A method for producing low-carbon heat-treatment-free aluminum alloy

Abstract

The invention relates to a method for preparing a low-carbon heat treatment-free aluminum alloy. The method comprises the following steps: preparing materials according to components in the alloy, placing crushed waste materials and silicon into a large furnace for heating and smelting, adding a master alloy until all the materials are melted; pressing the Al-Sr master alloy into aluminum liquid, and then performing degassing, refining, casting and quenching on the aluminum liquid; the quenching medium is prepared by using double-terminated amino polyethylene glycol, 1-BOC-4-allyl-4-piperidinic acid, 4-aminothiazole-2-carboxylate lithium, water and sodium nitrite; the aluminum alloy prepared by the method has excellent mechanical properties; the quenching liquid prepared by the method improves the quenching effect through synergistic action, including enhancing the cooling rate, reducing deformation, improving the hardness and wear resistance, and reducing surface corrosion and oxidation.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloys, in particular to a method for preparing a low-carbon heat-treatment-free aluminum alloy. Background Art

[0002] Integrated die-casting technology helps to improve rigidity, reduce weight, improve efficiency and reduce costs by integrating parts design and using large die-casting machines for one-time die-casting. At present, the integration is mainly integrated into the front cabin and the rear floor, and the maximum tonnage of the die-casting machine is 12,000 tons. Some domestic OEMs cooperate with supporting suppliers to develop an integrated lower body, focusing on the heat-treatment-free die-casting aluminum alloy composition and organization and performance regulation mechanism, large-scale integrated die-casting body structural parts optimization design and connection technology, ultra-large complex thin-walled parts die-casting process and mold technology, and heavy-duty die-casting equipment multi-rigid body and multi-flexible body system high reliability technology to create and build the world's first double-shot integrated die-casting process platform with a capacity of more than 10,000 tons. It is expected to achieve a 20% weight reduction in ultra-large integrated die-casting structural parts of the body.

[0003] Integrated die casting technology is an innovative manufacturing process that significantly improves structural rigidity, reduces weight, improves production efficiency and reduces manufacturing costs by integrating part design and achieving one-time molding using large die casting machines.

[0004] In view of the urgent need to improve product quality and reduce costs, the construction of a double-shot integrated die-casting process platform with a capacity of over 10,000 tons is promoted. The platform will make breakthroughs in key technologies such as material science, design innovation, process improvement and equipment upgrade, aiming to break the current technical barriers in the industry, realize the research and development and application of larger-sized and more integrated automotive parts, and continuously promote the development of lightweight technology in the automotive industry.

[0005] Therefore, it is urgent to develop an integrated lower body heat treatment-free alloy. Currently, the materials used for integrated die-casting mass production on the market include Alcoa C611, with a silicon content of about 7%, Shanghai Jiaotong University JDA1A, with a silicon content of about 8.5%, Shanxi Ruige RGA-6, with a silicon content of about 7%, and Suzhou Huijin heat-free alloy, with a silicon content of about 8%. These materials are currently mainly used for die-casting parts of 9,000-ton die-casting machines, and cannot meet the performance requirements of the integrated lower body in terms of die-casting process and mechanical properties.

[0006] The existing aluminum alloy casting technology generally has a heat treatment step, which is complex and costly. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a method for preparing a low-carbon heat-treatment-free aluminum alloy, and the operating steps are as follows:

[0008] A1: Prepare materials according to the alloy composition ratio, purchase AlSi7MnMg and AlSi10MnMg materials from the market for die-casting structural parts scraps, aluminum subframe parts and crush them; door and window materials and toothpaste shells and other scraps;

[0009] A2: The crushed waste and silicon are placed in a large furnace for heating and smelting. The temperature of the aluminum liquid is 590-620℃. After all the raw materials are melted, a large rake is used to rake out the unmelted iron and other high-melting-point items at the bottom of the furnace. After the rake is completed, the iron-absorbing device is inserted into the aluminum liquid, powered on, and small iron nails that cannot be picked up by the large rake in the furnace are absorbed until they cannot be absorbed. Then the temperature is raised to 730-740℃.

