A kind of AlSiNi high-strength aluminum alloy without heat treatment and preparation method thereof

Abstract

The present application discloses a heat-free AlSiNi high-strength aluminum alloy and a preparation method thereof, wherein the heat-free AlSiNi high-strength aluminum alloy includes the following components: Si 4‑8%, Ni 1‑3%, Ga 1‑3%, Mn0.5‑0.7%, Cu 0.45‑0.65%, Zn 0.1‑0.3%, Mg 0.08‑0.12%, Fe 0.08‑0.12%, Zr 0.03‑0.07%, Re 0.05‑0.15%, and the remainder is Al. The aluminum alloy provided in the present application can replace the traditional die-casting aluminum alloy material requiring heat treatment in the automotive industry, and it can also obtain high strength and high toughness without heat treatment, can meet the requirements of die-casting of large-scale automotive structural parts, and is suitable for producing high-strength and lightweight motor structural parts of new energy electric vehicles.

Description

Technical Field

[0001] The present application relates to the technical field of aluminum alloy processing, and in particular to a heat treatment-free AlSiNi high-strength aluminum alloy and a preparation method thereof. Background Art

[0002] Heat treatment is an important processing method for aluminum alloys, which can change the organizational structure and properties of aluminum alloy materials, with the aim of improving the strength, hardness, toughness and other properties of the materials. At present, with the continuous development of the manufacturing industry, the volume of one-piece die castings is getting larger and larger. Heat treatment will not only cause deformation, but also reduce production efficiency, consume a lot of energy and pollute the environment. Therefore, the development of heat-treatment-free aluminum alloy materials has become a trend. Heat-treatment-free aluminum alloy refers to the technology of obtaining aluminum alloy products with good strength, plasticity, toughness and other properties without heat treatment after die-casting by adding other metal alloy components.

[0003] Aluminum alloy materials that do not require heat treatment are widely used in aerospace, automobile manufacturing, electronic communications and other fields. Especially in the field of new energy vehicles, due to their high strength and light weight, aluminum alloys that do not require heat treatment are widely used in automotive structural parts, engine parts and other fields, which is of great significance for improving the performance and safety of new energy vehicles. However, at present, the die-casting aluminum alloy materials in the relevant technology still have shortcomings such as low strength and poor lightweight effect. Therefore, it is necessary to provide a new AlSiNi high-strength aluminum alloy that does not require heat treatment and its preparation method in response to this demand. Summary of the invention

[0004] The invention provides a heat treatment-free AlSiNi high-strength aluminum alloy and a preparation method thereof, so as to solve the problems of low strength, poor lightweight effect, etc. existing in the prior art.

[0005] To solve the above problems, this application provides the following technical solutions:

[0006] First, the present application provides a heat-treatment-free AlSiNi high-strength aluminum alloy, which is formulated by mass percentage and includes the following components: Si 4-8%, Ni 1-3%, Ga 1-3%, Mn 0.5-0.7%, Cu0.45-0.65%, Zn 0.1-0.3%, Mg 0.08-0.12%, Fe 0.08-0.12%, Zr 0.03-0.07%, Re 0.05-0.15%, and the balance is Al;

[0007] Further, the AlSiNi high-strength aluminum alloy comprises the following components: Si 5-7%, Ni 1-2%, Ga1-3%, Mn 0.5-0.7%, Cu 0.45-0.65%, Zn 0.1-0.3%, Mg 0.08-0.12%, Fe 0.08-0.12%, Zr0.03-0.07%, Re 0.05-0.15%, and the balance is Al;

[0008] Further, the AlSiNi high-strength aluminum alloy comprises the following components: Si 5.5-6.5%, Ni 1-2%, Ga1-3%, Mn 0.55-0.65%, Cu 0.50-0.60%, Zn 0.15-0.25%, Mg 0.09-0.11%, Fe 0.09-0.11%, Zr 0.04-0.06%, Re 0.09-0.11%, and the balance is Al;

