Method for forming a rotary body member from an aluminium alloy tailor welded blank

Abstract

The present application relates to the technical field of plate forming, in particular to a kind of aluminum alloy tailor welded blank rotary body component forming method;The method comprises: the aluminum alloy tailor welded blank is placed on preforming mould, at-160~‑190 ℃, the preforming mould is applied to the pressure to make the aluminum alloy tailor welded blank deformation, and first preforming rotary body component is obtained;After solid solution treatment, the first preforming rotary body component is welded, and it is re-welded to obtain second preforming rotary body component;The second preforming rotary body component is placed on final forming mould, at room temperature, the final forming mould is applied to the pressure to make the second preforming rotary body component deformation, and the depth of final forming rotary body component is obtained.The aluminum alloy tailor welded blank rotary body component forming method provided by the present application effectively solves the problem of weld cracking in the forming process of large-size thin-walled component, and the problem of weld performance degradation caused by weld grain growth after solid solution treatment.

Description

Technical Field

[0001] This invention relates to the field of sheet metal forming technology, and more specifically, to a method for forming a rotating component of an aluminum alloy welded sheet. Background Technology

[0002] Large-size thin-walled components are a crucial type of part in aerospace vehicles. Due to limitations in slab size, current technologies for these components generally employ a "large-size blank preparation by sheet metal welding + performance control through heat treatment + integral forming of the large-size component" approach. Taking the bottom of a rocket propellant tank as an example, it directly affects the rocket's carrying capacity and operational reliability. Existing technologies for forming such welded plate components mainly utilize two methods: room temperature forming and hot forming. However, room temperature forming results in a low weld forming limit and a high susceptibility to cracking; during hot forming, the weld softens, leading to a decline in weld performance and extremely poor service life. Based on these issues, researchers have proposed a method for forming such components at ultra-low temperatures. This method can improve the forming limit of the welded plate. However, before forming, these components generally require solution treatment at high temperatures, which causes abnormal grain growth in the weld, further degrading weld performance. Summary of the Invention

[0003] The technical problem solved by this invention is that existing forming methods for large-size thin-walled components cannot simultaneously avoid problems such as easy cracking of welds during the forming process and the decline in weld performance caused by the growth of weld grains after solution treatment.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A method for forming a rotary component from aluminum alloy welded plates includes:

[0006] Step S1: Place the aluminum alloy welded plate on the preforming mold, and apply pressure to the preforming mold at -160 to -190°C to deform the aluminum alloy welded plate and obtain the first preformed rotating body component.

[0007] Step S2: After solution treatment of the first preformed rotary component, the weld of the first preformed rotary component is cut off and re-welded to obtain the second preformed rotary component.

[0008] Step S3: Place the second preformed rotary component on the final forming mold, and apply pressure to the final forming mold at room temperature to deform the second preformed rotary component, thereby obtaining a deeper final formed rotary component.

[0009] Preferably, the depth of the first preformed rotary component is h, and the depth of the final formed rotary component is H, wherein the ratio of h to (Hh) is not less than 2.

[0010] Preferably, the top opening diameter of the first preformed rotary component is d, the top opening diameter of the final formed rotary component is D, and the ratio of h to d is 0.5 to 0.95 times the ratio of H to D.

[0011] Preferably, in step S1, the aluminum alloy welded plate is formed by friction stir welding, wherein the rotation speed of friction stir welding is 800-1200 rpm and the welding advance speed is 200-600 mm / min.

[0012] Preferably, in step S2, the welding method used for re-welding is friction stir welding, and the rotation speed of friction stir welding is 500-2000 rpm, and the welding advance speed is 200-1000 mm / min.

[0013] Preferably, in step S2, the solution treatment temperature is 450–550°C and the time is 30–60 min.

[0014] Preferably, the method for forming the aluminum alloy welded plate rotary body component further includes: step S4, subjecting the final formed rotary body component to artificial aging treatment.