[0010] A3: When the temperature of the aluminum liquid reaches 730-740℃, check the composition in the furnace, add the required supplementary components, weigh the required master alloy and bake it, add the dried Al-Mn master alloy, Al-V master alloy, Al-Ti and other master alloys into the aluminum liquid, heat the aluminum liquid to 740-760℃, keep it warm for 10-30 minutes, and ensure that all the added master alloys are melted;

[0011] A4: Press the Al-Sr master alloy into the aluminum liquid, and then degas the aluminum liquid to remove hydrogen in the aluminum liquid. The control parameters are: connect the equipment with a seamless steel pipe, and the gas introduced is high-purity argon gas with a purity of >99.99%. The bubble height cannot exceed 20mm; the refining temperature is 740-750℃, the time is 30-50min, the degassing time is 15-25min, and the refining is repeated twice;

[0012] A5: After refining and degassing, remove the scum on the surface of the aluminum liquid, let it stand for 15-25 minutes, then take the spectrum sample to detect the composition. If the composition meets the requirements, lower the temperature of the aluminum liquid;

[0013] A6: In the early, middle and late stages of casting, scoop aluminum liquid from the flow channel behind the filter box to test the composition; the surface of the aluminum ingot is required to be free of oil stains, corrosion spots, slag and non-metallic inclusions;

[0014] A7: Immerse the cast casting in the quenching medium to quench the casting.

[0015] The alloy composition is composed of the following by mass percentage:

[0016] 8.5-11.0% silicon,

[0017] 0.05-0.6% iron,

[0018] 0.05-0.5% copper,

[0019] 0.05-0.5% zinc,

[0020] 0.3-0.6% manganese,

[0021] 0.1-0.15% chromium,

[0022] 0.05-0.4% magnesium,

[0023] 0.01-0.1% vanadium,

[0024] 0.1-0.2% titanium,

[0025] 0.05-0.1% zirconium,

[0026] 0.05-0.1% nickel,

[0027] 0.01-0.03% strontium,

[0028] 0.005-0.01% calcium,

[0029] The alloy inevitably adds TiB2 seeds or AlNbB, AlLaB, AlTIB refiners;

[0030] Individual impurity elements are less than 0.05%, and the rest is aluminum.

[0031] The Si element is added in the form of elemental silicon, the Cr element is added in the form of an Al-Cr master alloy, the V element is added in the form of an Al-V master alloy, the Ti element is added in the form of an Al-Ti master alloy, the Mn element (if present) is added in the form of an Al-Mn master alloy, the Fe element is added in the form of an Al-Fe master alloy, and the Sr element is added in the form of an Al-Sr master alloy.

[0032] The titanium is one of aluminum titanium boron, aluminum titanium carbon boron and aluminum titanium niobium boron.

[0033] The temperature of the aluminum liquid in the casting furnace is 700-710°C, the temperature of the distribution hub is 630-650°C, the casting speed is 6-8 Hz / min, the nitrogen pressure is 0.8-1.2 kgf / cm², the nitrogen flow rate is 1.0-1.8 m³ / h, the rotor speed is 350-450 r / min, and the filter plate is 40 meshes.

[0034] The quenching treatment is carried out at a temperature of 540-560° C. and for a time of 15-30 minutes.

[0035] The preparation method of the quenching medium is:

[0036] S1: by weight, 20-30 parts of double-terminated amino polyethylene glycol, 2.7-5.4 parts of 1-BOC-4-allyl-4-piperidinic acid, 0.005-0.05 parts of 4-aminothiazole-2-carboxylic acid lithium CAS number: 2361644-16-6, 100-150 parts of water, adjust pH to 9 with sodium hydroxide, and react at 70-90°C with stirring for 50-100 minutes;

[0037] S2: Add 3-6 parts of sodium nitrite and stir for 120-150 minutes to obtain a quenching medium.

[0038] The double-terminated amino polyethylene glycol has a molecular weight of 1000, 2000 or 4000.

[0039] Reaction mechanism

[0040] The amino groups of double-terminated amino polyethylene glycol and 4-aminothiazole-2-carboxylic acid lithium undergo addition reaction with the olefin bond of 1-BOC-4-allyl-4-piperidinic acid, and are used as quenching agents for aluminum alloys.