[0009] Further, the AlSiNi high-strength aluminum alloy comprises the following components: Si 6%, Ni 1.5%, Ga1-3%, Mn 0.6%, Cu 0.55%, Zn 0.2%, Mg 0.1%, Fe 0.1%, Zr 0.05%, Re 0.1%, and the balance is Al;

[0010] Secondly, the present application also provides a method for preparing a heat-treatment-free AlSiNi high-strength aluminum alloy, comprising the following steps:

[0011] Step S1, pretreatment: prepare raw materials according to the mass percentage of each element in the formula of the aluminum alloy material, clean them and set them aside, wherein the mass percentage of each element is as described in any one of claims 1-3;

[0012] Step S2, smelting: firstly place the master alloy Al-Si and pure Al in a melting furnace for smelting, and after they are completely melted, add the remaining raw materials to obtain aluminum alloy liquid;

[0013] Step S3, refining: adding a refining agent to the aluminum alloy liquid, and then filtering to obtain a refined aluminum alloy liquid;

[0014] Step S4, forming: casting the refined aluminum alloy liquid into a mold to obtain a high-strength aluminum alloy that does not require heat treatment.

[0015] Further, the step S1 includes the following steps: grinding and polishing the intermediate alloys Al-Si, Al-Zn, Al-Ni, Al-Zr, Al-Fe, Al-Mn, Al-Re and pure Al, pure Mg, and pure Ga respectively, and then cleaning and drying them;

[0016] Further, the step S2 includes the following steps: firstly placing the master alloy Al-Si and pure Al in a melting furnace for smelting, and then adding the master alloy Al-Zn, Al-Ni, Al-Fe, Al-Mn and pure Al and pure Mg after they are completely melted to obtain a melt 1, and then adding the master alloy Al-Zr, Al-Re and pure Ga to the melt 1, and when all components are completely melted, obtaining an aluminum alloy liquid;

[0017] Furthermore, the smelting temperature of the intermediate alloy Al-Si and pure Al in a melting furnace for smelting is 720-780° C., preferably 740-760° C.;

[0018] Furthermore, the melting temperature of adding the intermediate alloy Al-Zr, Al-Re and pure Ga to the melt 1 is 700-740° C., preferably 710-730° C.;

[0019] Furthermore, before adding the intermediate alloy Al-Zr, Al-Re and pure Ga to the melt 1, the melt 1 is allowed to stand for 20-40 minutes;

[0020] Further, the step S3 includes the following steps: spraying a refining agent into the aluminum alloy liquid under nitrogen conditions for 20-40 minutes, then using a slag rake to clean the scum on the surface of the aluminum alloy liquid, and then filtering through a two-stage filter box to obtain a refined aluminum alloy liquid;

[0021] Furthermore, the refining device is an automatic refiner;

[0022] Further, the refining agent includes one or more of Kensec 101A refining agent, RJ-1 refining agent, and sodium-free refining agent;

[0023] Furthermore, the nitrogen conditions are specifically: nitrogen pressure of 0.1-0.3Mpa, flow rate of 10-20m 3 / min;

[0024] Further, the specific steps of step S4 are: when the temperature of the refined aluminum alloy liquid is 650-690° C., casting the refined aluminum alloy liquid into a mold with a temperature of 140-160° C. to obtain a test rod, and the casting cycle is 45-55s; performing aging heat treatment on the test rod at 180-200° C. for 2-4h to obtain a high-strength aluminum alloy that does not require heat treatment;

[0025] Preferably, when the temperature of the refined aluminum alloy liquid is 660-680° C., the refined aluminum alloy liquid is cast into a mold at a temperature of 140-160° C.;

[0026] More preferably, when the temperature of the refined aluminum alloy liquid is 665-675° C., the refined aluminum alloy liquid is cast into a mold at a temperature of 145-155° C.;

[0027] Preferably, the test bar is subjected to aging heat treatment at 185-195° C. for 2-4 hours to obtain a high-strength aluminum alloy that does not require heat treatment;

[0028] The present application also provides a heat-treatment-free AlSiNi high-strength aluminum alloy, which is prepared by the preparation method described above.

