6 series aluminum alloy and preparation method thereof

Abstract

The present invention relates to a 6-series aluminum alloy and a preparation method thereof. The 6-series aluminum alloy comprises, by mass percentage, Si: 1.15-1.35%, Cu: 0.30-0.50%, Mn: 0.30-0.60%, Mg: 0.90-1.30%, Cr: 0.15-0.20%, Zn≤0.20%, Ti: 0.05-0.15%, Zr: 0.05-0.10%, Fe≤0.15%, and the balance being Al. The precipitated phases of the 6-series aluminum alloy include Al₅Cu₂Mg₂Si₆ and Mg₂Si, and the total content of Al₅Cu₂Mg₂Si₆ and Mg₂Si in the 6-series aluminum alloy is 2.18-3.30% by mass of the 6-series aluminum alloy. The 6-series aluminum alloy of the present invention has both good anodizing blackening performance and high mechanical strength. After anodizing blackening, defects such as material lines and pitting are not easily formed, thus meeting the requirements of optical products.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloys, and in particular to a 6 series aluminum alloy and a preparation method thereof. Background Art

[0002] 6-series aluminum alloys, with their low density, excellent anodizing and mechanical properties, and high thermal conductivity, have been widely used in optical products. As optical products become thinner and lighter, 6-series aluminum alloys are required to possess not only good anodizing and blackening properties but also higher strength. However, conventional 6-series aluminum alloys (such as grades 6063 and 6061) lack strength to meet the performance requirements of these thinner and lighter products. Therefore, there is an urgent need to develop 6-series aluminum alloys that balance anodizing and mechanical strength.

[0003] It is understood that there are currently two ways to improve the strength of 6-series aluminum alloys. One is to adjust the alloy composition, such as adding a small amount of Fe to refine the grains. Although this improves the strength of the 6-series aluminum alloy to a certain extent, material lines appear after anodizing and blackening, resulting in it not meeting the requirements of optical products. The other is to use second-phase strengthening, such as introducing ceramic particles into the 6-series aluminum alloy. Although the strength is significantly improved, the ceramic particles are prone to agglomeration, and the 6-series aluminum alloy is prone to defects such as pitting after anodizing and blackening, resulting in the anodizing and blackening effect not meeting the requirements of optical products. Obviously, the currently improved 6-series aluminum alloy still cannot achieve the technical effect of taking into account both anodizing and blackening performance and mechanical strength performance. Summary of the Invention

[0004] Based on this, it is necessary to provide a 6 series aluminum alloy and a preparation method thereof to address the above problems; the 6 series aluminum alloy has both good anodizing blackening performance and high mechanical strength, and is not prone to defects such as material lines and pitting after anodizing blackening, and can meet the requirements of optical products.

[0005] A 6 series aluminum alloy, comprising, by mass percentage, Si: 1.15% to 1.35%, Cu: 0.30% to 0.50%, Mn: 0.30% to 0.60%, Mg: 0.90% to 1.30%, Cr: 0.15% to 0.20%, Zn: ≤0.20%, Ti: 0.05% to 0.15%, Zr: 0.05% to 0.10%, Fe: ≤0.15%, and the balance being Al;

[0006] The precipitated phases of the 6 series aluminum alloy include Al5Cu2Mg8Si6 and Mg2Si, and the total content of Al5Cu2Mg8Si6 and Mg2Si in the 6 series aluminum alloy is 2.18% to 3.30% by mass of the 6 series aluminum alloy.

[0007] In one embodiment, in the 6 series aluminum alloy, the content of Al5Cu2Mg8Si6 is 1.80%~2.46%, and the content of Mg2Si is 0.30%~1.20%.

[0008] In one embodiment, in the composition of the 6 series aluminum alloy, the mass ratio of Mg to Si is (0.73~1.10):1.

[0009] In one embodiment, in the composition of the 6 series aluminum alloy, the mass ratio of the sum of the masses of Mg and Si to Cu is (4.60-7.00):1.

