6-series aluminum alloy and preparation method and application thereof

Abstract

The invention discloses a 6-series aluminum alloy and a preparation method and application thereof. The preparation method comprises the following steps that S1, a 6-series aluminum alloy cast ingot is sequentially subjected to homogenizing annealing, extrusion and online quenching, and an extruded profile is obtained; and S2, the extruded profile is obtained through primary artificial aging, primary deformation, secondary artificial aging and secondary deformation in sequence. The 6-series aluminum alloy is prepared by designing online quenching, primary artificial aging, primary deformation, secondary artificial aging and secondary deformation, and the mechanical property of the 6-series aluminum alloy can be greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy materials, in particular to a 6-series aluminum alloy and a preparation method and application thereof. BACKGROUND

[0002] The 6-series aluminum alloy has been widely used in the fields of aerospace, automobile manufacturing, electronic products, etc. due to its lightweight, easy processing, good anodic appearance effect, corrosion resistance and other advantages. It not only meets the demand of multiple industries for high-performance materials, but also provides consumers with a better user experience.

[0003] At present, the development trend of the 6-series aluminum alloy in the field of 3C electronic products mainly focuses on performance enhancement, lightweight design, and sustainability and recycling. The practitioners in the field of aluminum alloy are constantly exploring to further improve the strength, toughness, corrosion resistance and fatigue performance of the 6-series aluminum alloy through alloy element optimization and innovation of heat treatment process. However, the current ultimate yield strength of the 6-series aluminum alloy is about 400-420 MPa, which cannot meet the increasingly demanding lightweight and strength requirements of manufacturers and consumers for 3C electronic products.

[0004] Therefore, it is urgent to develop a preparation method of a 6-series aluminum alloy with ultra-high strength. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides, in a first aspect, a preparation method of a 6-series aluminum alloy, and the 6-series aluminum alloy prepared by the method has ultra-high strength.

[0006] The present application provides, in a second aspect, a 6-series aluminum alloy.

[0007] The present application provides, in a third aspect, an application of the 6-series aluminum alloy.

[0008] The preparation method of the 6-series aluminum alloy according to the first aspect of the present application comprises the following steps:

[0009] S1, a 6-series aluminum alloy ingot is sequentially subjected to homogenization annealing, extrusion and online quenching to obtain an extruded profile;

[0010] S2, the extruded profile is sequentially subjected to primary artificial aging, primary deformation, secondary artificial aging and secondary deformation.

[0011] According to a preferred embodiment of the present application, in step S2, the temperature of the primary artificial aging is 120-180℃.

[0012] According to a preferred embodiment of the present application, in step S2, the temperature of the primary artificial aging is 145-180℃.

[0013] According to a preferred embodiment of the present application, in step S2, the holding time of the first artificial aging is 1-10 hours.

[0014] According to a preferred embodiment of the present application, in step S2, the holding time of the first artificial aging is 2-5 hours.

[0015] According to a preferred embodiment of the present application, in step S2, the temperature of the second artificial aging is 125-185℃.

[0016] According to a preferred embodiment of the present application, in step S2, the temperature of the second artificial aging is 125-175℃.

[0017] According to a preferred embodiment of the present application, in step S2, the holding time of the second artificial aging is 1-26 hours.

[0018] According to a preferred embodiment of the present application, in step S2, the holding time of the second artificial aging is 10-20 hours.

[0019] According to a preferred embodiment of the present application, in step S2, the stretching amount of the first deformation is 2-10%.

[0020] According to a preferred embodiment of the present application, in step S2, the stretching amount of the second deformation is 1-5%.

[0021] According to a preferred embodiment of the present application, the 6-series aluminum alloy comprises the following components in percentage by mass:

[0022] Mg: 0.5-1.5%; Si: 0.45-1.2%; Cu: 0.4-1.1%; Fe≤0.15%; Mn≤0.15%; Zr≤0.10%;

[0023] Zn≤0.10%; Ti≤0.10%; the balance being Al.

[0024] According to a preferred embodiment of the present application, the temperature of the homogenizing annealing is 520-580℃, and the holding time is 10-25 hours.

[0025] According to a preferred embodiment of the present application, the parameters of the extrusion include an aluminum rod heating temperature of 530-570℃ and a mold heating temperature of 440-490℃.