[0029] Beneficial effects:

[0030] The present application discloses a heat-treatment-free AlSiNi high-strength aluminum alloy and a preparation method thereof, wherein the heat-treatment-free AlSiNi high-strength aluminum alloy comprises the following components: Si 4-8%, Ni 1-2%, Ga 1-3%, Mn 0.5-0.7%, Cu0.45-0.65%, Zn 0.1-0.3%, Mg 0.08-0.12%, Fe 0.08-0.12%, Zr 0.03-0.07%, Re0.05-0.15%, and the balance is Al. The aluminum alloy provided by the present application can replace the traditional die-casting aluminum alloy material requiring heat treatment in the automotive industry, and can obtain high strength and high toughness without heat treatment, can meet the requirements of die-casting of large automotive structural parts, and is suitable for producing high-strength and lightweight motor structural parts of new energy electric vehicles. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present invention, and the terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. In the description of the present application, it should be understood that "and / or" describes the association relationship of the associated objects, indicating that three relationships may exist, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A, B can be singular or plural. In the present application, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one", "the following at least one (individual)" or similar expressions thereof refer to any combination of these items, including any combination of singular (individual) or plural (individual). For example, "at least one of a, b, or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e. a and b), ac, bc, or abc, where a, b, c can be single or plural, respectively.

[0033] Adding silicon to aluminum alloy can improve strength and hardness, which is mainly because silicon can form two hardness phases, α(Al)+Si eutectic system and Si dissolved in the matrix alloy, which significantly increases the strength and hardness of aluminum alloy. Silicon can also strengthen the strength of aluminum matrix in aluminum alloy and increase the elastic modulus of aluminum alloy, making the material harder and tougher. At the same time, silicon can reduce the proportion of twinning and subgrains in aluminum alloy, improve the mechanical properties of aluminum alloy, and increase the tensile and compressive strength of the material. In addition, the addition of silicon can also improve corrosion resistance, which is mainly because silicon can form a thin and dense oxide layer with aluminum to prevent further corrosion of aluminum oxide. Silicon can also increase the intergranular corrosion potential in aluminum alloy, delay the occurrence of intergranular corrosion, and thus improve the corrosion resistance of aluminum alloy, especially for aluminum-manganese alloy, the addition of silicon can significantly improve its corrosion resistance. Finally, the addition of silicon can also improve processing performance, which is mainly because silicon can make aluminum alloy have good casting performance and forming performance. Silicon can increase the liquid temperature range and liquid viscosity in aluminum alloy, thereby improving the material's flow performance and casting performance. In addition, silicon can also promote the recrystallization and grain refinement of aluminum alloy, making aluminum alloy easy to deform during processing and forming.

[0034] Adding nickel metal to aluminum alloy can also increase the strength of aluminum alloy and improve its heat resistance. The addition of nickel can improve the performance of aluminum alloy at high temperatures, improve its heat resistance, and enable it to maintain good strength and stability in high temperature environments.

[0035] Adding gallium metal to aluminum alloy can not only effectively improve the strength of aluminum alloy, but also generate different forms of binary compounds, such as Al2Ga, Al3Ga and Al4Ga, among which Al3Ga is the most stable compound, which can effectively enhance the strength and hardness of aluminum materials, especially in high temperature environment, and improve its wear resistance: after adding gallium, the wear resistance of aluminum alloy will also be improved, making it more suitable for manufacturing wear-resistant parts.

