High-toughness high-temperature-resistant Al-Si-Cu-Mg series aluminum alloy as well as preparation method and application thereof

Abstract

The invention provides a high-toughness and high-temperature-resistant Al-Si-Cu-Mg series aluminum alloy as well as a preparation method and application thereof. The Al-Si-Cu-Mg series aluminum alloy is prepared from the following components in parts by weight: 6.5 to 9 parts of Si, less than or equal to 0.2 part of Fe, 1.5 to 3.5 parts of Cu, 0.1 to 0.5 part of Mn, 0.2 to 0.8 part of Mg, 0.05 to 0.2 part of Ti, 0 to 0.1 part of Sr, 0 to 0.2 part of Re, 100 parts in total, and the balance of Al. The preparation method comprises the following steps: (1) burdening according to the ratio, preheating and drying the raw materials, sequentially adding the raw materials into smelting equipment, and heating and melting to obtain an alloy melt; (2) refining and modifying the alloy melt; (3) the refined alloy melt is subjected to forming machining, and an aluminum alloy blank product is obtained; and (4) the aluminum alloy blank product is subjected to T6 heat treatment, and the aluminum alloy is obtained. The aluminum alloy material with high mechanical property and high-temperature-resistant stability can be obtained by only adopting an Al-Si-Cu-Mg'vegetarizing 'formula without adding various trace elements and without redesigning and adjusting a production process, and the aluminum alloy material is simple in process, low in cost and particularly suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum alloy materials, and in particular relates to a high-strength, toughness, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy and a preparation method and application thereof. Background Art

[0002] Lightweight aluminum alloys, with their high strength and low density, can significantly reduce the weight of transportation vehicles, thereby reducing energy consumption and carbon emissions, perfectly matching the vision of "carbon peak" and "carbon neutrality". In order to better respond to this strategy and meet market demand, the manufacturing process and application technology of aluminum alloy materials urgently need to continue to innovate.

[0003] Al-Si aluminum alloys are favored in high-performance casting fields such as automobiles and aerospace due to their low density, high strength, excellent casting performance and good corrosion resistance. With the advancement of automobile technology, the demand for lightweight, high-strength, high-temperature resistance and high toughness of materials is growing. Especially in the application of engine cylinder heads, due to their complex structure and direct exposure to high-temperature and high-pressure combustion chambers, there are strict requirements on the high-temperature and high-pressure resistance of cylinder head materials.

[0004] In recent years, with the continuous improvement of engine power, the operating temperature and pressure of the cylinder head have also increased. For example, the pressure of the combustion chamber may reach 18 to 20MPa, and the operating temperature may exceed 200℃ in some areas. In order to meet the performance requirements under these harsh working conditions, the cast aluminum alloy materials used in the engine cylinder head must not only have good room temperature performance, but also ensure stable performance at high temperatures. However, the widely used aluminum alloy materials, such as A356, ZL101A and AC4B, will drop sharply at operating temperatures exceeding 200℃, which to a certain extent limits the further improvement of engine power. In the automotive industry, aluminum alloy materials commonly used in flywheel housings, gear chambers, brackets and other components, such as A380, ZL111, ADC12, etc., have high requirements for silicon phase modification during the production process, and the impurity components account for a large proportion. In the continuous casting process, these materials are very prone to oxidation, hydrogen absorption, and specific gravity segregation, resulting in insufficient toughness of the cast products and a high scrap rate.

[0005] The commonly used methods to improve the performance of Al-Si alloys are mainly the following: (1) Increasing the content of alloying elements: By increasing the content of alloying elements, the strength of the alloy can be improved. For example, the strength of the alloy can be improved by increasing the content of main elements such as Cu and Mg, or by adding trace elements such as Mo, V, Ni, Zr, and Ti for alloying to improve the performance of the alloy. (2) Grain refinement: Grain refinement can improve the strength of the alloy. Specifically, the grains can be refined by adding refiners or using heat treatment methods. (3) Controlling the impurity content of the alloy: Controlling the impurity content of the alloy can improve the strength of the alloy. Specifically, high-purity raw materials can be used or refining methods can be used to control the impurity content of the alloy. (4) Using heat treatment and other processes: Appropriate heat treatment and other processes can improve the structure and properties of the alloy, thereby improving the strength of the alloy.

