A double-stage continuous aging treatment method for aluminum-lithium alloy

Abstract

A two-stage continuous aging treatment method for an aluminum-lithium alloy. The invention belongs to the technical field of aluminum alloy processing and relates to a double-stage continuous aging heat treatment method for aluminum-lithium alloys. The main feature of the aging process of the aluminum-lithium alloy is to perform aging treatment on the aluminum alloy in the process of continuous temperature change. The characteristics of the alloy and the reasonable control of the temperature range and heating rate, as well as weakening the influence of dislocation recovery, significantly improved the tensile properties of the alloy. The two-stage continuous aging process not only improves the performance of the aluminum-lithium alloy, but also shortens the aging process time, reduces energy consumption, improves production efficiency, and can effectively meet the current demand for high comprehensive performance aluminum-lithium alloys.

Description

technical field

[0001] The invention belongs to the technical field of aluminum alloy processing, and relates to a double-stage continuous aging heat treatment method for aluminum-lithium alloys.

[0002] technical background

[0003] Li is the lightest metal element, adding 1% Li in the aluminum alloy can reduce the alloy density by 3% and increase the elastic modulus by 6%. Compared with traditional aluminum alloys, Al-Li alloys have the advantages of low density, high specific strength, high specific stiffness, high fracture toughness, and good corrosion resistance. It has more advantages in production cost, making it have a wide range of application prospects in the aerospace field. For example, Airbus, Boeing and COMAC have adopted aluminum-lithium alloy components in their latest commercial passenger aircraft, which better achieve the purpose of weight reduction.

[0004] Aging precipitation strengthening is the key to obtain good properties of aluminum alloys, so it ...

Examples

Embodiment 1

[0051] In this embodiment, an aluminum-lithium alloy plate prepared with the same composition and production process as in Comparative Example 1 is used, and the solution quenching and pre-deformation processes are also the same as those in Comparative Example 1.

[0052] Aging process: put the sample into a resistance furnace heated to 22°C, and then heat up to 130°C after 12h, with a heating rate of 9°C / h; ℃ / h, the cooling method is furnace cooling, the cooling rate with the furnace is less than 50 ℃ / h, and the final mechanical properties of the obtained materials are shown in Table 1.

[0053] figure 2 b is the TEM microstructure picture of the comparative example.

Embodiment 2

[0055] In this example, an aluminum-lithium alloy plate prepared with the same composition and production process as in Comparative Example 1 was used, and the sample was subjected to a stepwise temperature rise and solid solution treatment, and the solid solution was carried out in a salt bath. After the solution treatment, the sample was quickly taken out and cooled to room temperature. The quenched samples were pre-deformed by 5% cold rolling.

[0056] Aging process: put the sample into a resistance furnace heated to 21 °C, and then heat up to 140 °C after 17 h, during which the heating rate is 7 °C / h; ℃ / h, the cooling method is furnace cooling, the cooling rate with the furnace is less than 50 ℃ / h, and the final mechanical properties of the obtained materials are shown in Table 1.

Embodiment 3

[0058] In this example, an aluminum-lithium alloy plate prepared with the same composition and production process as in Comparative Example 1 was used, and the sample was subjected to a stepwise temperature rise and solid solution treatment, and the solid solution was carried out in a salt bath. After the solution treatment, the sample was quickly taken out and cooled to room temperature. The quenched samples were pre-deformed by 5% cold rolling.

[0059] Aging process: put the sample into a resistance furnace heated to 0 °C, and then heat up to 120 °C after 10 h, with a heating rate of 12 °C / h; 4 °C / h, the cooling method is furnace cooling, and the cooling rate with the furnace is less than 50 °C / h. The final mechanical properties of the obtained materials are shown in Table 1.

technical field

[0001] The invention belongs to the technical field of aluminum alloy processing, and relates to a double-stage continuous aging heat treatment method for aluminum-lithium alloys.

[0002] technical background

[0003] Li is the lightest metal element, adding 1% Li in the aluminum alloy can reduce the alloy density by 3% and increase the elastic modulus by 6%. Compared with traditional aluminum alloys, Al-Li alloys have the advantages of low density, high specific strength, high specific stiffness, high fracture toughness, and good corrosion resistance. It has more advantages in production cost, making it have a wide range of application prospects in the aerospace field. For example, Airbus, Boeing and COMAC have adopted aluminum-lithium alloy components in their latest commercial passenger aircraft, which better achieve the purpose of weight reduction.

[0004] Aging precipitation strengthening is the key to obtain good properties of aluminum alloys, so it ...

Examples

Embodiment 1

[0051] In this embodiment, an aluminum-lithium alloy plate prepared with the same composition and production process as in Comparative Example 1 is used, and the solution quenching and pre-deformation processes are also the same as those in Comparative Example 1.

[0052] Aging process: put the sample into a resistance furnace heated to 22°C, and then heat up to 130°C after 12h, with a heating rate of 9°C / h; ℃ / h, the cooling method is furnace cooling, the cooling rate with the furnace is less than 50 ℃ / h, and the final mechanical properties of the obtained materials are shown in Table 1.

[0053] figure 2 b is the TEM microstructure picture of the comparative example.

Embodiment 2

[0055] In this example, an aluminum-lithium alloy plate prepared with the same composition and production process as in Comparative Example 1 was used, and the sample was subjected to a stepwise temperature rise and solid solution treatment, and the solid solution was carried out in a salt bath. After the solution treatment, the sample was quickly taken out and cooled to room temperature. The quenched samples were pre-deformed by 5% cold rolling.

[0056] Aging process: put the sample into a resistance furnace heated to 21 °C, and then heat up to 140 °C after 17 h, during which the heating rate is 7 °C / h; ℃ / h, the cooling method is furnace cooling, the cooling rate with the furnace is less than 50 ℃ / h, and the final mechanical properties of the obtained materials are shown in Table 1.

Embodiment 3

[0058] In this example, an aluminum-lithium alloy plate prepared with the same composition and production process as in Comparative Example 1 was used, and the sample was subjected to a stepwise temperature rise and solid solution treatment, and the solid solution was carried out in a salt bath. After the solution treatment, the sample was quickly taken out and cooled to room temperature. The quenched samples were pre-deformed by 5% cold rolling.

[0059] Aging process: put the sample into a resistance furnace heated to 0 °C, and then heat up to 120 °C after 10 h, with a heating rate of 12 °C / h; 4 °C / h, the cooling method is furnace cooling, and the cooling rate with the furnace is less than 50 °C / h. The final mechanical properties of the obtained materials are shown in Table 1.

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