Micro-alloyed material of high-performance aluminum alloy and preparation method and application of micro-alloyed material

Abstract

The invention discloses a microalloying material of a high-performance aluminum alloy as well as a preparation method and application of the microalloying material, and belongs to the technical field of aluminum alloys. The microalloying material of the high-performance aluminum alloy comprises the following components in parts by weight: 0.8 to 1.6 weight percent of Mg, 1.0 to 1.5 weight percent of Si, 0.2 weight percent of La, 0.8 to 1.2 weight percent of rare earth elements, less than or equal to 0.07 weight percent of Mn, less than or equal to 0.12 weight percent of Fe, 0.2 to 0.4 weight percent of Ag and the balance of Al. The hardness of the alloy is larger than 151 HV at the normal temperature, the yield strength is larger than 276 MPa, the tensile strength is larger than 342 MPa, the average grain size is smaller than 45 micrometers, the yield strength is larger than 114 MPa at the temperature of 400 DEG C, and the tensile strength is larger than 127 MPa at the temperature of 400 DEG C. The hardness of the alloy is improved, the grain size is reduced, and the problems of grain coarsening and heat-resistant phase dissolution of the alloy for the automobile engine are solved.

Description

Technical Field

[0001] The present invention relates to a microalloyed material for high-performance aluminum alloy, its preparation method and application, belonging to the technical field of aluminum alloy. Background Art

[0002] The 6xxx series Al-Mg-Si alloy belongs to heat-treatable strengthening alloy, has high impact toughness, can withstand large impact forces without fracture, and has good weldability. Therefore, it has wide applications in automobile body panels and automobile engines. Compared with other aluminum alloy materials, the 6xxx aluminum alloy has better processing performance; in terms of heat treatment, it can reach peak hardness faster, reduce heat treatment time, and is beneficial to reducing energy consumption.

[0003] Traditional aluminum alloys have coarse grains, resulting in poor strength, plasticity and heat resistance.

[0004] With the continuous development of modern technology, the requirement for material lightweight is constantly increasing. Aluminum alloy, as an important material in China's automobile industry and aviation field, has problems of alloy grain coarsening and heat-resistant phase dissolution. How to improve the strength, toughness and heat resistance of aluminum alloy is the pain point in the development of aluminum alloy for high-performance automobile engines and also the key means to promote material lightweight. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the present invention provides a microalloyed material for high-performance aluminum alloy, which solves the problems of grain coarsening and heat-resistant phase dissolution of aluminum alloy for automobile engines by microalloying cast alloys.

[0006] Meanwhile, the present invention provides a preparation method of a microalloyed material for high-performance aluminum alloy.

[0007] Meanwhile, the present invention provides an application of a microalloyed material for high-performance aluminum alloy in high-performance automobile engines.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] A microalloyed material for high-performance aluminum alloy, comprising the following components in parts by weight: Mg: 0.8 - 1.6 wt%, Si: 1.0 - 1.5 wt%, La: 0.2 wt%, rare earth elements 0.8 - 1.2 wt%, Mn ≤ 0.07 wt%, Fe ≤ 0.12 wt%, Ag: 0.2 - 0.4 wt%, and the balance is Al.

[0010] Preferably, the rare earth elements are Gd, Sc, Zr, and the mass ratio is 8:(4 - 7):(3 - 6).

[0011] The present invention also provides a method for preparing the microalloyed material of the high-performance aluminum alloy, comprising the following steps:

[0012] Step 1: Ingredients: Select the above components and ingredients by mass percentage, thoroughly clean all raw materials, remove surface oil and impurities, then dehydrate to ensure that the raw materials are dry and water-free, and then dry for use.

