High-performance fine-grain structure Ce-containing 2219 aluminum alloy and preparation method thereof

Abstract

The invention relates to the technical field of aluminum alloys, in particular to a preparation method of a high-performance fine-grain structure Ce-containing 2219 aluminum alloy. The method comprises the steps that S1, pure aluminum, an Al-50Cu intermediate alloy, an Al-20Mn intermediate alloy, an Al-20Ce intermediate alloy and an Al-10Zr intermediate alloy are smelted in a molten pool at the temperature of 750-850 DEG C, and an aluminum alloy cast ingot is prepared; and after casting, a cast ingot is subjected to homogenization treatment, rolling and friction stir processing treatment. And finally, the Ce-containing 2219 aluminum alloy which contains a fine grain structure matrix, has a grain boundary pinning effect and a high internal friction capacity and is of an Al8Cu4Ce dispersed phase is prepared, and the Ce-containing 2219 aluminum alloy comprises the following components in percentage by weight: 5.8 to 6.8 percent of Cu, 0.2 to 0.4 percent of Mn, 0.10 to 0.15 percent of Zr and 0.1 to 0.8 percent of Ce. The method is easy to operate, low in cost and easy to popularize and apply, and the prepared aluminum alloy has the advantages of being small in grain, good in plasticity, high in damping value and good in thermal stability.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloys, and in particular to a Ce-containing 2219 aluminum alloy with fine grain structure and high plasticity, high damping and high thermal stability, and a preparation method thereof. Background Art

[0002] 2xxx (Al-Cu, 2 series) aluminum alloys are widely used in the aerospace field due to their excellent mechanical and physical properties such as high strength, high toughness, high plasticity and high thermal stability. With the progress of society and the development of industry, some special fields have put forward higher and higher requirements on the mechanical and damping properties of Al-Cu alloys.

[0003] 2219 aluminum alloy (Al-Cu-Mn-Zr) is one of the most widely used commercial aluminum alloys in the fields of aviation, aerospace, and national defense. However, with the rapid development of my country's aerospace and military fields, aluminum alloy equipment has put forward higher and higher requirements on the overall performance of 2219 alloy. Therefore, it is necessary to modify 2219 aluminum alloy and further optimize its mechanical, damping and thermal stability based on its original excellent performance.

[0004] Studies have shown that grain refinement can optimize the mechanical and damping properties of aluminum alloys. In recent years, rare earth elements such as scandium, yttrium, and lanthanum have been used to refine aluminum alloy grains. People have found that rare earth scandium Sc can be used to refine aluminum alloy grains, thereby effectively optimizing the comprehensive properties of Al-Mg and Al-Zn-Mg alloys. However, Sc easily reacts chemically with Cu in Al-Cu alloys to form a coarse W phase, which is not conducive to optimizing the mechanical properties of Al-Cu alloys. However, the above elements are expensive, which greatly limits the commercial application of Sc-containing aluminum alloys. In addition, traditional plastic processing processes such as rolling and extrusion are also difficult to significantly refine the grains of aluminum alloys. Summary of the invention

[0005] The main purpose of the present invention is to provide a high-performance fine-grained Ce2219 aluminum alloy with high plasticity, high damping and high thermal stability and a preparation method thereof, by adding a single rare earth Ce element to obtain an Al2219 aluminum alloy with grain boundary pinning effect and high internal friction capacity. 8 Cu 4 Combined with friction stir processing (FSP), the 2219 aluminum alloy grains are greatly refined while Al 8 Cu 4 Ce phase, and increase the Al matrix / Al 8 Cu 4 Ce phase interface density. Thus, a fine-grained aluminum alloy with high plasticity, high damping, high thermal stability and low cost is obtained.

[0006] To achieve the above object, the present invention provides a method for preparing a high-performance fine-grained Ce-containing 2219 aluminum alloy, comprising the steps of:

[0007] S1, pure aluminum, Al-50Cu master alloy, Al-20Mn, Al-20Ce master alloy and Al-10Zr master alloy are melted in a molten pool at 750-850° C., stirred thoroughly and then allowed to stand; an aluminum alloy ingot containing 5.8-6.8wt% Cu, 0.2-0.4wt% Mn, 0.10-0.15wt% Zr and 0.1-0.8wt% Ce is obtained;

[0008] S2, the aluminum alloy ingot obtained in step S1 is kept at 470°C to 530°C for 18-30 hours and then cooled with the furnace to complete homogenization treatment to obtain Al 3 Ingot of Zr precipitation phase;

[0009] S3, rolling the aluminum alloy ingot after the homogenization treatment in step S2 for 3 to 6 times, with the deformation temperature being 420 to 490° C. and the total deformation amount being 60-800%, to obtain an aluminum alloy having Al 8 Cu 4 Ce dispersed phase and Al matrix / Al 8 Cu 4 Ce phase interface plate;

[0010] S4, subjecting the plate obtained in step S3 to friction stir processing, with the processing tool rotating at a rate of 200 to 1500 rpm and a travel speed of 50 to 600 mm / min, to obtain the high-performance fine-grained Ce-containing 2219 aluminum alloy.

