Rolling pre-deformation method for improving toughness and plasticity of 2-series aluminum alloy

Abstract

The invention provides a rolling pre-deformation method for improving toughness and plasticity of 2-series aluminum alloy, and belongs to the technical field of aluminum alloy material processing. The rolling pre-deformation method comprises the following steps: sequentially carrying out solid solution quenching treatment, ultralow-temperature transverse rolling pre-deformation, rolling pre-deformation and aging treatment on a 2-series aluminum alloy hot-rolled plate. The quenching-state 2-series aluminum alloy is sequentially subjected to transverse and rolling-direction variable-temperature pre-deformation, the grain structure, dislocation configuration and distribution can be well regulated and controlled, a fine and uniform precipitated phase is obtained after aging, and the strength, toughness and forming performance of the 2-series aluminum alloy are improved while the anisotropy of the plate is reduced. The method is simple in process, convenient to operate and easy to industrialize.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy material processing, and particularly relates to a rolling pre-deformation method for improving the strength-toughness-plasticity of 2-series aluminum alloy. BACKGROUND

[0002] 2-series aluminum-copper alloy is a main structural material for lightweight in the fields of aerospace, national defense and military industry, etc. due to its small density, high specific strength and specific stiffness, good impact resistance and easy recycling. The aging precipitation of 2-series aluminum alloy has a significant strain-induced precipitation effect. Pre-deformation is generally performed before aging to introduce dislocations to promote aging precipitation. Pre-deformation at room temperature activates the {111} slip system of the aluminum alloy. Generally, with the increase of deformation, dislocations are prone to aggregation, and the anisotropy of the plate is more prominent, and the plasticity, strength and forming performance decrease.

[0003] Therefore, it is of great significance to provide a rolling pre-deformation method for effectively improving the strength, plasticity and forming performance of 2-series aluminum alloy. SUMMARY

[0004] The present application aims to provide a rolling pre-deformation method for improving the strength-toughness-plasticity of 2-series aluminum alloy, so as to control the dislocation configuration and distribution, reduce the anisotropy of the plate, and improve the strength, plasticity and forming performance of 2-series aluminum alloy.

[0005] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0006] The present application provides a rolling pre-deformation method for improving the strength-toughness-plasticity of 2-series aluminum alloy, comprising the following steps:

[0007] The 2-series aluminum hot-rolled plate is sequentially subjected to solid solution quenching treatment, ultra-low temperature cross-rolling pre-deformation, rolling direction pre-deformation and aging treatment.

[0008] Preferably, the temperature of the solid solution quenching treatment is 490-540℃, and the time of the solid solution quenching treatment is 0.5-5h.

[0009] Preferably, the solid solution quenching treatment is water quenching.

[0010] Preferably, the 2-series aluminum alloy is subjected to ultra-low temperature cross-rolling pre-deformation after cooling in an ultra-low temperature device; the temperature of the ultra-low temperature device is-196--50℃, and the cooling time is 0.2-1h.

[0011] Preferably, the ultra-low temperature cross-rolling pre-deformation is rolling pre-deformation perpendicular to the rolling direction of the hot-rolled plate, and the rolling deformation amount is 3-30%.

[0012] Preferably, the plate pre-deformed by the ultra-low temperature cross-rolling is heated to perform the rolling pre-deformation, the heating temperature is 20-200℃, and the heating time is 0.2-1h.

[0013] Preferably, the rolling pre-deformation is a rolling pre-deformation along the rolling direction of the hot-rolled plate, and the rolling deformation is 3-30%.

[0014] Preferably, the aging treatment temperature is 120-200℃, and the aging treatment time is 6-72h.

[0015] The present application has the following advantages:

[0016] 1) The present application performs the temperature-variable pre-deformation along the cross direction and the rolling direction on the quenched 2-series aluminum alloy, which can better control the grain structure, dislocation configuration and distribution, and obtain fine and uniform precipitates after aging, thereby reducing the anisotropy of the plate and improving the strength, toughness and formability of the 2-series aluminum alloy.

[0017] 2) The rolling pre-deformation method for improving the strength, toughness and plasticity of the 2-series aluminum alloy is simple in process and easy to operate, and can be easily industrialized; the method is also applicable to other metal materials with strain-induced precipitation effect. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The transmission electron microscope image of the high-strength and high-toughness 2519A aluminum alloy plate obtained in Example 2;

[0019] Figure 2 The transmission electron microscope image of the 2519A aluminum alloy plate obtained in Comparative Example 2. DETAILED DESCRIPTION

[0020] The present application provides a rolling pre-deformation method for improving the strength, toughness and plasticity of a 2-series aluminum alloy, comprising the following steps:

[0021] The hot-rolled plate of the 2-series aluminum alloy is sequentially subjected to solid solution quenching treatment, ultra-low temperature cross-rolling pre-deformation, rolling pre-deformation and aging treatment.

[0022] In the present application, the 2-series aluminum alloy is preferably 2519 aluminum alloy, 2024 aluminum alloy, 2195 aluminum-lithium alloy or 2060 aluminum-lithium alloy.