[0026] According to a preferred embodiment of the present application, the 6-series aluminum alloy ingot is obtained by melting and casting.

[0027] According to a preferred embodiment of the present application, the temperature of the melting is 700-780℃.

[0028] According to a preferred embodiment of the present application, the temperature of the casting is 690-720℃.

[0029] The preparation method according to the embodiments of the present application has at least the following beneficial effects:

[0030] The present application can greatly improve the mechanical properties of the 6-series aluminum alloy by designing online quenching, one-time artificial aging, one-time deformation, two-time artificial aging and two-time deformation. This is because the high-density precipitated phase particles are formed in the one-time artificial aging of the quenched profile, which increases the resistance of dislocation movement in the subsequent one-time deformation process, reduces the degree of dislocation accumulation in front of the grain boundary, and increases the density of dislocations and vacancies and uniformly distributes them. In the two-time artificial aging, the high-density dislocation entanglement area and high-density vacancies formed by the interaction between the particles precipitated in the one-time artificial aging and dislocations and vacancies in the subsequent deformation process provide more nucleation sites for subsequent precipitation, which not only increases the density of precipitated phase particles, but also is beneficial to the uniform distribution of precipitated phase particles inside and between the grains, thereby improving the hardness of the alloy. The final two-time deformation further increases the dislocation density inside the alloy and the degree of dislocation accumulation, thereby further improving the mechanical properties of the alloy.

[0031] According to a second aspect of the present application, a 6-series aluminum alloy is provided, which is prepared by the preparation method of the first aspect of the present application.

[0032] According to a preferred embodiment of the present application, the yield strength of the 6-series aluminum alloy is ≥440MPa.

[0033] The third aspect of the present application provides the use of the above-mentioned 6-series aluminum alloy in the preparation of 3C electronic products and automotive products.

[0034] Other features and advantages of the present application will be set forth in the specification, and in part will become apparent from the specification, or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0036] Figure 1 are grain structure diagrams of the 6-series aluminum alloys of Examples 1-6 and Comparative Examples 1-3 of the present application;

[0037] Figure 2 are digital photos of the 6-series aluminum alloys of Examples 1-6 and Comparative Examples 1-3 of the present application after anodic oxidation. DETAILED DESCRIPTION

[0038] The following are specific embodiments of the present application, and the technical solutions of the present application are further described in combination with the embodiments, but the present application is not limited to these embodiments.

[0039] The reagents, methods and equipment used in the present application are all conventional reagents, methods and equipment in the technical field unless otherwise specified.

[0040] Example 1

[0041] This example provides a 6-series aluminum alloy, the component content of which is shown in Table 1, and the preparation steps are as follows:

[0042] After accurately proportioning each raw material, the raw materials are melted in a furnace, the melting temperature is 750℃, and refining and degassing and deslagging are performed therebetween to ensure the purity of the melt;

[0043] The refined melt is removed of residual slag through a filtering system, and then the alloy round casting bar is obtained by casting, and the casting temperature is 700℃;

[0044] S1, the alloy round casting bar obtained above is heated in a homogenizing furnace at 520℃, and the homogenization treatment is performed for 10h, and after homogenization, the casting bar is water-cooled to room temperature;

[0045] The alloy aluminum bar obtained by homogenization treatment is extruded; the heating temperature of the aluminum bar is 530℃, the preheating temperature of the mold is 490℃, the temperature of the extruded profile at the discharge port is 550℃, and the quenching method is water immersion cooling;

[0046] S2, the extruded profile after online quenching is sawn into a fixed-length material according to the specified length, and is subjected to a first artificial aging at a temperature of 180℃ for 5h;

[0047] The short fixed-length material after the first artificial aging is cold-drawn by a drawing machine, and is cold-worked according to a drawing amount of 5% of the length of the fixed-length material;

[0048] The fixed-length material after the first deformation is subjected to a second artificial aging at a temperature of 125℃ for 20h;

[0049] The material after the second artificial aging is cold-drawn again by the drawing machine, and the drawing amount is 3% of the total length of the material, and a 6-series aluminum alloy is obtained.