[0013] Step 2: Initial smelting: Place the processed raw materials (aluminum ingots, aluminum silicon alloy, La, Mn, Fe, Ag) in a smelting furnace, control the temperature at 400-500°C, and introduce inert gas (such as argon) for protection to prevent the alloy from being oxidized during the smelting process. Heat until completely melted, and stir several times to ensure that the alloy composition is uniform to form alloy melt 1;

[0014] Step 3, rare earth element addition and mid-term smelting: After the aluminum melt reaches an appropriate temperature of 550-600°C, the pre-treated rare earth elements are added to the alloy melt 1 in the form of particles (rare earth element particles of 30-35 μm), and are fully stirred to make the rare earth elements evenly distributed in the melt to form the alloy melt 2;

[0015] Step 4: Refining treatment: When the solution temperature reaches 650-700°C, add the refining agent, sprinkle the refining agent on the liquid surface, and quickly press it into the aluminum liquid. After sufficient stirring, let it stand for 15-20 minutes and remove the slag;

[0016] Step 5: Casting: preheat the mold to 260-300°C, pour the refined aluminum alloy liquid into the pre-prepared mold, and cool it to obtain an alloy ingot;

[0017] Step 6: Peeling: Remove the riser and uneven surface of the alloy ingot after casting to make the surface of the alloy ingot smooth;

[0018] Step 7, double-stage solid solution: put the alloy of step 6 into a heating furnace for double-stage solid solution treatment; as the temperature rises, the first stage solid solution is carried out at a temperature of 530-550°C for 2-3 hours; then the second stage solid solution is carried out at a temperature of 560-580°C for 3-4 hours;

[0019] Step 8: Quenching: Take out the alloy after the double-stage solid solution treatment and immediately put it into a quenching medium for quenching treatment and cool it to room temperature; the quenching medium is water at a temperature of 35-45°C;

[0020] Step 9: Aging: Place the quenched alloy into a heating furnace for aging treatment.

[0021] Preferably, the refining agent is one of a sodium-free refining agent, a rare earth-containing refining agent, and a composite refining agent.

[0022] The sodium-free refining agent uses RC-WJ1 produced by Xuzhou Ruichi Metal Materials Co., Ltd., the rare-earth-containing refining agent uses DFCT-2 produced by Ningbo Jiangbei Dongfan Metal Technology Co., Ltd., and the composite refining agent uses SJ-JLJ composite aluminum liquid refining agent produced by Jiangxi Century Xing New Materials Co., Ltd.

[0023] Preferably, the heating rate in step two is controlled at 10-15 °C / min, and the heating rate in step three is controlled at 5-10 °C / min.

[0024] Preferably, the quenching transfer time of the quenching treatment in step eight ≤ 10 s.

[0025] Preferably, the aging treatment in step nine includes the following steps: heating the quenched alloy to 330-350 °C at a heating rate of 15-20 °C / min and holding for 3-4 h.

[0026] Preferably, the microalloying material of the high-performance aluminum alloy has a hardness greater than 151 HV, a yield strength greater than 276 MPa, a tensile strength greater than 342 MPa, an average grain size less than 45 μm at room temperature, a yield strength greater than 114 MPa, and a tensile strength greater than 127 MPa at 400 °C.

[0027] The present invention also provides the application of the microalloying material of the high-performance aluminum alloy as a lightweight material for automobile engines in the field of automobiles.

[0028] The present invention has the following beneficial effects:

[0029] (1) The microalloying of Al-Mg-Si alloy is to add transition metal and rare-earth metal elements on the basis of Al-Mg-Si alloy. After adding elements such as Mn and Fe to Al-Mg-Si alloy, heat-resistant phases Al 5 Mn 2 Mg 8 Si 6 , Al 15 Mn 3 Si 2 can be formed. After continuing to add Gd to the alloy, Gd preferentially forms Al 2 Gd compounds, accelerating the solidification of the Al matrix, thus further refining the heat-resistant phases, promoting dispersion distribution, and forming a closed network on the grain boundaries to hinder the dissolution of the heat-resistant phases. Sc, Zr, and La are also common elements for treating alloys, forming Al 3 Zr, Al 3 Sc, Al 3La plays a role in pinning dislocations, stabilizing the alloy substructure, refining the grains, enhancing the alloy strength and recrystallization temperature. Moreover, the combined addition of Sc and La can accumulate in the dendrite crystallization melt of the alloy, causing constitutional supercooling, reducing the dendrite arm spacing, thereby refining the crystal structure. Meanwhile, adding the Zr element can transform the as-cast dendritic structure of the alloy into a fine equiaxed crystal structure. The AlScZr phase releases the stress concentration at the dislocation pile-up group through fragmentation, thus improving the strength and plasticity of the alloy, and greatly improving the heat resistance performance.