[0041] Michael addition: Under alkaline conditions, an amino group (such as the amino group of double-terminated amino polyethylene glycol or lithium 4-aminothiazole-2-carboxylate) may act as a nucleophile to attack the β-carbon atom of an alkene (allylic moiety) to form a new carbon-nitrogen bond.

[0042] Technical Effects

[0043] The present invention provides a method for producing a low-carbon heat-treatment-free aluminum alloy. Compared with the prior art, the present invention has the following significant effects:

[0044] 1. Stability: The thiazole ring has certain stability and bactericidal properties, which helps to improve the chemical stability of the quenching agent. Performance adjustment: As a ligand or additive, it can adjust the performance of the quenching agent by interacting with other components, such as improving wettability and reducing surface tension.

[0045] 2. Solubilization effect: The piperidine group may enhance the solubility of the quencher in water or other solvents, which is beneficial to the uniform distribution and use of the quencher.

[0046] 3. Comprehensive effect

[0047] The combination of these compounds in a quenchant for aluminum alloys improves the quenching effect through synergistic effects, including enhanced cooling rate, reduced deformation, improved hardness and wear resistance, while reducing surface corrosion and oxidation. DETAILED DESCRIPTION

[0048] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description in combination with embodiments and comparative examples:

[0049] Tensile strength, yield strength and elongation test: refer to GB / T228.1-2021 "Tensile test of metallic materials Part 1: Room temperature test method" for testing.

[0050] Example 1

[0051] A method for preparing a low-carbon heat-treatment-free aluminum alloy, the operating steps of which are:

[0052] A1: Prepare materials according to the alloy composition ratio, purchase AlSi7MnMg and AlSi10MnMg materials from the market for die-casting structural parts scraps, aluminum subframe parts and crush them; door and window materials and toothpaste shells and other scraps;

[0053] A2: The crushed waste and silicon are placed in a large furnace for heating and smelting. The temperature of the aluminum liquid is 590℃. After all the raw materials are melted, a large rake is used to rake out the unmelted iron and other high-melting-point items at the bottom of the furnace. After the rake is completed, the iron-absorbing device is inserted into the aluminum liquid, powered on, and small iron nails that cannot be picked up by the large rake in the furnace are absorbed until they cannot be absorbed. Then the temperature is raised to 730℃.

[0054] A3: When the aluminum liquid temperature reaches 730℃, check the composition in the furnace, add the required supplementary components, weigh the required master alloy and bake it, add the dried Al-Mn master alloy, Al-V master alloy, Al-Ti and other master alloys into the aluminum liquid, heat the aluminum liquid to 740℃, keep it warm for 10 minutes, and ensure that all the added master alloys are melted;

[0055] A4: Press the Al-Sr master alloy into the aluminum liquid, and then degas the aluminum liquid to remove hydrogen in the aluminum liquid. The control parameters are: connect the equipment with a seamless steel pipe, and the gas introduced is high-purity argon gas with a purity of >99.99%. The bubble height cannot exceed 20mm; the refining temperature is 740℃ for 30min each time, the degassing time is 15min, and the refining is repeated twice;

[0056] A5: After refining and degassing, remove the scum on the surface of the aluminum liquid. After it is still for 15 minutes, take a spectrum sample to test the composition. If the composition meets the requirements, lower the temperature of the aluminum liquid.

[0057] A6: In the early, middle and late stages of casting, scoop aluminum liquid from the flow channel behind the filter box to test the composition; the surface of the aluminum ingot is required to be free of oil stains, corrosion spots, slag and non-metallic inclusions;

[0058] A7: Immerse the cast casting in the quenching medium to quench the casting.

[0059] The alloy composition is composed of the following by mass percentage:

[0060] 8.5% silicon,

[0061] 0.05% iron,

[0062] 0.05% copper,

[0063] 0.05% zinc,

[0064] 0.3% manganese,

[0065] 0.1% chromium,

[0066] 0.05% magnesium,

[0067] 0.01% vanadium,

[0068] 0.1% titanium,

[0069] 0.05% zirconium,

[0070] 0.05% nickel,

[0071] 0.01% strontium,

[0072] 0.005% calcium,

[0073] The alloy inevitably adds TiB2 seeds or AlNbB, AlLaB, AlTIB refiners;

[0074] Individual impurity elements are less than 0.05%, and the rest is aluminum.

