An aluminum alloy, a method for preparing the same, and use thereof in the manufacture of hardware products

Abstract

The application relates to the technical field of aluminum alloys, in particular to an aluminum alloy, a preparation method thereof and application of the aluminum alloy in preparation of hardware products. The aluminum alloy comprises the following chemical elements in percentage by mass: Si, 0.45-0.80%; Cu, 0.08-0.85%; Zn, 5.0-6.0%; Mg, 1.8-2.2%; Cr, 0.05-0.15%; Mn, 0.01-0.25%; Ti, 0.15-0.6%; rare earth elements, 0.03-0.05%; and the balance of Al and inevitable impurities. The aluminum alloy provided by the application has good strength and toughness by optimizing the components and contents and exerting the mutual synergistic effect of the components to improve the tensile strength, yield strength, Vickers hardness and elongation of the aluminum alloy.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy technology, and in particular to an aluminum alloy, its preparation method, and its application in the preparation of hardware products. Background Technology

[0002] With the rapid development of science and technology and the industrial economy in recent years, the demand for aluminum alloys has been increasing, leading to a gradual expansion of their application fields. Aluminum alloys are now widely used in 3C electronic devices and automotive parts. However, in fields such as aviation and aerospace, the strength and toughness of aluminum alloys are relatively poor, making it difficult to meet their application requirements and further limiting their use. Summary of the Invention

[0003] This invention provides an aluminum alloy, its preparation method, and its application in the manufacture of hardware products. The aluminum alloy has good strength and toughness, making its application more widespread.

[0004] The first aspect of this invention provides an aluminum alloy comprising, by mass percentage, the following chemical elements:

[0005] Si, 0.45%–0.80%;

[0006] Cu, 0.08%–0.85%;

[0007] Zn, 5.0%–6.0%;

[0008] Mg, 1.8%–2.2%;

[0009] Cr, 0.05%–0.15%;

[0010] Mn, 0.01%–0.25%;

[0011] Ti, 0.15%–0.6%;

[0012] Rare earth elements, 0.03% to 0.05%;

[0013] The balance consists of Al and unavoidable impurities.

[0014] In some embodiments of the present invention, the following chemical elements are included, by mass percentage:

[0015] Si, 0.55%–0.7%;

[0016] Cu, 0.10%–0.53%;

[0017] Zn, 5.2%–5.8%;

[0018] Mg, 1.8%–2.0%;

[0019] Cr, 0.08%–0.12%;

[0020] Mn, 0.06%–0.20%;

[0021] Ti, 0.2%–0.5%;

[0022] Rare earth elements, 0.035% to 0.045%;

[0023] The balance consists of Al and unavoidable impurities.

[0024] In some embodiments of the present invention, rare earth elements include yttrium and / or scandium.

[0025] In some embodiments of the present invention, the following chemical elements are also included, by mass percentage:

[0026] Zr, 0.05%–0.1%;

[0027] Sr, 0.01%–0.08%.

[0028] In some embodiments of the present invention, the following chemical elements are also included, by mass percentage:

[0029] Zr, 0.06%–0.09%;

[0030] Sr, 0.03%–0.07%.

[0031] In some embodiments of the present invention, the aluminum alloy includes precipitates having an average grain size of less than 60 μm.

[0032] In some embodiments of the present invention, the aluminum alloy satisfies any one or more of the following conditions:

[0033] (I) Yield strength σs≥430MPa;

[0034] (II) Tensile strength σb≥450MPa;

[0035] (III) Vickers hardness ≥ 150 HV;

[0036] (Ⅳ) Elongation δ≥13%.

[0037] The second aspect of the present invention provides a method for preparing the aluminum alloy described in any embodiment of the first aspect of the present invention, comprising:

[0038] The melting process involves heating and melting the raw material of the aluminum alloy and stirring it evenly to obtain an aluminum alloy melt.

[0039] In the refining process, under a protective atmosphere, the aluminum alloy melt is mixed with a refining agent and refined to remove gas and impurities, thereby obtaining a refined aluminum alloy melt.

[0040] In the casting process, the refined aluminum alloy melt is die-cast in a vacuum mold to obtain an ingot.