[0006] Chinese patent CN115852214A is a high-temperature resistant aluminum alloy material developed for engines. The alloy introduces trace elements such as Mo, Zn, Ti and TCB seeds, so that the alloy is modified and refined simultaneously, achieving the effect of synergistic refinement of α-Al and eutectic silicon. The Mo element precipitates in the form of nanoparticles during the aging stage to form dispersion strengthening, giving the alloy certain high-temperature mechanical properties. However, the introduction of many trace elements will face huge challenges in the actual production process, resulting in a significant increase in the difficulty of process control and material costs, thereby limiting the promotion and application of new materials and reducing the market competitiveness of products.

[0007] Chinese patent CN110724861 B is an aluminum alloy material developed for engine cylinder heads. The alloy scheme introduces alloy elements such as Zr and Ni, and also adds Sc elements to reduce the damage of Zr and Ni to the toughness of the material. However, the presence of Zr and Ni in aluminum alloys will inevitably cause poisoning.

[0008] In addition, from the perspective of preparation technology, most aluminum alloy casting manufacturers currently use traditional national or American standard grades, and most of the existing new aluminum alloy patents are achieved by introducing a variety of trace elements and adjusting the heat treatment process. The use of these new grades by manufacturers means that they need to redesign and adjust the production process, including but not limited to molds, smelting processes and quality control standards; these adjustments will inevitably incur additional costs, such as R&D expenses, raw material procurement costs, and a short-term decline in production efficiency.

[0009] Therefore, if we can avoid introducing multiple trace elements and only regulate the aluminum alloy from the perspective of alloy organization, main element (Al, Si, Cu, Mn, Mg) ratio and refining and modification process, the above-mentioned unfavorable factors can be greatly reduced. It can be seen that making the alloy composition "plain" and achieving the same performance level as the alloy regulated by adding multiple trace elements is the trend of the development of new aluminum alloys in the future, and it is also a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0010] The purpose of the present invention is to provide a high-strength, tough, and high-temperature resistant aluminum alloy solution, which specifically adopts a "primitive" formula of Al-Si-Cu-Mg, does not add a variety of trace elements, and does not require redesigning and adjusting the production process, so that an aluminum alloy material that takes into account both high mechanical properties and high-temperature stability can be obtained. The "primitive" formula can greatly reduce the control difficulty and material cost of the production process, and the standard grade can be adapted to the existing production line and production process without additional adjustment of the process standards. The optimized design of the two aspects can greatly reduce the production cost of the aluminum alloy material and improve the product competitiveness and economic benefits.

[0011] To achieve the above-mentioned purpose, the present invention provides a high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy, which includes the following components in parts by weight: 6.5-9 parts of Si, ≤0.2 parts of Fe, 1.5-3.5 parts of Cu, 0.1-0.5 parts of Mn, 0.2-0.8 parts of Mg, 0.05-0.2 parts of Ti, 0-0.1 parts of Sr, and 0-0.2 parts of Re, wherein the total of the components is 100 parts, and the balance is Al.

[0012] In a preferred embodiment, the Re is a rare earth element consisting of La and Ce.

[0013] In a preferred embodiment, the weight fraction of Sr and / or Re is not 0.

[0014] In a preferred embodiment, the prepared Al-Si-Cu-Mg aluminum alloy has a tensile strength of ≥350MPa, a yield strength of ≥300MPa, and an elongation at break of 3.0-5.0% at 25°C; a tensile strength of ≥280MPa, a yield strength of ≥250MPa, and an elongation at break of 6.0-15.0% at 200°C.

[0015] Another object of the present invention is to provide a method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy, comprising the following steps:

[0016] (1) preparing the raw materials according to the component ratio, preheating and drying the raw materials, and then sequentially adding the preheated raw materials into a smelting device, heating and melting the raw materials, and stirring the raw materials uniformly to obtain an alloy melt;

[0017] (2) Refining and modifying the alloy melt to complete degassing and impurity removal;

[0018] (3) forming the refined alloy melt to obtain an aluminum alloy blank product;

[0019] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment to obtain a high-strength, toughness, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0020] In a preferred embodiment, in step (1), the preheating temperature is 280-320°C, preferably, the preheating temperature is 300°C.