[0015] Preferably, in step S4, the temperature of the artificial aging treatment is 150–180°C, and the time is 12–48 hours.

[0016] Preferably, in step S1, the aluminum alloy welded plate is made of annealed aluminum alloy.

[0017] Preferably, the annealed aluminum alloy includes one of Al-Cu-Mg alloy, Al-Cu-Mn alloy, Al-Mg-Si alloy plate, Al-Zn-Mg-Cu alloy, and Al-Cu-Li alloy plate.

[0018] Compared with the prior art, the present invention first forms a first preformed rotary component at an ultra-low temperature (-160 to -190°C) using a preforming mold. After solution treatment, the weld area of ​​the first preformed rotary component is removed and re-welded to obtain a second preformed rotary component. At room temperature, pressure is applied to the final forming mold to deform the second preformed rotary component, resulting in a deeper final formed rotary component. Because the hardening index and plasticity coefficient of aluminum alloy welded plate joints are both high at ultra-low temperatures, the deformation uniformity and forming performance of the aluminum alloy welded plate are good. Therefore, the forming limit of the aluminum alloy welded plate is high, which is beneficial for forming a first pre-formed rotary component with a large depth. After solution treatment, the abnormally large grains in the weld are cut away, and new welds are formed. During this process, the weld grain size can be controlled by controlling the welding parameters, thereby solving the problem of weld performance degradation caused by weld grain growth after solution treatment, and thus ensuring the weld quality of the final formed rotary component. Since the weld area has already undergone a certain amount of deformation during the forming process of the first pre-formed rotary component, the deformation of the weld area during the forming process of the final formed rotary component at room temperature is relatively small, which can reduce the risk of weld cracking. In summary, the aluminum alloy welded plate rotary component forming method provided by this invention effectively solves the problems of easy weld cracking during the forming of large-size thin-walled components and weld performance degradation caused by weld grain growth after solution treatment. Attached Figure Description

[0019] Figure 1 This is a schematic flowchart of the forming method for the rotating aluminum alloy welded plate component in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the forming process of the first pre-formed rotating component in Embodiment 1 of the present invention;

[0021] Figure 3 This is a schematic diagram of the process of cutting and re-welding the weld of the first preformed rotary component to form the second preformed rotary component in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the forming process of the final formed rotating body component in Embodiment 1 of the present invention;

[0023] Figure 5 This is a schematic diagram of the final shaped rotating body component obtained in Example 1;

[0024] Figure 6 This is a schematic diagram of the final shaped rotating body component obtained in Example 2.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1-1 First punch, 1-2 First blank holder, 1-3 First die, 1-4 First support post, 2-1 Second blank holder, 2-2 Second die, 2-3 Second support post, 2-4 Second punch. Detailed Implementation

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other. The terms "comprising," "including," "containing," and "having" are not restrictive and can be used to add other steps and other components that do not affect the result.

[0029] like Figure 1 As shown, this embodiment of the invention provides a method for forming a rotating component from an aluminum alloy welded plate, comprising:

[0030] Step S1: Place the aluminum alloy welded plate on the preforming mold, and apply pressure to the preforming mold at -160 to -190°C to deform the aluminum alloy welded plate and obtain the first preformed rotating body component.

[0031] Step S2: After solution treatment of the first preformed rotary component, the weld of the first preformed rotary component is cut off and re-welded to obtain the second preformed rotary component.

[0032] Step S3: Place the second preformed rotary component on the final forming mold, and apply pressure to the final forming mold at room temperature to deform the second preformed rotary component, thereby obtaining a deeper final formed rotary component.

