A high-strength and high-toughness alloy material, its preparation method, product and application

Abstract

The present invention provides a high-strength and high-toughness alloy material, its preparation method, product and application, relating to the technical field of alloy materials. The high-strength and high-toughness alloy material, by weight percentage, comprises: Si: 9.7-10.3%, Fe: ≤0.15%, Mn: 0.55-0.65%, Mg: 0.27-0.32%, Ti: 0.05-0.15%, Cu: ≤0.03%, Cr: ≤0.02%, Zn: ≤0.03%, Zr: ≤0.03%, total impurities: ≤0.15% and the balance Al. The alloy material of the present invention has excellent mechanical properties without heat treatment, and also has the advantage of small deformation after heat treatment, and can be used for heat treatment to adjust the yield strength to meet the production requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy materials, and particularly relates to a high-strength and high-toughness alloy material, a preparation method thereof, a product and an application thereof. Background Art

[0002] The integrated die-casting technology specifically reduces the original multiple processes such as stamping and welding, and then injects the molten metal into the mold under high pressure to form a relatively large-sized die-casting part at one time, greatly reducing the assembly process, saving costs and labor.

[0003] Taking the rear floor of the Model 3 vehicle as an example, before the application of the integrated die-casting technology, more than 70 parts need to be stamped in its production process, and then go through 1-2 hours of welding, painting and general assembly manufacturing processes, and further assemble these parts into a chassis rear floor. When it comes to the Model Y vehicle that adopts the integrated die-casting technology, only one part needs to be die-cast, and its production time is only 45 seconds, eliminating the cumbersome process and reducing the cost by about 40%; at the same time, the integrated die-casting technology also has the advantages of reducing weight and space occupation.

[0004] With the application of the integrated die-casting technology, as one of the preferentially selectable materials, the heat-treatment-free aluminum alloy has also been widely used, and further promoted the development of the integrated die-casting technology. Specifically, for example, Patent CN116949306A discloses a preparation method of a heat-treatment-free integrated die-casting aluminum alloy using recycled aluminum as raw material, including melting, refining and casting processes. The recycled aluminum with a Fe content of 0.5-3.0% is used as raw material, and the ingredients are prepared according to the following mass percentages: aluminum (Al) 87.0-92.5%, silicon (Si) 6-10.0%, copper (Cu) 0.5-1.0%, magnesium (Mg) 0.1-0.5%, iron (Fe) 0.5-0.8%, manganese (Mn) 0.5-0.8%, lanthanum (La) 0.05-0.3%. Compared with the traditional production method, the alloy prepared by this method has high purity, few casting defects, excellent casting fluidity, can be used for large integrated die-casting machines, and the parts after die-casting can be directly put into use without heat treatment. By adding rare earth lanthanum to the alloy, the morphology of the hard and brittle second-phase particles is changed from needle-shaped to short rod-shaped, improving the performance of the casting.

[0005] For another example, invention patent CN116904810A provides a high-strength, tough and heat-free aluminum alloy for vacuum integrated die-casting and a preparation method thereof. The aluminum alloy comprises: 6.0-9.0 wt% of silicon, 4.0-6.0 wt% of zinc, 0.1-0.2 wt% of magnesium, 0.2-0.3 wt% of manganese, 0.2-0.42 wt% of iron, 0.01-0.04 wt% of strontium, 0.1-0.3 wt% of chromium, ≤0.6 wt% of copper, the content of a single element of trace impurities ≤0.05 wt%, and the total amount of trace impurities ≤0.15 wt%. The balance is aluminum and inevitable impurities, wherein the weight ratio of manganese to iron is 0.5-1.0, and the weight ratio of zinc to magnesium is 20-60. The aluminum alloy of this invention can be produced using a higher proportion of recycled aluminum, with a tensile strength ≥270 MPa, a yield strength ≥130 MPa, and an elongation after fracture ≥10%.

[0006] It can be seen that the performance of heat-free aluminum alloy is one of the basic requirements in the field of automotive die-casting. This is also because conventional integrated die-casting technology requires pretreatment, and during the pretreatment process, parts, especially thin-walled parts, are severely deformed, making it difficult to meet production needs.