[0021] In a preferred embodiment, in step (1), the order in which the raw materials are added to the smelting equipment is as follows: first, the Al-Si alloy ingot is added to the smelting furnace for melting, and after it is completely melted, pure metals or intermediate alloys of Cu, Mg, and Mn are added, and after it is completely melted, it is melted at 700°C for 30 minutes, and after it is completely melted, Al-Ti-B-Sc, AI-RE, and Al-Sr intermediate alloys are added.

[0022] When preparing the alloy, the present invention adds Al-Ti-B-Sc refiner, a small amount of Sr and rare earth (La, Ce) for modification treatment to obtain high-quality metallographic structure, the secondary dendrite spacing is less than 20μm, and the total amount of other impurities is less than or equal to 0.3wt.%. The alloy obtained from the raw materials is suitable for gravity casting, die casting, extrusion casting and other molding processes, and is convenient for subsequent processing.

[0023] In a preferred embodiment, the heating and melting temperature in step (1) is 700-750°C, and the heating and melting time is 10-60 minutes, that is, after all the raw materials are melted, they are kept warm at the above temperature for 10-60 minutes. Preferably, the heating and melting time is 30 minutes.

[0024] In a preferred embodiment, in step (2), the refining process includes: introducing nitrogen or argon as a protective gas into the alloy melt, adding RJ-01 refining agent, and refining for 10-40 minutes.

[0025] In a preferred embodiment, in step (2), the amount of the protective gas introduced is 3-6 L / min, the amount of the refining agent added is 0.1-0.5% of the mass of the alloy melt, and the degassing refining process is carried out using a rotary degasser.

[0026] In a preferred embodiment, in step (3), the forming process of the refined alloy melt specifically includes: one or more forming processes such as gravity casting, die casting, extrusion casting, etc., for which those skilled in the art can adopt conventional treatments. Preferably, the equipment used for the casting is a gravity rotary casting machine, a high-pressure die casting machine or a liquid die forging machine, wherein the high-pressure die casting machine and the liquid die forging machine have an injection pressure ratio of 50-100 MPa.

[0027] In a preferred embodiment, in step (4), the T6 heat treatment process includes: a solution temperature of 480-550°C, a holding time of 8-16 hours, quenching in water after the solution is completed, a quenching temperature of 50-80°C, an artificial aging temperature of 160-230°C, a holding time of 4-8 hours, and cooling to room temperature with the furnace.

[0028] Another object of the present invention is to provide an application of a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy, which is used to prepare parts of diesel / gasoline engine cylinder heads, flywheel housings, gear chambers, and brackets.

[0029] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0030] The technical solution provided by the present invention only uses the "primitive" formula of Al-Si-Cu-Mg, does not add a variety of trace elements, and does not require redesign and adjustment of the production process to obtain an aluminum alloy material that combines high mechanical properties and high temperature stability. The "primitive" formula can greatly reduce the control difficulty and material cost of the production process, and the standard grade can be adapted to the existing production line and production process without additional adjustment of the process standard. The optimized design of the two aspects can greatly reduce the production cost of the aluminum alloy material and improve the product competitiveness and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These and / or other aspects and advantages of the present invention will become more clear and easier to understand from the following detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0032] Figure 1 This is a structural image of the Al-Si-Cu-Mg aluminum alloy prepared in Example 1 of the present invention, taken under a metallographic microscope at 100x. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but it should be understood that the protection scope of the present invention is not limited to the specific implementation methods.

[0034] The technical solution of the present application is described in detail below through specific embodiments:

[0035] Unless otherwise specified, the technical means used in the present invention are conventional means well known to those skilled in the art, and the various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods. The reagents used in the present invention are analytically pure unless otherwise specified.

[0036] In the present invention, parts by weight may be μg, mg, g, kg or other weight units known in the art, or multiples thereof, such as 1 / 10, 1 / 100, 10 times, 100 times or the like.

