High-strength damage-resistant Al-Cu-Mg-Ag alloy and preparation method thereof

Abstract

The invention relates to the technical field of alloy material preparation, in particular to a high-strength damage-resistant Al-Cu-Mg-Ag alloy and a preparation method thereof. The preparation method of the high-strength damage-resistant Al-Cu-Mg-Ag alloy comprises the following steps: S1, carrying out two-stage homogenization treatment on a cast ingot; s2, the cast ingot treated in the step S1 is subjected to homogenizing cooling; s3, the cast ingot treated in the step S2 is subjected to hot rolling; s4, the hot-rolled cast ingot is subjected to two-stage solution treatment; and S5, quenching is carried out, and the high-strength damage-resistant Al-Cu-Mg-Ag series alloy is obtained. In the process of preparing the high-strength and damage-resistant Al-Cu-Mg-Ag alloy, two-stage homogenization treatment and two-stage solution treatment are adopted, and the comprehensive performance of the finally prepared high-strength and damage-resistant Al-Cu-Mg-Ag alloy is better.

Description

Technical Field

[0001] This invention relates to the field of alloy material preparation technology, and in particular to a high-strength, damage-resistant Al-Cu-Mg-Ag alloy and its preparation method. Background Technology

[0002] Compared to aluminum alloys such as Al-Cu-Mg-Ag and 2024, Al-Cu-Mg-Ag alloys exhibit higher room-temperature strength and damage resistance. The main drawbacks of existing Al-Cu-Mg-Ag alloy preparation methods include:

[0003] 1. The prepared Al-Cu-Mg-Ag series plates exhibit poor plane stress fracture toughness and fatigue crack propagation reduction ratio. The plane stress fracture toughness (kc) in the LT direction is 120~125 MPa, and Δk = 30 MPa·m. 1 / 2 , R=0.01, f=2~25 Hz, da / dn=4.0×10 -3 Observation of the fracture surface of the sample revealed a significant amount of residual second phase at the fracture site, such as... Figure 1 As shown.

[0004] 2. The ingot casting adopts a single-stage 498℃ homogenization process, which prevents the Al2Cu phase in the alloy from fully dissolving and also prevents the Zr and Mn elements in the alloy from exerting their effects, thus hindering the dissolution of Al3Zr particles and Al. 20 Cu2Mn3 particles are uniformly dispersed.

[0005] 3. The solid solution process uses a single-stage 498℃ solid solution. After solid solution, only the Al2CuMg phase can be dissolved back, but the Al2Cu phase cannot be dissolved back. After solid solution, a large amount of Al2Cu phase remains in the grain boundaries and grains, causing subsequent fracture to occur along the residual phase. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a high-strength and damage-resistant Al-Cu-Mg-Ag alloy and its preparation method. The high-strength and damage-resistant Al-Cu-Mg-Ag alloy prepared by the present invention has superior comprehensive performance.

[0007] This invention provides a method for preparing a high-strength, damage-resistant Al-Cu-Mg-Ag alloy, comprising the following steps:

[0008] S1. Perform a two-stage homogenization process on the ingot;

[0009] The two-stage homogenization process includes a first-stage homogenization process and a second-stage homogenization process;

[0010] The temperature of the first homogenization treatment is 390~410℃, and the temperature of the second homogenization treatment is 520~530℃;

[0011] S2. Cool the ingot after step S1 to homogenize it.

[0012] S3. Hot rolling is performed on the ingot processed in step S2.

[0013] S4. Perform a two-stage solution treatment on the hot-rolled ingot.

[0014] The two-stage solution treatment includes a primary solution treatment and a secondary solution treatment.

[0015] The temperature of the first-stage solution treatment is 490~500℃, and the temperature of the second-stage solution treatment is 520~530℃;

[0016] S5. Quenching yields a high-strength, damage-resistant Al-Cu-Mg-Ag alloy.