[0075] The Si element is added in the form of elemental silicon, the Cr element is added in the form of an Al-Cr master alloy, the V element is added in the form of an Al-V master alloy, the Ti element is added in the form of an Al-Ti master alloy, the Mn element (if present) is added in the form of an Al-Mn master alloy, the Fe element is added in the form of an Al-Fe master alloy, and the Sr element is added in the form of an Al-Sr master alloy.

[0076] The titanium is aluminum titanium boron.

[0077] The temperature of the aluminum liquid in the casting furnace is 700°C, the temperature of the distribution hub is 630°C, the casting speed is 6 Hz / min, the nitrogen pressure is 0.8kgf / cm², the nitrogen flow rate is 1.0m³ / h, the rotor speed is 350r / min, and the filter plate is 40 meshes.

[0078] The quenching treatment is carried out at a temperature of 540° C. and for a time of 15 minutes.

[0079] The preparation method of the quenching medium is:

[0080] S1: 20 kg of double-terminated amino polyethylene glycol, 2.7 kg of 1-BOC-4-allyl-4-piperidinic acid, 0.005 kg of 4-aminothiazole-2-carboxylic acid lithium CAS No.: 2361644-16-6, and 100 kg of water were added, the pH value was adjusted to 9 with sodium hydroxide, and the mixture was stirred at 70°C for 50 minutes;

[0081] S2: Add 3 kg of sodium nitrite and stir for 120 minutes to obtain a quenching medium.

[0082] The double-terminated amino polyethylene glycol has a molecular weight of 1000.

[0083] Example 2

[0084] A method for preparing a low-carbon heat-treatment-free aluminum alloy, the operating steps of which are:

[0085] A1: Prepare materials according to the alloy composition ratio, purchase AlSi7MnMg and AlSi10MnMg materials from the market for die-casting structural parts scraps, aluminum subframe parts and crush them; door and window materials and toothpaste shells and other scraps;

[0086] A2: The crushed waste and silicon are placed in a large furnace for heating and smelting. The temperature of the aluminum liquid is 600℃. After all the raw materials are melted, a large rake is used to rake out the unmelted iron and other high-melting-point items at the bottom of the furnace. After the rake is completed, the iron-absorbing device is inserted into the aluminum liquid, powered on, and small iron nails that cannot be picked up by the large rake are absorbed until they cannot be absorbed. Then the temperature is raised to 735℃.

[0087] A3: When the aluminum liquid temperature reaches 735℃, check the composition in the furnace, add the required supplementary components, weigh the required master alloy and bake it, add the dried Al-Mn master alloy, Al-V master alloy, Al-Ti and other master alloys into the aluminum liquid, heat the aluminum liquid to 745℃, keep it warm for 15 minutes, and ensure that all the added master alloys are melted;

[0088] A4: Press the Al-Sr master alloy into the aluminum liquid, and then degas the aluminum liquid to remove hydrogen in the aluminum liquid. The control parameters are: connect the equipment with a seamless steel pipe, and the gas introduced is high-purity argon gas with a purity of >99.99%. The bubble height cannot exceed 20mm; the refining temperature is 745℃ for each refining, the time is 35min, the degassing time is 18min, and the refining is repeated twice;

[0089] A5: After refining and degassing, remove the scum on the surface of the aluminum liquid. After it is still for 18 minutes, take a spectrum sample to test the composition. If the composition meets the requirements, lower the temperature of the aluminum liquid.

[0090] A6: In the early, middle and late stages of casting, scoop aluminum liquid from the flow channel behind the filter box to test the composition; the surface of the aluminum ingot is required to be free of oil stains, corrosion spots, slag and non-metallic inclusions;

[0091] A7: Immerse the cast casting in the quenching medium to quench the casting.

[0092] The alloy composition is composed of the following by mass percentage:

[0093] 9% silicon,

[0094] 0.2% iron,

[0095] 0.2% copper,

[0096] 0.2% zinc,

[0097] 0.4% manganese,

[0098] 0.12% chromium,

[0099] 0.2% magnesium,

[0100] 0.05% vanadium,

[0101] 0.13% titanium,

[0102] 0.05% zirconium,

[0103] 0.05% nickel,

[0104] 0.02% strontium,

[0105] 0.006% calcium,

[0106] The alloy inevitably adds TiB2 seeds or AlNbB, AlLaB, AlTIB refiners;

[0107] Individual impurity elements are less than 0.05%, and the rest is aluminum.