[0007] Although the above-mentioned two existing heat-free aluminum alloy technologies are mentioned, their mechanical properties still cannot reach the ideal properties in this field. Therefore, how to provide a high-strength and high-toughness alloy material, its preparation method, products and applications is a problem that those skilled in the art need to continuously solve. Summary of the Invention

[0008] Aiming at the problems existing in the prior art that the mechanical properties of heat-free aluminum alloy still need to be improved and there is a lack of optional types of high-strength heat-free aluminum alloy, the present invention provides a high-strength and high-toughness alloy material, its preparation method, products and applications. Through the effective combination of composition design, grain refinement, modification and die-casting process, an alloy material with the required mechanical properties can be obtained without heat treatment. After heat treatment, the performance of the aluminum alloy can be further improved, showing the characteristics of high strength and high toughness.

[0009] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0010] The present invention provides an alloy material, which comprises, by weight percentage:

[0011] Si: 9.7-10.3%, Fe: ≤0.15%, Mn: 0.55-0.65%, Mg: 0.27-0.32%, Ti: 0.05-0.15%, Cu: ≤0.03%, Cr: ≤0.02%, Zn: ≤0.03%, Zr: ≤0.03%, total impurities: ≤0.15% and the balance Al.

[0012] Preferably, the alloy material, by weight percentage, comprises:

[0013] Si: 9.7 - 10.3%, Fe: < 0.15%, Mn: 0.55 - 0.65%, Mg: 0.27 - 0.32%, Ti: 0.05 - 0.15%, Cu: < 0.03%, Cr: < 0.02%, Zn: < 0.03%, Zr: < 0.03%, total impurities: < 0.15% and the balance Al.

[0014] Preferably, 0.301 - 0.528% of the total weight of the alloy material is replaced with Sr and / or TCB seeds.

[0015] More preferably, 0.001 - 0.028% of the total weight of the alloy material is replaced with Sr.

[0016] Even more preferably, 0.0011 - 0.0273% of the total weight of the alloy material is replaced with Sr.

[0017] Even more preferably, 0.0011 - 0.0246% of the total weight of the alloy material is replaced with Sr.

[0018] More preferably, 0.3 - 0.5% of the total weight of the alloy material is replaced with TCB seeds.

[0019] In some specific embodiments, the alloy material, by weight percentage, comprises Si: 9.7 - 10.3%, Fe: ≤ 0.15%, Mn: 0.55 - 0.65%, Mg: 0.27 - 0.32%, Ti: 0.05 - 0.15%, Cu: ≤ 0.03%, Cr: ≤ 0.02%, Zn: ≤ 0.03%, Zr: ≤ 0.03%, Sr: 0.001 - 0.028%, total impurities: ≤ 0.15% and the balance Al.

[0020] In some specific embodiments, the alloy material, by weight percentage, comprises Si: 9.7 - 10.3%, Fe: ≤ 0.15%, Mn: 0.55 - 0.65%, Mg: 0.27 - 0.32%, Ti: 0.05 - 0.15%, Cu: ≤ 0.03%, Cr: ≤ 0.02%, Zn: ≤ 0.03%, Zr: ≤ 0.03%, Sr: 0.0011 - 0.0273%, total impurities: ≤ 0.15% and the balance Al.

[0021] In some specific embodiments, the alloy material, by weight percentage, comprises:

[0022] Si: 9.7 - 10.3%, Fe: ≤0.15%, Mn: 0.55 - 0.65%, Mg: 0.27 - 0.32%, Ti: 0.05 - 0.15%, Cu: ≤0.03%, Cr: ≤0.02%, Zn: ≤0.03%, Zr: ≤0.03%, TCB seed alloy: 0.3 - 0.5%, total impurities: ≤0.15% and the balance Al.

