Aluminum alloy for preparing built-in bogie framework support of train and preparation method of aluminum alloy

Abstract

The invention discloses an aluminum alloy for preparing a train built-in bogie frame support and a preparation method of the aluminum alloy, and belongs to the technical field of alloys for high-speed trains. The aluminum alloy contains Zn, Mg, Cu, Zr, Ti, Mn, Y, V, Si and other elements, vanadium can form a solid solution and an intermetallic compound with magnesium and aluminum, so that lattice slippage and dislocation movement are hindered, the overall strength of the aluminum alloy is improved, and the aluminum alloy can bear larger external force while keeping light. According to the method, the aluminum alloy is manufactured through two-step superplastic die forging, defects can be prevented from being formed in the die forging process, stress concentration is reduced, and the mechanical property of the aluminum alloy is effectively guaranteed; and after two-step die forging, the alloy is uniform in plastic deformation and small and uniform in grain size, the mechanical property of the aluminum alloy is favorably improved, the aluminum alloy particularly has better fatigue property, and the aluminum alloy has better safety and reliability while light weight of the aluminum alloy is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloys for high-speed trains, and in particular relates to an aluminum alloy for preparing a train built-in bogie frame support and a preparation method thereof. Background Art

[0002] With the gradual increase in the operating speed of high-speed trains and the important demand for energy conservation and environmental protection, the further lightweighting of high-speed trains has become a basic element in the design and manufacture of high-speed trains, and is also an inevitable trend.

[0003] In recent years, with the increasing requirements for high speed and lightweight in railway transportation, the performance requirements for key component support seats are also increasing. The high-speed requirements of trains have been seriously affected by the high density of steel support seat products. Achieving weight reduction while meeting the high-standard mechanical performance requirements of the support seat is a major reform and structural adjustment faced by the development of high-speed trains. The implementation of speed-up and safety development technologies requires in-depth structural optimization and lightweight transformation of support seat products. The component supports of currently operating high-speed trains are mainly made of ductile iron, resulting in a relatively high overall quality of the component supports. Aluminum alloy, as a lightweight structural material, has the advantages of low density, high strength, good electrical and thermal conductivity, good corrosion resistance, easy forming and processing, and has been widely used in the manufacturing field of high-speed trains. Summary of the invention

[0004] In view of the above-mentioned prior art, the present invention provides an aluminum alloy for preparing a train built-in bogie frame support and a preparation method thereof, so as to solve the technical problems of the existing built-in bogie frame support materials having heavy weight and poor mechanical properties.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is to provide an aluminum alloy for preparing a train built-in bogie frame support, comprising the following components in mass percentage:

[0006] Zn 5.5-8%, Mg 1.5-2.7%, Cu 1.5-3.0%, Zr 0.07-0.35%, Ti 0.04-0.2%, Mn 0.04-0.2%, Y 0.05-0.3%, V 0.05-0.2%, Si 0.1-0.5%, and the balance is Al and inevitable impurities.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the aluminum alloy used to prepare the train built-in bogie frame support includes the following components in percentage by mass:

[0009] Zn 6.5%, Mg 2.0%, Cu 2.7%, Zr 0.1%, Ti 0.08%, Mn 0.1%, Y 0.2%, V 0.1%, Si 0.3%, and the balance is Al and inevitable impurities.

[0010] The present invention also discloses a method for preparing the aluminum alloy for preparing a train built-in bogie frame support, comprising the following steps:

[0011] S1: preparing the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy by mixing the raw materials according to the mass percentage of each element in the aluminum alloy and melting and pouring the raw materials;

[0012] S2: homogenizing the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0013] S3: performing hot plastic deformation processing on the homogenized Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0014] S4: performing superplastic die forging on the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy that has been subjected to thermoplastic deformation processing;

[0015] S5: heat treating the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after superplastic die forging to obtain.

