Aluminum alloy with high pitting corrosion resistance, preparation method of aluminum alloy and aluminum alloy product

Abstract

The invention provides an aluminum alloy with high pitting corrosion resistance. The aluminum alloy comprises 0-0.10 wt% (not equal to 0) of Si; 0-0.20 wt% of Fe, which is not equal to 0; 0-0.01 wt% of Cu, which is not equal to 0; 1.1 to 1.2 wt% of Mn; 0-0.01 wt% of Mg, which is not equal to 0; 0-0.15 wt% of Cr, which is not equal to 0; ni is 0-0.01 wt% and is not equal to 0; 0-0.2 wt% of Zn and is not equal to 0; 0-0.02 wt% of Ti and is not equal to 0; and the balance of Al. The invention further provides a preparation method of the aluminum alloy. According to the aluminum alloy, the content of Fe and Si is reduced, the content of Cu, Mg, Cr, Ti, Ni and other elements is properly increased, generation of a harmful second phase is reduced, the area percentage of the aluminum alloy is reduced, generation of pitting corrosion is reduced, and the pitting corrosion is promoted to be converted into uniform corrosion, so that the aluminum alloy has good corrosion resistance.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloys, and in particular to an aluminum alloy with high pitting corrosion resistance, a preparation method thereof, and an aluminum alloy product. Background Art

[0002] Copper is widely used in key parts such as evaporators, condensers and indoor and outdoor unit connection pipes of heat exchangers in the air-conditioning industry due to its excellent electrical and thermal conductivity and long service life. With the scarcity of copper resources and the continuous rise in copper prices, the costs of air-conditioning companies have increased dramatically. In order to reduce the cost of air-conditioning and effectively utilize natural resources and break the dependence on copper resources, the home appliance air-conditioning industry has adopted aluminum tubes instead of copper tubes in heat exchangers, evaporators, radiators, etc.

[0003] Among the aluminum alloy series, 3 series aluminum alloys have good corrosion resistance, electrical conductivity, thermal conductivity, weldability and machinability, and are favored in the air conditioning field. At present, 3003, 3103 and other 3 series aluminum alloy tubes widely used in air conditioning heat exchangers face a variety of service environments. Under harsh working conditions, ordinary aluminum tubes are easily corroded. As the corrosion depth increases, aluminum tubes are prone to perforation corrosion, that is, corrosion that extends from the surface of the aluminum tube to the inside. This type of corrosion is called pitting corrosion, which can cause refrigerant leakage and heat exchanger scrapping.

[0004] The life of copper tubes used in air conditioner heat exchangers can reach more than 10 years, while the life of aluminum tubes is less than 1 year. In addition, according to industry requirements, the current SWAAT salt spray corrosion test is mainly used to evaluate the corrosion resistance of aluminum tubes. The SWAAT salt spray corrosion resistance time of ordinary 3003 aluminum alloy is about 700 hours, and the SWAAT salt spray corrosion resistance time of 3103 aluminum alloy is only about 400 hours. As customers' requirements for the corrosion resistance of air conditioners become more and more stringent, the corrosion resistance of existing aluminum tubes is difficult to meet the actual needs of enterprises, and there is an urgent need to provide an aluminum alloy pipe with high pitting resistance. Summary of the invention

[0005] The technical problem solved by the present invention is to provide an aluminum alloy resistant to high-pit corrosion. The aluminum alloy provided in the present application has good mechanical properties and corrosion resistance.

[0006] In view of this, the present application provides an aluminum alloy with high pitting corrosion resistance, comprising:

[0007] Si 0-0.10wt% and not equal to 0;

[0008] Fe 0~0.20wt% and not equal to 0;

[0009] Cu 0~0.01wt% and not equal to 0;

[0010] Mn 1.1-1.2wt%;

[0011] Mg 0~0.01wt% and not equal to 0;

[0012] Cr 0~0.15wt% and not equal to 0;

[0013] Ni 0~0.01wt% and not equal to 0;

[0014] Zn 0-0.2wt% and not equal to 0;

[0015] Ti 0-0.02wt% and not equal to 0;

[0016] Zr 0~0.10wt%;

[0017] The balance is Al.

[0018] Preferably, the content of Cu is 0-0.005wt%, the content of Cr is 0-0.10wt%, the content of Zn is 0-0.05wt%, and the content of Zr is 0.