[0030] (2) By controlling the heating rate and quenching transfer time during the melting process, the uniformity and stability of the alloy are ensured. The present invention improves the hardness of the alloy and reduces the grain size, solving the problems of grain coarsening and dissolution of heat-resistant phases in the alloy for automotive engines. Brief Description of the Drawings

[0031] Figure 1 It is the EBSD diagram of Example 1 of the present invention. Detailed Embodiments

[0032] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand the 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.

[0033] Example 1

[0034] A preparation method of a microalloyed material for a high-performance aluminum alloy includes the following steps:

[0035] Step 1. Batching: According to Mg: 0.8 wt%, Si: 1.0 wt%, La: 0.2 wt%, rare earth elements: 0.8 wt%, Mn: 0.07 wt%, Fe: 0.12 wt%, Ag: 0.2 wt%, and the balance is Al. The rare earth elements are Gd, Sc, and Zr, and the mass ratio is 8:5:6.

[0036] Thoroughly clean all raw materials to remove the oil and impurities on the surface. Then perform dehydration treatment to ensure that the raw materials are dry and anhydrous, and then dry them for standby.

[0037] Step 2. Initial melting: Place all raw materials except rare earth elements such as aluminum ingots and aluminum-silicon alloys in a melting furnace, control the heating rate at 10 °C / min, control the temperature at 400 °C, and introduce an inert gas (such as argon) for protection to prevent the alloy from being oxidized during the melting process. Heat until completely melted and stir multiple times to ensure uniform alloy composition and form alloy melt 1.

[0038] Step 3. Rare earth element addition and intermediate smelting: After the aluminum melt reaches an appropriate temperature of 550°C at a heating rate of 5°C / min, the pre-treated rare earth elements in the form of particles (rare earth element particles of about 30 μm) are added to Alloy Melt 1, and sufficient stirring is carried out to make the rare earth elements evenly distributed in the melt, forming Alloy Melt 2.

[0039] Step 4. Refining treatment: When the solution temperature reaches 650°C, a sodium-free refining agent is added. The refining agent is sprinkled on the liquid surface and quickly pressed into the aluminum liquid. After sufficient stirring, it is left standing for 15 minutes and then the slag is skimmed off.

[0040] Step 5. Casting: The mold is preheated to 260°C, and then the refined aluminum alloy liquid is poured into the pre-prepared mold, and after cooling, an alloy ingot is obtained.

[0041] Step 6. Debarking: The riser and uneven parts on the surface of the cast alloy ingot are removed to make the surface of the alloy ingot smooth.

[0042] Step 7. Double-stage solution treatment: The alloy from Step 6 is put into a heating furnace for double-stage solution treatment; as the temperature rises, the first-stage solution treatment is carried out: the temperature is 530°C and the holding time is 2 h; then the second-stage solution treatment is carried out: the temperature is 560°C and the holding time is 3 h.

[0043] Step 8. Quenching: The alloy after double-stage solution treatment is taken out and immediately put into a quenching medium. The quenching transfer time is 10 s. Quenching treatment is carried out and cooled to room temperature; the quenching medium is water with a temperature of 35°C.

[0044] Step 9. Aging: The alloy after quenching treatment is put into a heating furnace for aging treatment. The quenched alloy is heated to 330°C at a heating rate of 15°C / min and held for 3 h.

[0045] The microalloyed material of the high-performance aluminum alloy in this embodiment is used as an automotive engine lightweight material in the automotive field.