[0023] In some specific embodiments, the alloy material, by weight percentage, comprises:

[0024] Si: 9.7 - 10.3%, Fe: ≤0.15%, Mn: 0.55 - 0.65%, Mg: 0.27 - 0.32%, Ti: 0.05 - 0.15%, Cu: ≤0.03%, Cr: ≤0.02%, Zn: ≤0.03%, Zr: ≤0.03%, Sr: 0.0011 - 0.0246%, TCB seed alloy: 0.3 - 0.5%, total impurities: <0.15% and the balance Al.

[0025] In some embodiments, the content of Si in the alloy material is, for example, between 9.8 - 10.3%, such as between 10.0 - 10.3%, or between 10.0 - 10.2%.

[0026] In some embodiments, the content of Fe in the alloy material is, for example, between 0.12 - 0.14%, such as between 0.13 - 0.14%, or between 0.126 - 0.142%, or between 0.126 - 0.127%.

[0027] In some embodiments, the content of Mn in the alloy material is, for example, between 0.59 - 0.65%, such as between 0.59 - 0.62%, or between 0.593 - 0.648%, or between 0.596 - 0.617%.

[0028] In some embodiments, the content of Mg in the alloy material is, for example, between 0.28 - 0.30%, such as between 0.280 - 0.296%, or between 0.283 - 0.292%.

[0029] In some embodiments, the content of Ti in the alloy material is, for example, between 0.10 - 0.12%, such as between 0.105 - 0.117%, or between 0.106 - 0.117%.

[0030] In some embodiments, the content of Cu in the alloy material is, for example, between 0.0067 - 0.0289%, such as between 0.0069 - 0.0284%.

[0031] In some embodiments, the content of Cr in the alloy material is, for example, between 0.01% and 0.02%, such as between 0.012% and 0.018%, or between 0.014% and 0.016%.

[0032] In some embodiments, the content of Zn in the alloy material is, for example, between 0.017% and 0.030%, such as between 0.020% and 0.030%, or between 0.014% and 0.016%.

[0033] In some embodiments, the content of Zr in the alloy material is, for example, between 0.0042% and 0.0300%, such as between 0.012% and 0.018%, or between 0.014% and 0.016%.

[0034] Furthermore, the content of each single impurity in the total impurities is < 0.03%.

[0035] In the present invention, the content of Ti in the TCB seed alloy is not calculated together with the content of Ti added to the alloy material.

[0036] On the other hand, the present invention also provides a method for preparing the above alloy material, comprising the following steps:

[0037] (1) Melting the Al raw material to obtain a first aluminum liquid, detecting the content of each element, adding the Si raw material to the first aluminum liquid according to the formula dosage, after melting silicon, proportioning and smelting Fe, Mn, Mg, Ti, Cu, Cr, Zn and Zr according to the formula dosage to obtain a second aluminum liquid;

[0038] (2) After the second aluminum liquid obtained in step (1) is allowed to stand and slag is removed, a third aluminum liquid is obtained;

[0039] (3) Adding a grain refiner to the third aluminum liquid obtained in step (2) to obtain a fourth aluminum liquid;

[0040] (4) Performing first refining and degassing on the fourth aluminum liquid obtained in step (3) to obtain a fifth aluminum liquid;

[0041] (5) Adding a modifier to the fifth aluminum liquid obtained in step (4), and then performing second refining and degassing to obtain a sixth aluminum liquid;

[0042] (6) Allowing the sixth aluminum liquid obtained in step (5) to stand and cool, and die-casting to obtain the product.

[0043] Furthermore, in step (3), the grain refiner is a TCB seed alloy, and in step (6), the modifier is Al-Sr10.

[0044] Furthermore, the time for the second refining and degassing in step (5) is 10-15 minutes. When the refining time is 2 minutes, a modifier is added to refine the alloy grains to obtain a fifth aluminum liquid.

[0045] Furthermore, the first refining described in step (4) is specifically as follows: when the temperature of the fourth aluminum liquid reaches 720-750°C, a refining agent is added, and the refining time is 15-25 minutes; the second refining described in step (5) is specifically as follows: when the temperature of the fifth aluminum liquid after adding the modifier reaches 720-750°C, a refining agent is added, and the refining time is 2-5 minutes.