[0050] Table 1

[0051]

[0052]

[0053] Example 2

[0054] The example provides a 6 series aluminum alloy, the component dosage is the same as that of example 1, and the preparation steps are as follows:

[0055] After the accurate proportioning of each raw material, the raw material is melted in a furnace, the smelting temperature is 750 DEG C, and refining and degassing and deslagging are carried out in the process, so as to ensure the purity of the melt;

[0056] The refined melt is removed from the residual slag through a filtering system, and then an alloy round casting rod is obtained by casting at a casting temperature of 700 DEG C;

[0057] S1, the alloy round casting rod obtained above is heated in a homogenizing furnace at 520 DEG C, the holding time is 10h for homogenization treatment, and the casting rod is sprayed and cooled to room temperature after homogenization;

[0058] The alloy aluminum rod obtained by homogenization treatment is extruded; the heating temperature of the aluminum rod is 530 DEG C, the preheating temperature of the mold is 490 DEG C, the temperature of the extruded profile discharge port is 550 DEG C, and the quenching method is water immersion cooling;

[0059] S2, the extruded profile after online quenching is sawn into a fixed-length material according to the specified length, and is subjected to one-time artificial aging at a temperature of 180 DEG C for 2h;

[0060] The short fixed-length material after one-time artificial aging is cold-drawn by a drawing machine, and is cold-worked according to a drawing amount of 5% of the length of the fixed-length material;

[0061] The fixed-length material after one deformation is subjected to two-time artificial aging at a temperature of 125 DEG C for 20h;

[0062] The material after two-time artificial aging is cold-drawn again by the drawing machine, the drawing amount is 3% of the total length of the material, and a 6 series aluminum alloy is obtained.

[0063] Example 3

[0064] The example provides a 6 series aluminum alloy, the component dosage is the same as that of example 1, and the preparation steps are as follows:

[0065] After the accurate proportioning of each raw material, the raw material is melted in a furnace, the smelting temperature is 750 DEG C, and refining and degassing and deslagging are carried out in the process, so as to ensure the purity of the melt;

[0066] The refined melt is removed from the residual slag through a filtering system, and then an alloy round casting rod is obtained by casting at a casting temperature of 700 DEG C;

[0067] S1, the alloy round casting rod obtained above is heated in a homogenizing furnace at 520 DEG C, the holding time is 10h for homogenization treatment, and the casting rod is sprayed and cooled to room temperature after homogenization;

[0068] The alloy aluminum rod obtained by homogenization treatment is extruded into a shape; the heating temperature of the aluminum rod is 530°C, the preheating temperature of the mold is 490°C, the outlet temperature of the extruded profile is 550°C, and the quenching method is immersion cooling;

[0069] S2. Cut the extruded profiles that have undergone online quenching into fixed-length materials according to the specified length, and perform artificial aging at a temperature of 180°C for 5 hours;

[0070] The short length material that has undergone one artificial aging is cold stretched and deformed by a stretching machine, and cold worked according to a stretching amount of 10% of the length of the length material;

[0071] The fixed-length material after the primary deformation is subjected to secondary artificial aging at a temperature of 125°C for 20 hours;

[0072] After the second artificial aging, the material is again cold stretched by a stretching machine, with the stretching amount being 3% of the total length of the material, to obtain a 6 series aluminum alloy.

[0073] Example 4

[0074] This example provides a 6 series aluminum alloy, the components and amounts of which are the same as those in Example 1, and the preparation steps are as follows:

[0075] After the raw materials are accurately proportioned, they are melted in a furnace at a melting temperature of 750°C. During this process, refining, degassing and deslagging are carried out to ensure the purity of the melt.

[0076] The refined melt is filtered to remove residual slag and then cast into alloy round bars at a casting temperature of 700°C.

[0077] S1. The alloy round cast rod obtained above was heated in a homogenizing furnace at 520° C. for 10 h for homogenization treatment. After homogenization, the cast rod was sprayed with water and cooled to room temperature;

[0078] The alloy aluminum rod obtained by homogenization treatment is extruded into a shape; the heating temperature of the aluminum rod is 530°C, the preheating temperature of the mold is 490°C, the outlet temperature of the extruded profile is 550°C, and the quenching method is immersion cooling;

[0079] S2. Cut the extruded profiles that have undergone online quenching into fixed-length materials according to the specified length, and perform artificial aging at a temperature of 145°C for 5 hours;

[0080] The short length material that has undergone one artificial aging is cold stretched and deformed by a stretching machine, and cold worked according to a stretching amount of 10% of the length of the length material;

[0081] The fixed-length material after the primary deformation is subjected to secondary artificial aging at a temperature of 125°C for 20 hours;

[0082] After the secondary artificial aging, the material is cold-drawn again by the drawing machine, and the drawing amount is 3% of the total length of the material, to obtain the 6 series aluminum alloy.