[0041] The heat treatment process involves solution heat treatment of the ingot to obtain the heat-treated ingot.

[0042] The aging process involves extruding and aging the heat-treated ingot to obtain an aluminum alloy. The aluminum alloy comprises, by mass percentage, the following chemical elements: Si, 0.45%–0.80%; Cu, 0.08%–0.85%; Zn, 5.0%–6.0%; Mg, 1.8%–2.2%; Cr, 0.05%–0.15%; Mn, 0.01%–0.25%; Ti, 0.15%–0.6%; rare earth elements, 0.03%–0.05%; the balance being Al and unavoidable impurities.

[0043] In some embodiments of the present invention, the heating and melting temperature in the melting process is 700°C to 850°C.

[0044] In some embodiments of the present invention, the die-casting process satisfies at least one of the following conditions:

[0045] (I) The temperature is 600℃~550℃;

[0046] (II) The temperature of the vacuum mold is 250℃~300℃.

[0047] The third aspect of the present invention provides the application of the aluminum alloy described in any embodiment of the first aspect of the present invention or the aluminum alloy prepared by the preparation method described in any embodiment of the second aspect of the present invention in the preparation of hardware products.

[0048] The aluminum alloy, its preparation method, and its application in the preparation of hardware products provided by this invention improve the tensile strength, yield strength, Vickers hardness, and elongation of the aluminum alloy by optimizing its components and their content and leveraging their synergistic effects, thus giving the aluminum alloy good strength and toughness.

[0049] The above description is merely an overview of the technical solution in this specification. In order to better understand the technical means in this specification and to implement it in accordance with the contents of this specification, and to make the above and other objects, features and advantages of this specification more apparent and understandable, specific embodiments of this specification are given below. Detailed Implementation

[0050] Unless otherwise stated, the terminology used in this invention has the common meaning as generally understood by those skilled in the art.

[0051] Unless otherwise stated, the values ​​of the parameters mentioned in this invention can be determined using various testing methods commonly used in the art, for example, according to the testing methods given in the embodiments of this invention.

[0052] The first aspect of this invention provides an aluminum alloy comprising, by mass percentage, the following chemical elements:

[0053] Si, 0.45%–0.80%;

[0054] Cu, 0.08%–0.85%;

[0055] Zn, 5.0%–6.0%;

[0056] Mg, 1.8%–2.2%;

[0057] Cr, 0.05%–0.15%;

[0058] Mn, 0.01%–0.25%;

[0059] Ti, 0.15%–0.6%;

[0060] Rare earth elements, 0.03% to 0.05%;

[0061] The balance consists of Al and unavoidable impurities.

[0062] In some embodiments of the present invention, the following chemical elements are included, by mass percentage:

[0063] Si, 0.55%–0.7%;

[0064] Cu, 0.10%–0.53%;

[0065] Zn, 5.2%–5.8%;

[0066] Mg, 1.8%–2.0%;

[0067] Cr, 0.08%–0.12%;

[0068] Mn, 0.06%–0.20%;

[0069] Ti, 0.2%–0.5%;

[0070] Rare earth elements, 0.035% to 0.045%;

[0071] The balance consists of Al and unavoidable impurities.

[0072] The aluminum alloy provided by this invention improves the tensile strength, yield strength, Vickers hardness and elongation of the aluminum alloy by optimizing the composition and its content and giving full play to their synergistic effect, thus giving the aluminum alloy good strength and toughness.

[0073] The following is a detailed introduction to the chemical elements contained in aluminum alloys and their contents.

[0074] (Si: 0.45%–0.80%)

[0075] When the silicon (Si) content is within a suitable range, it can improve the fluidity of the alloy melt and also enhance the strength of the aluminum alloy. Therefore, in the technical solution of this invention, the silicon content is set in the range of 0.45% to 0.80%.

[0076] For example, the content of Si element may be, but is not limited to, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.6%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.7%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, or a range of any two of the above values.