[0010] A method for preparing the 6 series aluminum alloy as described above comprises the following steps:

[0011] The aluminum alloy raw materials are melted and refined according to the component formula to form cast rods;

[0012] The cast rod is sequentially subjected to homogenization treatment, extrusion treatment, first quenching treatment, heat treatment and aging treatment to obtain a 6 series aluminum alloy, wherein the cooling intensity of the first quenching treatment is 110°C / s to 150°C / s.

[0013] In one embodiment, the homogenization step satisfies at least one of the following conditions:

[0014] (1) Temperature is 540℃~560℃;

[0015] (2) The insulation time is 8h~12h.

[0016] In one embodiment, the extrusion step satisfies at least one of the following conditions:

[0017] (1) The preheating temperature of the cast rod is 510℃~530℃;

[0018] (2) The temperature of the extrusion device is 400℃~520℃;

[0019] (3) The extrusion speed is 3m / min~4m / min.

[0020] In one embodiment, the heat treatment step satisfies at least one of the following conditions:

[0021] (1) Temperature is 540℃~560℃;

[0022] (2) The insulation time is 1h~3h.

[0023] In one embodiment, the aging treatment step satisfies at least one of the following conditions:

[0024] (1) Temperature is 160℃~190℃;

[0025] (2) Heating time is 1h~2h;

[0026] (3) The insulation time is 8h~12h.

[0027] In one embodiment, after the heat treatment and before the aging treatment, a second quenching treatment is performed, the transfer time of the second quenching treatment is less than or equal to 10s, and the cooling intensity of the second quenching treatment is greater than or equal to 100°C / s.

[0028] The 6 series aluminum alloy described in the present invention has a specific component formula by regulating the element content, and has a specific content of precipitation phases Al5Cu2Mg8Si6 and Mg2Si. It can not only achieve the effect of grain refinement and effectively improve the mechanical strength, but also avoid defects such as material lines and pitting caused by anodizing blackening, so that the oxidation coloring has good uniformity and continuity.

[0029] Therefore, the 6 series aluminum alloy provided by the present invention has both good anodizing blackening performance and high mechanical strength, overcomes the performance defects of traditional 6 series aluminum alloys, can meet the requirements of optical products, and especially can meet the performance requirements of lightweight and thin products. DETAILED DESCRIPTION

[0030] To facilitate understanding of the present invention, the present invention 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. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments or examples only and are not intended to limit the present invention. In the present invention, reference is made to numerical ranges, and unless otherwise specified, the numerical ranges are deemed continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Furthermore, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise indicated, all ranges disclosed herein are understood to include any and all subranges therein.

[0032] The present invention provides a 6 series aluminum alloy. The components of the 6 series aluminum alloy include, by mass percentage, Si: 1.15%-1.35%, Cu: 0.30%-0.50%, Mn: 0.30%-0.60%, Mg: 0.90%-1.30%, Cr: 0.15%-0.20%, Zn: ≤0.20%, Ti: 0.05%-0.15%, Zr: 0.05%-0.10%, Fe: ≤0.15%, and the balance is Al; the precipitated phases of the 6 series aluminum alloy include Al5Cu2Mg8Si6 and Mg2Si, and the total content of Al5Cu2Mg8Si6 and Mg2Si in the 6 series aluminum alloy is 2.18%-3.30% of the mass of the 6 series aluminum alloy.

[0033] The 6 series aluminum alloy described in the present invention has a specific component formula by regulating the element content, and has a specific content of precipitation phases Al5Cu2Mg8Si6 and Mg2Si. It can not only achieve the effect of grain refinement and effectively improve the mechanical strength, but also avoid defects such as material lines and pitting caused by anodizing blackening, so that the oxidation coloring has good uniformity and continuity.

[0034] Therefore, the 6 series aluminum alloy provided by the present invention has both good anodizing blackening performance and high mechanical strength, overcomes the performance defects of traditional 6 series aluminum alloys, can meet the requirements of optical products, and especially can meet the performance requirements of lightweight and thin products.

[0035] By regulating the content of Si and Mg elements in 6 series aluminum alloys, it is beneficial to further promote the formation of Mg2Si phase between Si and Mg elements and avoid defects caused by anodizing blackening.