[0046] Example 2

[0047] A preparation method of a microalloyed material of a high-performance aluminum alloy, comprising the following steps:

[0048] Step 1. Batching: According to Mg: 1.2 wt%, Si: 1.3 wt%, La: 0.2 wt%, rare earth elements: 1.1 wt%, Mn: 0.06 wt%, Fe: 0.11 wt%, Ag: 0.3 wt%, and the balance is Al. The rare earth elements are Gd, Sc, Zr, and the mass ratio is 8:5:4.

[0049] All raw materials are thoroughly cleaned to remove surface oil and impurities. After that, they are dehydrated to ensure that the raw materials are dry and free of water, and then dried for use.

[0050] Step 2, initial smelting: Place all raw materials except rare earth elements such as processed aluminum ingots and aluminum silicon alloy in a smelting furnace, control the heating rate to 12℃ / min, control the temperature to 460℃, and introduce inert gas (such as argon) for protection to prevent the alloy from being oxidized during the smelting process. Heat until completely melted, and stir several times to ensure uniform alloy composition to form alloy melt 1.

[0051] Step 3. Addition of rare earth elements and mid-term smelting: The heating rate is controlled at 8°C / min. After the aluminum melt reaches an appropriate temperature of 570°C, the pre-treated rare earth elements are added to the alloy melt one in the form of particles (rare earth element particles of about 35 μm), and fully stirred to make the rare earth elements evenly distributed in the melt to form alloy melt two.

[0052] Step 4: Refining treatment: When the solution temperature reaches 670°C, add the composite refining agent, sprinkle the refining agent on the liquid surface, and quickly press it into the aluminum liquid. After sufficient stirring, let it stand for 18 minutes and skim off the slag.

[0053] Step 5: Casting: Preheat the mold to 280°C, pour the refined aluminum alloy liquid into the pre-prepared mold, and cool it to obtain an alloy ingot.

[0054] Step 6: Peeling: Remove the riser and uneven surface of the alloy ingot after casting to make the surface of the alloy ingot smooth.

[0055] Step 7, double-stage solid solution: put the alloy of step 6 into a heating furnace for double-stage solid solution treatment; as the temperature rises, the first stage solid solution is carried out at a temperature of 540°C for 2.3 hours; and the second stage solid solution is carried out at a temperature of 570°C for 3.4 hours.

[0056] Step 8: Quenching: Take out the alloy after the double-stage solid solution treatment and immediately put it into the quenching medium. The quenching transfer time is 8 seconds. Perform quenching treatment and cool to room temperature. The quenching medium is water at a temperature of 39°C.

[0057] Step 9: Aging: Place the quenched alloy into a heating furnace for aging treatment. Heat the quenched alloy to 340°C at a heating rate of 18°C / min and keep it warm for 3.4h.

[0058] The high-performance aluminum alloy microalloyed material of this embodiment is used in the automotive field as a lightweight material for automobile engines.

[0059] Example 3

[0060] Preparation of a microalloyed material for a high-performance aluminum alloy, comprising the following steps:

[0061] Step 1, batching: According to Mg: 1.4 wt%, Si: 1.2 wt%, La: 0.2 wt%, rare earth elements: 1.1 wt%, Mn: 0.05 wt%, Fe: 0.11 wt%, Ag: 0.3 wt%, the balance is Al. The rare earth elements are Gd, Sc, Zr, and the mass ratio is 8:4:5.

[0062] Thoroughly clean all raw materials to remove oil and impurities on the surface. Then perform dehydration treatment to ensure that the raw materials are dry and water-free, and then dry and reserve them.

[0063] Step 2, initial melting: Place all the raw materials except rare earth elements such as aluminum ingots and aluminum-silicon alloys in a melting furnace, control the heating rate at 12 °C / min, control the temperature at 470 °C, and introduce an inert gas (such as argon) for protection to prevent the alloy from being oxidized during melting. Heat until completely melted and stir multiple times to ensure uniform alloy composition and form alloy melt 1.