[0077] (Cu: 0.08%–0.85%)

[0078] When the Cu content is within a suitable range, it not only readily accumulates on the surface of the workpiece during heating to form a dense oxide layer (i.e., CuO layer), but also helps to strengthen the aluminum alloy through solid solution treatment. This further enhances the aluminum alloy's resistance to high-temperature oxidation and its overall strength. Therefore, in the technical solution of this invention, the Cu content is set within the range of 0.08% to 0.85%.

[0079] For example, the content of Cu element may be, but is not limited to, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0. 33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.4%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.50%, 0.51%, 0.52%, 0.53%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, or a range of values ​​consisting of any two of the above.

[0080] (Zn: 5.0%–6.0%) and (Mg: 1.8%–2.2%)

[0081] When Zn and Mg are within a suitable range, they can work synergistically to improve the tensile strength, hardness and fluidity of the workpiece. Therefore, in the technical solution of the present invention, the Zn element content is set in the range of 5.0% to 6.0%, and the Mg element content is set in the range of 1.8% to 2.2%.

[0082] For example, the Zn content may be, but is not limited to, 5.0%, 5.1%, 5.2%, 5.22%, 5.24%, 5.26%, 5.28%, 5.3%, 5.32%, 5.34%, 5.36%, 5.38%, 5.4%, 5.42%, 5.44%, 5.46%, 5.48%, 5.5%, 5.52%, 5.54%, 5.56%, 5.58%, 5.6%, 5.62%, 5.64%, 5.66%, 5.68%, 5.7%, 5.72%, 5.74%, 5.76%, 5.78%, 5.8%, 5.9%, 6.0%, or a range of any two of the above values.

[0083] For example, the content of Mg element may be, but is not limited to, 1.8%, 1.82%, 1.84%, 1.86%, 1.88%, 1.9%, 1.92%, 1.94%, 1.96%, 1.98%, 2%, 2.1%, 2.2% or any combination of two of the above values.

[0084] (Cr: 0.05%–0.15%)

[0085] When the chromium content is within a suitable range, it can improve the strength, toughness and corrosion resistance of aluminum alloys. Therefore, in the technical solution of this invention, the chromium content is set in the range of 0.05% to 0.15%.

[0086] For example, the Cr content may be, but is not limited to, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, or any combination of two of the above values.

[0087] (Mn: 0.01%~0.25%)

[0088] Within a suitable range, manganese (Mn) can improve the strength and elongation of aluminum alloys. Therefore, in the technical solution of this invention, the manganese content is set in the range of 0.01% to 0.25%.

[0089] For example, the content of Mn element may be, but is not limited to, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, or any combination of two of the above values.

[0090] (Ti: 0.15%~0.6%)

[0091] Within a suitable range, titanium (Ti) can refine the grain size and improve the elongation of aluminum alloys. Therefore, in the technical solution of this invention, the titanium content is set in the range of 0.15% to 0.6%.

[0092] For example, the content of element Ti can be, but is not limited to, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, or a range of any two of the above values.

[0093] Rare earth elements (0.03%–0.05%)

[0094] Rare earth elements, when within a suitable range, can help improve the strength and toughness of aluminum alloys. Therefore, in the technical solution of this invention, the rare earth element content is set in the range of 0.03% to 0.05%.

[0095] In some embodiments, rare earth elements include yttrium and / or scandium.

[0096] For example, the content of rare earth elements may be, but is not limited to, 0.03%, 0.031%, 0.032%, 0.033%, 0.034%, 0.035%, 0.036%, 0.037%, 0.038%, 0.039%, 0.04%, 0.041%, 0.042%, 0.043%, 0.044%, 0.045%, 0.046%, 0.047%, 0.048%, 0.049%, 0.05%, or any combination of two of the above values.

[0097] (Zr: 0.05% ~ 0.1%) and (Sr: 0.01% ~ 0.08%).

[0098] Within appropriate ranges, Zr and Sr elements can refine the texture of materials, resulting in more uniform grain structure and higher gloss. This not only improves the aesthetics of the material but also enhances its corrosion resistance and toughness. Therefore, in the technical solution of this invention, the zirconium content is set within the range of 0.05% to 0.1%, and the strontium content is set within the range of 0.01% to 0.08%.

[0099] For example, the Zr content may be, but is not limited to, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, or any combination of two of the above values.