[0017] Preferably, the time for the first-stage homogenization process is 6 to 10 hours.

[0018] Preferably, the time for the secondary homogenization process is 23-27 hours.

[0019] Preferably, the first-stage solution treatment time is 0.5 to 1.5 hours.

[0020] Preferably, the duration of the secondary solution treatment is 0.5 to 1.5 hours.

[0021] Preferably, the homogenization cooling method is air cooling.

[0022] Preferably, the hot rolling temperature is 455~465℃.

[0023] Preferably, the components of the ingot, by mass percentage, include:

[0024] Si < 0.08%, Fe < 0.12%, Cu 4.5%~5.5%, Mn 0.3%~1.0%, Mg 0.6%~1.4%, Ti < 0.10%, Ag 0.2%~0.6%, Zr 0.08%~0.15%, balance Al.

[0025] The present invention also provides a high-strength, damage-resistant Al-Cu-Mg-Ag alloy prepared by the preparation method described above.

[0026] This invention improves the content of Al3Zr particles and Al in Al-Cu-Mg-Ag alloys by adding a homogenization treatment at 390~410℃. 20The dispersed precipitation of Cu2Mn3 particles and the increase of the secondary homogenization temperature to 520-530℃ enhance the re-dissolution of the Al2Cu phase in the alloy. Due to the rapid solution heating process, the Al2CuMg phase cannot fully re-dissolve during this process. This invention, by holding the solution at 490-500℃ for a period of time, allows for sufficient re-dissolution of the Al2CuMg phase, preventing overheating or insufficient dissolution of the alloy. Then, by further increasing the solution temperature to 520-530℃, sufficient re-dissolution of the Al2Cu phase is achieved. Experimental results show that the high-strength, damage-resistant Al-Cu-Mg-Ag alloy prepared by this invention exhibits superior overall performance. Attached Figure Description

[0027] Figure 1 The fracture surface SEM image of the high-strength, damage-resistant Al-Cu-Mg-Ag alloy of Example 1 of the present invention is shown.

[0028] Figure 2 This is a fracture morphology diagram of the Al-Cu-Mg-Ag alloy of Comparative Example 1 of the present invention. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] This invention provides a method for preparing the high-strength, damage-resistant Al-Cu-Mg-Ag alloy described above, comprising the following steps:

[0031] S1. Perform a two-stage homogenization process on the ingot;

[0032] The two-stage homogenization process includes a first-stage homogenization process and a second-stage homogenization process;

[0033] The temperature of the first homogenization treatment is 390~410℃, and the temperature of the second homogenization treatment is 520~530℃;

[0034] S2. Cool the ingot after step S1 to homogenize it.

[0035] S3. Hot rolling is performed on the ingot processed in step S2.

[0036] S4. Perform a two-stage solution treatment on the hot-rolled ingot.

[0037] The two-stage solution treatment includes a primary solution treatment and a secondary solution treatment.

[0038] The temperature of the first-stage solution treatment is 490~500℃, and the temperature of the second-stage solution treatment is 520~530℃;

[0039] S5. Quenching yields a high-strength, damage-resistant Al-Cu-Mg-Ag alloy.

[0040] Regarding step S1:

[0041] In some embodiments of the present invention, the components of the ingot, by mass percentage, include:

[0042] Si < 0.06%, Fe < 0.10%, Cu 4.7%~5.3%, Mn 0.4%~0.8%, Mg 0.8%~1.2%, Ti < 0.10%, Ag 0.3%~0.5%, Zr 0.08%~0.15%, balance Al.

[0043] Specifically, the composition of the ingot, by mass percentage, includes: Si 0.04%, Fe 0.08%, Cu 5.0%, Mn 0.60%, Mg 0.95%, Ti 0.03%, Ag 0.41%, Zr 0.11%, with the balance being Al.

[0044] In some embodiments of the present invention, the temperature of the primary homogenization process is 400°C, and the time is 6 to 10 hours, for example, 8 hours.