[0011] Preferably, in step S1, pure aluminum, Al-50Cu master alloy, Al-20Mn, Al-20Ce master alloy and Al-10Zr master alloy are placed in a resistance furnace for smelting at a smelting temperature of 800°C, and are allowed to stand for 30 minutes after being fully stirred; the temperature of the resistance furnace is lowered to 700-780°C, and the alloy is kept warm for 10 minutes before casting to obtain an aluminum alloy ingot.

[0012] Preferably, the thickness of the cast aluminum alloy ingot is 80-120 mm.

[0013] Preferably, in step S2, the insulation time is 24 hours.

[0014] Preferably, in step S3, the plate after rolling is a 30 mm thick plate.

[0015] Preferably, in step S3, the rolling times are 3 times and the total deformation amount is 70%.

[0016] Preferably, the thickness of the cast aluminum alloy ingot is 100 mm.

[0017] The present invention also provides a high-performance fine-grained Ce-containing 2219 aluminum alloy, which is prepared by any of the preparation methods described above.

[0018] In the high-performance fine-grained Ce-containing 2219 aluminum alloy and the preparation method thereof, industrial pure Al ingots, Al-50Cu master alloys, Al-20Mn master alloys, Al-10Zr master alloys and Al-20Ce master alloys are used as raw materials, and Al with grain boundary pinning effect and high internal friction capacity is introduced into the 2219 aluminum alloy by means of smelting, casting, heat treatment and the like. 8 Cu 4 Ce phase, FSP is used to effectively refine the matrix grains and second phase of the alloy, and increase the Al matrix / Al 8 Cu 4 Ce phase interface density. Thus, a fine-grained Ce2219 alloy with low cost, excellent mechanical properties, high damping and high thermal stability is obtained.

[0019] Compared with the existing Al-Cu alloys on the market, the present invention has the following advantages:

[0020] 1) The ultrafine grain structure improves the plasticity of aluminum alloy, and its room temperature tensile plasticity can reach more than 30%;

[0021] 2) Fine grain structure synergistic with Al 8 Cu 4 Ce phase / matrix interface improves the damping performance of the alloy, and its room temperature damping value can reach 0.03Q -1 above;

[0022] 3) Dispersed Al 8 Cu 4 The Ce phase has a grain boundary pinning effect, which improves the thermal stability of the alloy.

[0023] 4) After annealing at 430°C for 3 hours, the average grain size increase does not exceed 18%.

[0024] 5) Cerium (Ce) is also a rare earth element, but as a metallurgical byproduct of rare earth permanent magnet materials, its price is extremely low. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0026] Figure 1 This is an EBSD photograph of the alloy prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The technical solution in this embodiment will be described clearly and completely below in conjunction with the drawings in this embodiment. Obviously, the described embodiment is only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in 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.

[0028] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0030] Embodiment 1:

[0031] Industrial pure Al ingot, Al-50Cu master alloy, Al-20Mn master alloy, Al-20Ce master alloy and Al-10Zr master alloy were placed in a resistance furnace for smelting at a smelting temperature of 800°C. After being fully stirred, they were allowed to stand for 30 minutes, and the temperature of the resistance furnace was lowered to 780°C. After being kept warm for 10 minutes, casting was performed. The casting process did not require atmosphere protection and vacuum environment. Finally, a 100mm thick aluminum alloy ingot containing 5.8wt% Cu, 0.2wt% Mn, 0.1wt% Zr and 0.15wt% Ce was obtained. The ingot was placed in a muffle furnace at 530°C for 24 hours and then cooled with the furnace to complete the homogenization treatment. The alloy ingot after homogenization treatment was subjected to three rolling deformations, with a deformation temperature of 420°C and a total deformation of 70%, to obtain a 30mm thick rolled plate. The obtained plate was subjected to FSP, with the processing tool rotating at a rate of 200 rpm and a travel speed of 50 mm / min, thereby obtaining a 2219 aluminum alloy with a fine grain structure and containing 0.15 Ce.

[0032] Please combine Figure 1 , is the EBSD photograph of the alloy prepared in Example 1 of the present invention.