[0046] Preferably, the first refining in step (4) is specifically as follows: when the temperature of the fourth aluminum liquid reaches 730°C, a refining agent is added, and the refining time is 20 minutes; the second refining in step (5) is specifically as follows: when the temperature of the fifth aluminum liquid after adding the modifier reaches 730°C, a refining agent is added, and the refining time is 3 minutes.

[0047] Furthermore, the temperature of the molten silicon in step (1) is 780-800°C.

[0048] In some specific implementations, the method for preparing the alloy material comprises the following steps:

[0049] S1: Melting Al raw material to obtain first aluminum liquid, detecting the content of each element, adding Si raw material to the first aluminum liquid according to the formula, melting silicon, and then smelting according to the formula amount of Fe, Mn, Mg, Ti, Cu, Cr, Zn and Zr to obtain second aluminum liquid;

[0050] S2: The second aluminum liquid obtained in step S1 is allowed to stand and deslagging to obtain a third aluminum liquid;

[0051] S3: performing a first refining and degassing on the third aluminum liquid obtained in step S2 to obtain a fourth aluminum liquid;

[0052] S4: adding a modifier to the fourth aluminum liquid obtained in step S3, and then performing a second refining and degassing to obtain a fifth aluminum liquid;

[0053] S5: The fifth aluminum liquid obtained in step S4 is allowed to stand for cooling, and then die-casted to obtain the fifth aluminum liquid.

[0054] Furthermore, the modifier described in step S4 is Al-Sr10.

[0055] In some specific implementations, the method for preparing the alloy material comprises the following steps:

[0056] ①Melt the Al raw material to obtain the first aluminum liquid, detect the content of each element, add the Si raw material to the first aluminum liquid according to the formula dosage, after melting silicon, charge and smelt according to the formula dosage of Fe, Mn, Mg, Ti, Cu, Cr, Zn and Zr to obtain the second aluminum liquid;

[0057] ②After the second aluminum liquid obtained in step ① is statically placed to remove slag, the third aluminum liquid is obtained;

[0058] ③Add a grain refiner to the third aluminum liquid obtained in step ② to obtain the fourth aluminum liquid;

[0059] ④Carry out the first refining and degassing on the fourth aluminum liquid obtained in step ③ to obtain the fifth aluminum liquid;

[0060] ⑤Carry out the second refining and degassing on the fifth aluminum liquid obtained in step ④ to obtain the sixth aluminum liquid;

[0061] ⑥Let the sixth aluminum liquid obtained in step ⑤ stand still to cool down, and then carry out die-casting to obtain the product.

[0062] Further, the grain refiner in step ③ is the TCB seed alloy.

[0063] Further, the present invention provides a heat-treated aluminum alloy obtained by heat-treating the alloy material prepared by the above alloy material or the above preparation method.

[0064] Further, the present invention also provides a method for preparing a heat-treated aluminum alloy using the above alloy material, including the following steps:

[0065] Carry out T5 heat treatment on the said alloy material.

[0066] It should be noted that the T5 heat treatment refers to the process of solution treatment plus incomplete artificial aging.

[0067] Preferably, the temperature of the solution treatment in the T5 heat treatment is 520 - 540 °C, and the time is 110 - 130 min.

[0068] Further preferably, the cooling method of the solution treatment is to place it in water at 60 - 100 °C.

[0069] Preferably, the temperature of the incomplete artificial aging in the T5 heat treatment is 150 - 170 °C, and the time is 3 - 5 h.

[0070] Further, the above alloy material provided by the present invention or the alloy material prepared by the above preparation method can be applied to automotive die-casting, 5G base stations or motorcycle parts.

[0071] Further, the above alloy material provided by the present invention or the alloy material prepared by the above preparation method can be applied to the preparation of materials for automotive subframes.