[0100] For example, the content of Sr element may be, but is not limited to, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, or any combination of two of the above values.

[0101] In some embodiments of the present invention, the aluminum alloy includes precipitates with an average grain size of less than 60 μm.

[0102] In some embodiments of the present invention, the aluminum alloy satisfies any one or more of the following conditions:

[0103] (I) Yield strength σs≥430MPa;

[0104] (II) Tensile strength σb≥450MPa;

[0105] (III) Vickers hardness ≥ 150 HV;

[0106] (Ⅳ) Elongation δ≥13%.

[0107] The second aspect of the present invention provides a method for preparing the aluminum alloy described in any embodiment of the first aspect of the present invention, comprising:

[0108] S100, Melting process: The aluminum alloy raw material is heated and melted and stirred evenly to obtain aluminum alloy melt;

[0109] S200, refining process: Under a protective atmosphere, the aluminum alloy melt is mixed with a refining agent and refined to remove gas and impurities, resulting in a refined aluminum alloy melt.

[0110] S300, Casting process: The refined aluminum alloy melt is die-cast in a vacuum mold to obtain an ingot;

[0111] S400, heat treatment process, the ingot is subjected to solution heat treatment to obtain the heat-treated ingot;

[0112] S500, aging process: The heat-treated ingot is subjected to extrusion aging treatment to obtain an aluminum alloy, wherein the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.45%–0.80%; Cu, 0.08%–0.85%; Zn, 5.0%–6.0%; Mg, 1.8%–2.2%; Cr, 0.05%–0.15%; Mn, 0.01%–0.25%; Ti, 0.15%–0.6%; rare earth elements, 0.03%–0.05%; the balance being Al and unavoidable impurities.

[0113] In some embodiments of the present invention, the heating and melting temperature in the melting process is 700°C to 850°C.

[0114] In some embodiments of the present invention, the die-casting process satisfies at least one of the following conditions:

[0115] (I) The temperature is 600℃~650℃;

[0116] (II) The temperature of the vacuum mold is 250℃~300℃.

[0117] The third aspect of the present invention provides the application of the aluminum alloy described in any embodiment of the first aspect of the present invention or the aluminum alloy prepared by the preparation method described in any embodiment of the second aspect of the present invention in the preparation of hardware products.

[0118] The following describes embodiments of the present invention. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0119] Example 1

[0120] This embodiment provides a method for preparing an aluminum alloy, including:

[0121] Pure aluminum ingots, aluminum-silicon alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-titanium alloys, magnesium ingots, aluminum-zinc alloys, and aluminum-chromium alloys are melted in a 740°C furnace, with electromagnetic stirring during the process.

[0122] Nitrogen and a refining agent, consisting of 50% sodium nitrate, 10% graphite powder and 40% sodium chloride, are introduced into the bottom of the smelting furnace. The furnace is degassed for 20 minutes, allowed to stand for 10 minutes, and then slag is removed.

[0123] The refined aluminum alloy melt is die-cast in a vacuum mold to obtain an aluminum alloy ingot. The die-casting temperature is 600℃ and the temperature of the vacuum mold is 250℃.

[0124] An aluminum alloy ingot was subjected to solution heat treatment and aging treatment to obtain an aluminum alloy. The solution heat treatment temperature was 300℃ and the time was 2h; the aging treatment temperature was 150℃ and the time was 10h. The aluminum alloy contained the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Mn, 0.20%; Ti, 0.15%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0125] Example 2

[0126] Pure aluminum ingots, aluminum-silicon alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-titanium alloys, magnesium ingots, aluminum-zinc alloys, and aluminum-chromium alloys are melted in a 750°C furnace, with electromagnetic stirring during the process.

[0127] Nitrogen and a refining agent, consisting of 50% sodium nitrate, 10% graphite powder and 40% sodium chloride, are introduced into the bottom of the smelting furnace. The furnace is degassed for 20 minutes, allowed to stand for 10 minutes, and then slag is removed.

[0128] The refined aluminum alloy melt is die-cast in a vacuum mold to obtain an aluminum alloy ingot. The die-casting temperature is 620℃ and the temperature of the vacuum mold is 280℃.

