Novel integrated die-casting heat-treatment-free aluminum alloy material and preparation method thereof

Abstract

The invention provides a novel integrated die-casting heat-treatment-free aluminum alloy material which comprises the following element components based on the overall weight of the alloy material: Si, Mn, Fe, Ti, Mo, Sr, Zr, Mg, V, Cr and the balance of Al and inevitable impurities. Compared with the prior art, the tensile strength, the yield strength and the elongation of the alloy material are improved, the iron-rich phase size is smaller, the morphology tends to be spherical, crystal grains are more refined, higher performance is achieved, and the requirement for high-strength performance component integrated die castings can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and in particular to an integrated die-casting heat-treatment-free aluminum alloy new material and a preparation method thereof. Background Art

[0002] Aluminum alloys have been widely used in aerospace, machinery manufacturing, shipbuilding, electronic communications, and especially new energy vehicles due to their low density, high specific strength, good plasticity, excellent mechanical properties, low thermal expansion coefficient, good corrosion resistance, electrical conductivity, easy processing, and recyclability. For example, they are used in the casings of smart phones, laptops, and other electronic products, the heat dissipation backplanes and lampshades of LED lights, the heat dissipation substrates, filters and cabinet casings of wireless communication base stations, the heating plates of rice cookers and induction cookers, the power battery casings, control power supply chassis, drive motor casings, subframes and chassis of new energy vehicles, and other complex structural parts.

[0003] Integrated die-casting for automobiles has become an important way to achieve lightweight automobiles. Integrated die-casting technology is to redesign multiple independent parts that need to be assembled in the original design, and use super-large die-casting machines to die-cast them at one time to directly obtain complete parts and realize the original functions. Based on this technology, the number of parts required for production is greatly reduced, while the welding and gluing links are significantly reduced, which significantly improves manufacturing efficiency, reduces labor intensity, and shortens the manufacturing time of the whole vehicle. In order to meet the high elongation performance of die-casting parts, heat treatment is usually required. However, as the size of integrated castings becomes larger and the thickness difference is large, heat treatment is likely to cause dimensional deformation of castings and bubbles on the surface of castings, which leads to an increase in the scrap rate of castings and an increase in production costs. Therefore, integrated die-casting high thermal conductivity aluminum alloy materials that do not require heat treatment came into being. Summary of the invention

[0004] The purpose of the present invention is to provide a new integrated die-casting heat-treatment-free aluminum alloy material and a preparation method thereof.

[0005] One of the purposes of the present invention is to provide an integrated die-casting aluminum alloy new material that does not require heat treatment, and the technical solution adopted is: The integrated die-casting heat-treatment-free aluminum alloy new material contains the following components in percentage by weight based on the overall weight of the alloy material: Si: 7.7-8.1%; Mn: 0.04-0.06%; Fe: 0.2-0.35% Ti: 0.06-0.15%; Mo: 0.015-0.035%; Sr: 0.015-0.035%; Zr: 0.15-0.30%; Mg: 0.2-0.5%; V: 0.1-0.5%; Cr: 0.1-0.5%; The balance is Al and inevitable impurities.

[0006] Furthermore, the weight percentages of the components are as follows: Si: 7.75%; Mn: 0.05%; Fe: 0.32%; Ti: 0.09%; Mo: 0.025%; Sr: 0.030%; Zr: 0.20%; Mg: 0.3%; V: 0.5%; Cr: 0.3%; the remainder is Al and unavoidable impurities.

[0007] Another object of the present invention is to provide a method for preparing a new integrated die-casting aluminum alloy material without heat treatment, the technical solution adopted is: The preparation method of the integrated die-casting heat-treatment-free aluminum alloy new material comprises the following steps: S1. Melting: Melt the aluminum alloy under the protection of inert gas and add appropriate amount of alloy elements.

[0008] S2. Homogenization treatment: Homogenization treatment is carried out after smelting is completed to reduce component segregation.

[0009] S3. Rapid cooling: Rapid solidification to prepare aluminum alloy powder.

[0010] S4. Hot pressing: The prepared aluminum alloy powder is hot pressed to obtain a blank of a desired shape.

[0011] S5. Cold working: The hot pressed blank is subjected to cold working treatment such as cold rolling or cold drawing to improve the strength and toughness of the material.

[0012] S6. Annealing: Annealing is performed on cold-processed materials to improve the plasticity and toughness of the materials while maintaining high strength.

[0013] Furthermore, in step S3, the aluminum alloy powder is obtained by rapid cooling and solidification by gas atomization or water atomization.