[0016] Further, the raw materials include aluminum ingots, Al-Cu master alloys, Al-5Zr master alloys, Al-5Ti master alloys, Al-10Mn master alloys, Al-10Y master alloys, Al-5V master alloys, zinc ingots, magnesium ingots and silicon powder.

[0017] Further, the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy is prepared by the following steps:

[0018] The aluminum ingot of the formula amount is melted, and the melt is heated to 670-710°C, and then the Al-Cu master alloy is added, and the melt is kept warm for 30-60 minutes; then the melt temperature is raised to 730-750°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy and Al-5V master alloy are added, and the melt is kept warm for 20-30 minutes; then the melt is heated to 780-820°C, silicon powder is added, and the melt is kept warm for 30-60 minutes; then the melt temperature is lowered to 670-710°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 30-60 minutes; then the melt is heated to 720-740°C, stirred for 2-10 minutes, and then allowed to stand until the melt temperature is 710-730°C, and then cast to obtain a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy.

[0019] Furthermore, the homogenization treatment method in S2 is: remove the outer skin of the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy, then heat to 400-480°C, keep warm for 8-72h; then heat to 455-500°C, keep warm for 36-72h, and then water-cool at 10-35°C.

[0020] Furthermore, the hot plastic deformation processing method in S3 is: heating the homogenized Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy to 400-450°C, keeping it warm for 2-10 hours, and then hot extruding it with an extrusion ratio of 9-30:1.

[0021] Furthermore, the superplastic die forging process in S4 is divided into superplastic die forging pre-forging and superplastic die forging final forging.

[0022] Furthermore, the superplastic die forging process comprises the following steps: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy that has been subjected to the hot plastic deformation process to 400-470°C, keeping the temperature for 2-12 hours, and then heating the alloy at 400-470°C for 10 -5 ~10 -1 mm / s die forging rate to obtain a pre-forged billet; then at 400-470℃ for 10 -5 ~10 -1 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet.

[0023] Furthermore, the heat treatment in S5 is as follows: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after superplastic forging to 480-520°C, keeping it at that temperature for 2-10 hours, and water cooling it at room temperature; then heating it to 110-150°C, keeping it at that temperature for 9-26 hours, and then air cooling it to room temperature.

[0024] The beneficial effects of the present invention are:

[0025] 1. The aluminum alloy of the present invention contains elements such as Zn, Mg, Cu, Zr, Ti, Mn, Y, V, Si, etc. Among them, Cu, Zr, Ti, Mn, and Y are introduced through the master alloy, which can not only effectively improve the utilization rate of the elements, but also reduce the occurrence of impurities and segregation, thereby ensuring the performance of the obtained aluminum alloy.

[0026] 2. In the smelting process of the present invention, the Al-Cu master alloy is first added to the aluminum melt for smelting, and Cu is evenly distributed in the aluminum melt to form a solid solution and intermetallic compounds such as CuAl2, which can improve the alloy properties and provide a heterogeneous nucleation core, so that after adding Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy and Al-5V master alloy, Al-Mn solid solution and Al6Mn phase, Al3Zr, Al3Ti, Al8Cu4Y and other metal phases can be formed, thereby achieving the purpose of improving the alloy properties.

[0027] 3. Vanadium is introduced into the aluminum alloy of the present invention. The introduced vanadium can form a solid solution and an intermetallic compound with magnesium and aluminum. These structures can effectively hinder lattice slip and dislocation movement, thereby improving the overall strength of the aluminum alloy, which makes the aluminum alloy more stable when subjected to external forces and is not prone to deformation or fracture. In addition, vanadium can co-precipitate with elements such as Y and Si in the alloy to form a dense protective film, thereby effectively preventing oxidation and corrosion of the alloy. In addition, vanadium can regulate the grain growth inside the aluminum alloy and refine the formed grains, thereby improving the uniformity of the organization, reducing defects and stress concentration in the alloy, and thus improving the overall performance and reliability of the alloy. Furthermore, adding vanadium to the aluminum alloy does not significantly increase the density of the alloy. On the contrary, since vanadium can improve the strength and hardness of the alloy, the alloy can withstand greater external forces while maintaining lightweight, which is crucial for the lightweight of the aluminum alloy.