[0108] The Si element is added in the form of elemental silicon, the Cr element is added in the form of an Al-Cr master alloy, the V element is added in the form of an Al-V master alloy, the Ti element is added in the form of an Al-Ti master alloy, the Mn element (if present) is added in the form of an Al-Mn master alloy, the Fe element is added in the form of an Al-Fe master alloy, and the Sr element is added in the form of an Al-Sr master alloy.

[0109] The titanium is aluminum titanium carbon boron.

[0110] The temperature of the aluminum liquid in the casting furnace is 705°C, the temperature of the distribution hub is 635°C, the casting speed is 7 Hz / min, the nitrogen pressure is 0.9 kgf / cm², the nitrogen flow rate is 1.3 m³ / h, the rotor speed is 380 r / min, and the filter plate is 40 meshes.

[0111] The quenching treatment is carried out at a temperature of 545° C. and for 20 minutes.

[0112] The preparation method of the quenching medium is:

[0113] S1: 23 kg of double-terminated amino polyethylene glycol, 3.5 kg of 1-BOC-4-allyl-4-piperidinic acid, 0.02 kg of 4-aminothiazole-2-carboxylic acid lithium CAS No.: 2361644-16-6, and 110 kg of water were added, the pH value was adjusted to 9 with sodium hydroxide, and the mixture was stirred at 75°C for 70 minutes;

[0114] S2: Add 4 kg of sodium nitrite and stir for 130 minutes to obtain a quenching medium.

[0115] The double-terminated amino polyethylene glycol has a molecular weight of 2000.

[0116] Example 3

[0117] A method for preparing a low-carbon heat-treatment-free aluminum alloy, the operating steps of which are:

[0118] A1: Prepare materials according to the alloy composition ratio, purchase AlSi7MnMg and AlSi10MnMg materials from the market for die-casting structural parts scraps, aluminum subframe parts and crush them; door and window materials and toothpaste shells and other scraps;

[0119] A2: The crushed waste and silicon are placed in a large furnace for heating and smelting. The temperature of the aluminum liquid is 610℃. After all the raw materials are melted, a large rake is used to rake out the unmelted iron and other high-melting-point items at the bottom of the furnace. After the rake is completed, the iron-absorbing device is inserted into the aluminum liquid, powered on, and small iron nails that cannot be picked up by the large rake are absorbed until they cannot be absorbed. Then the temperature is raised to 735℃.

[0120] A3: When the temperature of the aluminum liquid reaches 735℃, check the composition in the furnace, add the required supplementary components, weigh the required master alloy and bake it, add the dried Al-Mn master alloy, Al-V master alloy, Al-Ti and other master alloys into the aluminum liquid, heat the aluminum liquid to 755℃, keep it warm for 25 minutes, and ensure that all the added master alloys are melted;

[0121] A4: Press the Al-Sr master alloy into the aluminum liquid, and then degas the aluminum liquid to remove hydrogen in the aluminum liquid. The control parameters are: connect the equipment with a seamless steel pipe, and the gas introduced is high-purity argon gas with a purity of >99.99%. The bubble height cannot exceed 20mm; the refining temperature is 745℃ for each refining, the refining time is 45min, the degassing time is 23min, and the refining is repeated twice;

[0122] A5: After refining and degassing, remove the scum on the surface of the aluminum liquid. After 23 minutes of rest, take a spectrum sample to test the composition. If the composition meets the requirements, lower the temperature of the aluminum liquid.

[0123] A6: In the early, middle and late stages of casting, scoop aluminum liquid from the flow channel behind the filter box to test the composition; the surface of the aluminum ingot is required to be free of oil stains, corrosion spots, slag and non-metallic inclusions;

[0124] A7: Immerse the cast casting in the quenching medium to quench the casting.