[0064] Step 3, rare earth element addition and intermediate melting: Control the heating rate at 8 °C / min. After the aluminum melt reaches an appropriate temperature of 570 °C, add the pre-treated rare earth elements in granular form (rare earth element particles of about 35 μm) to alloy melt 1 and stir thoroughly to make the rare earth elements evenly distributed in the melt to form alloy melt 2.

[0065] Step 4, refining treatment: When the solution temperature reaches 680 °C, add a refining agent, sprinkle the refining agent on the liquid surface, and quickly press it into the aluminum liquid. After thorough stirring, let it stand for 18 minutes and skim the slag.

[0066] Step 5, casting: Preheat the mold to 300 °C, and then pour the refined aluminum alloy liquid into the pre-prepared mold to obtain an alloy ingot after cooling.

[0067] Step 6, skin removal: Remove the riser and uneven parts on the surface of the cast alloy ingot to make the surface of the alloy ingot smooth.

[0068] Step 7, double-stage solution treatment: Put the alloy in step 6 into a heating furnace for double-stage solution treatment; perform the first-stage solution treatment as the temperature rises: the temperature is 535 °C and keep it warm for 2.3 h; then perform the second-stage solution treatment: the temperature is 570 °C and keep it warm for 3.6 h.

[0069] Step 8, quenching: Take out the alloy after double-stage solution treatment and immediately put it into a quenching medium. The quenching transfer time is 9 s. Perform quenching treatment and cool it to room temperature; the quenching medium is water with a temperature of 38 °C.

[0070] Step 9: Aging: Place the quenched alloy into a heating furnace for aging treatment. Heat the quenched alloy to 345°C at a heating rate of 18°C / min and keep it warm for 3.5 hours.

[0071] The high-performance aluminum alloy microalloyed material of this embodiment is used in the automotive field as a lightweight material for automobile engines.

[0072] Example 4

[0073] A method for preparing a microalloyed material of a high-performance aluminum alloy comprises the following steps:

[0074] Step 1: Ingredients: Mg: 1.6wt%, Si: 1.5wt%, La: 0.2wt%, rare earth elements 1.2wt%, Mn 0.05wt%, Fe 0.11wt%, Ag: 0.4wt%, and the balance is Al. Rare earth elements are Gd, Sc, and Zr, with a mass ratio of 8:7:3.

[0075] All raw materials are thoroughly cleaned to remove surface oil and impurities. After that, they are dehydrated to ensure that the raw materials are dry and free of water, and then dried for use.

[0076] Step 2, initial smelting: Place all the processed aluminum ingots, aluminum silicon alloys and other raw materials except rare earth elements in a smelting furnace, control the heating rate to 15℃ / min, control the temperature to 500℃, and introduce inert gas (such as argon) for protection to prevent the alloy from being oxidized during the smelting process. Heat until completely melted, and stir several times to ensure that the alloy composition is uniform to form an alloy melt.

[0077] Step 3. Addition of rare earth elements and mid-term smelting: The heating rate is controlled at 10°C / min. After the aluminum melt reaches an appropriate temperature of 600°C, the pre-treated rare earth elements are added to the alloy melt one in the form of particles (rare earth element particles of about 32 μm), and are fully stirred to make the rare earth elements evenly distributed in the melt to form alloy melt two.

[0078] Step 4: Refining treatment: When the solution temperature reaches 700°C, add the sodium-free refining agent, sprinkle the refining agent on the liquid surface, and quickly press it into the aluminum liquid. After sufficient stirring, let it stand for 20 minutes and skim off the slag.

[0079] Step 5: Casting: Preheat the mold to 275°C, pour the refined aluminum alloy liquid into the pre-prepared mold, and cool it to obtain an alloy ingot.

[0080] Step 6: Peeling: Remove the riser and uneven surface of the alloy ingot after casting to make the surface of the alloy ingot smooth.

[0081] Step 7: Double-stage solution treatment: Put the alloy obtained in Step 6 into a heating furnace for double-stage solution treatment. Conduct the first-stage solution treatment as the temperature rises: the temperature is 550°C and hold for 3 hours. Then conduct the second-stage solution treatment: the temperature is 580°C and hold for 4 hours.