[0028] 4. Silicon is also added to the aluminum alloy of the present invention, and the final aluminum alloy contains eutectic silicon phase structures such as α-Al / Si eutectic, which can not only significantly improve the casting performance of the alloy and make it easier to process and shape, but also these eutectic silicon phases exist in the form of rods, which can improve the metallographic structure of the aluminum alloy, so that the obtained aluminum alloy has excellent mechanical and fatigue resistance.

[0029] 5. The present invention adopts two-step superplastic die forging to manufacture aluminum alloy. The design of two-step superplastic die forging avoids the formation of defects of the aluminum alloy frame support during the die forging process, reduces stress concentration, and effectively guarantees the mechanical properties of the aluminum alloy; and after two-step die forging, the plastic deformation of the alloy is uniform, and the grain size is small and uniform, which is conducive to improving and enhancing the mechanical properties of the aluminum alloy, especially having better fatigue performance, ensuring the lightweight of the aluminum alloy while having better safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the built-in bogie frame support. DETAILED DESCRIPTION

[0031] The specific implementation modes of the present invention are described in detail below with reference to the embodiments.

[0032] Example 1

[0033] An aluminum alloy for preparing a train built-in bogie frame support comprises the following components in percentage by mass:

[0034] Zn 6.5%, Mg 2.0%, Cu 2.7%, Zr 0.1%, Ti 0.08%, Mn 0.1%, Y 0.2%, V 0.1%, Si 0.3%, and the balance is Al and inevitable impurities.

[0035] The aluminum alloy used to prepare the train built-in bogie frame support in this embodiment is prepared by the following steps:

[0036] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy, Al-5V master alloy, zinc ingot, magnesium ingot and silicon powder; smelting and pouring the raw materials according to the following steps to prepare a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0037] The aluminum ingot of the formula amount is melted, and the melt is heated to 680°C, and then Al-Cu master alloy is added, and the melt is kept warm for 45 minutes; then the melt temperature is raised to 740°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy and Al-5V master alloy are added, and the melt is kept warm for 25 minutes; then the melt is heated to 800°C, silicon powder is added, and the melt is kept warm for 45 minutes; then the melt temperature is reduced to 680°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 45 minutes; then the melt is heated to 730°C, stirred for 5 minutes, and then allowed to stand until the temperature reaches 720°C, and cast to obtain a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0038] S2: removing the outer skin of the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy, then heating to 450°C at a heating rate of 5°C / min and keeping it warm for 36 hours; then heating to 480°C at a heating rate of 5°C / min and keeping it warm for 48 hours, followed by water cooling at 25°C to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0039] S3: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after homogenization is heated to 430°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and then hot extruded with an extrusion ratio of 25:1 to complete the hot plastic deformation processing;

[0040] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy that had been subjected to thermoplastic deformation was heated to 450°C at a heating rate of 5°C / min, kept at this temperature for 8 h, and then heated at 450°C for 10 -3 mm / s die forging rate to obtain a pre-forged billet; then, the pre-forged billet was heated at 420°C for 10 -3 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0041] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after superplastic forging treatment is heated to 500°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and water-cooled at room temperature; then, the temperature is heated to 120°C at a heating rate of 5°C / min, kept at this temperature for 16 hours, and then air-cooled to room temperature.

[0042] Example 2

[0043] An aluminum alloy for preparing a train built-in bogie frame support comprises the following components in percentage by mass:

[0044] Zn 5.5%, Mg 2.7%, Cu 1.5%, Zr 0.35%, Ti 0.04%, Mn 0.2%, Y 0.05%, V 0.2%, Si 0.1%, and the balance is Al and inevitable impurities.