[0019] Preferably, the content of Si is 0-0.05wt%, the content of Fe is 0-0.10wt%, the content of Cu is 0-0.005wt%, the content of Cr is 0-0.10wt%, the content of Zn is 0-0.05wt%, and the content of Zr is 0.

[0020] Preferably, the content of Si is 0-0.05wt%, the content of Fe is 0-0.10wt%, the content of Cu is 0-0.005wt%, the content of Cr is 0-0.10wt%, the content of Zn is 0-0.05wt%, and the content of Zr is 0-0.10wt% and is not equal to 0.

[0021] Preferably, the content of Si is 0.04-0.09 wt%, and / or the content of Fe is 0.07-0.16 wt%, and / or the content of Cu is 0.002-0.008 wt%.

[0022] Preferably, the content of Mn is 1.12-1.17 wt %, and / or the content of Mg is 0.002-0.007 wt %, and / or the content of Cr is 0.07-0.14 wt %.

[0023] Preferably, the content of Ni is 0.002-0.008 wt %, and / or the content of Zn is 0.002-0.180 wt %, and / or the content of Ti is 0.013-0.016 wt %, and / or the content of Zr is 0-0.081 wt %.

[0024] The present application also provides a method for preparing the aluminum alloy, comprising the following steps:

[0025] Aluminum raw materials, copper raw materials, magnesium raw materials, nickel raw materials and zinc raw materials are mixed and heated to melt to obtain a melt 1;

[0026] After deslagging the first melt, a second melt is obtained;

[0027] Adding iron, manganese, titanium, chromium and zirconium to the second melt to obtain a third melt;

[0028] Refining the molten solution 3, removing slag and gas, and obtaining molten solution 4;

[0029] The molten metal is cast and then homogenized to obtain an aluminum alloy.

[0030] Preferably, the melting temperature is 730-760°C, the temperature of melt two is 730-760°C, the temperature of melt three is 750-790°C, the temperature of melt four is 740-770°C, argon is introduced for degassing before casting, and aluminum titanium boron wire is added for degassing again; the temperature of the homogenization treatment is 590-620°C, and the insulation time is 10-12h.

[0031] The present application also provides an aluminum alloy product, which is prepared from the aluminum alloy or the aluminum alloy prepared by the preparation method.

[0032] The present application provides an aluminum alloy with high pitting corrosion resistance, which includes: Si 0-0.10wt% and not equal to 0; Fe 0-0.20wt% and not equal to 0; Cu 0-0.01wt% and not equal to 0; Mn 1.1-1.2wt%; Mg 0-0.01wt% and not equal to 0; Cr 0-0.15wt% and not equal to 0; Ni 0-0.01wt% and not equal to 0; Zn 0-0.2wt% and not equal to 0; Ti 0-0.02wt% and not equal to 0; Zr 0-0.10wt%; and the balance is Al. The aluminum alloy provided by the present application can reduce the generation of harmful second phases, reduce the area percentage of the second phase, reduce the generation of pitting corrosion of the aluminum alloy, promote the transformation of pitting corrosion into uniform corrosion, and improve the corrosion performance of the aluminum alloy by reducing the content of Fe and Si and appropriately increasing the content of elements such as Cu, Mg, Cr, Ti, and Ni. At the same time, by adjusting the content of each element in the aluminum alloy, the mechanical properties of the aluminum alloy are improved; further, the present application can diffuse the alloying elements in the aluminum alloy through homogenization treatment, so that the second phase is evenly distributed in the grains, reducing the possibility of local concentration differences in the alloy, which is conducive to improving the uniformity and stability of the aluminum alloy. Experimental results show that the aluminum alloy provided by the present application has good strength and plasticity, with a tensile strength of 110-130MPa, a yield strength of 60-70MPa, and an elongation of ≥40%; the aluminum alloy provided by the present application is resistant to salt spray corrosion for ≥1000h. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The corrosion depth photos of the aluminum alloy tubes prepared in Comparative Examples 1 and 2 of the present invention after corrosion;

[0034] Figure 2 This is a photo of the corrosion depth of the aluminum alloy tube prepared in Example 1 of the present invention after corrosion;

[0035] Figure 3 The second phase structure observation photos of the aluminum alloy tubes prepared in Comparative Examples 1 and 2 of the present invention;

[0036] Figure 4 This is a photograph of the second phase structure of the aluminum alloy tube prepared in the embodiment of the present invention;

[0037] Figure 5 A statistical bar chart of the second phase area percentage of the aluminum alloy tubes prepared in the embodiments of the present invention and the comparative examples;