[0036] The addition of copper metal to aluminum alloy can significantly improve the strength and hardness of aluminum alloy, making aluminum alloy have better tensile strength and fatigue resistance, which is mainly due to the fact that copper can strengthen the grain boundary strength and solid solution strength in aluminum alloy. Copper can also improve the corrosion resistance of aluminum alloy, especially in corrosive environments such as seawater, because copper increases the potential difference of aluminum alloy, thereby avoiding electrochemical corrosion of aluminum alloy. On the other hand, the addition of copper can also improve the processing performance of alloy, making aluminum alloy easier to process and form, because copper can improve the flowability of aluminum alloy, thereby reducing the difficulty and cost of processing. On the other hand, the addition of copper can also effectively improve the heat resistance, so that aluminum alloy can be used in high temperature environment, because copper can promote the solid solution phase transformation in aluminum alloy and improve the grain boundary barrier of aluminum alloy, thereby improving the heat resistance of the material.

[0037] The addition of manganese metal to aluminum alloy can increase the strength of grain boundaries and hinder the slip of grain boundaries, thereby improving the strength and hardness of aluminum alloy. In addition, manganese can also promote the refinement of aluminum alloy grains. Fine grains help to further improve the strength and plasticity of the alloy, making it have better processing performance. In addition, the addition of manganese helps to reduce the heat treatment temperature of aluminum alloy and reduce energy consumption during processing, thereby improving production efficiency; the addition of manganese can also improve the formation of oxide film of aluminum alloy, form a dense oxide film, effectively prevent further oxidation of the alloy, thereby improving its corrosion resistance; the addition of manganese can also inhibit grain growth and precipitate dissolution, which helps to improve the thermal stability of the alloy; manganese can also form stable compounds with other elements, reduce the phase change and organizational changes of the alloy at high temperature, and maintain the performance stability of the alloy. Manganese can prevent the recrystallization process of aluminum alloy, increase the recrystallization temperature, and significantly refine the recrystallized grains. The refinement of recrystallized grains is mainly achieved by the hindering effect of MnAl compound dispersed particles on the growth of recrystallized grains.

[0038] Adding rhenium metal to aluminum alloy can also improve the hardness of aluminum alloy, and can also enhance wear resistance and corrosion resistance. Rhenium alloy has strong wear resistance and corrosion resistance, so adding rhenium metal to aluminum alloy can improve these properties and is suitable for various complex engineering environments. In addition, the addition of trace Zr elements to aluminum alloy gives the alloy good corrosion resistance and thermal cracking resistance.

[0039] The present application is described in detail below through specific embodiments. The following embodiments are only partial embodiments of the present application and are not limitations of the present application.

[0040] Example 1

[0041] The present embodiment provides a heat-treatment-free AlSiNi high-strength aluminum alloy, whose composition, by mass percentage, includes: Si 6%, Ga 2%, Ni 1.5%, Mn 0.6%, Cu 0.55%, Zn 0.2%, Mg 0.1%, Fe0.1%, Zr0.05%, Re 0.1%, and the balance is aluminum.

[0042] The preparation method of the above-mentioned heat-treatment-free AlSiNi high-strength aluminum alloy comprises the following steps:

[0043] Step S1, pretreatment: grinding and polishing the intermediate alloys Al-Si, Al-Zn, Al-Ni, Al-Zr, Al-Fe, Al-Mn, Al-Re and pure Al, pure Mg, and pure Ga to remove the oxide scale on the surface, and then washing and drying them, and then weighing each component according to the above raw material ratio;

[0044] Step S2, smelting: firstly place the master alloy Al-Si and pure Al in a melting furnace for smelting at 750° C., and then add master alloys Al-Zn, Al-Ni, Al-Fe, Al-Mn and pure Al and pure Mg after they are completely melted, and then stand for 30 minutes after they are completely melted, and then add master alloys Al-Zr, Al-Re and pure Ga at 720° C., and when all components are completely melted, obtain aluminum alloy liquid;