[0045] The aluminum alloy used to prepare the train built-in bogie frame support in this embodiment is prepared by the following steps:

[0046] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy, Al-5V master alloy, zinc ingot, magnesium ingot and silicon powder; smelting and pouring the raw materials according to the following steps to prepare a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0047] The aluminum ingot of the formula amount is melted, and the melt is heated to 670°C, and then Al-Cu master alloy is added, and the melt is kept warm for 60 minutes; then the melt temperature is raised to 730°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy and Al-5V master alloy are added, and the melt is kept warm for 30 minutes; then the melt is heated to 780°C, silicon powder is added, and the melt is kept warm for 60 minutes; then the melt temperature is reduced to 670°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 60 minutes; then the melt is heated to 720°C, stirred for 10 minutes, and then allowed to stand until the temperature is 710°C, and cast to obtain a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0048] S2: removing the outer skin of the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy, then heating to 400°C at a heating rate of 5°C / min and keeping it warm for 72 hours; then heating to 455°C at a heating rate of 5°C / min and keeping it warm for 72 hours, followed by water cooling at 10°C to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0049] S3: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after homogenization is heated to 400°C at a heating rate of 5°C / min, kept at this temperature for 10 hours, and then hot extruded with an extrusion ratio of 30:1 to complete the hot plastic deformation processing;

[0050] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy that had been subjected to thermoplastic deformation was heated to 400°C at a heating rate of 5°C / min, kept at this temperature for 12 h, and then heated at 400°C for 10 -5 mm / s die forging rate to obtain a pre-forged billet; then at 400℃ for 10 -5 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0051] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after superplastic forging treatment is heated to 480°C at a heating rate of 5°C / min, kept at this temperature for 10 hours, and water-cooled at room temperature; then, the temperature is heated to 110°C at a heating rate of 5°C / min, kept at this temperature for 26 hours, and then air-cooled to room temperature.

[0052] Example 3

[0053] An aluminum alloy for preparing a train built-in bogie frame support comprises the following components in percentage by mass:

[0054] Zn 8%, Mg 1.5%, Cu 3.0%, Zr 0.07%, Ti 0.2%, Mn 0.04%, Y 0.3%, V 0.05%, Si 0.5%, and the balance is Al and inevitable impurities.

[0055] The aluminum alloy used to prepare the train built-in bogie frame support in this embodiment is prepared by the following steps:

[0056] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy, Al-5V master alloy, zinc ingot, magnesium ingot and silicon powder; smelting and pouring the raw materials according to the following steps to prepare a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0057] The aluminum ingot of the formula amount is melted, and the melt is heated to 710°C, and then Al-Cu master alloy is added, and the melt is kept warm for 30 minutes; then the melt temperature is raised to 750°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy and Al-5V master alloy are added, and the melt is kept warm for 20 minutes; then the melt is heated to 820°C, silicon powder is added, and the melt is kept warm for 30 minutes; then the melt temperature is lowered to 710°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 30 minutes; then the melt is heated to 740°C, stirred for 2 minutes, and then allowed to stand until the temperature reaches 730°C, and then cast to obtain a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0058] S2: removing the outer skin of the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy, then heating to 480°C at a heating rate of 5°C / min and keeping it warm for 8 hours; then heating to 500°C at a heating rate of 5°C / min and keeping it warm for 36 hours, followed by water cooling at 35°C to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy;

[0059] S3: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after homogenization is heated to 450°C at a heating rate of 5°C / min, kept at this temperature for 2 hours, and then hot extruded with an extrusion ratio of 9:1 to complete the hot plastic deformation processing;

[0060] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy that had been subjected to thermoplastic deformation was heated to 470°C at a heating rate of 5°C / min, kept at this temperature for 2h, and then heated at 470°C for 10 -1 mm / s die forging rate to obtain a pre-forged billet; then, the pre-forged billet was heated at 470°C for 10 -1 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0061] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after superplastic forging treatment is heated to 520°C at a heating rate of 5°C / min, kept at this temperature for 2 hours, and water-cooled at room temperature; then, the temperature is heated to 150°C at a heating rate of 5°C / min, kept at this temperature for 9 hours, and then air-cooled to room temperature.