[0036] It should be noted that, in the 6 series aluminum alloy, the mass percentage of Si includes but is not limited to any value among 1.15%, 1.20%, 1.25%, 1.30%, 1.35% or a range between any two values; the mass percentage of Mg includes but is not limited to any value among 0.90%, 1.00%, 1.10%, 1.20%, 1.30% or a range between any two values.

[0037] In one embodiment of the present invention, in the components of the 6-series aluminum alloy, the mass ratio of Mg to Si is preferably (0.73-1.10):1, more preferably (0.77-1.08):1, which is beneficial to avoid the problem that the solubility of the Mg2Si phase in solid aluminum is reduced due to excess Mg element, resulting in the precipitation of the strengthening phase from the matrix and the appearance of spots after oxidation, thereby further improving the uniformity and continuity of the oxidation coloring.

[0038] By regulating the content of Cu in 6 series aluminum alloys, not only can the mechanical strength of the aluminum alloy be significantly improved, but the Cu in the aluminum alloy will also disperse and precipitate Al2Cu phase and Al2CuMg phase after heat treatment, forming a multi-equilibrium phase system in the aluminum alloy, thereby ensuring the blackening performance of anodizing.

[0039] It should be noted that, in the 6 series aluminum alloy, the mass percentage of Cu includes but is not limited to any value among 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, or a range between any two values.

[0040] Furthermore, by regulating the mass relationship between Cu, Mg and Si, it is beneficial to further optimize the component formula of the 6-series aluminum alloy, so that both the anodizing blackening performance and the mechanical properties can achieve better results. Preferably, in the components of the 6-series aluminum alloy, the mass ratio of the sum of the masses of Mg and Si to Cu is (4.60~7.00):1, and more preferably (4.70~6.50):1.

[0041] By regulating the content of Mn elements in 6 series aluminum alloys, it is not only beneficial to further improve the grain refinement effect, but also to avoid the uneven distribution of Al6Mn phase due to Mn element segregation, which leads to problems such as pitting after anodizing, thereby further improving the uniformity and continuity of oxidation coloring.

[0042] It should be noted that in the 6 series aluminum alloy, the mass percentage of Mn includes but is not limited to any value among 0.30%, 0.35%, 0.40%, 0.45%, 0.50%, 0.55%, and 0.60%, or a range between any two values, and is preferably 0.30% to 0.50%.

[0043] By regulating the Ti element in the 6-series aluminum alloy, it is beneficial to further improve the grain refinement effect while avoiding the formation of Al-Ti based crystalline products and precipitates, so that the 6-series aluminum alloy can take into account both the anodizing blackening performance and the mechanical strength. Preferably, in the 6-series aluminum alloy, the mass percentage of Ti is 0.05%~0.12%.

[0044] By regulating the content of Zr in the 6-series aluminum alloy, the dynamic recrystallization of the aluminum alloy can be suppressed during the extrusion process, and the formation of Al-Zr-based crystalline products and precipitates can be avoided, so that the 6-series aluminum alloy can have both anodizing blackening performance and mechanical properties. Preferably, in the 6-series aluminum alloy, the mass percentage of Zr is 0.06%~0.09%.

[0045] By regulating the content of Fe in the 6 series aluminum alloy, it is beneficial to avoid the formation of AlFeSi or AlFeMnSi phases due to the consumption of Si and Mn elements due to excessive Fe content, thereby further improving the mechanical properties and the uniformity and continuity of oxidation coloring. Preferably, in the 6 series aluminum alloy, the mass percentage of Fe is less than or equal to 0.13%.

[0046] By adjusting the mass ratio of Al5Cu2Mg8Si6 precipitated phase and Mg2Si precipitated phase in 6 series aluminum alloy, it is not only beneficial to further balance the anodizing blackening performance and mechanical properties, but also beneficial to avoid the yellowing appearance of the anodized film caused by the excessive production of red copper oxide during the anodizing process due to excessive Cu element, thereby further improving the uniformity of oxidation coloring. It can be understood that in the 6 series aluminum alloy, the total content of Al5Cu2Mg8Si6 and Mg2Si includes but is not limited to any point value of 2.20%, 2.45%, 2.50%, 2.80%, 3.00%, 3.02%, 3.20%, 3.30% or the range value between any two of them, preferably 2.58%~3.30%.