[0072] Compared with the prior art, the present invention has the following beneficial effects:

[0073] The alloy material provided by the present invention has excellent mechanical properties without heat treatment, and also has the advantage of small deformation after heat treatment. It can be used for heat treatment to adjust the yield strength to meet the production needs. Detailed Embodiments

[0074] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0075] Before further describing the specific embodiments of the present invention, it should be understood that the protection scope of the present invention is not limited to the specific embodiments described below; it should also be understood that the terms used in the embodiments of the present invention are for describing specific embodiments, rather than for limiting the protection scope of the present invention.

[0076] When the embodiments give a numerical range, it should be understood that unless otherwise specified in the present invention, any value between the two endpoints of each numerical range and either endpoint can be selected. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0077] To make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. Those conditions not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. All reagents or instruments not specified by the manufacturer can be obtained through commercially available conventional products. To better illustrate the present invention, numerous specific details are given in the following detailed embodiments. The specific embodiments described herein are only used to explain the present invention and do not constitute any limitation to the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concept of the present invention. Such structures and technologies are also described in many publications.

[0078] In the present invention, the experimental device used is an electronic universal testing machine, with the specification model: CMT5105 (100KN), and the test speed: 3 mm / min; the experimental reference standard: GB / T228.1-2021 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature".

[0079] In the present invention, the TCB seed alloy was purchased from Shandong Lvmei Melt Technology Co., Ltd., with the brand name AlTiCB; the recycled casting aluminum alloy raw material originated from Hong Kong Hongji Industry Development Co., Ltd., and met the requirements of GB / T38472-2019 "Recycled Casting Aluminum Alloy Raw Materials"; the refining agent was purchased from Sihui Hongda Metal Materials Co., Ltd., with the model number Hongda HD-J26.

[0080] The alloy material and the heat-treated aluminum alloy test sample used in the present invention have a diameter of 6.3 mm and a length of 170 mm.

[0081] Basic Example 1

[0082] Embodiment 1-5 A kind of alloy material and heat-treated aluminum alloy

[0083] Examples 1-5 are implemented based on modified raw materials and their amounts in the basic example. The formulas of specific raw materials and raw material amounts are as follows:

[0084] Table 1 Raw material formula of alloy materials

[0085]

[0086] The preparation method of the alloy material of Examples 1-2 in the above table is specifically the following steps:

[0087] S1: melting Al raw material (specifically recycled cast aluminum alloy raw material) to obtain a first aluminum liquid, detecting the content of each element, adding Si single substance to the first aluminum liquid according to the formula, melting silicon at 800°C, and then smelting according to the formula amount of Fe, Mn, Mg, Ti, Cu, Cr, Zn and Zr to obtain a second aluminum liquid;

[0088] S2: The second aluminum liquid obtained in step S1 is allowed to stand and deslagging to obtain a third aluminum liquid;

[0089] S3: performing a first refining and degassing on the third aluminum liquid obtained in step S2. Specifically, when the temperature of the fourth aluminum liquid reaches 750° C., a refining agent is added, and the refining time is 15 minutes to obtain a fourth aluminum liquid.

[0090] S4: adding a modifier to the fourth aluminum liquid obtained in step S3, and then performing a second refining and degassing. The second refining is specifically when the temperature of the fifth aluminum liquid after adding the modifier (specifically Al-Sr10, i.e., the only source of Sr in the table) reaches 750° C., adding a refining agent, and the refining time is 2 minutes to obtain the fifth aluminum liquid;

[0091] S5: The fifth aluminum liquid obtained in step S4 is allowed to stand for cooling, and then die-casted to obtain the fifth aluminum liquid.