[0062] Comparative Example 1

[0063] An aluminum alloy for preparing a train built-in bogie frame support comprises the following components in percentage by mass:

[0064] Zn 6.5%, Mg 2.0%, Cu 2.7%, Zr 0.1%, Ti 0.08%, Mn 0.1%, Y 0.2%, Si 0.3%, and the balance is Al and inevitable impurities.

[0065] The aluminum alloy used to prepare the train built-in bogie frame support in this comparative example is prepared by the following steps:

[0066] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy, zinc ingot, magnesium ingot and silicon powder; smelting and pouring the raw materials according to the following steps to prepare a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-Y-Si alloy;

[0067] The aluminum ingot of the formula amount is melted, and the melt is heated to 680°C, and then Al-Cu master alloy is added, and the melt is kept warm for 45 minutes; then the melt temperature is raised to 740°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy and Al-10Y master alloy are added, and the melt is kept warm for 25 minutes; then the melt is heated to 800°C, silicon powder is added, and the melt is kept warm for 45 minutes; then the melt temperature is reduced to 680°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 45 minutes; then the melt is heated to 730°C, stirred for 5 minutes, and then allowed to stand until the temperature reaches 720°C, and then cast to obtain a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-Y-Si alloy;

[0068] S2: removing the outer skin of the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-Y-Si alloy, then heating to 450°C at a heating rate of 5°C / min, keeping the temperature for 36 hours; then heating to 480°C at a heating rate of 5°C / min, keeping the temperature for 48 hours, and then water cooling at 25°C to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Y-Si alloy;

[0069] S3: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Y-Si alloy after homogenization is heated to 430°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and then hot extruded with an extrusion ratio of 25:1 to complete the hot plastic deformation processing;

[0070] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Y-Si alloy that had been subjected to thermoplastic deformation was heated to 450°C at a heating rate of 5°C / min, kept at this temperature for 8 h, and then heated at 450°C for 10 -3mm / s die forging rate to obtain a pre-forged billet; then, the pre-forged billet was heated at 420°C for 10 -3 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0071] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Y-Si alloy after superplastic forging treatment is heated to 500°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and water-cooled at room temperature; then, the temperature is heated to 120°C at a heating rate of 5°C / min, kept at this temperature for 16 hours, and then air-cooled to room temperature.

[0072] Comparative Example 2

[0073] An aluminum alloy for preparing a train built-in bogie frame support comprises the following components in percentage by mass:

[0074] Zn 6.5%, Mg 2.0%, Cu 2.7%, Zr 0.1%, Ti 0.08%, Mn 0.1%, Y 0.2%, V 0.1%, and the balance is Al and inevitable impurities.

[0075] The aluminum alloy used to prepare the train built-in bogie frame support in this comparative example is prepared by the following steps:

[0076] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy, Al-5V master alloy, zinc ingot and magnesium ingot; smelting and pouring the raw materials according to the following steps to prepare a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV alloy;

[0077] The aluminum ingot of the formula amount is melted, and the melt is heated to 680°C, and then Al-Cu master alloy is added, and the melt is kept warm for 45 minutes; then the melt temperature is raised to 740°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy and Al-5V master alloy are added, and the melt is kept warm for 25 minutes; then the melt temperature is lowered to 680°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 45 minutes; then the melt is heated to 730°C, stirred for 5 minutes, and then allowed to stand until the temperature reaches 720°C, and then cast to obtain a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV alloy;

[0078] S2: removing the outer skin of the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV alloy, then heating to 450°C at a heating rate of 5°C / min and keeping it warm for 36 hours; then heating to 480°C at a heating rate of 5°C / min and keeping it warm for 48 hours, followed by water cooling at 25°C to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV alloy;

[0079] S3: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV alloy after homogenization is heated to 430°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and then hot extruded with an extrusion ratio of 25:1 to complete the hot plastic deformation processing;

[0080] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV alloy that had been subjected to thermoplastic deformation was heated to 450°C at a heating rate of 5°C / min, kept at this temperature for 8 h, and then heated at 450°C for 10 -3 mm / s die forging rate to obtain a pre-forged billet; then, the pre-forged billet was heated at 420°C for 10 -3 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0081] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-YV alloy after superplastic forging treatment is heated to 500°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and water-cooled at room temperature; then, the temperature is heated to 120°C at a heating rate of 5°C / min, kept at this temperature for 16 hours, and then air-cooled to room temperature to obtain.