[0045] Step S3, refining: using an automatic refining machine, at a nitrogen pressure of 0.2 MPa and a flow rate of 15 m 3 / min, the refining agent is evenly sprayed into the aluminum alloy liquid (the aluminum alloy liquid temperature is 720℃ at this time), the refining agent spraying time is 30min, the scum on the surface of the aluminum alloy liquid is cleaned by a slag rake, and then the high-temperature aluminum alloy liquid is fully filtered through a two-stage filtering box, and foreign matter with a diameter of more than 20um is completely purified to obtain refined aluminum alloy liquid;

[0046] Step S4, forming: when the temperature of the refined aluminum alloy liquid is 670°C, the refined aluminum alloy liquid is cast into a mold with a temperature of 150°C to obtain a test rod, and the casting cycle is 50s; the test rod is subjected to aging heat treatment at 190°C for 3h to obtain a high-strength aluminum alloy that does not require heat treatment.

[0047] Example 2

[0048] The present embodiment provides a heat-treatment-free AlSiNi high-strength aluminum alloy, whose composition, by mass percentage, includes: Si 6%, Ga 1%, Ni 1.5%, Mn 0.6%, Cu 0.55%, Zn 0.2%, Mg 0.1%, Fe 0.1%, Zr0.05%, Re 0.1%, and the balance is aluminum.

[0049] The preparation method of the above-mentioned heat-treatment-free AlSiNi high-strength aluminum alloy comprises the following steps:

[0050] Step S1, pretreatment: grinding and polishing the intermediate alloys Al-Si, Al-Zn, Al-Ni, Al-Zr, Al-Fe, Al-Mn, Al-Re and pure Al, pure Mg, and pure Ga to remove the oxide scale on the surface, and then washing and drying them, and then weighing each component according to the above raw material ratio;

[0051] Step S2, smelting: firstly place the master alloy Al-Si and pure Al in a melting furnace for smelting at 750° C., and then add master alloys Al-Zn, Al-Ni, Al-Fe, Al-Mn and pure Al and pure Mg after they are completely melted, and then stand for 30 minutes after they are completely melted, and then add master alloys Al-Zr, Al-Re and pure Ga at 720° C., and when all components are completely melted, obtain aluminum alloy liquid;

[0052] Step S3, refining: using an automatic refining machine, at a nitrogen pressure of 0.2 MPa and a flow rate of 15 m 3 / min, the refining agent is evenly sprayed into the aluminum alloy liquid (the aluminum alloy liquid temperature is 720℃ at this time), the refining agent spraying time is 30min, the scum on the surface of the aluminum alloy liquid is cleaned by a slag rake, and then the high-temperature aluminum alloy liquid is fully filtered through a two-stage filtering box, and foreign matter with a diameter of more than 20um is completely purified to obtain refined aluminum alloy liquid;

[0053] Step S4, forming: when the temperature of the refined aluminum alloy liquid is 670°C, the refined aluminum alloy liquid is cast into a mold with a temperature of 150°C to obtain a test rod, and the casting cycle is 50s; the test rod is subjected to aging heat treatment at 190°C for 3h to obtain a high-strength aluminum alloy that does not require heat treatment.

[0054] Example 3

[0055] The present embodiment provides a heat-treatment-free AlSiNi high-strength aluminum alloy, whose composition, by mass percentage, includes: Si 6%, Ga 3%, Ni 1.5%, Mn 0.6%, Cu 0.55%, Zn 0.2%, Mg 0.1%, Fe 0.1%, Zr0.05%, Re 0.1%, and the balance is aluminum.

[0056] The preparation method of the above-mentioned heat-treatment-free AlSiNi high-strength aluminum alloy comprises the following steps:

[0057] Step S1, pretreatment: grinding and polishing the intermediate alloys Al-Si, Al-Zn, Al-Ni, Al-Zr, Al-Fe, Al-Mn, Al-Re and pure Al, pure Mg, and pure Ga to remove the oxide scale on the surface, and then washing and drying them, and then weighing each component according to the above raw material ratio;