[0082] Step 8: Quenching: Take out the alloy after double-stage solution treatment and immediately put it into a quenching medium. The quenching transfer time is 7 seconds. Conduct quenching treatment and cool it to room temperature. The quenching medium is water with a temperature of 45°C.

[0083] Step 9: Aging: Put the alloy after quenching treatment into a heating furnace for aging treatment. Heat the quenched alloy to 350°C at a heating rate of 20°C / min and hold for 4 hours.

[0084] The application of the microalloyed material of the high-performance aluminum alloy in this embodiment as a lightweight material for automobile engines in the field of automobiles.

[0085] Comparative Example 1

[0086] The difference between this comparative example and Example 3 is that the rare earth elements Gd, Sc, and Zr are not added;

[0087] A preparation method of a microalloyed material of an aluminum alloy, comprising the following steps:

[0088] Step 1: Batching: According to Mg: 1.4 wt%, Si: 1.2 wt%, La: 0.2 wt%, Mn: 0.05 wt%, Fe: 0.11 wt%, Ag: 0.3 wt%, and the balance is Al.

[0089] Comparative Example 2

[0090] The difference between this comparative example and Example 3 is only that the rare earth elements Gd and Sc are not added;

[0091] A preparation method of a microalloyed material of an aluminum alloy, comprising the following steps:

[0092] Step 1: Batching: According to Mg: 1.4 wt%, Si: 1.2 wt%, La: 0.2 wt%, Zr: 1.1 wt%, Mn: 0.05 wt%, Fe: 0.11 wt%, Ag: 0.3 wt%, and the balance is Al.

[0093] Comparative Example 3

[0094] The difference between this comparative example and Example 3 is only that the rare earth elements Gd and Zr are not added;

[0095] A preparation method of a microalloyed material of an aluminum alloy, comprising the following steps:

[0096] Step 1. Ingredients: Mg: 1.4wt%, Si: 1.2wt%, La: 0.2wt%, Sc: 1.1wt%, Mn: 0.05wt%, Fe: 0.11wt%, Ag: 0.3wt%, and the balance is Al.

[0097] Comparative Example 4

[0098] The difference between this comparative example and Example 3 is that rare earth elements Sc and Zr are not added;

[0099] A method for preparing a microalloyed aluminum alloy material comprises the following steps:

[0100] Step 1. Ingredients: Mg: 1.4wt%, Si: 1.2wt%, La: 0.2wt%, Gd: 1.1wt%, Mn: 0.05wt%, Fe: 0.11wt%, Ag: 0.3wt%, and the balance is Al.

[0101] Comparative Example 5

[0102] The difference between this comparative example and Example 3 is that: no rare earth element Gd is added;

[0103] A method for preparing a microalloyed aluminum alloy material comprises the following steps:

[0104] Step 1: Ingredients: Mg: 1.4wt%, Si: 1.2wt%, La: 0.2wt%, rare earth elements: 1.1wt%, Mn: 0.05wt%, Fe: 0.11wt%, Ag: 0.3wt%, and the balance is Al. The ratio of Sc to Zr is 5:4.

[0105] Comparative Example 6

[0106] The difference between this comparative example and Example 3 is only that:

[0107] Step 2: Initial smelting: Place the treated aluminum ingots and aluminum-silicon alloy in a smelting furnace, control the heating rate to 12°C / min, control the temperature to 510°C, and introduce inert gas (such as argon) for protection to prevent the alloy from being oxidized during the smelting process. Heat until completely melted, and stir several times to ensure that the alloy composition is uniform to form an alloy melt.

[0108] Step 3. Addition of rare earth elements and mid-term smelting: The heating rate is controlled at 8°C / min. After the aluminum melt reaches an appropriate temperature of 610°C, the pre-treated rare earth elements are added to the alloy melt one in the form of particles, and fully stirred to make the rare earth elements evenly distributed in the melt to form the alloy melt two.