[0082] Comparative Example 3

[0083] An aluminum alloy for preparing a train built-in bogie frame support comprises the following components in percentage by mass:

[0084] Zn 6.5%, Mg 2.0%, Cu 2.7%, Zr 0.1%, Ti 0.08%, Mn 0.1%, Y 0.2%, and the balance is Al and inevitable impurities.

[0085] The aluminum alloy used to prepare the train built-in bogie frame support in this comparative example is prepared by the following steps:

[0086] S1: preparing raw materials according to the mass percentage of each element in the alloy, the raw materials including aluminum ingot, Al-Cu master alloy, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy, zinc ingot and magnesium ingot; smelting and pouring the raw materials according to the following steps to prepare a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-Y alloy;

[0087] The aluminum ingot of the formula amount is melted, and the melt is heated to 680°C, and then Al-Cu master alloy is added, and the melt is kept warm for 45 minutes; then the melt temperature is raised to 740°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy and Al-10Y master alloy are added, and the melt is kept warm for 25 minutes; then the melt temperature is lowered to 680°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 45 minutes; then the melt is heated to 730°C, stirred for 5 minutes, and then allowed to stand until the temperature reaches 720°C, and then cast to obtain a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-Y alloy;

[0088] S2: removing the outer skin of the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-Y alloy, then heating to 450°C at a heating rate of 5°C / min and keeping it warm for 36 hours; then heating to 480°C at a heating rate of 5°C / min and keeping it warm for 48 hours, followed by water cooling at 25°C to complete the homogenization treatment of the Al-Zn-Mg-Cu-Zr-Ti-Mn-Y alloy;

[0089] S3: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Y alloy after homogenization is heated to 430°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and then hot extruded with an extrusion ratio of 25:1 to complete the hot plastic deformation processing;

[0090] S4: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Y alloy that had been subjected to thermoplastic deformation was heated to 450°C at a heating rate of 5°C / min, kept at this temperature for 8 h, and then heated at 450°C for 10 -3 mm / s die forging rate to obtain a pre-forged billet; then, the pre-forged billet was heated at 420°C for 10 -3 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet, completing the superplastic die forging process;

[0091] S5: The Al-Zn-Mg-Cu-Zr-Ti-Mn-Y alloy after superplastic forging treatment is heated to 500°C at a heating rate of 5°C / min, kept at this temperature for 8 hours, and water-cooled at room temperature; then, the temperature is heated to 120°C at a heating rate of 5°C / min, kept at this temperature for 16 hours, and then air-cooled to room temperature to obtain.

[0092] Results Analysis

[0093] The aluminum alloys for preparing the train built-in bogie frame supports prepared in the above-mentioned embodiments and comparative examples are respectively made into built-in bogie frame supports. The structure of the built-in bogie frame supports is as follows: Figure 1Then, the performance test of the prepared built-in bogie frame support was carried out, and the test items included tensile strength, yield strength, fatigue resistance, etc. Among them, the fatigue test parameters were: stress ratio of 0.1, vibration frequency of 60-70HZ, and number of cycles of 1×10 7 The test results are shown in Table 1.

[0094] Table 1 Comprehensive performance of built-in bogie frame support

[0095]

[0096] Although the specific implementation of the present invention is described in detail in conjunction with the embodiments, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. An aluminum alloy for preparing a train built-in bogie frame support, characterized in that: The following components are included in mass percentage: Zn 5.5~8%, Mg 1.5~2.7%, Cu 1.5~3.0%, Zr 0.07~0.35%, Ti 0.04~0.2%, Mn 0.04~0.2%, Y 0.05~0.3%, V 0.05~0.2%, Si 0.1~0.5%, and the balance is Al and inevitable impurities.