[0083] Example 5

[0084] This example provides a 6 series aluminum alloy, which has the same component amount as that of Example 1, and the preparation steps are as follows:

[0085] After the accurate proportioning of each raw material, the raw material is melted in a furnace, and the smelting temperature is 750°C. During this process, refining and degassing and deslagging are performed to ensure the purity of the melt.

[0086] The refined melt is removed of residual slag through a filtering system, and then an alloy round casting bar is obtained by casting at a casting temperature of 700°C.

[0087] S1, the alloy round casting bar obtained above is heated in a homogenizing furnace at 520°C, and the homogenization treatment is performed for 10h, and after homogenization, the casting bar is cooled to room temperature by water spraying;

[0088] The alloy aluminum bar obtained by homogenization treatment is extruded; the heating temperature of the aluminum bar is 530°C, the preheating temperature of the mold is 490°C, the temperature of the extruded profile at the discharge port is 550°C, and the quenching method is water immersion cooling;

[0089] S2, the extruded profile after online quenching is sawn into a fixed-length material according to the specified length, and the first artificial aging is performed at a temperature of 145°C for 5h;

[0090] The short fixed-length material after the first artificial aging is cold-drawn by a drawing machine, and the cold working is performed according to a drawing amount of 10% of the length of the fixed-length material;

[0091] The fixed-length material after the first deformation is subjected to the second artificial aging at a temperature of 175°C for 20h;

[0092] After the secondary artificial aging, the material is cold-drawn again by the drawing machine, and the drawing amount is 3% of the total length of the material, to obtain the 6 series aluminum alloy.

[0093] Example 6

[0094] This example provides a 6 series aluminum alloy, which has the same component amount as that of Example 1, and the preparation steps are as follows:

[0095] After the accurate proportioning of each raw material, the raw material is melted in a furnace, and the smelting temperature is 750°C. During this process, refining and degassing and deslagging are performed to ensure the purity of the melt.

[0096] The refined melt is removed of residual slag through a filtering system, and then an alloy round casting bar is obtained by casting at a casting temperature of 700°C.

[0097] S1, the obtained alloy round casting bar is heated at 520°C in a homogenizing furnace, and the holding time is 10 h for homogenization treatment. After homogenization, the casting bar is cooled to room temperature by water spraying;

[0098] The alloy aluminum bar obtained by homogenization treatment is extruded. The heating temperature of the aluminum bar is 530°C, the preheating temperature of the mold is 490°C, the temperature of the extruded profile at the discharge port is 550°C, and the quenching method is water immersion cooling;

[0099] S2, the extruded profile after online quenching is sawn into a fixed-size material according to the specified length, and is subjected to a first artificial aging at a temperature of 145°C for 5 h;

[0100] The short fixed-size material after the first artificial aging is cold stretched by a stretching machine, and is cold worked according to a stretching amount of 10% of the length of the fixed-size material;

[0101] The fixed-size material after the first deformation is subjected to a second artificial aging at a temperature of 175°C for 10 h;

[0102] The material after the second artificial aging is cold stretched again by the stretching machine, and the stretching amount is 3% of the total length of the material, to obtain the 6-series aluminum alloy.

[0103] Comparative Example 1

[0104] This example provides a 6-series aluminum alloy, which has the same component amount as Example 1, and the preparation method is as follows:

[0105] After the raw materials are accurately proportioned, they are melted in a melting furnace at a melting temperature of 750°C. During the melting, refining and degassing and deslagging are performed to ensure the purity of the melt.

[0106] The refined melt is filtered to remove residual slag, and then an alloy round casting bar is obtained by casting at a casting temperature of 700°C.