[0047] In one embodiment of the present invention, in the 6 series aluminum alloy, the content of Al5Cu2Mg8Si6 is preferably 1.80% to 2.46%, including but not limited to any point value of 1.80%, 1.97%, 2.10%, 2.20%, 2.30%, and 2.46%, or a range value between any two of them, and more preferably 1.97% to 2.46%; the content of Mg2Si is preferably 0.30% to 1.20%, including but not limited to any point value of 0.30%, 0.37%, 0.50%, 0.70%, 0.90%, 1.09%, and 1.20%, or a range value between any two of them, and more preferably 0.37% to 1.09%.

[0048] It is understandable that the 6 series aluminum alloy may also contain other precipitated phases, and the present invention does not impose any limitation on this.

[0049] The present invention also provides a method for preparing the 6 series aluminum alloy as described above, comprising the following steps:

[0050] S1, melting and refining the aluminum alloy raw materials according to the component formula to form cast bars;

[0051] S2, sequentially subjecting the cast rod to homogenization treatment, extrusion treatment, first quenching treatment, heat treatment and aging treatment to obtain a 6 series aluminum alloy, wherein the cooling intensity of the first quenching treatment is 110°C / s to 150°C / s.

[0052] The present invention adjusts the cooling intensity of the first quenching treatment to 110°C / s-150°C / s on the basis of controlling the element content, which is beneficial to avoiding problems such as coarse grain defects caused by recrystallization and material lines caused by anodizing, thereby ensuring that the prepared 6 series aluminum alloy can have both good anodizing blackening performance and high mechanical strength.

[0053] In step S1, it can be understood that the component formula includes, by mass percentage, Si: 1.15%~1.35%, Cu: 0.30%~0.50%, Mn: 0.30%~0.60%, Mg: 0.90%~1.30%, Cr: 0.15%~0.20%, Zn: ≤0.20%, Ti: 0.05%~0.15%, Zr: 0.05%~0.10%, Fe: ≤0.15%, and the balance is Al.

[0054] It should be noted that the present invention does not limit the specific process of melting and refining the aluminum alloy raw materials to produce cast rods, and conventional processes can be used. For example, after the aluminum alloy raw materials are melted, the cast rods are produced after stirring, refining, slagging, degassing, filtering, casting and other processes.

[0055] In step S2, homogenization treatment is performed to improve the structural uniformity of the cast rod and reduce the residual internal stress during the continuous casting process.

[0056] In one embodiment of the present invention, the temperature of the homogenization treatment is 540°C~560°C. By regulating the temperature of the homogenization treatment, it is beneficial to fully dissolve the coarse precipitate phase inside the cast rod, thereby increasing the degree of elimination of residual stress, and at the same time avoiding the melting of the low-melting-point precipitate phase in the cast rod, thereby reducing the risk of defects such as holes in the cast rod, thereby improving the overall performance of the extruded rod.

[0057] It should be noted that the temperature of the homogenization treatment includes but is not limited to any value among 540°C, 545°C, 550°C, 555°C, 560°C or any range between any two values.

[0058] In one embodiment of the present invention, the holding time of the homogenization treatment is 8h~12h, including but not limited to any point value among 8h, 9h, 10h, 11h, 12h or any range value between two of them.

[0059] In one embodiment of the present invention, in the extrusion treatment step, the preheating temperature of the cast rod is 510°C~530°C, which is beneficial to reducing the deformation resistance of the cast rod and reducing the difficulty of extrusion treatment. At the same time, it avoids the melting of the low-melting-point precipitated phase in the cast rod during the preheating process, thereby reducing the risk of defects such as holes in the cast rod, and further improving the comprehensive performance of the extruded rod.

[0060] It should be noted that the preheating temperature of the cast rod includes but is not limited to any value among 510°C, 515°C, 520°C, 525°C, and 530°C, or a range between any two of them.

[0061] In one embodiment of the present invention, in the extrusion treatment step, the temperature of the extrusion device is 400°C~520°C. It should be noted that the extrusion device includes an extrusion barrel and an extrusion die. Preferably, the temperature of the extrusion barrel is 400°C~420°C, and the temperature of the extrusion die is 500°C~520°C.