[0037] The test methods adopted in the effect examples of the present invention are GB / T 228.1-2021 and GB / T 228.2-2015.

[0038] Example 1

[0039] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0040] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 6.58, Fe≤0.2, Cu 1.58, Mn 0.36, Mg 0.36, Ti 0.11, Sr 0.02, La+Ce 0.15, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0041] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0042] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0043] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0044] The structure image of the Al-Si-Cu-Mg aluminum alloy prepared in Example 1 taken under a metallographic microscope at 100x is as follows: Figure 1 As shown in the figure, it can be seen that the α-Al matrix is ​​evenly distributed, the grains are fine, the secondary dendrite spacing is less than 20μm, and the eutectic silicon is refined into dispersed particles. The introduction of Al-Ti-B-Sc and rare earth La and Ce makes the size of the matrix structure and compound phase more uniform and refined. The metallographic structure morphology obtained in the other embodiments is similar to Figure 1 The α-Al matrix shows uniform distribution and fine grains, and the secondary dendrite spacing is less than 20 μm.

[0045] Example 2

[0046] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0047] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 7.12, Fe≤0.2, Cu 1.82, Mn 0.25, Mg 0.38, Ti 0.12, Sr 0.018, La+Ce 0.14, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0048] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0049] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0050] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0051] Example 3

[0052] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0053] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 7.35, Fe≤0.2, Cu 2.12, Mn 0.14, Mg 0.52, Ti 0.11, Sr 0.019, La+Ce 0.15, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0054] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0055] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0056] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0057] Example 4

[0058] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0059] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 8.99, Fe≤0.2, Cu 2.24, Mn 0.17, Mg 0.72, Ti 0.15, Sr 0.021, La+Ce 0.16, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0060] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0061] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0062] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0063] Example 5

[0064] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0065] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 9.12, Fe≤0.2, Cu 2.58, Mn 0.16, Mg 0.31, Ti 0.13, Sr 0.021, La+Ce 0.21, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0066] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0067] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0068] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0069] Example 6

[0070] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0071] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 6.54, Fe≤0.2, Cu 2.83, Mn 0.31, Mg 0.48, Ti 0.17, Sr 0.022, La+Ce 0.11, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0072] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0073] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0074] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0075] Example 7

[0076] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0077] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 6.93, Fe≤0.2, Cu 3.15, Mn 0.38, Mg 0.51, Ti 0.16, Sr 0.019, La+Ce 0.12, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0078] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0079] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0080] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0081] Example 8

[0082] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0083] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 7.31, Fe≤0.2, Cu 3.24, Mn 0.43, Mg 0.68, Ti 0.19, Sr 0.018, La+Ce 0.11, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0084] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0085] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0086] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0087] Example 9

[0088] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0089] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 7.94, Fe≤0.2, Cu 3.21, Mn 0.49, Mg 0.75, Ti 0.13, Sr 0.02, La+Ce 0.14, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0090] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0091] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0092] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0093] Example 10

[0094] A method for preparing a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy comprises the following steps:

[0095] (1) Formula design, the weight ratio (chemical composition) of each component wt% includes: Si 8.68, Fe≤0.2, Cu 3.48, Mn 0.21, Mg 0.65, Ti 0.05, Sr 0.023, La+Ce 0.15, Al and the rest, and the ingredients are prepared. The raw materials are preheated and dried at 300°C, and then the preheated raw materials are added to the smelting equipment in sequence. The specific sequence is: first add the Al-Si alloy ingot to the smelting furnace for melting, and after it is completely melted, add the pure metal or intermediate alloy of Cu element, Mg element, and Mn element, and after it is completely melted, keep it warm at 700°C for 30 minutes, and after it is completely melted, add Al-Ti-B-Sc, AI-RE and Al-Sr intermediate alloy, heat to 700°C until all the raw materials are melted, stir evenly, and obtain an alloy melt;

[0096] (2) Refining the alloy melt to complete degassing and impurity removal; specifically, the process includes: introducing protective gas (nitrogen) into the alloy melt at a flow rate of 3 L / min, adding RJ-01 refining agent at 0.1% of the mass of the alloy melt, and refining for 20 minutes. The degassing and refining process is carried out using a rotary degasser.