[0109] Step 4: Refining treatment: When the solution temperature reaches 640°C, add the refining agent, sprinkle the refining agent on the liquid surface, and quickly press it into the aluminum liquid. After sufficient stirring, let it stand for 18 minutes and skim off the slag.

[0110] Step 5: Casting: Preheat the mold to 300°C, pour the refined aluminum alloy liquid into the pre-prepared mold, and cool it to obtain an alloy ingot.

[0111] Step 6: Peeling: Remove the riser and uneven surface of the alloy ingot after casting to make the surface of the alloy ingot smooth.

[0112] Step 7, double-stage solid solution: put the alloy of step 6 into a heating furnace for double-stage solid solution treatment; as the temperature rises, the first stage solid solution is carried out at a temperature of 510°C for 2.5 hours; and the second stage solid solution is carried out at a temperature of 550°C for 3.4 hours.

[0113] Step 8: Quenching: Take out the alloy after the double-stage solid solution treatment and immediately put it into the quenching medium. The quenching transfer time is 20 seconds. Perform quenching treatment and cool to room temperature. The quenching medium is water at a temperature of 35°C.

[0114] Step 9: Aging: Place the quenched alloy into a heating furnace for aging treatment. Heat the quenched alloy to 365°C at a heating rate of 18°C / min and keep it warm for 3.5 hours.

[0115] Performance test: The alloy samples obtained by different processes in the above Examples 1 to 4 and Comparative Examples 1 to 6 were subjected to room temperature hardness performance test, room temperature tensile performance test and 400° C. tensile performance test. The results are shown in Table 1 below.

[0116] The test method for room temperature hardness performance is as follows:

[0117] The test was conducted using an MH-5L hardness tester with a load of 500g and a holding time of 15s. No less than 10 points were taken from the entire surface of each sample to ensure data accuracy, with an error of no more than ±3%.

[0118] The room temperature tensile properties test method is as follows:

[0119] Use Zwick / RollZ030TH electronic universal material tensile testing machine with a tensile rate of 1mm / min. Before the experiment, the workbench of the Zwick / RollZ030TH electronic universal material tensile testing machine needs to be raised by about 10mm to eliminate the influence of the deadweight of the workbench system. Each group of experiments is equipped with three parallel specimens for comparison to reduce experimental errors.

[0120] The microstructure analysis method is as follows:

[0121] The microstructure of the alloy was observed using an optical microscope or a scanning electron microscope (EBSD).

[0122] Table 1 Comparison of the properties of the alloys produced in Examples 1-4 and Comparative Examples 1-6

[0123]

[0124] From Table 1 and Figure 1 it can be seen that the microalloyed material of the high-performance aluminum alloy has the best performance in Example 1, with a hardness of 154 HV, a yield strength of 283 MPa, a tensile strength of 354 MPa, and an average grain size of 40 μm at room temperature; at 400 °C, the yield strength is 117 MPa and the tensile strength is 131 MPa;

[0125] From the test results in Table 1, it can be seen that different rare earth element ratios and solution treatment processes have a greater impact on the hardness and grain size of the prepared Al-Mg-Si alloy. The three rare earth element mixing ratios provided by the present invention, the heating rate and quenching transfer time during the control process can maximize the hardness of the prepared alloy and reduce the grain size.

[0126] It should be understood that, in order to streamline the present disclosure and assist in understanding one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, or the description thereof. However, the disclosed method should not be construed as reflecting the intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected by the claims, the inventive aspects lie in less than all the features of the foregoing disclosed embodiments. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim itself serves as a separate embodiment of the present invention.

[0127] Although the present invention has been described in terms of a limited number of embodiments, those skilled in the art in this technical field will appreciate, from the foregoing description, that other embodiments can be contemplated within the scope of the invention thus described. In addition, it should be noted that the language used in this specification has been principally selected for readability and instructional purposes, rather than for the purpose of explaining or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those of ordinary skill in the art in this technical field without departing from the scope and spirit of the appended claims. For the scope of the present invention, the disclosure of the present invention is illustrative, not restrictive, and the scope of the present invention is defined by the appended claims.

