Anti-fatigue long-acting stable aluminum alloy and preparation method thereof

Abstract

The invention discloses an anti-fatigue long-acting stable aluminum alloy and a preparation method thereof, and relates to the technical field of alloys. The aluminum alloy comprises the following components in percentage by mass: 3 to 8 percent of Si, 0.4 to 1.0 percent of Mg, 2 to 3.5 percent of Cu, 0.2 to 0.6 percent of Mn, 0.05 to 0.2 percent of Zr, 0.1 to 0.3 percent of Cr, less than or equal to 0.3 percent of Fe and the balance of Al. By optimizing alloy components, especially the adding amount of copper, zinc and magnesium and combining multiple processes such as homogenization, solid solution and aging, it is ensured that the microstructure of the aluminum alloy is uniform and fine, the mechanical property and stability of the material are remarkably improved, precipitated phases in the alloy are evenly distributed after aging treatment, the strength and toughness of the material are enhanced, and the service life of the material is prolonged. The risk of performance degradation in a complex environment is reduced, and the stability of the material in long-term use is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of alloys, and in particular to a fatigue-resistant, long-acting and stable aluminum alloy and a preparation method thereof. Background Art

[0002] Aluminum alloy is a general term for alloys with aluminum as the matrix element. As the most widely used type of non-ferrous metal structural material in industry, it has the advantages of low density, high strength, good plasticity, easy processing, corrosion resistance, excellent electrical conductivity, thermal conductivity and corrosion resistance, easy surface coloring, and recyclability. It has been widely used in aviation, aerospace, automobile, building packaging, shipbuilding and chemical industries. With the rapid development of science and technology and industrial economy in recent years, new requirements have been put forward for the performance of materials. Aluminum alloy profiles are facing unprecedented challenges. Although my country has indeed achieved many results in aluminum alloy research, there are many types of aluminum alloys on the market, but there is still a certain gap with foreign countries. Some properties of existing aluminum alloy profiles are still not very ideal, such as strength, fatigue resistance and heat resistance, which makes aluminum alloy components easy to fail in practical applications, and its application scope is subject to certain restrictions.

[0003] Metal fatigue is a very complex process. During repeated loading, due to the effect of stress, local areas of the metal undergo plastic deformation. When the deformation accumulates to the limit, it will break and eventually cause the specimen to rupture. Therefore, in order for the alloy to have excellent fatigue performance, it is required not only to have high strength (the ability to resist external forces without deformation), but also to maintain good elongation (the ability to accumulate deformation without damage). Summary of the invention

[0004] The purpose of the present invention is to provide a fatigue-resistant, long-acting and stable aluminum alloy and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a fatigue-resistant and long-acting stable aluminum alloy, wherein the fatigue-resistant and long-acting stable aluminum alloy comprises the following components (mass percentage):

[0006] Si: 3-8%;

[0007] Mg: 0.4-1.0%;

[0008] Cu: 2-3.5%;

[0009] Mn: 0.2-0.6%;

[0010] Zr: 0.05-0.2%;

[0011] Cr: 0.1~0.3%;

[0012] Fe: ≤0.3%;

[0013] The rest is Al and inevitable impurities.

[0014] Furthermore, the preparation method of the fatigue-resistant and long-lasting stable aluminum alloy comprises the following steps:

[0015] (1) Melting;

[0016] (2) Casting;

[0017] (3) Homogenization;

[0018] (4) rolling;

[0019] (5) solid solution;

[0020] (6) Time limit.

[0021] Furthermore, the smelting temperature in step (1) is 1000-1100°C.

[0022] Furthermore, in step (2), the casting is performed by pouring the molten alloy at a temperature of 710° C., a water pressure of 0.08 MPa and a casting speed of 50 mm / min.

[0023] Furthermore, in step (3), the homogenization temperature is 500-550° C., and the homogenization time is 4-8 hours.

[0024] Furthermore, in step (4), the rolling is hot rolling, the rolling temperature is controlled at 400-500° C., and the number of rolling passes is 3-5.