[0129] An aluminum alloy ingot was subjected to solution heat treatment and aging treatment to obtain an aluminum alloy. The solution heat treatment temperature was 300℃ and the time was 2h; the aging treatment temperature was 150℃ and the time was 10h. The aluminum alloy contained the following chemical elements by mass percentage: Si, 0.60%; Cu, 0.57%; Zn, 5.2%; Mg, 2.1%; Cr, 0.15%; Mn, 0.18%; Ti, 0.2%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0130] Example 3

[0131] The preparation method of this embodiment is similar to that of Example 1, except that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.71%; Cu, 0.61%; Zn, 5.7%; Mg, 1.9%; Cr, 0.10%; Mn, 0.15%; Ti, 0.25%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0132] Example 4

[0133] The preparation method of this embodiment is similar to that of Example 1, except that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.76%; Cu, 0.80%; Zn, 6.0%; Mg, 2.2%; Cr, 0.09%; Mn, 0.25%; Ti, 0.5%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0134] Example 5

[0135] The preparation method of this embodiment is similar to that of Example 1, except that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.80%; Cu, 0.85%; Zn, 5.2%; Mg, 1.8%; Cr, 0.07%; Mn, 0.22%; Ti, 0.21%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0136] Example 6

[0137] This embodiment provides a method for preparing an aluminum alloy, including:

[0138] Pure aluminum ingots, aluminum-silicon alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-strontium alloys, aluminum-zirconium alloys, aluminum-titanium alloys, magnesium ingots, aluminum-zinc alloys, and aluminum-chromium alloys are melted in a 740°C furnace, with electromagnetic stirring during the process.

[0139] Nitrogen and a refining agent, consisting of 50% sodium nitrate, 10% graphite powder and 40% sodium chloride, are introduced into the bottom of the smelting furnace. The furnace is degassed for 20 minutes, allowed to stand for 10 minutes, and then slag is removed.

[0140] The refined aluminum alloy melt is die-cast in a vacuum mold to obtain an aluminum alloy ingot. The die-casting temperature is 600℃ and the temperature of the vacuum mold is 250℃.

[0141] An aluminum alloy ingot was subjected to solution heat treatment and aging treatment to obtain an aluminum alloy. The solution heat treatment temperature was 300℃ and the time was 2h; the aging treatment temperature was 150℃ and the time was 10h. The aluminum alloy contained the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Mn, 0.20%; Ti, 0.18%; Y, 0.03%; Zr, 0.1%; Sr, 0.05%; with the balance being Al and unavoidable impurities.

[0142] Example 7

[0143] This embodiment provides a method for preparing an aluminum alloy, including:

[0144] Pure aluminum ingots, aluminum-silicon alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-strontium alloys, aluminum-zirconium alloys, aluminum-titanium alloys, magnesium ingots, aluminum-zinc alloys, and aluminum-chromium alloys are melted in a 740°C furnace, with electromagnetic stirring during the process.

[0145] Nitrogen and a refining agent, consisting of 50% sodium nitrate, 10% graphite powder and 40% sodium chloride, are introduced into the bottom of the smelting furnace. The furnace is degassed for 20 minutes, allowed to stand for 10 minutes, and then slag is removed.

[0146] The refined aluminum alloy melt is die-cast in a vacuum mold to obtain an aluminum alloy ingot. The die-casting temperature is 600℃ and the temperature of the vacuum mold is 250℃.

[0147] An aluminum alloy ingot was subjected to solution heat treatment and aging treatment to obtain an aluminum alloy. The solution heat treatment temperature was 300℃ and the time was 2h; the aging treatment temperature was 150℃ and the time was 10h. The aluminum alloy contained the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Mn, 0.20%; Ti, 0.18%; Y, 0.05%; Zr, 0.1%; Sr, 0.05%; with the balance being Al and unavoidable impurities.

[0148] Example 8

[0149] This embodiment provides a method for preparing an aluminum alloy, including:

[0150] Pure aluminum ingots, aluminum-silicon alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-strontium alloys, aluminum-zirconium alloys, aluminum-titanium alloys, magnesium ingots, aluminum-zinc alloys, and aluminum-chromium alloys are melted in a 740°C furnace, with electromagnetic stirring during the process.