[0033] Compared with the prior art, the present invention first forms a first preformed rotary component at an ultra-low temperature (-160 to -190°C) using a preforming mold. After solution treatment, the weld area of ​​the first preformed rotary component is removed and re-welded to obtain a second preformed rotary component. At room temperature, pressure is applied to the final forming mold to deform the second preformed rotary component, resulting in a deeper final formed rotary component. Because the hardening index and plasticity coefficient of aluminum alloy welded plate joints are both high at ultra-low temperatures, the deformation uniformity and formability of the aluminum alloy welded plate are good, resulting in a high forming limit. This is beneficial for forming a first pre-formed rotary component with a large depth. After solution treatment, the abnormally large grains in the weld are cut off and re-welded to form a new weld. During this process, the weld grain size can be controlled by controlling the welding parameters, thereby solving the problem of weld performance degradation caused by weld grain growth after solution treatment, and thus ensuring the weld quality of the final formed rotary component. Since the weld area has already undergone a certain amount of deformation during the forming of the first pre-formed rotary component, the deformation of the weld area during the forming of the final formed rotary component at room temperature is small, which can reduce the risk of weld cracking. In summary, the aluminum alloy welded plate rotary component forming method provided by this invention effectively solves the problems of easy weld cracking during the forming of large-size thin-walled components and weld performance degradation caused by weld grain growth after solution treatment.

[0034] In this invention, the depth of the first pre-formed rotary component is h, the depth of the final formed rotary component is H, the top opening diameter of the first pre-formed rotary component is d, the top opening diameter of the final formed rotary component is D, and the diameter of the aluminum alloy welded plate is D0. The depth h of the first pre-formed rotary component can be determined according to the following formula:

[0035]

[0036] In the above formula, n is the material hardening index, k is a coefficient, and the value of k ranges from 0.5 to 0.95. When the thickness of the aluminum alloy welded plate is thin, k takes a small value, and vice versa.

[0037] In some embodiments of the present invention, the depth of the first pre-formed rotary component is h, and the depth of the final formed rotary component is H, wherein the ratio of h to (Hh) is not less than 2. In this invention, the aluminum alloy welded plate is deformed into the final formed rotary component through the following two deformations: First deformation: the aluminum alloy welded plate is deformed into the first pre-formed rotary component; Second deformation: the second pre-formed rotary component is deformed into the final formed rotary component. Since the first deformation is performed at ultra-low temperatures, the deformation uniformity and forming performance of the aluminum alloy welded plate are good at ultra-low temperatures. During the first deformation process, even if a large amount of deformation occurs in the weld area, weld cracking will not occur. In this embodiment, the deformation amount generated by the first deformation is relatively large, and the weld area has already undergone a large amount of deformation during the first deformation process. Therefore, during the second deformation process to form the final formed rotary component, the deformation amount in the weld area is small, which can further reduce the risk of weld cracking.

[0038] In some embodiments of the present invention, the top opening diameter of the first preformed rotary component is d, the top opening diameter of the final formed rotary component is D, and the ratio of h to d is 0.5 to 0.95 times the ratio of H to D.

[0039] In some embodiments of the present invention, in step S1, the aluminum alloy welded plate is formed by friction stir welding. The rotation speed of the friction stir welding is 800-1200 rpm, and the welding advance speed is 200-600 mm / min. Friction stir welding is more suitable for welding low melting point materials such as aluminum alloys, and has the advantages of low energy consumption and high efficiency.

[0040] In some embodiments of the present invention, in step S2, the re-welding is performed using friction stir welding, with a rotation speed of 500–2000 rpm and a welding advance speed of 200–1000 mm / min. By controlling the welding parameters, the average grain size of the weld zone of the obtained second preformed rotating component is 1–100 μm.

[0041] In some embodiments of the present invention, in step S2, the solution treatment temperature is 450–550°C and the time is 30–60 min.

[0042] In some embodiments of the present invention, the method for forming the aluminum alloy welded plate rotary body component further includes: step S4, subjecting the final formed rotary body component to artificial aging treatment; the temperature of the artificial aging treatment is 150-180°C, and the time is 12-48h.