[0125] The alloy composition is composed of the following by mass percentage:

[0126] 10% silicon,

[0127] 0.4% iron,

[0128] 0.4% copper,

[0129] 0.4% zinc,

[0130] 0.5% manganese,

[0131] 0.14% chromium,

[0132] 0.3% magnesium,

[0133] 0.08% vanadium,

[0134] 0.18% titanium,

[0135] 0.08% zirconium,

[0136] 0.08% nickel,

[0137] 0.02% strontium,

[0138] 0.008% calcium,

[0139] The alloy inevitably adds TiB2 seeds or AlNbB, AlLaB, AlTIB refiners;

[0140] Individual impurity elements are less than 0.05%, and the rest is aluminum.

[0141] The Si element is added in the form of elemental silicon, the Cr element is added in the form of an Al-Cr master alloy, the V element is added in the form of an Al-V master alloy, the Ti element is added in the form of an Al-Ti master alloy, the Mn element (if present) is added in the form of an Al-Mn master alloy, the Fe element is added in the form of an Al-Fe master alloy, and the Sr element is added in the form of an Al-Sr master alloy.

[0142] The titanium is one of aluminum titanium boron, aluminum titanium carbon boron and aluminum titanium niobium boron.

[0143] The temperature of the aluminum liquid in the casting furnace is 705°C, the temperature of the distribution hub is 645°C, the casting speed is 7 Hz / min, the nitrogen pressure is 1.1 kgf / cm², the nitrogen flow rate is 1.6 m³ / h, the rotor speed is 430 r / min, and the filter plate is 40 meshes.

[0144] The quenching treatment is carried out at a temperature of 555°C and for a time of 25 minutes.

[0145] The preparation method of the quenching medium is:

[0146] S1: 28 kg of double-terminated amino polyethylene glycol, 5 kg of 1-BOC-4-allyl-4-piperidinic acid, 0.04 kg of 4-aminothiazole-2-carboxylic acid lithium CAS No.: 2361644-16-6, and 140 kg of water were added, the pH value was adjusted to 9 with sodium hydroxide, and the mixture was stirred at 85°C for 90 minutes;

[0147] S2: Add 5 kg of sodium nitrite and stir for 140 minutes to obtain a quenching medium.

[0148] The double-terminated amino polyethylene glycol has a molecular weight of 2000.

[0149] Example 4

[0150] A method for preparing a low-carbon heat-treatment-free aluminum alloy, the operating steps of which are:

[0151] A1: Prepare materials according to the alloy composition ratio, purchase AlSi7MnMg and AlSi10MnMg materials from the market for die-casting structural parts scraps, aluminum subframe parts and crush them; door and window materials and toothpaste shells and other scraps;

[0152] A2: The crushed waste and silicon are placed in a large furnace for heating and smelting. The temperature of the aluminum liquid is 620℃. After all the raw materials are melted, a large rake is used to rake out the unmelted iron and other high-melting-point items at the bottom of the furnace. After the rake is completed, the iron-absorbing device is inserted into the aluminum liquid, powered on, and small iron nails that cannot be picked up by the large rake in the furnace are absorbed until they cannot be absorbed. Then the temperature is raised to 740℃.

[0153] A3: When the aluminum liquid temperature reaches 740℃, check the composition in the furnace, add the required supplementary components, weigh the required master alloy and bake it, add the dried Al-Mn master alloy, Al-V master alloy, Al-Ti and other master alloys into the aluminum liquid, heat the aluminum liquid to 760℃, keep it warm for 30 minutes, and ensure that all the added master alloys are melted;

[0154] A4: Press the Al-Sr master alloy into the aluminum liquid, and then degas the aluminum liquid to remove hydrogen in the aluminum liquid. The control parameters are: connect the equipment with a seamless steel pipe, and the gas introduced is high-purity argon gas with a purity of >99.99%. The bubble height cannot exceed 20mm; the refining temperature is 750℃, the time is 50min, the degassing time is 25min, and the refining is repeated twice;

[0155] A5: After refining and degassing, remove the scum on the surface of the aluminum liquid. After it is still for 25 minutes, take a spectrum sample to test the composition. If the composition meets the requirements, lower the temperature of the aluminum liquid.