[0023] In the present application, the solid solution quenching treatment temperature is preferably 490-540℃, further preferably 500-530℃, and more preferably 510-520℃, and the solid solution quenching treatment time is preferably 0.5-5h, further preferably 1-4h, and more preferably 2-3h.

[0024] In the present application, the solid solution quenching treatment is preferably water quenching; the water temperature of the water quenching is preferably 5-30℃, further preferably 10-25℃, and more preferably 15-20℃.

[0025] In the present application, the 2-series aluminum alloy is cooled in the ultra-low temperature equipment and then subjected to ultra-low temperature cross-rolling pre-deformation; the temperature of the ultra-low temperature equipment is preferably -196 to -50℃, further preferably -190 to -120℃, and the cooling time is preferably 0.2-1h, further preferably 0.4-0.75h, and more preferably 0.5-0.6h.

[0026] In the present application, the ultra-low temperature cross-rolling pre-deformation is preferably rolling pre-deformation perpendicular to the rolling direction of the hot-rolled plate, and the rolling deformation amount is preferably 3-30%, further preferably 4-20%, and more preferably 7-15%.

[0027] In the present application, the plate subjected to the ultra-low temperature cross-rolling pre-deformation is heated and then subjected to rolling direction pre-deformation; the heating temperature is preferably 20-200℃, further preferably 60-180℃, and more preferably 100-160℃, the heating time is preferably 0.2-1h, further preferably 0.5-0.8h, and more preferably 0.6-0.7h; and the heating is preferably carried out in a heating furnace.

[0028] In the present application, the rolling direction pre-deformation is preferably rolling pre-deformation along the rolling direction of the hot-rolled plate, and the rolling deformation amount is preferably 3-30%, further preferably 4-20%, and more preferably 7-15%.

[0029] In the present application, the aging treatment temperature is preferably 120-200℃, further preferably 140-180℃, and more preferably 150-170℃, and the aging treatment time is preferably 6-72h, further preferably 10-48h, and more preferably 12-24h.

[0030] The technical solutions provided by the present application will be described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present application.

[0031] Example 1

[0032] A 2195 aluminum alloy hot-rolled plate is subjected to solid solution treatment at 510℃ for 2h, quenched with 20℃ water, then cooled at -190℃ for 0.5h, and subjected to ultra-low temperature cross-rolling pre-deformation perpendicular to the rolling direction of the hot-rolled plate, the deformation amount of the ultra-low temperature cross-rolling pre-deformation is 4%, then heated at 150℃ for 0.5h, and subjected to rolling direction pre-deformation along the rolling direction of the hot-rolled plate, the deformation amount of the rolling direction pre-deformation is 3%, and finally subjected to aging treatment at 155℃ for 24h, to obtain a 2mm-thick high-strength and high-toughness 2195 aluminum alloy plate.

[0033] Comparative Example 1

[0034] A 2195 aluminum alloy hot-rolled plate was solution treated at 510°C for 2h, quenched by 20°C water, then pre-deformed by rolling at 20°C with a deformation of 7%, and finally aged at 155°C for 24h to obtain a 2mm thick 2195-T87 aluminum alloy plate.

[0035] The mechanical properties of the 2195 aluminum alloy plates obtained in Example 1 and Comparative Example 1 were tested by using a CMT-5205 type universal mechanical tensile testing machine and a CBZ-60B type microcomputer controlled full-automatic cupping testing machine, and the results are shown in Table 1.

[0036] Table 1 Performance test results of 2195 aluminum alloy plates

[0037]

[0038] As can be seen from Table 1, the tensile strength and elongation of the 2195 aluminum alloy plate obtained by the traditional T87 process of Comparative Example 1 are 564.2MPa and 9.5% respectively, and the cupping value is 7.2mm; the tensile strength and elongation of the 2195 aluminum alloy plate obtained by the processing method of Example 1 are 587.1MPa and 11.6% respectively, and the cupping value is 8.5mm, the strength, elongation and cupping value of the 2195 aluminum alloy plate obtained in Example 1 are all higher than those of the traditional T87 state.

[0039] Example 2

[0040] A 2519A aluminum alloy hot-rolled plate was solution treated at 530°C for 2h, quenched by 20°C water, then pre-deformed by ultra-low temperature cross-rolling perpendicular to the rolling direction of the hot-rolled plate at -190°C with a deformation of 4%, then pre-deformed by rolling along the rolling direction of the hot-rolled plate at 160°C for 0.5h with a deformation of 3%, and finally aged at 165°C for 12h to obtain a 2mm thick high-performance 2519A aluminum alloy plate.

[0041] Comparative Example 2

[0042] A 2519A aluminum alloy hot-rolled plate was solution treated at 530°C for 2h, quenched by 20°C water, then pre-deformed by rolling at 20°C with a deformation of 7%, and finally aged at 165°C for 12h to obtain a 2mm thick 2519A-T8 aluminum alloy plate.