[0107] S3, the obtained aluminum bar is heated at 520°C in a homogenizing furnace, and the holding time is 10 h for homogenization treatment. After homogenization, the casting bar is cooled to room temperature by water spraying;

[0108] S4, the alloy aluminum bar obtained by homogenization treatment is extruded. The heating temperature of the aluminum bar is 530°C, the preheating temperature of the mold is 490°C, the temperature of the extruded profile at the discharge port is 550°C, and the quenching method is water immersion cooling;

[0109] S5, the extruded material is subjected to aging heat treatment, and the aging system is single-stage aging at a temperature of 180°C for 12 h, to obtain the above-mentioned aluminum alloy.

[0110] Comparative Example 2

[0111] The example provides a 6 series aluminum alloy, the component dosage is the same as that of example 1, and the preparation method is as follows:

[0112] S1, after the raw materials are accurately proportioned, melting is carried out in a melting furnace, the smelting temperature is 750 DEG C, and refining and degassing and deslagging are carried out in the process, so as to ensure the purity of the melt;

[0113] S2, the residual slag in the refined melt is removed through a filtering system, and then an alloy round casting rod is obtained by casting, and the casting temperature is 700 DEG C;

[0114] S3, the aluminum rod obtained above is heated in a homogenizing furnace at 520 DEG C, and the holding time is 10h for homogenization treatment, and the casting rod is sprayed and cooled to room temperature after homogenization;

[0115] S4, the alloy aluminum rod obtained by homogenization treatment is extruded. The heating temperature of the aluminum rod is 530 DEG C, the preheating temperature of the mold is 490 DEG C, the temperature of the extruded profile discharge port is 550 DEG C, and the quenching method is water immersion cooling;

[0116] S5, the extruded profile after online quenching is sawn into a fixed-size material according to the specified length, and is subjected to aging heat treatment, and the aging system is single-stage aging, the aging temperature is 180 DEG C, and the holding time is 12h;

[0117] S6, the fixed-size material after aging is deformed by cold stretching through a stretching machine, and is cold worked according to the stretching amount of 5% of the length of the fixed-size material, to obtain the above-mentioned aluminum alloy.

[0118] Comparative example 3

[0119] The example provides a 6 series aluminum alloy, the component dosage is the same as that of example 1, and the preparation method is as follows:

[0120] S1, after the raw materials are accurately proportioned, melting is carried out in a melting furnace, the smelting temperature is 750 DEG C, and refining and degassing and deslagging are carried out in the process, so as to ensure the purity of the melt;

[0121] S2, the residual slag in the refined melt is removed through a filtering system, and then an alloy round casting rod is obtained by casting, and the casting temperature is 700 DEG C;

[0122] S3, the aluminum rod obtained above is heated in a homogenizing furnace at 520 DEG C, and the holding time is 10h for homogenization treatment, and the casting rod is sprayed and cooled to room temperature after homogenization;

[0123] S4, the alloy aluminum rod obtained by homogenization treatment is extruded. The heating temperature of the aluminum rod is 530 DEG C, the preheating temperature of the mold is 490 DEG C, the temperature of the extruded profile discharge port is 550 DEG C, and the quenching method is water immersion cooling;

[0124] S5, the extruded profile after on-line quenching is sawed into a fixed-size material according to a specified length, and is cold-drawn by a drawing machine, and is cold-worked according to a drawing amount of 10% of the length of the fixed-size material;

[0125] S6, the fixed-size material after cold deformation is subjected to aging heat treatment at a temperature of 180 DEG C for 12h to obtain the above-mentioned aluminum alloy.

[0126] Performance test

[0127] The 6-series aluminum alloys prepared in Examples 1-6 and Comparative Examples 1-3 are characterized, Figure 1 The grain structures of the 6-series aluminum alloys prepared in Examples 1-6 and Comparative Examples 1-3 are shown in Figs. 1-6, wherein, Figure 1 (a), (b), (c), (d), (e), (f) in Fig. 1 correspond to the grain structures of Examples 1, 2, 3, 4, 5, and 6, respectively, Figure 1 (g), (h), (i) in Fig. 1 correspond to the grain structures of Comparative Examples 1, 2, and 3, respectively.

[0128] As can be seen from Fig. 1, Figure 1 it can be seen that the grain structures of the 6-series aluminum alloys prepared in Examples 1-6 and Comparative Examples 1-3 are all uniform distribution of recrystallized equiaxed grains.