[0062] In one embodiment of the present invention, in the extrusion treatment step, the extrusion speed is 3m / min~4m / min, which is beneficial to avoid problems such as coarse grains caused by recrystallization, ensure the high mechanical strength of the aluminum alloy, and avoid the quality of the aluminum alloy product being reduced due to extrusion cracking on the surface of the cast rod.

[0063] It should be noted that the extrusion speed includes but is not limited to any value among 3 m / min, 3.2 m / min, 3.5 m / min, 3.8 m / min, 4 m / min or any range between any two values.

[0064] In one embodiment of the present invention, after the first quenching treatment, the temperature of the cast rod is reduced to below 50°C.

[0065] In one embodiment of the present invention, the heat treatment temperature is 540° C. to 560° C., which is conducive to the full dissolution of the precipitated phase and the improvement of the solid solution degree, thereby fully exerting the mechanical strength of the aluminum alloy.

[0066] It should be noted that the temperature of the heat treatment includes but is not limited to any value among 540°C, 545°C, 550°C, 555°C, 560°C or any range between any two values.

[0067] In one embodiment of the present invention, the holding time of the heat treatment is 1 hour to 3 hours, including but not limited to any point value among 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, or any range value between two of them.

[0068] In one embodiment of the present invention, the temperature of the aging treatment is 160° C. to 190° C., which is conducive to ensuring that the strengthening phase is fully precipitated and has a smaller size, thereby further improving the mechanical strength of the aluminum alloy.

[0069] It should be noted that the temperature of the aging treatment includes but is not limited to any value among 160°C, 170°C, 180°C, 190°C or any range between them.

[0070] In one embodiment of the present invention, the heating time of the aging treatment is 1 h to 2 h, including but not limited to any point value among 1 h, 1.2 h, 1.5 h, 1.7 h, 2 h, or any range between two values.

[0071] In one embodiment of the present invention, the holding time of the aging treatment is 8h~12h, including but not limited to any point value among 8h, 9h, 10h, 11h, 12h or any range value between two of them.

[0072] In one embodiment of the present invention, a second quenching treatment is performed after the heat treatment and before the aging treatment. The transfer time of the second quenching treatment is less than or equal to 10 seconds, and the cooling intensity of the second quenching treatment is greater than or equal to 100°C / s. Preferably, the time interval between the second quenching treatment and the aging treatment is less than or equal to 4 hours, which is beneficial to improving the degree of solid solution, thereby fully precipitating the strengthening phase in the subsequent aging treatment step, and further improving the mechanical strength of the aluminum alloy.

[0073] The 6 series aluminum alloy and its preparation method will be further described below through the following specific examples. However, those skilled in the art will understand that the following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the present invention. Where specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, for which the manufacturer is not specified, are all commercially available conventional products.

[0074] Example 1

[0075] According to the component formula: Si is 1.15%, Cu is 0.40%, Mn is 0.45%, Mg is 1.00%, Cr is 0.15%, Zn is 0.10%, Ti is 0.10%, Zr is 0.07%, Fe is 0.13% and the balance is Al. The raw materials are melted and then subjected to processes such as stirring, refining, slagging, degassing, filtering and casting to obtain cast rods.

[0076] The cast rods were homogenized at a temperature of 560°C for 8 hours; the homogenized cast rods were preheated to 510°C and then placed in an extruder for extrusion, with an extrusion barrel temperature of 420°C, an extrusion die temperature of 500°C, and a product extrusion speed of 4m / min; after extrusion, the cast rods were cooled to below 50°C by a first quenching with a cooling intensity of 130°C / s; the cooled cast rods were heat treated at a temperature of 560°C for 2 hours, and then quenched in water for a second time with a quenching transfer time of 10s and a cooling intensity of 150°C / s; aging treatment was immediately performed after the second quenching, with the temperature rising to 170°C for 2 hours and being kept for 10 hours to produce a 6 series aluminum alloy.

[0077] Example 2

[0078] According to the component formula: Si is 1.25%, Cu is 0.45%, Mn is 0.50%, Mg is 1.30%, Cr is 0.15%, Zn is 0.10%, Ti is 0.10%, Zr is 0.07%, Fe is 0.13% and the balance is Al. The raw materials are melted and then subjected to processes such as stirring, refining, slagging, degassing, filtering and casting to obtain cast rods.