[0025] Furthermore, in step (5), the solution temperature is 520-540° C. and the time is 4-6 hours.

[0026] Furthermore, in step (6), the aging temperature is controlled at 150-180° C. and the aging time is controlled at 12-16 h.

[0027] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0028] (1) By optimizing the alloy composition, especially the addition of copper, zinc and magnesium, combined with a reasonable heat treatment process, the fatigue resistance of the aluminum alloy is significantly improved. The fatigue test results show that the aluminum alloy of the present invention exhibits a fatigue life that is superior to that of traditional aluminum alloys under high cycle fatigue conditions, and can effectively resist fatigue cracks and fractures that may occur during long-term use, ensuring the safety and reliability of the structure.

[0029] (2) The present invention adopts multiple processes such as homogenization, solution treatment and aging to ensure that the microstructure of the aluminum alloy is uniform and fine, significantly improving the mechanical properties and stability of the material. After aging treatment, the precipitated phase in the alloy is evenly distributed, which enhances the strength and toughness of the material, reduces the risk of performance degradation in complex environments, and ensures the stability of the material in long-term use.

[0030] (3) The aluminum alloy of the present invention exhibits good plasticity and formability during hot rolling and subsequent processing, and can adapt to various processing requirements. This enables the aluminum alloy to be conveniently processed into components of various shapes and sizes in practical applications to meet the needs of different fields.

[0031] (4) Due to its excellent fatigue resistance and long-term stability, the aluminum alloy of the present invention is particularly suitable for fields with extremely high requirements on material performance, such as aerospace, automobile manufacturing, and building structures. In the field of aerospace, it can effectively reduce the weight of the structure and improve fuel efficiency; in automobile manufacturing, it can improve the safety and durability of the vehicle; in building structures, it can extend the service life and reduce maintenance costs. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1

[0034] (1) According to the mass percentage of Si being 3%, the mass percentage of Mg being 0.4%, the mass percentage of Cu being 2%, the mass percentage of Mn being 0.2%, the mass percentage of Zr being 0.05%, the mass percentage of Cr being 0.1%, the mass percentage of Fe being ≤0.3%, and the balance being Al, pure aluminum ingots, pure magnesium ingots, pure copper ingots, aluminum-silicon master alloys, aluminum-manganese master alloys, aluminum-chromium master alloys, and aluminum-zirconium master alloys are weighed and smelted at 1000° C.;

[0035] (2) casting the molten alloy at a temperature of 710° C., a water pressure of 0.08 MPa, and a casting speed of 50 mm / min to obtain an ingot;

[0036] (3) homogenizing the ingot at 500°C for 8 h;

[0037] (4) hot rolling at 400°C with three passes;

[0038] (5) Solution at 520°C for 4 h;

[0039] (6) Aging treatment at 150°C for 16 h.

[0040] Example 2

[0041] (1) According to the mass percentage of Si being 4%, the mass percentage of Mg being 0.52%, the mass percentage of Cu being 2.3%, the mass percentage of Mn being 0.28%, the mass percentage of Zr being 0.08%, the mass percentage of Cr being 0.14%, the mass percentage of Fe being ≤0.3%, and the balance being Al, pure aluminum ingots, pure magnesium ingots, pure copper ingots, aluminum-silicon master alloys, aluminum-manganese master alloys, aluminum-chromium master alloys, and aluminum-zirconium master alloys are weighed and smelted at 1020° C.;

[0042] (2) casting the molten alloy at a temperature of 710° C., a water pressure of 0.08 MPa, and a casting speed of 50 mm / min to obtain an ingot;

[0043] (3) homogenizing the ingot at 510°C for 4 h;

[0044] (4) hot rolling at 420°C with 4 passes;

[0045] (5) Solution at 524°C for 5 h;

[0046] (6) Aging treatment at 156°C for 13 h.