[0097] (3) forming the refined alloy melt by a gravity rotary casting machine to obtain an aluminum alloy blank product;

[0098] (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment, wherein the solid solution temperature is 500°C±5°C, the holding time is 10 hours, and after the solid solution is completed, it is quenched in water at a quenching temperature of 50°C, the artificial aging temperature is 170°C±5°C, the holding time is 5 hours, and the product is cooled to room temperature in the furnace to obtain a high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

[0099] Comparative Example 1

[0100] (1) Formula design: the weight ratio (chemical composition) of each component includes: Si 7.1, Fe 0.1, Mn 0.005, Mg 0.39, Ti 0.11, La+Ce 0.02, Al and the rest, and the ingredients are prepared.

[0101] (2) The aluminum alloy material is prepared by using a conventional smelting method in the prior art and a heat treatment process that is exactly the same as that in the embodiment (solutionizing temperature is 500°C ± 5°C, holding time is 10 hours, quenching in water after solutionizing, quenching temperature is 50°C, artificial aging temperature is 170°C ± 5°C, holding time is 5 hours, and cooling to room temperature with the furnace).

[0102] Comparative Example 2

[0103] (1) Formula design: the weight ratio (chemical composition) of each component includes: Si 9.56, Fe 0.31, Cu 1.42, Mn 0.27, Mg 0.47, Ti 0.1, Sr 0.07, La+Ce 0.001, Al and the rest, and the ingredients are prepared.

[0104] (2) The aluminum alloy material is prepared by using a conventional smelting method in the prior art and a heat treatment process that is exactly the same as that in the embodiment (solutionizing temperature is 500°C ± 5°C, holding time is 10 hours, quenching in water after solutionizing, quenching temperature is 50°C, artificial aging temperature is 170°C ± 5°C, holding time is 5 hours, and cooling to room temperature with the furnace).

[0105] Comparative Example 3

[0106] (1) Formula design: the weight ratio (chemical composition) of each component includes: Si 10.75, Fe 1, Cu 2.18, Mn 0.22, Mg 0.17, Ti 0.02, Sr 0.14, La+Ce 0.002, Al and the rest, and the ingredients are prepared.

[0107] (2) The aluminum alloy material is prepared by using a conventional smelting method in the prior art and a heat treatment process that is exactly the same as that in the embodiment (solutionizing temperature is 500°C ± 5°C, holding time is 10 hours, quenching in water after solutionizing, quenching temperature is 50°C, artificial aging temperature is 170°C ± 5°C, holding time is 5 hours, and cooling to room temperature with the furnace).

[0108] Comparative Example 4

[0109] (1) Formula design: the weight ratio (chemical composition) of each component includes: Si 9.12, Fe 0.78, Cu 3.43, Mn 0.26, Mg 0.06, Ti 0.03, Sr 0.54, La+Ce 0.006, Al and the rest, and the ingredients are prepared.

[0110] (2) The aluminum alloy material is prepared by using a conventional smelting method in the prior art and a heat treatment process that is exactly the same as that in the embodiment (solutionizing temperature is 500°C ± 5°C, holding time is 10 hours, quenching in water after solutionizing, quenching temperature is 50°C, artificial aging temperature is 170°C ± 5°C, holding time is 5 hours, and cooling to room temperature with the furnace).

[0111] Comparative Example 5

[0112] (1) Formula design: the weight ratio (chemical composition) of each component includes: Si 8.1, Fe 0.25, Cu 2.23, Mn 0.24, Mg 0.28, Ti 0.1, Sr 0.02, La+Ce 0.09, Al and the rest, and the ingredients are prepared.

[0113] (2) The aluminum alloy material is prepared by using a conventional smelting method in the prior art and a heat treatment process that is exactly the same as that in the embodiment (solutionizing temperature is 500°C ± 5°C, holding time is 10 hours, quenching in water after solutionizing, quenching temperature is 50°C, artificial aging temperature is 170°C ± 5°C, holding time is 5 hours, and cooling to room temperature with the furnace).