2. The aluminum alloy for preparing a train built-in bogie frame support according to claim 1, characterized in that: The following components are included in mass percentage: Zn 6.5%, Mg 2.0%, Cu 2.7%, Zr 0.1%, Ti 0.08%, Mn 0.1%, Y 0.2%, V 0.1%, Si 0.3%, and the balance is Al and inevitable impurities.

3. The method for preparing an aluminum alloy for preparing a train built-in bogie frame support according to claim 1 or 2, characterized in that: The following steps are involved: S1: preparing the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy by mixing the raw materials according to the mass percentage of each element in the aluminum alloy and melting and pouring the raw materials; S2: homogenizing the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy; S3: performing hot plastic deformation processing on the homogenized Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy; S4: performing superplastic die forging on the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy that has been subjected to hot plastic deformation processing; S5: heat treating the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after superplastic die forging to obtain.

4. The preparation method according to claim 3, characterized in that: The raw materials include aluminum ingots, Al-Cu master alloys, Al-5Zr master alloys, Al-5Ti master alloys, Al-10Mn master alloys, Al-10Y master alloys, Al-5V master alloys, zinc ingots, magnesium ingots and silicon powder.

5. The preparation method according to claim 4, characterized in that: The cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy is prepared by the following steps: The aluminum ingot of the formula amount is melted, and the melt is heated to 670-710°C, and then the Al-Cu master alloy is added, and the melt is kept warm for 30-60 minutes; then the melt temperature is raised to 730-750°C, Al-5Zr master alloy, Al-5Ti master alloy, Al-10Mn master alloy, Al-10Y master alloy and Al-5V master alloy are added, and the melt is kept warm for 20-30 minutes; then the melt is heated to 780-820°C, silicon powder is added, and the melt is kept warm for 30-60 minutes; then the melt temperature is lowered to 670-710°C, zinc ingot and magnesium ingot are added, and the melt is kept warm for 30-60 minutes; then the melt is heated to 720-740°C, stirred for 2-10 minutes, and then allowed to stand until the melt temperature is 710-730°C, and then cast to obtain a cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy.

6. The preparation method according to claim 3, characterized in that: The homogenization treatment method in S2 is: remove the outer skin of the cast Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy, then heat it to 400-480°C, keep it warm for 8-72 hours; then heat it to 455-500°C, keep it warm for 36-72 hours, and then water-cool it at 10-35°C.

7. The preparation method according to claim 3, characterized in that: The hot plastic deformation processing method in S3 is: heating the homogenized Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy to 400-450°C, keeping it warm for 2-10 hours, and then hot extruding it with an extrusion ratio of 9-30:

1.

8. The preparation method according to claim 3, characterized in that: The superplastic die forging process in S4 is divided into superplastic die forging pre-forging and superplastic die forging final forging.

9. The preparation method according to claim 8, characterized in that: The superplastic die forging process includes the following steps: heating the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy that has been subjected to thermoplastic deformation to 400-470°C, keeping the temperature for 2-12 hours, and then heating the alloy at 400-470°C for 10 -5 ~10 -1 mm / s die forging rate to obtain a pre-forged billet; then at 400-470℃ for 10 -5 ~10 -1 The pre-forged billet is final forged at a die forging rate of mm / s to obtain a final forging billet.

10. The preparation method according to claim 3, characterized in that: The heat treatment in S5 is as follows: the Al-Zn-Mg-Cu-Zr-Ti-Mn-YV-Si alloy after superplastic forging is heated to 480-520°C, kept at this temperature for 2-10 hours, and water-cooled at room temperature; then the temperature is raised to 110-150°C, kept at this temperature for 9-26 hours, and then air-cooled to room temperature.

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