[0014] The beneficial effects produced by the present invention are as follows: Compared with the prior art, the technical solution provided by the present invention changes the composition ratio of the alloy and has a unique preparation method and process in terms of the preparation method, thereby improving the tensile strength, yield strength and elongation of the alloy material, being able to reduce the size of the primary iron-rich phase, and making the morphology tend to be spherical. After adding the Sr element, the nucleation temperature of the primary α-Al phase can be reduced, thereby promoting the grain refinement of the α-Al phase; at the same time, Ti and Zr elements are added to precipitate the AlSi(Ti, Zr)x phase, which has a good lattice mismatch with the primary α-Al phase, further contributing to grain refinement, improving the performance of the overall alloy, and meeting the needs of integrated die-castings requiring high-strength performance components. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a flow chart of the method.

[0016] Figure 2 It is the metallographic diagram of the alloy material of the present invention.

[0017] Figure 3 It is a comparison diagram of the primary phases of other elements and the primary α-Al phase of the alloy material of the present invention. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with the embodiments and drawings, and the contents mentioned in the embodiments are not intended to limit the present invention. The present invention is described in detail below in conjunction with the drawings.

[0019] See also Figure 1 , which is a preparation method of the integrated die-casting heat-treatment-free aluminum alloy new material provided by the present invention.

[0020] Embodiment 1 In this embodiment, an integrated die-casting heat-treatment-free aluminum alloy new material is provided, which, based on the overall weight of the alloy material, contains the following components in weight percentage: Si: 8.1%; Fe: 0.35%; Mn: 0.04%; Ti: 0.06%; Mo: 0.015%; Sr: 0.035%; Mg: 0.4%; V: 0.1%; Cr: 0.1%; the remainder is Al and unavoidable impurities.

[0021] The above components are used to prepare the new aluminum alloy material through the following steps: S1. Melting: Melting aluminum alloy under the protection of inert gas, adding the above weight percentage components into a blast furnace for melting.

[0022] S2. Homogenization treatment: Homogenization treatment is carried out after smelting is completed to reduce component segregation.

[0023] S3, rapid cooling: rapid solidification to prepare aluminum alloy powder. In this step, gas atomization or water atomization can be used for rapid cooling to obtain alloy powder.

[0024] S4. Hot pressing: The prepared aluminum alloy powder is hot pressed to obtain a blank of a desired shape.

[0025] S5. Cold working: The hot pressed blank is subjected to cold working treatment such as cold rolling or cold drawing to improve the strength and toughness of the material.

[0026] S6. Annealing: Annealing is performed on cold-processed materials to improve the plasticity and toughness of the materials while maintaining high strength.

[0027] In this embodiment, Mn, Cr, Mo, and V elements are added, and the morphology of the primary iron-rich phase tends to be spherical, and the size can be controlled at about 5um. At the same time, Ti and Zr are added to precipitate AlSi(Ti)x phase, which has a good lattice mismatch with the primary α-Al phase, is conducive to grain refinement and improves alloy properties. When the element Sr is not added, the nucleation temperature of the primary α-Al phase is 604 degrees Celsius. The addition of the element Sr reduces the nucleation temperature of the primary α-Al phase, and the nucleation temperature of the primary α-Al phase is 596 degrees Celsius, which promotes the grain refinement of the primary α-Al phase.

[0028] Embodiment 2 In this embodiment, an integrated die-casting heat-treatment-free aluminum alloy new material is provided, which, based on the overall weight of the alloy material, contains the following components in weight percentage: Si: 8.0%; Fe: 0.42%; Mn: 0.06%; Ti: 0.15%; Mo: 0.025%; Sr: 0.025%; Mg: 1.45%; V: 0.5%; Cr: 0.5%; Zr: 0.3% and the remainder is Al and unavoidable impurities.

[0029] In a further optimized technical solution, the alloy material also includes the element Sr in an amount of 0.5 weight percent.

[0030] The above components are used to prepare the new aluminum alloy material through the following steps: S1. Melting: Melting aluminum alloy under the protection of inert gas, adding the above weight percentage components into a blast furnace for melting.

[0031] S2. Homogenization treatment: Homogenization treatment is carried out after smelting is completed to reduce component segregation.

[0032] S3, rapid cooling: rapid solidification to prepare aluminum alloy powder. In this step, gas atomization or water atomization can be used for rapid cooling to obtain alloy powder.

[0033] S4. Hot pressing: The prepared aluminum alloy powder is hot pressed to obtain a blank of a desired shape.

[0034] S5. Cold working: The hot pressed blank is subjected to cold working treatment such as cold rolling or cold drawing to improve the strength and toughness of the material.

[0035] S6. Annealing: Annealing is performed on cold-processed materials to improve the plasticity and toughness of the materials while maintaining high strength.

[0036] In this embodiment, Mn, Cr, Mo, and V are added, and the morphology of the primary iron-rich phase tends to be spherical, and the size can be controlled at about 5um. At the same time, Ti and Zr are added to precipitate AlSi(Ti, Zr)x phase, which has a good lattice mismatch with the primary α-Al phase, which is conducive to grain refinement and improves alloy properties. In this embodiment, although the Sr ratio is increased, the temperature reduction is small.