[0129] Figure 2 The digital photos of the anodizing effects of the aluminum alloys prepared in Examples 1-6 and Comparative Examples 1-3 are shown in Figs. 7-12, wherein, Figure 2 (a), (b), (c), (d), (e), (f) in Fig. 7 correspond to the digital photos of the anodizing effects of Examples 1, 2, 3, 4, 5, and 6, respectively, Figure 2 (g), (h), (i) in Fig. 7 correspond to the anodizing effects of Comparative Examples 1, 2, and 3, respectively.

[0130] As can be seen from Fig. 7, Figure 2 it can be seen that the 6-series aluminum alloys prepared in Examples 1-6 have a bright and transparent luster after anodizing, and have no appearance defects.

[0131] (g) as the anodizing effect of Comparative Example 1, it is observed that the surface has a bright and transparent luster after anodizing, and has no appearance defects; (h) as the anodizing effect of Comparative Example 2, it is observed that the surface has a significant tingling phenomenon. (i) as the anodizing effect of Comparative Example 3, it is observed that the surface has a slight tingling phenomenon, which does not meet the appearance requirements of 3C product shells.

[0132] Further, the 6-series aluminum alloys prepared in Examples 1-6 and Comparative Examples 1-3 of the present application are subjected to mechanical property testing, and the mechanical properties of the alloys are tested according to GB / T 228.1-2010 Metallic Materials-Tensile Testing-Part 1: Method of Test at Room Temperature.

[0133] The tensile specimens are sampled along the extrusion direction, with a size of 200*20 mm, and are turned into A50 specimens. The tensile test is performed on a LEGEND 2382 universal testing machine, with an original gauge length of 50 mm and a tensile speed of 2 mm / min. The results are shown in Table 2.

[0134] Table 2 Examples 1-6 and Comparative Examples 1-3

[0135] Test sample Tensile strength (MPa) Yield strength (MPa) Elongation (%) Example 1 447 440 7.8 Example 2 455 455 5.2 Example 3 473 472 1.7 Example 4 468 466 2.5 Example 5 467 461 5.7 Example 6 463 461 3.4 Comparative Example 1 406 403 8.6 Comparative Example 2 425 424 3.2 Comparative Example 3 418 411 7.7

[0136] As can be seen from Table 2, the 6-series aluminum alloys of Examples 1-6 of the present application have excellent comprehensive mechanical properties compared with Comparative Examples 1-3.

[0137] The above is a detailed description of the present application in combination with the examples, but the present application is not limited to the above examples, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present application.

Claims

1. A method for preparing a 6 series aluminum alloy, characterized in that: The steps include: S1, subjecting a 6 series aluminum alloy ingot to homogenization annealing, extrusion, and online quenching to obtain an extruded profile; S2, subjecting the extruded profile to primary artificial aging, primary deformation, secondary artificial aging, and secondary deformation in sequence.

2. The preparation method according to claim 1, characterized in that In step S2, the temperature of the primary artificial aging is 120°C to 180°C.

3. The preparation method according to claim 1, characterized in that In step S2, the temperature of the secondary artificial aging is 125°C to 185°C.

4. The preparation method according to claim 1, characterized in that In step S2, the stretching amount of the primary deformation is 2% to 10%.

5. The preparation method according to claim 1, characterized in that In step S2, the stretching amount of the secondary deformation is 1% to 5%.

6. The preparation method according to claim 1, characterized in that The 6 series aluminum alloy includes the following components calculated by mass percentage: Mg: 0.5%~1.5%; Si: 0.45%~1.2%; Cu: 0.4%~1.1%; Fe≤0.15%; Mn≤0.15%; Zr≤0.10%; Zn≤0.10%; Ti≤0.10%; the balance is Al.

7. The preparation method according to claim 1, characterized in that The homogenization annealing temperature is 520-580° C., and the heat preservation time is 10 hours-25 hours.

8. A 6 series aluminum alloy, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 7.

9. The 6 series aluminum alloy according to claim 8, characterized in that The yield strength of the 6 series aluminum alloy is ≥440 MPa.

10. Use of the 6 series aluminum alloy according to claim 8 in the preparation of 3C electronic products and automobile products.

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