[0033] Embodiment 2:

[0034] Industrial pure Al ingot, Al-50Cu master alloy, Al-20Mn master alloy, Al-20Ce master alloy and Al-10Zr master alloy were placed in a resistance furnace for smelting at a smelting temperature of 800°C. After being fully stirred, they were allowed to stand for 30 minutes, and the temperature of the resistance furnace was lowered to 750°C. After being kept warm for 10 minutes, casting was performed. The casting process did not require atmosphere protection and vacuum environment. Finally, a 100mm thick aluminum alloy ingot containing 6.3wt% Cu, 0.25wt% Mn, 0.15wt% Zr and 0.3wt% Ce was obtained. The ingot was placed in a 510°C muffle furnace for 24 hours and then cooled with the furnace to complete the homogenization treatment. The alloy ingot after homogenization treatment was subjected to three rolling deformations, with a deformation temperature of 450°C and a total deformation of 70%, to obtain a 30mm thick rolled plate. The obtained plate was subjected to FSP, with a tool rotation rate of 400 rpm and a travel speed of 100 mm / min, thereby obtaining a 2219 aluminum alloy with a fine grain structure and containing 0.3Ce.

[0035] Embodiment 3:

[0036] Industrial pure Al ingot, Al-50Cu master alloy, Al-20Mn master alloy, Al-20Ce master alloy and Al-10Zr master alloy were placed in a resistance furnace for smelting at a melting temperature of 800℃. After being fully stirred, they were allowed to stand for 30 minutes, and then the temperature of the resistance furnace was reduced to 710℃. After being kept warm for 10 minutes, casting was performed. No atmosphere protection or vacuum environment was required during the casting process. Finally, a 100 mm thick aluminum alloy ingot containing 6.3 wt% Cu, 0.3 wt% Mn, 0.15 wt% Zr and 0.5 wt% Ce was obtained. The ingot was placed in a muffle furnace at 490℃ for 24 hours and then cooled with the furnace to complete the homogenization treatment. The alloy ingot after homogenization treatment was rolled and deformed for 3 times at a deformation temperature of 460℃ and a total deformation of 70%, and a 30 mm thick rolled plate was obtained. The obtained plate was subjected to FSP, with the processing tool rotation rate of 500 rpm and the travel speed of 200 mm / min, to obtain a 2219 aluminum alloy with a fine grain structure and containing 0.5Ce.

[0037] The mechanical properties, damping properties and thermal stability properties of the Ce-containing 2219 aluminum alloys prepared in Examples 1 to 3 were tested. The aluminum alloy of the present invention has a tensile elongation of ≥30%; a damping of ≥0.03 Q-1 at room temperature; and an average grain size increase of ≤18% after annealing at 430°C for 3 hours. The specific test data are shown in Table 1.

[0038] Table 1 Performance test of Ce-containing 2219 aluminum alloy obtained in Examples 1 to 3

[0039]

[0040] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a high-performance fine-grained Ce-containing 2219 aluminum alloy, characterized in that: Includes steps: S1, pure aluminum, Al-50Cu master alloy, Al-20Mn, Al-20Ce master alloy and Al-10Zr master alloy are melted in a molten pool at 750-850° C., stirred thoroughly and then allowed to stand; an aluminum alloy ingot containing 5.8-6.8wt% Cu, 0.2-0.4wt% Mn, 0.10-0.15wt% Zr and 0.1-0.8wt% Ce is obtained; S2, the aluminum alloy ingot obtained in step S1 is kept at 470° C. to 530° C. for 18 to 30 hours and then cooled with the furnace to complete homogenization treatment to obtain an ingot with Al3Zr precipitation phase; S3, subjecting the aluminum alloy ingot homogenized in step S2 to 3-6 rolling deformations, with a deformation temperature of 420-490° C. and a total deformation amount of 60-800%, to obtain a plate having an Al8Cu4Ce dispersed phase and an Al matrix / Al8Cu4Ce phase interface; S4, subjecting the plate obtained in step S3 to friction stir processing, with the processing tool rotating at a rate of 200 to 1500 rpm and a travel speed of 50 to 600 mm / min, to obtain the high-performance fine-grained Ce-containing 2219 aluminum alloy.

2. The method according to claim 1, characterized in that In the step S1, pure aluminum, Al-50Cu master alloy, Al-20Mn, Al-20Ce master alloy and Al-10Zr master alloy are placed in a resistance furnace for smelting at a temperature of 800° C., and are fully stirred and allowed to stand for 30 minutes; the temperature of the resistance furnace is lowered to 700-780° C., and the alloy is kept warm for 10 minutes before casting to obtain an aluminum alloy ingot.

3. The method according to claim 2, characterized in that The thickness of the cast aluminum alloy ingot is 80-120 mm.

4. The method according to claim 1, characterized in that In step S2, the insulation time is 24 hours.

5. The method according to claim 1, characterized in that In step S3, the plate after rolling is a 30 mm thick plate.

6. The method according to claim 1, characterized in that In the step S3, the rolling times are 3 times, and the total deformation amount is 70%.

7. The method according to claim 3, characterized in that The thickness of the cast aluminum alloy ingot was 100 mm.

8. A high performance fine grain Ce 2219 aluminum alloy, characterized in that: The method is prepared according to any one of claims 1 to 7.

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