[0092] The preparation method of the alloy material of Examples 3-5 in the above table is specifically the following steps:

[0093] (1) melting an Al raw material (specifically, a recycled cast aluminum alloy raw material) to obtain a first aluminum liquid, detecting the content of each element, adding Si single substance to the first aluminum liquid according to the formula amount, melting silicon at 800° C., and then smelting the ingredients of Fe, Mn, Mg, Ti, Cu, Cr, Zn and Zr according to the formula amount to obtain a second aluminum liquid;

[0094] (2) allowing the second aluminum liquid obtained in step (1) to stand and drain the slag to obtain a third aluminum liquid;

[0095] (3) adding a grain refiner (specifically a TCB seed alloy, i.e., TCB* in the table) to the third aluminum liquid obtained in step (2), etc., to obtain a fourth aluminum liquid;

[0096] (4) performing a first refining and degassing on the fourth aluminum liquid obtained in step (3). Specifically, when the temperature of the fourth aluminum liquid reaches 730° C., a refining agent is added, and the refining time is 20 min to obtain a fifth aluminum liquid;

[0097] (5) Add a modifier (specifically Al-Sr10, which is the only source of Sr in the table) to the fifth aluminum liquid obtained in step (4), and then perform a second refining and degassing. The second refining is specifically when the temperature of the fifth aluminum liquid after adding the modifier reaches 730°C, add a refining agent, and the refining time is 3 minutes to obtain the sixth aluminum liquid; (6) Allow the sixth aluminum liquid obtained in step (5) to stand and cool, and then die-cast to obtain the sixth aluminum liquid.

[0098] The alloy materials corresponding to Examples 1-5 were obtained from the above formulations, and the alloy materials were further subjected to T5 heat treatment.

[0099] T5 heat treatment refers to the process of solution treatment plus incomplete artificial aging.

[0100] The temperature of the solution treatment in the T5 heat treatment is 530°C, the time is 2h, and the cooling method is to place it in 60°C water. The temperature of the incomplete artificial aging in the T5 heat treatment is 160°C, and the time is 3h or 5h. See Table 4 for details.

[0101] Then, the heat-treated aluminum alloys corresponding to Examples 1-5 were obtained.

[0102] Comparative Example 1-4: An alloy material and heat-treated aluminum alloy

[0103] Comparative Examples 1-4 are based on the modified raw materials and their dosages of the basic examples. The preparation methods are the same as those of Examples 3-5. The specific raw materials and their dosages are as follows:

[0104] Table 2 Raw material formula of alloy materials

[0105]

[0106]

[0107] The alloy materials corresponding to Comparative Examples 1-4 were obtained from the above formula, and the alloy materials were further subjected to T5 heat treatment. The specific operation steps were the same as those in Examples 1-5.

[0108] Furthermore, the heat-treated aluminum alloys corresponding to Comparative Examples 1-4 were obtained.

[0109] Mechanical properties of the alloy materials in Test Example 1

[0110] Referring to GB / T228.1-2021, the mechanical properties (tensile strength, yield strength, and elongation at break) of the alloy materials in each example and comparative example were tested, and the following table was obtained:

[0111] Table 3 Mechanical properties of the alloy materials

[0112] Example Tensile strength (MPa) Yield strength (MPa) Elongation at break (%) Example 1 314.69 151.27 7.19 Example 2 326.67 155.06 8.86 Example 3 307.68 146.14 7.73 Example 4 319.37 153.59 8.91 Example 5 324.50 154.36 8.81 Comparative Example 1 259.06 113.28 5.45 Comparative Example 2 268.53 118.74 5.79 Comparative Example 3 243.30 106.71 5.02 Comparative Example 4 277.43 125.60 5.98

[0113] According to the results in the above table, it can be seen that the alloy materials that do not require heat treatment in the present invention have better mechanical properties. The tensile strength reaches above 307.68 MPa, the yield strength reaches above 146.14 MPa, and the elongation rate reaches above 7.19%. That is, the required mechanical properties can be obtained without heat treatment. In comparison, the mechanical properties of the alloy materials in Comparative Example 1 and Comparative Example 3 decreased significantly, indicating the key role of the formula with specific contents. The decrease in the mechanical properties of the alloy materials in Comparative Example 2 indicates the influence of specific types of elements on the materials. The decrease in the properties of the alloy materials in Comparative Example 4 indicates the key role of the TCB crystal alloy with specific contents in the formula.