[0038] Figure 6 Energy spectrum analysis of the second phase structure of the aluminum alloy tube prepared in Comparative Example 1 of the present invention;

[0039] Figure 7 Energy spectrum analysis of the second phase structure of the aluminum alloy tube prepared in Comparative Example 2 of the present invention;

[0040] Figure 8 Energy spectrum analysis of the second phase structure of the aluminum alloy tube prepared in the embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0042] In view of the problem that the mechanical properties and corrosion resistance of aluminum alloy products in the prior art cannot meet the actual needs of enterprises, the present application discloses an aluminum alloy with high pitting corrosion resistance, which reduces the amount of harmful second phases and the occurrence of pitting corrosion by adjusting the type and content of alloying elements added, and promotes the conversion of pitting corrosion into uniform corrosion, so that the aluminum alloy has both mechanical properties and corrosion resistance; specifically, the embodiment of the present invention discloses Si 0 to 0.10wt% and not equal to 0;

[0043] Fe 0~0.20wt% and not equal to 0;

[0044] Cu 0~0.01wt% and not equal to 0;

[0045] Mn 1.1~1.2wt%;

[0046] Mg 0~0.01wt% and not equal to 0;

[0047] Cr 0~0.15wt% and not equal to 0;

[0048] Ni 0~0.01wt% and not equal to 0;

[0049] Zn 0-0.2wt% and not equal to 0;

[0050] Ti 0-0.02wt% and not equal to 0;

[0051] Zr 0~0.10wt%;

[0052] The balance is Al.

[0053] The aluminum alloy provided in the present application specifically includes: Si: 0~0.10wt%, Fe: 0~0.20wt%, Cu: 0~0.01wt%, Mn: 1.1~1.2wt%, Mg: 0~0.01wt%, Cr: 0~0.15wt%, Ni: 0~0.01wt%, Zn: 0~0.2wt%, : 0~0.02wt%, Zr=0, and the balance is Al.

[0054] Specifically, it includes: Si: 0-0.10wt%, Fe: 0-0.20wt%, Cu: 0-0.005wt%, Mn: 1.1-1.2wt%, Mg: 0-0.01wt%, Cr: 0-0.10wt%, Ni: 0-0.01wt%, Zn: 0-0.05wt%, Ti: 0-0.02wt%, Zr=0, and the balance is Al.

[0055] Specifically, it includes: Si: 0-0.05wt%, Fe: 0-0.10wt%, Cu: 0-0.005wt%, Mn: 1.1-1.2wt%, Mg: 0-0.01wt%, Cr: 0-0.10wt%, Ni: 0-0.01wt%, Zn: 0-0.05wt%, Ti: 0-0.02, Zr=0wt%, and the balance is Al.

[0056] Specifically, it includes: Si: 0~0.05wt%, Fe: 0~0.10wt%, Cu: 0~0.005wt%, Mn: 1.1~1.2wt%, Mg: 0~0.01wt%, Cr: 0~0.10wt%, Ni: 0~0.01wt%, Zn: 0~0.05wt%, Ti: 0~0.02wt%, Zr: 0~0.10wt%, and the balance is Al.

[0057] Further, the content of Si is 0.04-0.09wt%, specifically, the energy of Si is 0.05-0.08wt%. The content of Fe is 0.07-0.16wt%, specifically, the content of Fe is 0.09-0.15wt%. The content of Cu is 0.002-0.008wt%, specifically, the content of Cu is 0.003-0.006wt%. The content of Mn is 1.12-1.17wt%, specifically, the content of Mn is 1.13-1.16wt%. The content of Mg is 0.002-0.007wt%, specifically, the content of Mg is 0.003-0.006wt%. The content of Cr is 0.07-0.14wt%, specifically, the content of Cr is 0.09-0.12wt%. The content of Ni is 0.002-0.008wt%, specifically, the content of Ni is 0.003-0.005wt%. The content of Zn is 0.002-0.180 wt%, specifically, the content of Zn is 0.005-0.120 wt%. The content of Ti is 0.013-0.016 wt%, specifically, the content of Ti is 0.014-0.015 wt%. The content of Zr is 0-0.081 wt%.