[0047] Example 3

[0048] (1) According to the mass percentage of Si being 5%, the mass percentage of Mg being 0.64%, the mass percentage of Cu being 2.6%, the mass percentage of Mn being 0.36%, the mass percentage of Zr being 0.11%, the mass percentage of Cr being 0.18%, the mass percentage of Fe being ≤0.3%, and the balance being Al, pure aluminum ingots, pure magnesium ingots, pure copper ingots, aluminum-silicon master alloys, aluminum-manganese master alloys, aluminum-chromium master alloys, and aluminum-zirconium master alloys are weighed and smelted at 1050° C.;

[0049] (2) casting the molten alloy at a temperature of 710° C., a water pressure of 0.08 MPa, and a casting speed of 50 mm / min to obtain an ingot;

[0050] (3) homogenizing the ingot at 520°C for 4 to 8 hours;

[0051] (4) hot rolling at 440°C with three passes;

[0052] (5) Solution at 530°C for 5 h;

[0053] (6) Aging treatment at 160°C for 15 h.

[0054] Example 4

[0055] (1) According to the mass percentage of Si being 6%, the mass percentage of Mg being 0.76%, the mass percentage of Cu being 2.9%, the mass percentage of Mn being 0.44%, the mass percentage of Zr being 0.14%, the mass percentage of Cr being 0.22%, the mass percentage of Fe being ≤0.3%, and the balance being Al, pure aluminum ingots, pure magnesium ingots, pure copper ingots, aluminum-silicon master alloys, aluminum-manganese master alloys, aluminum-chromium master alloys, and aluminum-zirconium master alloys are weighed and smelted at 1100° C.;

[0056] (2) casting the molten alloy at a temperature of 710° C., a water pressure of 0.08 MPa, and a casting speed of 50 mm / min to obtain an ingot;

[0057] (3) homogenizing the ingot at 550°C for 4 h;

[0058] (4) hot rolling at 500°C with 5 passes;

[0059] (5) Solution treatment at 540°C for 4 h;

[0060] (6) Aging treatment at 180°C for 16 h.

[0061] Example 5

[0062] (1) According to the mass percentage of Si being 7%, the mass percentage of Mg being 0.88%, the mass percentage of Cu being 3.2%, the mass percentage of Mn being 0.52%, the mass percentage of Zr being 0.17%, the mass percentage of Cr being 0.26%, the mass percentage of Fe being ≤0.3%, and the balance being Al, pure aluminum ingots, pure magnesium ingots, pure copper ingots, aluminum-silicon master alloys, aluminum-manganese master alloys, aluminum-chromium master alloys, and aluminum-zirconium master alloys are weighed and smelted at 1100° C.;

[0063] (2) casting the molten alloy at a temperature of 710° C., a water pressure of 0.08 MPa, and a casting speed of 50 mm / min to obtain an ingot;

[0064] (3) homogenizing the ingot at 550°C for 8 h;

[0065] (4) hot rolling at 500°C with three passes;

[0066] (5) Solution at 540°C for 6 h;

[0067] (6) Aging treatment at 180°C for 16 h.

[0068] Example 6

[0069] (1) According to the mass percentage of Si being 8%, the mass percentage of Mg being 1.0%, the mass percentage of Cu being 3.5%, the mass percentage of Mn being 0.6%, the mass percentage of Zr being 0.2%, the mass percentage of Cr being 0.3%, the mass percentage of Fe being ≤0.3%, and the balance being Al, pure aluminum ingots, pure magnesium ingots, pure copper ingots, aluminum-silicon master alloys, aluminum-manganese master alloys, aluminum-chromium master alloys, and aluminum-zirconium master alloys are weighed and smelted at 1100° C.;

[0070] (2) casting the molten alloy at a temperature of 710° C., a water pressure of 0.08 MPa, and a casting speed of 50 mm / min to obtain an ingot;

[0071] (3) homogenizing the ingot at 525°C for 6 h;

[0072] (4) hot rolling at 450°C with 4 passes;

[0073] (5) Solution at 530°C for 5 h;

[0074] (6) Aging treatment at 165°C for 14 h.

