balance is Al.

[0016] from Figure 1 It can be found from the tensile curve that the tensile strength of the alloy can reach 350MPa.

[0017] The above-mentioned method for treating an aluminum alloy with high strength and strong corrosion resistance first performs a solid solution aging treatment on the aluminum alloy, and then performs micro-arc oxidation on the treated aluminum alloy. The specific steps are as follows: S1: Prepare ingredients according to the chemical composition and mass percentage of the aluminum alloy; S2: Use a melting resistance furnace to melt the raw materials at a melting temperature of 680-740°C and keep warm for 30 minutes; S3: Using N2 as refining gas, the completely molten metal liquid is refined by rotary blowing, and the refining temperature should be maintained in the range of 690-730℃; S4: Keep the refined metal liquid warm for 10 minutes, add the modifier and refiner and stir thoroughly for 5 minutes; S5: After the stirring is completed, the temperature is kept at 15 minutes and casting begins. During casting, the temperature of the molten metal is maintained at 700-720°C; S6: performing solution treatment and aging treatment on the ingot; S7: grinding, polishing, degreasing and cleaning the ingot after solution treatment and aging treatment; S8: performing micro-arc oxidation treatment on the ingot.

[0018] Among them, the process of solution treatment in S6 is: solution temperature is 520-530°C, solution time is 6-8h, and cooling method is water cooling.

[0019] Among them, the aging treatment process in S6 is: aging temperature is 160-170°C, aging time is 8-10h, and cooling method is air cooling.

[0020] By implementing appropriate solution aging treatment, such as Figure 2 As shown in the high-resolution TEM morphology of the Al2Cu phase after solution aging, the bulk Al2Cu phase can be dissolved into the matrix to form a nanophase, thereby reducing the impact of local corrosion.

[0021] Specifically, the process of micro-arc oxidation treatment in S8 is: the solution composition ratio is: 10g / L NaAlO2+1.1g / LNaOH, the process parameters are: forward voltage is 430V, frequency is 50Hz, duty cycle is 45%, oxidation time is 30min, and the aluminum alloy after micro-arc oxidation treatment is compared with the aluminum alloy without micro-arc oxidation treatment. Figure 3 As shown in the AC impedance diagram, it can be found that the RC arc radius of the sample after micro-arc oxidation is larger than that of the original sample, indicating that the corrosion resistance is improved after micro-arc oxidation. Example

[0022] Different from the first embodiment, the aluminum alloy in this embodiment is prepared from raw materials in the following mass percentages: Si: 5.5-6.5%, Mg: 0.55-0.65%, Cu: 1.35-1.45%, other impurities are ≤0.05% each, and the balance is Al. Example

[0023] Different from the first embodiment, the aluminum alloy in this embodiment is prepared from raw materials in the following mass percentages: Si: 5.7-6.3%, Mg: 0.57-0.63%, Cu: 1.37-1.43%, other impurities are ≤0.05% each, and the balance is Al. Example

[0024] Different from the first embodiment, the aluminum alloy in this embodiment is prepared from raw materials in the following mass percentages: Si: 6%, Mg: 0.6%, Cu: 1.4%, other impurities are ≤0.05% each, and the balance is Al. Example

[0025] Different from the first embodiment, the aluminum alloy in this embodiment is prepared from raw materials with the following mass percentages: Si: 5.5%, Mg: 0.55%, Cu: 1.35%, other impurities are ≤0.05% each, and the balance is Al. Example

[0026] Different from the first embodiment, the aluminum alloy in this embodiment is prepared from raw materials with the following mass percentages: Si: 6.5%, Mg: 0.65%, Cu: 1.45%, other impurities are ≤0.05% each, and the balance is Al. Example

[0027] Different from the first embodiment, the aluminum alloy in this embodiment is prepared from raw materials with the following mass percentages: Si: 5.7%, Mg: 0.57%, Cu: 1.37%, other impurities are ≤0.05% each, and the balance is Al.

[0028] In all the above embodiments, high-purity Al (99.99%), pure Mg (99.92%), Al-25% Si, and Al-50% Cu are used as raw materials.

[0029] In addition to the above-mentioned preferred embodiments, the present invention also has other implementation modes. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present invention.

Claims

1. A high-strength and corrosion-resistant aluminum alloy, characterized in that: The aluminum alloy is prepared from the following raw materials in mass percentage: Si: 5% to 7%, Mg: 0.5 to 0.7%, Cu: 1.3 to 1.5%, other impurities are ≤ 0.05% each, and the balance is Al.

2. The high-strength and highly corrosion-resistant aluminum alloy according to claim 1, characterized in that: The aluminum alloy is prepared from the following raw materials in mass percentage: Si: 5.5% to 6.5%, Mg: 0.55 to 0.65%, Cu: 1.35 to 1.45%, other impurities are ≤0.05% each, and the balance is Al.

3. The high-strength and highly corrosion-resistant aluminum alloy according to claim 1, characterized in that: The aluminum alloy is prepared from the following raw materials in mass percentage: Si: 5.7-6.3%, Mg: 0.57-0.63%, Cu: 1.37-1.43%, other impurities are ≤0.05% each, and the balance is Al.

4. A method for processing an aluminum alloy having high strength and strong corrosion resistance, characterized in that: The specific steps are: S1: Prepare ingredients according to the chemical composition and mass percentage of the aluminum alloy; S2: Use a melting resistance furnace to melt the raw materials at a melting temperature of 680-740°C and keep warm for 30 minutes; S3: Using N2 as refining gas, the completely molten metal liquid is refined by rotary blowing, and the temperature during refining is maintained in the range of 690-730°C; S4: Keep the refined metal liquid warm for 10 minutes, add the modifier and refiner and stir thoroughly for 5 minutes; S5: After the stirring is completed, the temperature is kept at 15 minutes and casting begins. During casting, the temperature of the molten metal is maintained at 700-720°C; S6: performing solution treatment and aging treatment on the ingot; S7: grinding, polishing, degreasing and cleaning the ingot after solution treatment and aging treatment; S8: performing micro-arc oxidation treatment on the ingot.

5. The method for processing the high-strength and highly corrosion-resistant aluminum alloy according to claim 4, characterized in that: The process of solution treatment in S6 is: solution temperature is 520-530°C, solution time is 6-8h, and cooling method is water cooling.

6. The method for processing the high-strength and highly corrosion-resistant aluminum alloy according to claim 4, characterized in that: The aging treatment process in S6 is: aging temperature is 160-170°C, aging time is 8-10h, and cooling method is air cooling.

7. The method for processing the high-strength and highly corrosion-resistant aluminum alloy according to claim 4, characterized in that: The process of micro-arc oxidation treatment in S8 is: the solution composition ratio is: 10g / L NaAlO2+1.1g / L NaOH, and the process parameters are: forward voltage is 430V, frequency is 50Hz, duty cycle is 45%, and oxidation time is 30min.

Images