[0151] Nitrogen and a refining agent, consisting of 50% sodium nitrate, 10% graphite powder and 40% sodium chloride, are introduced into the bottom of the smelting furnace. The furnace is degassed for 20 minutes, allowed to stand for 10 minutes, and then slag is removed.

[0152] The refined aluminum alloy melt is die-cast in a vacuum mold to obtain an aluminum alloy ingot. The die-casting temperature is 600℃ and the temperature of the vacuum mold is 250℃.

[0153] An aluminum alloy ingot was subjected to solution heat treatment and aging treatment to obtain an aluminum alloy. The solution heat treatment temperature was 300℃ and the time was 2h; the aging treatment temperature was 150℃ and the time was 10h. The aluminum alloy contained the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Mn, 0.20%; Ti, 0.18%; Sc, 0.05%; Zr, 0.1%; Sr, 0.05%; with the balance being Al and unavoidable impurities.

[0154] Example 9

[0155] This embodiment provides a method for preparing an aluminum alloy, including:

[0156] Pure aluminum ingots, aluminum-silicon alloys, aluminum-copper alloys, aluminum-manganese alloys, aluminum-strontium alloys, aluminum-zirconium alloys, aluminum-titanium alloys, magnesium ingots, aluminum-zinc alloys, and aluminum-chromium alloys are melted in a 740°C furnace, with electromagnetic stirring during the process.

[0157] Nitrogen and a refining agent, consisting of 50% sodium nitrate, 10% graphite powder and 40% sodium chloride, are introduced into the bottom of the smelting furnace. The furnace is degassed for 20 minutes, allowed to stand for 10 minutes, and then slag is removed.

[0158] The refined aluminum alloy melt is die-cast in a vacuum mold to obtain an aluminum alloy ingot. The die-casting temperature is 600℃ and the temperature of the vacuum mold is 250℃.

[0159] An aluminum alloy ingot was subjected to solution heat treatment and aging treatment to obtain an aluminum alloy. The solution heat treatment temperature was 300℃ and the time was 2h; the aging treatment temperature was 150℃ and the time was 10h. The aluminum alloy contained the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Mn, 0.20%; Ti, 0.18%; Y, 0.03%; Sc, 0.02%; Zr, 0.1%; Sr, 0.05%; with the balance being Al and unavoidable impurities.

[0160] Comparative Example 1

[0161] The difference between this comparative example and Example 1 is that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Mn, 0.20%; Ti, 0.1%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0162] Comparative Example 2

[0163] The difference between this comparative example and Example 1 is that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.4%; Cu, 0.9%; Zn, 7.0%; Mg, 2.5%; Cr, 0.05%; Mn, 0.20%; Ti, 0.65%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0164] Comparative Example 3

[0165] The difference between this comparative example and Example 1 is that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.01%; Mn, 0.20%; Ti, 0.15%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0166] Comparative Example 4

[0167] The difference between this comparative example and Example 1 is that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.18%; Mn, 0.20%; Ti, 0.15%; with the balance being Al and unavoidable impurities.

[0168] Comparative Example 5

[0169] The difference between this comparative example and Example 1 is that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Ti, 0.15%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0170] Comparative Example 6

[0171] The difference between the comparative example and Example 1 is that the aluminum alloy comprises the following chemical elements by mass percentage: Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Mn, 0.3%; Ti, 0.15%; Y, 0.03%; with the balance being Al and unavoidable impurities.

[0172] Comparative Example 7

[0173] Si, 0.55%; Cu, 0.24%; Zn, 5.0%; Mg, 2.0%; Cr, 0.05%; Mn, 0.20%; Ti, 0.15%; balance Al and unavoidable impurities.

[0174] The test results of tensile strength, yield strength, Vickers hardness and elongation of the aluminum alloys in Examples 1-9 and Comparative Examples 1-7 are shown in Table 1.