[0058] The present application also provides a method for preparing the above aluminum alloy, comprising smelting → online degassing → casting → homogenization → rod casting in sequence, specifically comprising the following steps:

[0059] The aluminum ingot and the master alloy are heated to be melted to obtain a melt 1;

[0060] After deslagging the first melt, a second melt is obtained;

[0061] Adding iron, manganese, titanium, chromium and zirconium to the second melt to obtain a third melt;

[0062] Refining the molten solution 3, removing slag and gas, and obtaining molten solution 4;

[0063] The molten metal is cast and then homogenized to obtain an aluminum alloy.

[0064] In the above aluminum alloy preparation process, the melting temperature is 730-760°C, the temperature of the second melt is 730-760°C, the temperature of the third melt is 750-790°C, and the temperature of the fourth melt is 740-770°C. Argon is introduced for degassing before casting, and then aluminum titanium boron wire is added for degassing. The temperature of the homogenization treatment is 590-620°C, and the holding time is 10-12h; specifically, the temperature of the equalization treatment is 600-610°C, and the holding time is 10-11h.

[0065] Furthermore, the preparation method of the aluminum alloy is specifically as follows:

[0066] S1) mixing aluminum raw material, copper raw material, magnesium raw material, nickel raw material and zinc raw material, putting them into a furnace and heating them to 730-760° C. to melt them, thereby obtaining a melt 1;

[0067] S2) Sprinkling the slag remover evenly into the molten metal 1 and stirring for 5 to 10 minutes, then scraping off the slag on the surface of the aluminum liquid to obtain the molten metal 2;

[0068] S3) controlling the temperature of the second melt to 730-760° C., then adding iron, manganese, titanium, chromium and zirconium to the second melt and stirring for 10-15 minutes to obtain a third melt;

[0069] S4) controlling the temperature of the melt 3 to 750-790° C., then adding a refining agent to the melt 3, stirring and then skimming off the slag, and introducing pure argon gas for degassing for 15-20 minutes, and then standing for 50-60 minutes to skim off the slag on the liquid surface to obtain the melt 4;

[0070] S5) controlling the temperature of the melt 4 to 740-770° C., introducing pure argon gas for degassing for 10 minutes, then adding aluminum titanium boron wire, degassing for 5 minutes after melting, and then filtering the melt through a fully preheated filter box, allowing it to enter a casting system for casting to obtain an ingot;

[0071] S6) Cut the ingot into short aluminum alloy round cast bars, heat them to 590-620°C in a soaking furnace, keep them warm for 10-12 hours, and air cool them.

[0072] The present application also provides an aluminum alloy product, which is prepared from the aluminum alloy described in the above scheme.

[0073] In the aluminum alloy provided in the present application, by reducing the content of Fe and Si and appropriately increasing the content of elements such as Cu, Mg, Cr, Ti, and Ni, the generation of harmful second phases is reduced, the area percentage thereof is reduced, pitting corrosion is reduced, and the transformation of pitting corrosion into uniform corrosion is promoted; at the same time, the content of zinc element is reduced and the rare earth element zirconium is increased; in the production process, the process steps and process parameters are optimized, and the alloying elements in the aluminum alloy can be diffused through homogenization treatment, so that the second phase is evenly distributed in the grains, reducing the possibility of local concentration differences in the alloy, which helps to improve the uniformity and stability of the alloy.

[0074] In order to further understand the present invention, the aluminum alloy with high pitting corrosion resistance provided by the present invention is described in detail below in conjunction with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0075] The salt spray corrosion resistance in the following examples is a salt spray corrosion test conducted in accordance with "ASTM G85-2011 Standard Operating Procedure for Improved Salt Spray Test and its Appendix A3 Seawater Acidification Cycle Test".

[0076] Example

[0077] S1) putting aluminum ingots, master alloys and other raw materials into a furnace and heating them to 760° C. to melt to obtain a melt 1;

[0078] S2) evenly sprinkle the slag remover into the melt 1 and stir for 8 minutes, then scrape off the slag on the surface of the melt to obtain the melt 2;

[0079] S3) controlling the temperature of the second melt to 760° C., then adding iron, manganese, titanium, chromium and zirconium to the second melt and stirring for 12 minutes to obtain a third melt;

[0080] S4) controlling the temperature of the melt 3 to 790° C., then adding a refining agent to the melt 3, stirring and then skimming off the slag, and introducing pure argon gas for degassing for 20 minutes, and then standing for 60 minutes to skim off the slag on the liquid surface to obtain a melt 4;

[0081] S5) controlling the temperature of the melt 4 to 770° C., introducing pure argon gas for degassing for 10 minutes, then adding aluminum titanium boron wire, degassing for 5 minutes after melting, and then filtering the melt through a fully preheated filter box, allowing it to enter a casting system for casting to obtain an ingot;

[0082] S6) cutting the ingot into short aluminum alloy round cast bars, heating them to 620°C in a soaking furnace, keeping them warm for 12 hours, and air cooling them to obtain aluminum alloy ingots, which are then drawn by extrusion, thread forming and other processes to obtain aluminum alloy tubes.