[0114] In addition, when the material cost of the Sr-containing element is about 28.8 yuan / kg and the raw material cost of the TCB crystal alloy is about 35 yuan / kg, the overall cost of the alloy materials in each example is within an acceptable range. The input cost of the TCB crystal alloy raw material in Comparative Example 4 is relatively high, and at the same time, the mechanical properties of the corresponding alloy materials even decrease, which is not suitable for actual industrial production.

[0115] Mechanical properties of the heat-treated aluminum alloys in Test Example 2

[0116] Referring to GB / T228.1-2021, the mechanical properties (tensile strength, yield strength, and elongation at break) of the heat-treated aluminum alloy materials (in the cases of incomplete artificial aging treatments for 3 h and 5 h respectively) in each example and comparative example were tested, and the following table was obtained:

[0117] Table 4 Mechanical properties of the heat-treated aluminum alloys

[0118]

[0119] As can be seen from the above table, after the T5 treatment, the tensile strength as a whole shows a downward trend, and with the increase of the incomplete artificial aging time, the tensile strength gradually rebounds; except for a slight decrease in some groups at 3 h, the yield strength of the alloy materials in each example shows a linear increase as a whole, indicating that the heat treatment has a greater impact on the yield strength of the examples; the fracture elongation rate of the material shows a trend of increasing first and then decreasing, indicating that the longer the incomplete artificial aging time, the more the fracture elongation rate gradually decreases. Generally speaking, however, the mechanical properties of the heat-treated aluminum alloy in the examples of the present invention are compared with those of the heat-treated aluminum alloy in each comparative example, indicating that the alloy material with a specific formulation in the present invention can maintain a high level in terms of tensile strength, yield strength, and elongation at break after heat treatment processing.

[0120] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than a limitation on the protection scope of the present invention. Any simple modification or equivalent replacement made by those of ordinary skill in the art to the technical solution of the present invention does not depart from the essence and scope of the technical solution of the present invention.

Claims

1. An alloy material, characterized in that: The alloy comprises, by weight percentage, 9.7-10.3% Si, ≤0.15% Fe, ≤0.55-0.65% Mn, 0.27-0.32% Mg, 0.05-0.15% Ti, ≤0.03% Cu, ≤0.02% Cr, ≤0.03% Zn, ≤0.03% Zr, ≤0.03% Sr, 0.0011-0.0246% TCB seed alloy, 0.3-0.5% total impurities, ≤0.15% and the balance Al; the alloy material is subjected to T5 heat treatment; in the T5 heat treatment, the temperature of the solid solution treatment is 520-540°C, the time of the solid solution treatment is 110-130min, the incomplete artificial aging treatment is 5h, and the temperature of the incomplete artificial aging is 150-170°C.

2. The method for preparing the alloy material according to claim 1, characterized in that: The following steps are involved: (1) Melting Al raw material to obtain first aluminum liquid, detecting the content of each element, adding Si raw material to the first aluminum liquid according to the formula, melting silicon, and then smelting according to the formula amount of Fe, Mn, Mg, Ti, Cu, Cr, Zn and Zr to obtain second aluminum liquid; (2) The second aluminum liquid obtained in step (1) is allowed to stand and deslagging to obtain a third aluminum liquid; (3) adding a grain refiner to the third aluminum liquid obtained in step (2) to obtain a fourth aluminum liquid; (4) refining and degassing the fourth aluminum liquid obtained in step (3) to obtain a fifth aluminum liquid; (5) adding a modifier to the fifth aluminum liquid obtained in step (4), and then performing a second refining and degassing to obtain a sixth aluminum liquid; (6) The sixth aluminum liquid obtained in step (5) is allowed to stand and cool, and then die-casted to obtain the aluminum liquid.

3. The preparation method according to claim 2, characterized in that: The grain refiner in step (3) is TCB seed alloy, and the modifier in step (5) is Al-Sr10.

4. The preparation method according to claim 2, characterized in that: The temperature of the molten silicon in step (1) is 780-800°C.

5. Application of the alloy material according to claim 1 or the alloy material prepared by the preparation method according to any one of claims 2 to 4 in automotive die-casting, 5G base stations or motorcycle accessories.

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