[0114] Effect example

[0115] The aluminum alloy materials prepared in the examples and comparative examples were subjected to performance tests, and the results are shown in Table 1.

[0116] Table 1

[0117]

[0118] It can be seen from the table that the Al-Si-Cu-Mg aluminum alloy prepared by the scheme of the present invention has obvious high strength and high temperature resistance. At an ambient temperature of 25°C, the tensile strength is ≥350MPa, the yield strength is ≥300MPa, and the elongation after fracture is 3.0-5.0%; at a high temperature of 200°C, the tensile strength is ≥280MPa, the yield strength is ≥250MPa, and the elongation after fracture is 6.0-15.0%. It can be widely used in the preparation of wear-resistant parts such as diesel / gasoline engine cylinder heads, flywheel housings, gear chambers, brackets, etc.

[0119] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A high-strength, tough, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy, characterized in that: The invention comprises the following components by weight: 6.5-9 parts of Si, ≤0.2 parts of Fe, 1.5-3.5 parts of Cu, 0.1-0.5 parts of Mn, 0.2-0.8 parts of Mg, 0.05-0.2 parts of Ti, 0-0.1 parts of Sr and 0-0.2 parts of Re, the total of the components is 100 parts, and the balance is Al.

2. The high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to claim 1, characterized in that: The prepared Al-Si-Cu-Mg aluminum alloy has a tensile strength of ≥350MPa, a yield strength of ≥300MPa, and an elongation of 3.0-5.0% at 25°C; a tensile strength of ≥280MPa, a yield strength of ≥250MPa, and an elongation of 6.0-15.0% at 200°C.

3. The method for preparing the high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to claim 1 or 2, characterized in that: The following steps are involved: (1) preparing the raw materials according to the component ratio, preheating and drying the raw materials, and then sequentially adding the preheated raw materials into a smelting device, heating and melting the raw materials, and stirring the raw materials uniformly to obtain an alloy melt; (2) Refining and modifying the alloy melt; (3) forming the refined alloy melt to obtain an aluminum alloy blank product; (4) The obtained aluminum alloy blank product is subjected to T6 heat treatment to obtain a high-strength, toughness, and high-temperature resistant Al-Si-Cu-Mg aluminum alloy.

4. The method for preparing the high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to claim 3, characterized in that: In step (1), the preheating temperature is 280-320°C.

5. The method for preparing the high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to claim 3, characterized in that: In step (1), the order in which the raw materials are added to the smelting equipment is as follows: first, the Al-Si alloy ingot is added to the smelting furnace for melting, and after it is completely melted, pure metals or intermediate alloys of Cu, Mg, and Mn are added, and after it is completely melted, it is melted at 700°C for 30 minutes, and after it is completely melted, Al-Ti-B-Sc, AI-RE, and Al-Sr intermediate alloys are added.

6. The method for preparing the high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to claim 3, characterized in that: The heating and melting temperature in step (1) is 700-750° C., and the heating and melting time is 10-60 min.

7. The method for preparing the high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to claim 3, characterized in that: In step (2), the refining process includes: introducing nitrogen or argon as a protective gas into the alloy melt, adding RJ-01 refining agent, and refining for 10-40 minutes.

8. The method for preparing the high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to claim 7, characterized in that: In step (2), the amount of the protective gas introduced is 3-6 L / min, and the amount of the refining agent added is 0.1-0.5% of the mass of the alloy melt.

9. The method for preparing the high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to claim 3, characterized in that: In step (4), the T6 heat treatment process includes: a solution temperature of 480-550°C, a holding time of 8-16 hours, quenching in water after the solution is completed, a quenching temperature of 50-80°C, an artificial aging temperature of 160-230°C, a holding time of 4-8 hours, and cooling to room temperature with the furnace.

10. The use of the high-strength, toughness and high-temperature resistant Al-Si-Cu-Mg aluminum alloy according to any one of claims 1 or 2, characterized in that: The aluminum alloy is used for preparing parts of diesel and / or gasoline engine cylinder heads, flywheel housings, gear chambers, and brackets.

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