[0043] The mechanical properties of the 2519A aluminum alloy plates obtained in Example 2 and Comparative Example 2 were tested by using a CMT-5205 type universal mechanical tensile testing machine and a CBZ-60B type microcomputer controlled full-automatic cupping testing machine, and the results are shown in Table 2.

[0044] Table 2 Performance test results of 2519A aluminum alloy plate

[0045]

[0046] As can be seen from Table 2, the tensile strength and elongation of the plate in the rolling direction obtained by the conventional T8 process of Comparative Example 2 are 430.2 MPa and 8.5%, respectively, and the cupping value is 7.9 mm; the tensile strength and elongation of the 2519A aluminum alloy plate obtained by the processing method of Example 2 are obviously higher than those of the plate of the conventional T8 process, and the tensile strength and elongation of the 2519A aluminum alloy plate prepared in Example 2 are 458.6 MPa and 11.2%, respectively, and the cupping value is 9.1 mm. The tensile strength, elongation and cupping value of Example 2 are increased by 6.6%, 31.8% and 15.2%, respectively, compared with those of the conventional T8 state.

[0047] The microstructure of the 2519A aluminum alloy plate obtained in Example 2 and Comparative Example 2 was detected by using a transmission electron microscope, and the transmission electron microscope image of the high-strength and high-toughness 2519A aluminum alloy plate obtained by the processing method of Example 2 is shown in FIG. 2; the transmission electron microscope image of the 2519A aluminum alloy plate obtained by the processing method of Comparative Example 2 is shown in FIG. 3. As can be seen from FIGS. 2 and 3, the precipitated phase of the 2519A aluminum alloy plate obtained in Example 2 is uniformly distributed and has a smaller size. This is mainly because the rolling pre-deformation method of Example 2 can obtain a uniform grain structure, the ultra-low temperature and medium temperature pre-deformation can start {100} and {111} slip systems, avoid local pile-up of dislocations, make the defects more uniformly distributed in space, increase the non-uniform nucleation of precipitated phase, and thus obtain fine and dispersed intragranular precipitated phase. Figure 1 Figure 2 Figure 1 Figure 2 As can be seen from FIGS. 2 and 3, the precipitated phase of the 2519A aluminum alloy plate obtained in Example 2 is uniformly distributed and has a smaller size. This is mainly because the rolling pre-deformation method of Example 2 can obtain a uniform grain structure, the ultra-low temperature and medium temperature pre-deformation can start {100} and {111} slip systems, avoid local pile-up of dislocations, make the defects more uniformly distributed in space, increase the non-uniform nucleation of precipitated phase, and thus obtain fine and dispersed intragranular precipitated phase.

[0048] As can be seen from the above examples, the present application provides a rolling pre-deformation method for improving the strength, toughness and plasticity of 2-series aluminum alloy, which sequentially performs solid solution quenching treatment, ultra-low temperature cross-rolling pre-deformation, rolling direction pre-deformation and aging treatment on the hot-rolled plate of 2-series aluminum alloy, to obtain a microstructure of fine precipitated phase, and improve the strength, plasticity and forming performance of the 2-series aluminum alloy.

[0049] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.​​​

Claims

1. A rolling pre-deformation method for improving the strength, toughness, and plasticity of 2-series aluminum alloys, characterized in that, It includes the following steps: The 2-series aluminum alloy hot-rolled plates were subjected to solution quenching, ultra-low temperature transverse rolling pre-deformation, rolling direction pre-deformation, and aging treatment in sequence.

2. The rolling pre-deformation method according to claim 1, characterized in that, The solution quenching temperature is 490–540℃, and the solution quenching time is 0.5–5h.

3. The rolling pre-deformation method according to claim 1 or 2, characterized in that, The solution quenching process is water quenching.

4. The rolling pre-deformation method according to claim 1, characterized in that, The 2-series aluminum alloy is cooled in an ultra-low temperature equipment and then subjected to ultra-low temperature cross rolling pre-deformation; the temperature of the ultra-low temperature equipment is -196 to -50℃, and the cooling time is 0.2 to 1 hour.

5. The rolling pre-deformation method according to claim 4, characterized in that, The ultra-low temperature transverse rolling pre-deformation is a rolling pre-deformation perpendicular to the rolling direction of the hot-rolled plate, with a rolling deformation amount of 3-30%.

6. The rolling pre-deformation method according to claim 1, characterized in that, After the sheet material is pre-deformed by ultra-low temperature transverse rolling, it is heated and then pre-deformed by rolling in the direction of rolling. The heating temperature is 20-200℃ and the heating time is 0.2-1h.

7. The rolling pre-deformation method according to claim 6, characterized in that, The pre-deformation along the rolling direction is a pre-deformation process performed along the rolling direction of the hot-rolled plate, with a deformation amount of 3% to 30%.

8. The rolling pre-deformation method according to any one of claims 4 to 7, characterized in that, The aging treatment temperature is 120–200℃, and the aging treatment time is 6–72 hours.

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