[0079] The cast rods were homogenized at a temperature of 540°C for 12 hours; the homogenized cast rods were preheated to 530°C and then placed in an extruder for extrusion, with an extrusion barrel temperature of 420°C, an extrusion die temperature of 500°C, and a product extrusion speed of 3m / min; after extrusion, the cast rods were cooled to below 50°C by a first quenching at a cooling intensity of 110°C / s; the cooled cast rods were heat treated at a temperature of 540°C for 2 hours, and then quenched in water for a second time, with a quenching transfer time of 10s and a cooling intensity of 120°C / s; aging treatment was immediately performed after the second quenching, with the temperature rising to 170°C for 2 hours and being kept for 10 hours to produce a 6 series aluminum alloy.

[0080] Example 3

[0081] According to the component formula: Si is 1.23%, Cu is 0.42%, Mn is 0.50%, Mg is 1.20%, Cr is 0.15%, Zn is 0.10%, Ti is 0.10%, Zr is 0.07%, Fe is 0.13% and the balance is Al. The raw materials are melted and then subjected to processes such as stirring, refining, slagging, degassing, filtering and casting to obtain cast rods.

[0082] The cast rods were homogenized at a temperature of 550°C for 12 hours; the homogenized cast rods were preheated to 520°C and then placed in an extruder for extrusion, with an extrusion barrel temperature of 420°C, an extrusion die temperature of 500°C, and a product extrusion speed of 3m / min; after extrusion, the cast rods were cooled to below 50°C by a first quenching at a cooling intensity of 110°C / s; the cooled cast rods were heat treated at a temperature of 550°C for 2 hours, and then quenched in water for a second time, with a quenching transfer time of 10s and a cooling intensity of 150°C / s; aging treatment was immediately performed after the second quenching, with the temperature rising to 170°C for 2 hours and being kept for 10 hours to produce a 6 series aluminum alloy.

[0083] Example 4

[0084] According to the component formula: Si is 1.30%, Cu is 0.50%, Mn is 0.50%, Mg is 1.30%, Cr is 0.18%, Zn is 0.10%, Ti is 0.05%, Zr is 0.09%, Fe is 0.13% and the balance is Al. The raw materials are melted and then subjected to processes such as stirring, refining, slagging, degassing, filtering and casting to obtain cast rods.

[0085] The cast rods were homogenized at a temperature of 540°C for 12 hours; the homogenized cast rods were preheated to 530°C and then placed in an extruder for extrusion, with an extrusion barrel temperature of 400°C, an extrusion die temperature of 520°C, and a product extrusion speed of 3m / min; after extrusion, the cast rods were cooled to below 50°C by a first quenching with a cooling intensity of 110°C / s; the cooled cast rods were heat treated at a temperature of 540°C for 2 hours, and then quenched in water for a second time with a quenching transfer time of 9s and a cooling intensity of 120°C / s; aging treatment was immediately performed after the second quenching, with the temperature rising to 160°C for 2 hours and then being kept for 12 hours to produce a 6 series aluminum alloy.

[0086] Example 5

[0087] The difference between Example 5 and Example 2 is that the Cu content is adjusted to 0.3%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0088] Example 6

[0089] The difference between Example 6 and Example 2 is that the Mg content is adjusted to 0.9%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0090] Example 7

[0091] The difference between Example 7 and Example 2 is that Si is adjusted to 1.15%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0092] Example 8

[0093] The difference between Example 8 and Example 2 is that Si is adjusted to 1.15%, Mg is adjusted to 0.90%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0094] Comparative Example 1

[0095] The difference between Comparative Example 1 and Example 1 is that Si is adjusted to 0.80%, Mg is adjusted to 0.80%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0096] Comparative Example 2

[0097] The difference between Comparative Example 2 and Example 1 is that the Cu content is adjusted to 0.80%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0098] Comparative Example 3

[0099] The difference between Comparative Example 3 and Example 1 is that the Ti content is adjusted to 0.30%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0100] Comparative Example 4

[0101] The difference between Comparative Example 4 and Example 1 is that the Zr content is adjusted to 0.30%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0102] Comparative Example 5

[0103] The difference between Comparative Example 5 and Example 1 is that Fe is adjusted to 0.30%, and the balance of Al is adjusted accordingly, while the formula of other elements remains unchanged.