[0083] The aluminum alloys provided in the embodiments and comparative examples are prepared according to the above method. Table 1 is a composition data table of the four aluminum alloys designed by the present invention, and Table 2 is a chemical composition data table of 3003 aluminum alloy and 3103 aluminum alloy;

[0084] Table 1 Composition data of the four alloys in the embodiment

[0085] Si Fe Cu Mn Mg Cr Ni Zn Ti Zr Al Example 1 0.091 0.158 0.008 1.125 0.007 0.142 0.008 0.198 0.016 _ margin Example 2 0.087 0.152 0.006 1.138 0.003 0.094 0.005 0.005 0.015 _ margin Example 3 0.045 0.078 0.002 1.169 0.006 0.082 0.003 0.003 0.013 _ margin Example 4 0.039 0.074 0.002 1.156 0.002 0.076 0.002 0.002 0.016 0.081 margin

[0086] Table 2 Composition data of two alloys in comparative example

[0087] Si Fe Cu Mn Mg Cr Zn Al Comparative Example 1 0.518 0.586 0.154 1.52 - - 0.115 margin Comparative Example 2 0.527 0.697 0.101 1.47 0.304 0.112 0.203 margin

[0088] The properties of the aluminum alloy tubes prepared in the above examples and comparative examples were tested, and the results are shown in Table 3, which is a data table of mechanical properties and corrosion resistance of the aluminum alloy tubes prepared in the examples;

[0089] Table 3 Mechanical properties and corrosion resistance data of aluminum alloy tubes provided in the examples

[0090] Example Tensile strength / Mpa Yield strength / Mpa Elongation / % Salt spray corrosion resistance / h Example 1 112 67 44 1000 Example 2 116 61 46 1300 Example 3 114 60 48 1650 Example 4 120 64 47 1800

[0091] It can be seen from Table 3 that the aluminum alloy tube prepared in the embodiment has a tensile strength of 110-120 MPa, a yield strength of ≥60 MPa, an elongation of ≥40%, and a corrosion resistance of 1000-2000 h.

[0092] The corrosion resistance of the aluminum alloy tube prepared in the embodiment and the aluminum alloy tube prepared in the comparative example were compared, as shown in Table 4;

[0093] Table 4 Comparative data of corrosion resistance of aluminum alloy tubes prepared in Examples and Comparative Examples

[0094] alloy Salt spray corrosion resistance / h Example 1 1000 Example 2 1300 Example 3 1650 Example 4 1800 Comparative Example 1 700 Comparative Example 2 500

[0095] It can be seen from Table 4 that the corrosion resistance of the aluminum alloy tube prepared in the present invention is better than that of the comparative example.

[0096] The aluminum alloy tube prepared in Example 1 of the present invention and the aluminum alloy tubes prepared in Comparative Examples 1 and 2 were subjected to corrosion evaluation tests, and the depths of the corrosion pits were compared. Figure 1 and Figure 2 shown.

[0097] Figure 1 The corrosion depth photos of the aluminum alloy tubes prepared in Comparative Example 1 (left) and Comparative Example 2 (right) after corrosion are shown in FIG. Figure 1 It can be seen that the corrosion depths of the aluminum alloy tubes prepared in Comparative Example 1 and Comparative Example 2 are 363.77 μm and 457.1 μm, respectively. Figure 2 The corrosion depth of the aluminum alloy tube prepared in Example 1 after corrosion is 86.83 μm; Figure 1 and Figure 2 It can be observed that the corrosion occurring in the aluminum alloy tube prepared in the comparative example is pitting corrosion, while the corrosion occurring in the aluminum alloy tube prepared in the embodiment of the present invention is uniform corrosion.