[0058] Step S2, smelting: firstly place the master alloy Al-Si and pure Al in a melting furnace for smelting at 750° C., and then add master alloys Al-Zn, Al-Ni, Al-Fe, Al-Mn and pure Al and pure Mg after they are completely melted, and then stand for 30 minutes after they are completely melted, and then add master alloys Al-Zr, Al-Re and pure Ga at 720° C., and when all components are completely melted, obtain aluminum alloy liquid;

[0059] Step S3, refining: using an automatic refining machine, at a nitrogen pressure of 0.2 MPa and a flow rate of 15 m 3 / min, the refining agent is evenly sprayed into the aluminum alloy liquid (the aluminum alloy liquid temperature is 720℃ at this time), the refining agent spraying time is 30min, the scum on the surface of the aluminum alloy liquid is cleaned by a slag rake, and then the high-temperature aluminum alloy liquid is fully filtered through a two-stage filtering box, and foreign matter with a diameter of more than 20um is completely purified to obtain refined aluminum alloy liquid;

[0060] Step S4, forming: when the temperature of the refined aluminum alloy liquid is 670°C, the refined aluminum alloy liquid is cast into a mold with a temperature of 150°C to obtain a test rod, and the casting cycle is 50s; the test rod is subjected to aging heat treatment at 190°C for 3h to obtain a high-strength aluminum alloy that does not require heat treatment.

[0061] Comparative Example 1

[0062] Compared with Example 1, the only difference is that pure gallium is not added in step S1, that is, the aluminum alloy obtained in Comparative Example 1 is different from the aluminum alloy obtained in Example 1 only in that gallium is not included in the alloy composition.

[0063] Comparative Example 2

[0064] Compared with Example 1, the only difference is that Al-Ni alloy is not added in step S1, that is, the aluminum alloy obtained in Comparative Example 1 is different from the aluminum alloy obtained in Example 1 only in that the alloy composition does not contain nickel.

[0065] Comparative Example 3

[0066] Compared with Example 1, the only difference is that Al-Re alloy is not added in step S1, that is, the aluminum alloy obtained in Comparative Example 1 is different from the aluminum alloy obtained in Example 1 only in that its alloy composition does not contain rhenium.

[0067] The die castings provided by Examples 1-3 and Comparative Examples 1-3 were selected, and their tensile mechanical properties were tested respectively. The specific data are shown in Table 1.

[0068] Table 1 Tensile mechanical properties data of the embodiments and comparative examples of the present application

[0069] project Tensile strength / Mpa Yield strength / Mpa Elongation / % Example 1 346 210 12.6 Example 2 334 199 11.8 Example 3 336 202 10.9 Comparative Example 1 308 177 8.3 Comparative Example 2 315 182 8.7 Comparative Example 3 323 187 9.9

[0070] As can be seen from Table 1, compared with the products of Comparative Examples 1-3, the products prepared in Examples 1 to 3 have higher tensile strength, yield strength and elongation. From the test results in the above table, it can be seen that the tensile strength of the heat-free die-cast aluminum alloy prepared in the embodiment of the present application is >334MPa, the yield strength is >199MPa, and the elongation is >10.9%. It has high strength and high toughness, and meets the mechanical property requirements of large automotive structural parts. That is, the process provided in this application can prepare products with better performance.

[0071] The above is a detailed introduction to a heat-treatment-free AlSiNi high-strength aluminum alloy and a preparation method thereof provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of ​​the present application; ordinary technicians in this field should understand that: they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A heat-treatment-free AlSiNi high-strength aluminum alloy, characterized in that: The ingredients are formulated according to mass percentage, including the following components: Si 4-8%, Ni 1-3%, Ga 1-3%, Mn 0.5-0.7%, Cu 0.45-0.65%, Zn 0.1-0.3%, Mg0.08-0.12%, Fe 0.08-0.12%, Zr 0.03-0.07%, Re 0.05-0.15%, and the balance is Al.