[0156] A6: In the early, middle and late stages of casting, scoop aluminum liquid from the flow channel behind the filter box to test the composition; the surface of the aluminum ingot is required to be free of oil stains, corrosion spots, slag and non-metallic inclusions;

[0157] A7: Immerse the cast casting in the quenching medium to quench the casting.

[0158] The alloy composition is composed of the following by mass percentage:

[0159] 11.0% silicon,

[0160] 0.6% iron,

[0161] 0.5% copper,

[0162] 0.5% zinc,

[0163] 0.6% manganese,

[0164] 0.15% chromium,

[0165] 0.4% magnesium,

[0166] 0.1% vanadium,

[0167] 0.2% titanium,

[0168] 0.1% zirconium,

[0169] 0.1% nickel,

[0170] 0.03% strontium,

[0171] 0.01% calcium,

[0172] The alloy inevitably adds TiB2 seeds or AlNbB, AlLaB, AlTIB refiners;

[0173] Individual impurity elements are less than 0.05%, and the rest is aluminum.

[0174] The Si element is added in the form of elemental silicon, the Cr element is added in the form of an Al-Cr master alloy, the V element is added in the form of an Al-V master alloy, the Ti element is added in the form of an Al-Ti master alloy, the Mn element (if present) is added in the form of an Al-Mn master alloy, the Fe element is added in the form of an Al-Fe master alloy, and the Sr element is added in the form of an Al-Sr master alloy.

[0175] The titanium is aluminum titanium niobium boron.

[0176] The temperature of the aluminum liquid in the casting furnace is 710°C, the temperature of the distribution hub is 650°C, the casting speed is 8 Hz / min, the nitrogen pressure is 1.2 kgf / cm², the nitrogen flow rate is 1.8 m³ / h, the rotor speed is 450 r / min, and the filter plate is 40 meshes.

[0177] The quenching treatment is carried out at a temperature of 560° C. and for 30 minutes.

[0178] The preparation method of the quenching medium is:

[0179] S1: 30 kg of double-terminated amino polyethylene glycol, 5.4 kg of 1-BOC-4-allyl-4-piperidinic acid, 0.05 kg of 4-aminothiazole-2-carboxylic acid lithium CAS No.: 2361644-16-6, and 150 kg of water were added, the pH value was adjusted to 9 with sodium hydroxide, and the mixture was stirred at 90°C for 100 minutes;

[0180] S2: Add 6 kg of sodium nitrite and stir for 150 minutes to obtain a quenching medium.

[0181] The double-terminated amino polyethylene glycol has a molecular weight of 4000.

[0182] Comparative Example 1

[0183] No quenching medium was added, and the rest was the same as in Example 1.

[0184] Comparative Example 2

[0185] The other steps were the same as in Example 1 except that 1-BOC-4-allyl-4-piperidinic acid was not added.

[0186] Comparative Example 3

[0187] The other steps were the same as in Example 1 except that lithium 4-aminothiazole-2-carboxylate was not added.

[0188] Tensile strength / Mpa Yield strength / MPa Elongation / % Quenching conditions Example 1 315 150 13.1 No deformation and cracking Example 2 316 151 13.7 No deformation and cracking Example 3 319 153 14.3 No deformation and cracking Example 4 321 155 14.6 No deformation and cracking Comparative Example 1 285 133 10.2 Deformation, cracking Comparative Example 2 296 143 11.6 Deformation Comparative Example 3 300 146 11.8 Deformation

[0189] Through the data analysis of the above embodiments and comparative examples, the aluminum alloy prepared by the present invention has excellent mechanical properties; the quenching liquid prepared by the present invention helps to reduce deformation and cracking that may occur during the heat treatment process.