[0098] In order to further study the corrosion mechanism of the aluminum alloy tube, the second phase structure analysis of the aluminum alloy tube was carried out. Figure 3 to Figure 5 shown. Figure 3 The second phase structure observation photos of the aluminum alloy tubes prepared in Comparative Example 1 (left picture) and Comparative Example 2 (right picture) are shown in FIG. Figure 4 The second phase structure observation photo of the aluminum alloy tube prepared in Example 1; the second phase of the aluminum alloy tube prepared in Example 1 and the comparative example was quantitatively counted, as shown in FIG. Figure 5 shown; from Figure 5 It can be seen that the area percentage of the second phase of each alloy is: Comparative Example 2>Comparative Example 1>Example 1.

[0099] To further study the element content of the second phase, scanning microstructure energy spectrum analysis was performed on the aluminum alloy tubes prepared in Comparative Example 1, Comparative Example 2 and Example 1, respectively. Figures 6 to 8 shown; from Figures 6 to 8It was observed that the second phases of the aluminum alloy tube prepared in Example 1 and the aluminum alloy tube prepared in Comparative Example 1 were AlFeMnSi and AlFeMnSiCr, and there were obvious differences in their quantity, size and morphology.

[0100] In summary, the AlFeMnSi(Cr) second phase with a large area percentage and large size provides a path for the expansion of pitting corrosion of the aluminum alloy, accelerating the pitting corrosion of the aluminum alloy; while the aluminum alloy product prepared by the present invention has a smaller amount of second phase and a more rounded morphology, which promotes the transformation of pitting corrosion to uniform corrosion of the aluminum alloy during the corrosion process.

[0101] Compared with the existing 3 series aluminum alloys, the aluminum alloy product prepared by the present invention takes into account the mechanical properties of the alloy and improves the corrosion resistance of the alloy, which is beneficial to promoting the use of aluminum alloy pipes in air-conditioning heat exchangers.

[0102] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0103] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A highly pitting corrosion resistant aluminum alloy comprising: The balance is Al.

2. The aluminum alloy according to claim 1, characterized in that The content of Cu is 0-0.005wt%, the content of Cr is 0-0.10wt%, the content of Zn is 0-0.05wt%, and the content of Zr is 0.

3. The aluminum alloy according to claim 1, characterized in that The content of Si is 0-0.05wt%, the content of Fe is 0-0.10wt%, the content of Cu is 0-0.005wt%, the content of Cr is 0-0.10wt%, the content of Zn is 0-0.05wt%, and the content of Zr is 0.

4. The aluminum alloy according to claim 1, characterized in that The content of Si is 0-0.05wt%, the content of Fe is 0-0.10wt%, the content of Cu is 0-0.005wt%, the content of Cr is 0-0.10wt%, the content of Zn is 0-0.05wt%, and the content of Zr is 0-0.10wt% and is not equal to 0.

5. The aluminum alloy according to claim 1, characterized in that The content of Si is 0.04 to 0.09 wt %, and / or the content of Fe is 0.07 to 0.16 wt %, and / or the content of Cu is 0.002 to 0.008 wt %.

6. The aluminum alloy according to claim 1, characterized in that The content of Mn is 1.12 to 1.17 wt %, and / or the content of Mg is 0.002 to 0.007 wt %, and / or the content of Cr is 0.07 to 0.14 wt %.

7. The aluminum alloy according to claim 1, characterized in that The content of Ni is 0.002 to 0.008 wt %, and / or the content of Zn is 0.002 to 0.180 wt %, and / or the content of Ti is 0.013 to 0.016 wt %, and / or the content of Zr is 0 to 0.081 wt %.

8. The method for preparing the aluminum alloy according to any one of claims 1 to 7, comprising the following steps: Aluminum raw materials, copper raw materials, magnesium raw materials, nickel raw materials and zinc raw materials are mixed and heated to melt to obtain a melt 1; After deslagging the first melt, a second melt is obtained; Adding iron, manganese, titanium, chromium and zirconium to the second melt to obtain a third melt; Refining the molten solution 3, removing slag and gas, and obtaining molten solution 4; The molten metal is cast and then homogenized to obtain an aluminum alloy.

9. The preparation method according to claim 8, characterized in that: The melting temperature is 730-760°C, the temperature of the melt two is 730-760°C, the temperature of the melt three is 750-790°C, the temperature of the melt four is 740-770°C, argon is introduced for degassing before casting, and then aluminum titanium boron wire is added for degassing; the temperature of the homogenization treatment is 590-620°C, and the insulation time is 10-12h.

10. An aluminum alloy product, prepared from the aluminum alloy according to any one of claims 1 to 7 or the aluminum alloy prepared by the preparation method according to any one of claims 8 to 9.

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