[0037] Embodiment 3 In this embodiment, an integrated die-casting heat-treatment-free aluminum alloy new material is provided, which, based on the overall weight of the alloy material, contains the following components in weight percentage: Si: 7.83; Fe: 0.48%; Mn: 0.50%; Ti: 0.09%; Mo: 0.025%; Sr: 0.030%; Zr: 0.20%; Mg: 0.5%; V: 0.5%; Cr: 0.5%; the remainder is Al and unavoidable impurities.

[0038] The above components are used to prepare the new aluminum alloy material through the following steps: S1. Melting: Melting aluminum alloy under the protection of inert gas, adding the above weight percentage components into a blast furnace for melting.

[0039] S2. Homogenization treatment: Homogenization treatment is carried out after smelting is completed to reduce component segregation.

[0040] S3, rapid cooling: rapid solidification to prepare aluminum alloy powder. In this step, gas atomization or water atomization can be used for rapid cooling to obtain alloy powder.

[0041] S4. Hot pressing: The prepared aluminum alloy powder is hot pressed to obtain a blank of a desired shape.

[0042] S5. Cold working: The hot pressed blank is subjected to cold working treatment such as cold rolling or cold drawing to improve the strength and toughness of the material.

[0043] S6. Annealing: Annealing is performed on cold-processed materials to improve the plasticity and toughness of the materials while maintaining high strength.

[0044] In this embodiment, Mn, Cr, Mo, and V elements are added, and the morphology of the primary iron-rich phase tends to be spherical, and the size can be controlled at about 3um. At the same time, Ti and Zr are added to precipitate AlSi(Ti, Zr)x phase, which has a good lattice mismatch with the primary α-Al phase, is conducive to grain refinement and improves alloy performance. In this embodiment, the proportion of Sr is adjusted to 0.035%, which reduces the nucleation temperature of the primary α-Al phase, promotes the grain refinement of the primary α-Al phase, and ensures the performance of the alloy.

[0045] In alloys: Silicon (Si): It is an important alloying element in aluminum alloys and is used to improve the hardness and strength of the material.

[0046] Manganese (Mn): As a strengthening agent, it improves the strength and hardness of the material and prevents thermal cracking of the material.

[0047] Titanium (Ti): Used to refine grains and improve the mechanical properties of materials, especially in terms of toughness and welding performance.

[0048] Molybdenum (Mo): As an alloying element, it can improve the strength and hardness of materials.

[0049] Strontium (Sr): Used to refine grains, improve the casting properties of materials, reduce intergranular branched structures, reduce pores and cracks, and increase elongation.

[0050] Zirconium (Zr): can increase the recrystallization temperature of the material and improve its thermal stability.

[0051] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention is disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technology of the present invention, which do not depart from the content of the technical solution of the present invention, are within the scope of the technical solution of the present invention.

Claims

1. Integrated die-casting heat-treatment-free aluminum alloy new material, characterized by: Based on the overall weight of the alloy material, it contains the following components in weight percentage: Si: 7.7-8.1%; Mn: 0.04-0.06%; Fe: 0.2-0.4% Ti: 0.06-0.15%; Mo: 0.015-0.035%; Sr：0.015-0.035%； Zr：0.15-0.30%； Mg: 0.2-0.5%; V：0.1-0.5%； Cr：0.1-0.5%； The balance is Al and inevitable impurities.

2. The integrated die-casting heat-treatment-free aluminum alloy new material according to claim 1 is characterized in that: The alloy material also includes 0.1-0.5% by weight of the element Zn.

3. The integrated die-casting heat-treatment-free aluminum alloy new material according to claim 2 is characterized in that: The weight percentages of the components are: Si: 7.75%; Mn: 0.05%; Fe: 0.32%; Ti: 0.09%; Mo: 0.025%; Sr：0.030%； Zr ：0.20%； Mg: 0.3%; V： 0.5%； Cr: 0.3%; the balance is Al and inevitable impurities.

4. A method for preparing a new integrated die-casting aluminum alloy material free of heat treatment, characterized in that: The following steps are included: S1. Melting: Melt the aluminum alloy under the protection of inert gas and add appropriate amount of alloy elements; S2. Homogenization treatment: Homogenization treatment is performed after smelting to reduce component segregation; S3, rapid cooling: rapid solidification to prepare aluminum alloy powder; S4, hot pressing: hot pressing the prepared aluminum alloy powder to obtain a blank of a desired shape; S5. Cold working: cold rolling or cold drawing is performed on the hot pressed blank to improve the strength and toughness of the material; S6. Annealing: Annealing is performed on cold-processed materials to improve the plasticity and toughness of the materials while maintaining high strength.

5. The method for preparing the integrated die-casting heat-treatment-free aluminum alloy new material according to claim 4 is characterized in that: In step S3, the aluminum alloy powder is obtained by rapid cooling and solidification by gas atomization or water atomization.

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