2. The AlSiNi high-strength aluminum alloy according to claim 1, characterized in that: The high-strength aluminum alloy includes the following components: Si 5-7%, Ni 1-2%, Ga 1-3%, Mn 0.5-0.7%, Cu 0.45-0.65%, Zn 0.1-0.3%, Mg0.08-0.12%, Fe 0.08-0.12%, Zr 0.03-0.07%, Re 0.05-0.15%, and the balance is Al.

3. The AlSiNi high-strength aluminum alloy according to claim 1, characterized in that: The high-strength aluminum alloy includes the following components: Si 6%, Ni 1.5%, Ga 1-3%, Mn 0.6%, Cu 0.55%, Zn 0.2%, Mg 0.1%, Fe 0.1%, Zr0.05%, Re 0.1%, and the balance is Al.

4. A method for preparing a high-strength aluminum alloy of AlSiNi without heat treatment, characterized in that: The steps include: Step S1, pretreatment: prepare raw materials according to the mass percentage of each element in the formula of the aluminum alloy material, clean them and set them aside, wherein the mass percentage of each element is as described in any one of claims 1-3; Step S2, smelting: firstly place the master alloy Al-Si and pure Al in a melting furnace for smelting, and after they are completely melted, add the remaining raw materials to obtain aluminum alloy liquid; Step S3, refining: adding a refining agent to the aluminum alloy liquid, and then filtering to obtain a refined aluminum alloy liquid; Step S4, forming: casting the refined aluminum alloy liquid into a mold to obtain a high-strength aluminum alloy that does not require heat treatment.

5. The preparation method according to claim 4, characterized in that: The step S1 includes the following steps: grinding and polishing the intermediate alloys Al-Si, Al-Zn, Al-Ni, Al-Zr, Al-Fe, Al-Mn, Al-Re and pure Al, pure Mg, and pure Ga respectively, and then cleaning and drying them.

6. The preparation method according to claim 4, characterized in that: The step S2 comprises the following steps: firstly placing the master alloy Al-Si and pure Al in a melting furnace for smelting, and then adding master alloys Al-Zn, Al-Ni, Al-Fe, Al-Mn and pure Al and pure Mg after they are completely melted to obtain a melt 1, and then adding master alloys Al-Zr, Al-Re and pure Ga to the melt 1, and when all components are completely melted, obtaining an aluminum alloy liquid; And / or, the intermediate alloy Al-Si and pure Al are first placed in a melting furnace for melting at a melting temperature of 720-780° C.; And / or, the melting temperature of adding the intermediate alloy Al-Zr, Al-Re and pure Ga to the melt 1 is 700-740°C; And / or, before adding the intermediate alloys Al-Zr, Al-Re and pure Ga into the melt 1, the melt 1 is allowed to stand for 20-40 minutes.

7. The preparation method according to claim 4, characterized in that: The step S3 comprises the following steps: spraying a refining agent into the aluminum alloy liquid under nitrogen conditions for 20-40 minutes, then cleaning the scum on the surface of the aluminum alloy liquid with a slag rake, and then filtering it through a two-stage filter box to obtain a refined aluminum alloy liquid.

8. The preparation method according to claim 7, characterized in that: The refining device is an automatic refiner; And / or, the refining agent includes one or more of Kensec 101A refining agent, RJ-1 refining agent, and sodium-free refining agent; And / or, the nitrogen conditions are specifically: nitrogen pressure of 0.1-0.3MPa, flow rate of 10-20 m 3 / min.

9. The preparation method according to claim 4, characterized in that: The specific steps of step S4 are: when the temperature of the refined aluminum alloy liquid is 650-690°C, casting the refined aluminum alloy liquid into a mold with a temperature of 140-160°C to obtain a test rod, and the casting cycle is 45-55s; performing aging heat treatment on the test rod at 180-200°C for 2-4h to obtain a high-strength aluminum alloy that does not require heat treatment.

10. A heat treatment-free AlSiNi high-strength aluminum alloy, characterized in that: The heat treatment-free AlSiNi high-strength aluminum alloy is prepared by the preparation method described in any one of claims 4-9.