[0075] Effect example

[0076] Table 1 below shows the performance analysis results of the fatigue-resistant and long-lasting stable aluminum alloys of Examples 1 to 6 of the present invention.

[0077] Table 1

[0078] Yield strength(MPa) Tensile strength(MPa) Example 1 336.8 388.9 Example 2 337.0 399.9 Example 3 341.5 401.3 Example 4 348.4 405.8 Example 5 342.0 400.2 Example 6 344.8 403.9

[0079] The present invention significantly improves the fatigue resistance of aluminum alloy by optimizing alloy components, especially the addition of copper, zinc and magnesium, combined with a reasonable heat treatment process. Fatigue test results show that the aluminum alloy of the present invention exhibits a fatigue life superior to that of traditional aluminum alloys under high cycle fatigue conditions, can effectively resist fatigue cracks and fractures that may occur during long-term use, and ensure the safety and reliability of the structure. The present invention adopts multiple processes such as homogenization, solid solution and aging to ensure that the microstructure of the aluminum alloy is uniform and fine, and significantly improves the mechanical properties and stability of the material. After aging treatment, the precipitated phase in the alloy is evenly distributed, which enhances the strength and toughness of the material, reduces the risk of performance degradation in complex environments, and ensures the stability of the material in long-term use. The aluminum alloy of the present invention exhibits good plasticity and formability during hot rolling and subsequent processing, and can adapt to a variety of processing technology requirements. This enables the aluminum alloy to be easily processed into components of various shapes and sizes in practical applications to meet the needs of different fields. Due to its excellent fatigue resistance and long-term stability, the aluminum alloy of the present invention is particularly suitable for fields with extremely high material performance requirements such as aerospace, automobile manufacturing, and building structures. In the aerospace field, it can effectively reduce structural weight and improve fuel efficiency; in automobile manufacturing, it can improve vehicle safety and durability; in building structures, it can extend service life and reduce maintenance costs.

[0080] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A fatigue-resistant, long-lasting and stable aluminum alloy, characterized in that: The fatigue-resistant and long-lasting stable aluminum alloy comprises the following components (in mass percentage): Si: 3-8%; Mg: 0.4-1.0%; Cu: 2-3.5%; Mn: 0.2-0.6%; Zr:0.05-0.2％； Cr：0.1～0.3％； Fe: ≤0.3%; The rest is Al and inevitable impurities.

2. The method for preparing a fatigue-resistant, long-lasting and stable aluminum alloy according to claim 1, characterized in that: The method comprises the following preparation steps: (1) Melting; (2) Casting; (3) Homogenization; (4) rolling; (5) solid solution; (6) Time limit.

3. The method for preparing a fatigue-resistant, long-lasting and stable aluminum alloy according to claim 2, characterized in that: The melting temperature in step (1) is 1000-1100°C.

4. The method for preparing a fatigue-resistant, long-lasting and stable aluminum alloy according to claim 2, characterized in that: In step (2), the casting is performed by pouring the molten alloy at a temperature of 710° C., a water pressure of 0.08 MPa and a casting speed of 50 mm / min.

5. The method for preparing a fatigue-resistant, long-lasting and stable aluminum alloy according to claim 2, characterized in that: In step (3), the homogenization temperature is 500-550° C. and the homogenization time is 4-8 hours.

6. The method for preparing a fatigue-resistant, long-lasting and stable aluminum alloy according to claim 2, characterized in that: The rolling in step (4) is hot rolling, the rolling temperature is controlled at 400-500° C., and the number of rolling passes is 3-5.

7. The method for preparing a fatigue-resistant, long-lasting and stable aluminum alloy according to claim 2, characterized in that: In step (5), the solution temperature is 520-540° C. and the time is 4-6 hours.

8. The method for preparing a fatigue-resistant, long-lasting and stable aluminum alloy according to claim 2, characterized in that: In step (6), the aging temperature is controlled at 150-180° C. and the aging time is controlled at 12-16 h.