[0045] In some embodiments of the present invention, the temperature of the secondary homogenization process is 525°C; the time is 23~27h, for example 25h.

[0046] The applicant creatively discovered that adding a homogenization treatment at 390~410℃ can improve the content of Al3Zr particles and Al in Al-Cu-Mg-Ag alloys. 20 The dispersed precipitation of Cu2Mn3 particles increases the secondary homogenization temperature to 520~530℃, which can enhance the dissolution of the Al2Cu phase in the alloy.

[0047] Regarding step S2:

[0048] In some embodiments of the present invention, the homogenization cooling method is air cooling.

[0049] Regarding step S3:

[0050] In some embodiments of the present invention, the hot rolling temperature is 455~465°C, for example 460°C.

[0051] Regarding step S4:

[0052] In some embodiments of the present invention, the temperature of the primary solution treatment is 495°C; the time is 0.5~1.5h, for example 1h.

[0053] In some embodiments of the present invention, the temperature of the secondary solution treatment is 525°C; the time is 0.5~1.5h, for example 1h.

[0054] Because the solution heating process is relatively rapid, the Al2CuMg phase cannot be fully dissolved during the heating process. The applicant creatively discovered that holding the solution at 490~500℃ for a period of time can allow the Al2CuMg phase to be fully dissolved, preventing the alloy from overheating or becoming too dry. Then, by increasing the solution temperature to 520~530℃, the Al2Cu phase can be fully dissolved.

[0055] Regarding step S5:

[0056] In the process of preparing the high-strength and damage-resistant Al-Cu-Mg-Ag alloy, the present invention employs a two-stage homogenization treatment and a two-stage solid solution treatment, resulting in a high-strength and damage-resistant Al-Cu-Mg-Ag alloy with superior overall performance.

[0057] The present invention does not impose any special restrictions on the source of the raw materials used above, and they can be commercially available.

[0058] The present invention also provides a high-strength, damage-resistant Al-Cu-Mg-Ag alloy prepared by the preparation method described above.

[0059] To further illustrate the present invention, the following detailed description of a high-strength, damage-resistant Al-Cu-Mg-Ag alloy and its preparation method provided by the present invention is provided in conjunction with embodiments, but it should not be construed as limiting the scope of protection of the present invention.

[0060] In the examples and comparative examples, the components of the ingots used, by mass percentage, included: Si 0.04%, Fe 0.08%, Cu 5.0%, Mn 0.60%, Mg 0.95%, Ti 0.03%, Ag 0.41%, Zr 0.11%, with the balance being Al.

[0061] Example 1

[0062] 1. Perform a two-stage homogenization process on the ingot;

[0063] The two-stage homogenization process includes a first-stage homogenization process and a second-stage homogenization process;

[0064] The first homogenization treatment is carried out at a temperature of 400℃ for 8 hours; the second homogenization treatment is carried out at a temperature of 520~530℃ for 25 hours.

[0065] 2. The ingot processed in step 1 is cooled uniformly by air cooling;

[0066] 3. The ingot processed in step 2 is hot rolled at 460℃;

[0067] 4. The hot-rolled ingot is subjected to a two-stage solution treatment;

[0068] The two-stage solution treatment includes a primary solution treatment and a secondary solution treatment.

[0069] The first-stage solution treatment was performed at a temperature of 495°C for 1 hour; the second-stage solution treatment was performed at a temperature of 525°C for 1 hour.

[0070] 5. Quenching yields a high-strength, damage-resistant Al-Cu-Mg-Ag alloy.