[0190] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for producing a low-carbon heat-treatment-free aluminum alloy, characterized in that: The operation steps are: A1: Prepare materials according to the alloy composition ratio, and purchase AlSi7MnMg and AlSi10MnMg material die-casting structural parts scraps, aluminum subframe parts and crushed, door and window materials, toothpaste shells and other scraps on the market; A2: The crushed waste and silicon are placed in a large furnace for heating and smelting. The temperature of the aluminum liquid is 590-620℃. After all the raw materials are melted, a large rake is used to rake out the unmelted iron and other high-melting-point items at the bottom of the furnace. After the rake is completed, the iron-absorbing device is inserted into the aluminum liquid, powered on, and small iron nails that cannot be picked up by the large rake in the furnace are absorbed until they cannot be absorbed anymore. Then the temperature is raised to 730-740℃. A3: When the temperature of the aluminum liquid reaches 730-740℃, check the composition in the furnace, add the required supplementary components, weigh the required master alloy and bake it, add the dried Al-Mn master alloy, Al-V master alloy, Al-Ti and other master alloys into the aluminum liquid, heat the aluminum liquid to 740-760℃, keep it warm for 10-30 minutes, and ensure that all the added master alloys are melted; A4: Press the Al-Sr master alloy into the aluminum liquid, and then degas the aluminum liquid to remove hydrogen in the aluminum liquid. The control parameters are: connect the equipment with a seamless steel pipe, and the gas introduced is high-purity argon gas with a purity of >99.99%. The bubble height cannot exceed 20mm; the refining temperature is 740-750℃, the time is 30-50min, the degassing time is 15-25min, and the refining is repeated twice; A5: After refining and degassing, remove the scum on the surface of the aluminum liquid, let it stand for 15-25 minutes, then take the spectrum sample to detect the composition. If the composition meets the requirements, lower the temperature of the aluminum liquid; A6: In the early, middle and late stages of casting, scoop aluminum liquid from the flow channel behind the filter box to test the composition; the surface of the aluminum ingot is required to be free of oil stains, corrosion spots, slag and non-metallic inclusions; the temperature of the aluminum liquid in the casting furnace is 700-710℃, the distribution hub temperature is 630-650℃, the casting speed is 6-8 Hz / min, the nitrogen pressure is 0.8-1.2kgf / cm², the nitrogen flow rate is 1.0-1.8m³ / h, the rotor speed is 350-450r / min, and the filter plate is 40 mesh; A7: Immerse the cast casting in a quenching medium to quench the casting; The quenching treatment temperature is 540-560°C and the time is 15-30 minutes. The alloy composition is composed of the following by mass percentage: 8.5-11.0% silicon, 0.05-0.6% iron, 0.05-0.5% copper, 0.05-0.5% zinc, 0.3-0.6% manganese, 0.1-0.15% chromium, 0.05-0.4% magnesium, 0.01-0.1% vanadium, 0.1-0.2% titanium, 0.05-0.1% zirconium, 0.05-0.1% nickel, 0.01-0.03% strontium, 0.005-0.01% calcium, The alloy inevitably adds TiB2 seed crystals or AlNbB, AlLaB, AlTIB refiners; individual impurity elements are less than 0.05%, and the rest is aluminum.

2. The method for producing a low-carbon heat-treatment-free aluminum alloy according to claim 1, characterized in that: The preparation method of the quenching medium is as follows: S1: by weight, 20-30 parts of double-terminated amino polyethylene glycol, 2.7-5.4 parts of 1-BOC-4-allyl-4-piperidinic acid, 0.005-0.05 parts of 4-aminothiazole-2-carboxylic acid lithium CAS number: 2361644-16-6, 100-150 parts of water, adjusted to pH = 9 with sodium hydroxide, stirred and reacted at 70-90°C for 50-100 minutes; S2: Add 3-6 parts of sodium nitrite and stir for 120-150 minutes to obtain a quenching medium.

3. The method for producing a low-carbon heat-treatment-free aluminum alloy according to claim 1, characterized in that: The Si element is added in the form of elemental silicon, the Cr element is added in the form of an Al-Cr master alloy, the V element is added in the form of an Al-V master alloy, the Ti element is added in the form of an Al-Ti master alloy, the Mn element is added in the form of an Al-Mn master alloy, the Fe element is added in the form of an Al-Fe master alloy, and the Sr element is added in the form of an Al-Sr master alloy.

4. The method for producing a low-carbon heat-treatment-free aluminum alloy according to claim 3, characterized in that: Titanium is one of aluminum titanium boron, aluminum titanium carbon boron, and aluminum titanium niobium boron.

5. The method for producing a low-carbon heat-treatment-free aluminum alloy according to claim 1, characterized in that: The double-terminated amino polyethylene glycol includes those with a molecular weight of 1000, 2000 or 4000.