[0104] The 6 series aluminum alloys prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were characterized, and the results are shown in Table 1.

[0105] Table 1

[0106]

[0107] The 6 series aluminum alloys prepared in all examples and comparative examples and the commercial conventional 6061 aluminum alloy were evaluated for mechanical strength and anodic oxidation blackening performance, and the results are shown in Table 2. The evaluation criteria for anodic oxidation blackening performance are: mainly based on visual inspection, requiring the blackening oxidation effect of the rod to be uniform, without blocky spots, material lines, pitting, and color difference.

[0108] Table 2

[0109]

[0110] According to Tables 1 and 2, the 6-series aluminum alloy provided by the present invention has both good anodizing blackening performance and high mechanical strength, and is not prone to defects such as material lines and pitting after anodizing blackening, and can meet the requirements of optical products.

[0111] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A 6 series aluminum alloy, characterized in that: The components of the 6 series aluminum alloy include Si: 1.15% to 1.35%, Cu: 0.30% to 0.50%, Mn: 0.30% to 0.60%, Mg: 0.90% to 1.30%, Cr: 0.15% to 0.20%, Zn: ≤0.20%, Ti: 0.05% to 0.15%, Zr: 0.06% to 0.09%, Fe: ≤0.15%, and the balance is Al; The precipitated phases of the 6 series aluminum alloy include Al5Cu2Mg8Si6 and Mg2Si, and the total content of Al5Cu2Mg8Si6 and Mg2Si in the 6 series aluminum alloy is 2.18%~3.30% of the mass of the 6 series aluminum alloy, wherein the content of Al5Cu2Mg8Si6 is 1.80%~2.46%, and the content of Mg2Si is 0.30%~1.20%.

2. The 6 series aluminum alloy according to claim 1, characterized in that In the components of the 6 series aluminum alloy, the mass ratio of Mg to Si is (0.73-1.10):

1.

3. The 6 series aluminum alloy according to claim 1 or claim 2, characterized in that: In the components of the 6 series aluminum alloy, the mass ratio of the sum of the masses of Mg and Si to Cu is (4.60-7.00):

1.

4. A method for preparing a 6 series aluminum alloy according to any one of claims 1 to 3, characterized in that: The steps include: The aluminum alloy raw materials are melted and refined according to the component formula to form cast rods; The cast rod is sequentially subjected to homogenization treatment, extrusion treatment, first quenching treatment, heat treatment and aging treatment to obtain a 6 series aluminum alloy, wherein the cooling intensity of the first quenching treatment is 110°C / s to 150°C / s.

5. The method for preparing a 6 series aluminum alloy according to claim 4, wherein: The homogenization step satisfies at least one of the following conditions: (1) Temperature is 540℃~560℃; (2) The insulation time is 8h~12h.

6. The method for preparing a 6 series aluminum alloy according to claim 4, wherein: The step of extrusion treatment satisfies at least one of the following conditions: (1) The preheating temperature of the cast rod is 510℃~530℃; (2) The temperature of the extrusion device is 400℃~520℃; (3) The extrusion speed is 3m / min~4m / min.

7. The method for preparing a 6 series aluminum alloy according to claim 4, wherein: The heat treatment step satisfies at least one of the following conditions: (1) Temperature is 540℃~560℃; (2) The insulation time is 1h~3h.

8. The method for preparing a 6 series aluminum alloy according to claim 4, wherein: The aging treatment step satisfies at least one of the following conditions: (1) Temperature is 160℃~190℃; (2) Heating time is 1h~2h; (3) The insulation time is 8h~12h.

9. The method for preparing a 6 series aluminum alloy according to claim 4, wherein: After the heat treatment and before the aging treatment, a second quenching treatment is performed, the transfer time of the second quenching treatment is less than or equal to 10s, and the cooling intensity of the second quenching treatment is greater than or equal to 100°C / s.

Images