[0071] The fracture morphology of the high-strength, damage-resistant Al-Cu-Mg-Ag alloy in Example 1 was studied, and the results are as follows: Figure 1 As shown. Figure 1 The images show SEM images of the fracture surfaces of the high-strength, damage-resistant Al-Cu-Mg-Ag alloy from Example 1 of this invention. The left image is a 50x magnified SEM image of the plane strain fracture toughness specimen, and the right image is a 500x magnified SEM image of the plane strain fracture toughness specimen. Figure 1 As can be seen, by using two-stage homogenization heat treatment and two-stage solution heat treatment, the coarse compounds at the fracture site are reduced, which can improve the plane strain fracture toughness of the material.

[0072] Comparative Example 1

[0073] The difference from Example 1 is as follows:

[0074] Step 1 is:

[0075] The ingot was subjected to a single-stage homogenization treatment at 498℃ for 24 hours.

[0076] Step 4 is:

[0077] The hot-rolled ingot was subjected to a single-stage solution treatment at 498°C for 1 hour.

[0078] The remaining steps and parameters are the same as those in Example 1 of this invention, and an Al-Cu-Mg-Ag alloy is obtained.

[0079] The fracture morphology of the Al-Cu-Mg-Ag alloy in Comparative Example 1 was studied, and the results are as follows: Figure 2 As shown. Figure 2The images show SEM images of the fracture surface of the Al-Cu-Mg-Ag alloy of Comparative Example 1 of this invention. The left image is a 50x magnified SEM image of the plane strain fracture toughness specimen, and the right image is a 500x magnified SEM image of the plane strain fracture toughness specimen. It can be seen that the fracture surface contains a relatively large amount of coarse compound phases, significantly more than in the normal matrix. Under cyclic stress, cracks in the thin alloy sheet material mainly initiate and propagate along these coarse compound phases. To increase the material's damage resistance, the amount of coarse compound phases needs to be reduced.

[0080] The properties of the Al-Cu-Mg-Ag alloys of Example 1 and Comparative Example 1 were tested, and the results are shown in Table 1.

[0081] Table 1. Performance test results of Al-Cu-Mg-Ag alloys in Example 1 and Comparative Example 1

[0082]

[0083] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a high-strength, damage-resistant Al-Cu-Mg-Ag alloy, comprising the following steps: S1. Perform a two-stage homogenization process on the ingot; The two-stage homogenization process includes a first-stage homogenization process and a second-stage homogenization process; The temperature of the first homogenization treatment is 390~410℃, and the temperature of the second homogenization treatment is 520~530℃; S2. Cool the ingot after step S1 to homogenize it. S3. Hot rolling is performed on the ingot processed in step S2. S4. Perform a two-stage solution treatment on the hot-rolled ingot. The two-stage solution treatment includes a primary solution treatment and a secondary solution treatment. The temperature of the first-stage solution treatment is 490~500℃, and the temperature of the second-stage solution treatment is 520~530℃; S5. Quenching yields a high-strength, damage-resistant Al-Cu-Mg-Ag alloy.

2. The preparation method according to claim 1, characterized in that, The time for the first-stage homogenization process is 6 to 10 hours.

3. The preparation method according to claim 1, characterized in that, The time for the secondary homogenization process is 23~27 hours.

4. The preparation method according to claim 1, characterized in that, The first-stage solution treatment takes 0.5 to 1.5 hours.

5. The preparation method according to claim 1, characterized in that, The duration of the secondary solution treatment is 0.5 to 1.5 hours.

6. The preparation method according to claim 1, characterized in that, The homogenization cooling method is air cooling.

7. The preparation method according to claim 1, characterized in that, The hot rolling temperature is 455~465℃.

8. The preparation method according to claim 1, characterized in that, The components of the ingot, by mass percentage, include: Si < 0.08%, Fe < 0.12%, Cu 4.5%~5.5%, Mn 0.3%~1.0%, Mg 0.6%~1.4%, Ti < 0.10%, Ag 0.2%~0.6%, Zr 0.08%~0.15%, balance Al.

9. A high-strength, damage-resistant Al-Cu-Mg-Ag alloy prepared by the preparation method according to any one of claims 1 to 8.

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