[0175] Table 1. Test results of aluminum alloys in Examples 1-9 and Comparative Examples 1-7

[0176] Serial Number Tensile strength σb Yield strength σs Vickers hardness Elongation δ Example 1 462MPa 432MPa 159HV 13.2％ Example 2 481MPa 454MPa 165HV 15.4％ Example 3 476MPa 447MPa 161HV 14.1％ Example 4 528MPa 485MPa 184HV 18.7％ Example 5 557MPa 502MPa 197HV 20.9％ Example 6 482MPa 446MPa 160HV 14.5％ Example 7 484MPa 451MPa 168HV 16.4％ Example 8 491MPa 455MPa 170HV 15.0％ Example 9 502MPa 463MPa 176HV 17.3％ Comparative Example 1 404MPa 362MPa 135HV 6.9％ Comparative Example 2 361MPa 301MPa 112HV 9.2％ Comparative Example 3 443MPa 415MPa 142HV 11.2％ Comparative Example 4 438MPa 407MPa 137HV 10.4％ Comparative Example 5 373MPa 332MPa 122HV 7.7％ Comparative Example 6 415MPa 380MPa 129HV 8.5％ Comparative Example 7 411MPa 392MPa 131HV 8.8％

[0177] According to Table 1, Example 1 ～ 9 and Comparative Example 1 ～ The test results of 7 show that the aluminum alloy provided by the present invention improves the tensile strength, yield strength, Vickers hardness and elongation of the aluminum alloy by optimizing the composition and its content and giving full play to their synergistic effect, thus making the aluminum alloy have good strength and toughness.

[0178] A comparison of the tests in Example 1 and Comparative Examples 3-4 shows that when the mass fraction of Cr element is below or above the range of 0.05% to 0.15%, the strength and toughness of the aluminum alloy decrease significantly. Similarly, the test results in Example 1 and Comparative Examples 5-6 show that when the mass fraction of Mn element is below or above the range of 0.01% to 0.25%, the strength and toughness of the aluminum alloy also decrease significantly.

[0179] The test results from Examples 1 and 7 show that as the content of rare earth elements increases, the strength and toughness of the aluminum alloy also increase.

[0180] The test results from Examples 7, 8, and 9 show that adding the same mass content of rare earth elements (Y) to aluminum alloys significantly increases the toughness of the alloy compared to Sc, while Sc increases the strength of the alloy compared to Y. Furthermore, the simultaneous addition of Y and Sc results in significantly higher strength and toughness compared to adding Y and Sc alone.

[0181] Finally, it should be noted that the above experimental examples are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing experimental examples, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing experimental examples, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the experimental examples of the present invention.

Claims

1. An aluminum alloy, characterized in that, The chemical elements included, expressed as a percentage by mass, are as follows: Si, 0.80%; Cu, 0.85%; Zn, 5.2%; Mg, 1.8%; Cr，0.07%； Mn, 0.22%; Ti, 0.21%; Y，0.03%; The balance consists of Al and unavoidable impurities; The aluminum alloy includes precipitates, the average grain size of which is less than 60 μm; the aluminum alloy satisfies the following conditions: (I) Yield strength σs = 502 MPa; (II) Tensile strength σb = 557 MPa; (III) Vickers hardness = 197 HV; (Ⅳ) Elongation δ = 20.9%.

2. A method for preparing the aluminum alloy as described in claim 1, characterized in that, include: The melting process involves heating and melting the raw material of the aluminum alloy and stirring it evenly to obtain an aluminum alloy melt. In the refining process, under a protective atmosphere, the aluminum alloy melt is mixed with a refining agent and refined to remove gas and impurities, thereby obtaining a refined aluminum alloy melt. In the casting process, the refined aluminum alloy melt is die-cast in a vacuum mold to obtain an ingot. The heat treatment process involves solution heat treatment of the ingot to obtain the heat-treated ingot. The aging process involves aging the heat-treated ingot to obtain an aluminum alloy.

3. The preparation method according to claim 2, characterized in that, In the melting process, the heating and melting temperature is 700℃~850℃.

4. The preparation method according to claim 2, characterized in that, The die-casting process satisfies at least one of the following conditions: (I) The temperature is 600℃~550℃; (II) The temperature of the vacuum mold is 250℃~300℃.

5. The application of an aluminum alloy as described in claim 1 or an aluminum alloy prepared by any one of claims 2-4 in the manufacture of hardware products.