[0128] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A high performance aluminum alloy microalloy material, characterized in that: The invention comprises the following components in parts by weight: Mg: 0.8-1.6wt%, Si: 1.0-1.5wt%, La: 0.2wt%, rare earth elements 0.8-1.2wt%, Mn≤0.07wt%, Fe≤0.12wt%, Ag: 0.2-0.4wt%, and the balance is Al.

2. A high performance aluminum alloy microalloyed material according to claim 1, characterized in that: The rare earth elements used are Gd, Sc and Zr, and the mass ratio is 8:(4-7):(3-6).

3. The high performance aluminum alloy microalloy material according to claim 1, characterized in that: The micro-alloyed material of high-performance aluminum alloy has a hardness greater than 151HV, a yield strength greater than 276MPa, a tensile strength greater than 342MPa, an average grain size less than 45μm at room temperature, a yield strength greater than 114MPa, and a tensile strength greater than 127MPa at 400°C.

4. The method for preparing a microalloyed material of a high performance aluminum alloy according to any one of claims 1 to 3, characterized in that: The steps include: Step 1: Ingredients: Select the above components and ingredients by mass percentage, clean all raw materials, remove oil and impurities on the surface, then dehydrate them to ensure that the raw materials are dry and free of water, and then dry them for use; Step 2, initial smelting: placing the processed raw materials except the rare earth elements in a smelting furnace, controlling the temperature at 400-500°C, introducing an inert gas, heating until completely melted, and stirring several times to ensure uniform alloy composition to form an alloy melt; Step 3, rare earth element addition and mid-term smelting: after the alloy melt 1 reaches 550-600° C., the treated rare earth element particles are added to the alloy melt 1 and stirred to make the rare earth element evenly distributed in the alloy melt 1 to form alloy melt 2; Step 4: Refining treatment: When the temperature of the alloy melt reaches 650-700°C, add the refining agent, sprinkle the refining agent on the liquid surface, and quickly press it into the aluminum liquid. After sufficient stirring, let it stand for 15-20 minutes and skim off the slag. Step 5: Casting: preheat the mold to 260-300°C, pour the refined aluminum alloy liquid into the mold, and cool it to obtain an alloy ingot; Step 6: Peeling: Remove the riser and uneven surface of the alloy ingot after casting to make the surface of the alloy ingot smooth; Step 7: Double-stage solid solution treatment: Place the alloy from step 6 into a heating furnace for double-stage solid solution treatment; As the temperature rises, the first stage of solid solution is carried out: the temperature is 530-550°C, and the temperature is kept for 2-3 hours; then the second stage of solid solution is carried out: the temperature is 560-580°C, and the temperature is kept for 3-4 hours; Step 8: Quenching: Take out the alloy after the double-stage solid solution treatment and immediately put it into a quenching medium for quenching treatment and cool it to room temperature; the quenching medium is water at a temperature of 35-45°C; Step 9: Aging: Place the quenched alloy into a heating furnace for aging treatment.

5. The preparation method according to claim 4, characterized in that: In step 2, the inert gas includes argon; in step 3, the rare earth element particles are 30-35 μm.

6. The preparation method according to claim 4, characterized in that: In step 4, the refining agent is one of a sodium-free refining agent, a rare earth-containing refining agent, and a composite refining agent.

7. The preparation method according to claim 4, characterized in that: The heating rate in step 2 is controlled at 10-15°C / min, and the heating rate in step 3 is controlled at 5-10°C / min.

8. The preparation method according to claim 4, characterized in that: In step eight, the quenching transfer time of the quenching treatment is ≤10s.

9. The preparation method according to claim 4, characterized in that: In step nine, the aging treatment includes the following steps: heating the quenched alloy to 330-350° C. at a heating rate of 15-20° C. / min, and keeping the temperature for 3-4 hours.

10. Use of a microalloyed material of a high performance aluminum alloy according to any one of claims 1 to 3 as a lightweight material for automobile engines in the automotive field.

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