[0043] In some embodiments of the present invention, in step S1, the aluminum alloy welded plate is made of annealed aluminum alloy. The annealed aluminum alloy includes one of Al-Cu-Mg alloy, Al-Cu-Mn alloy, Al-Mg-Si alloy plate, Al-Zn-Mg-Cu alloy, and Al-Cu-Li alloy plate.

[0044] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. It should be noted that... Figure 2-4 In the diagram, P0 is an aluminum alloy welded plate, P1 is the first pre-formed rotating body component, P2 is the second pre-formed rotating body component, and P3 is the final formed rotating body component. The downward thick arrow indicates the direction of the applied force.

[0045] Example 1

[0046] This embodiment provides a method for forming a hemispherical component from an aluminum alloy welded plate. The molds used in the forming process include a pre-forming mold and a final forming mold, such as... Figure 2 As shown, the preforming mold includes a first punch 1-1, a first die 1-3, a first pressure ring 1-2, and two first support pillars 1-4. The two first support pillars 1-4 jointly support the first die 1-3. The pressure ring 1-2 is disposed above the first die 1-3. The first punch 1-1 includes an integrally formed upper end and a lower end, the lower end being frustum-shaped. The first punch 1-1 is used to apply pressure to the aluminum alloy welded plate P0 to promote its forming. Figure 4 As shown, the preforming mold includes a second punch 2-4, a second die 2-2, a second pressure ring 2-1, and two second support pillars 2-3. The two second support pillars 2-3 jointly support the second die 2-2. The second pressure ring 2-1 is disposed above the second die 1-3. The second punch 2-4 includes an integrally formed upper end and a lower end, the lower end being hemispherical. The second punch 2-4 is used to apply pressure to the second preforming rotating body component P2 to promote its forming.

[0047] The specific forming steps are as follows:

[0048] The first step is to prepare an aluminum alloy welded plate P0 using friction stir welding. The aluminum alloy welded plate P0 has a diameter of 380 mm and a thickness of 2 mm. The material used to prepare it is an Al-Cu-Mn alloy, specifically an annealed 2219 aluminum alloy plate. The friction stir welding parameters are: welding advance speed of 200 mm / min and welding rotation speed of 800 rpm.

[0049] Step 2: As Figure 2As shown, the aluminum alloy welded plate P0 is placed on the first concave mold 1-3 and fixed by the first pressure ring 1-2. The aluminum alloy welded plate P0 is cooled to below -160°C by immersion in liquid nitrogen. The first punch 1-1 is used to press the aluminum alloy welded plate P0 to deform it, thus obtaining the first pre-formed rotating component P1. Figure 2 As shown, the first preformed rotating component P1 is shaped like a washbasin; its depth h is 100 mm, the diameter of the top opening is d, and h / d = 0.416.

[0050] Step 3: The first preformed rotary component P1 is solution treated at 535℃ and kept at that temperature for 40 minutes. After being taken out and quickly water-quenched, the weld of the first preformed rotary component P1 is cut off and re-performed by friction stir welding to obtain the second preformed rotary component P2. The friction stir welding parameters are: welding advance speed of 200mm / min and welding rotation speed of 800rpm. Figure 3 A schematic diagram of the process of cutting and re-welding the weld of the first preformed rotating component P1 to form the second preformed rotating component P2;

[0051] Step 4: As Figure 4 As shown, the second pre-formed rotary component P2 is placed on the second die 2-2 and fixed by the second pressure ring 2-1. At room temperature, the second punch 2-4 is used to press the second pre-formed rotary component P2 to deform it, resulting in the final formed rotary component P3. Figure 5 As shown, the main body shape of the final formed rotating component P3 is hemispherical;

[0052] Step 5: The final shaped rotary component P3 is subjected to artificial aging treatment. The artificial aging treatment includes: placing the final shaped rotary component P3 in an aging furnace, holding it at 175°C for 18 hours, and then removing it and air-cooling it to room temperature. The artificial aging treatment results in an average tensile strength of 420 MPa and an elongation of 6% for the weld of the hemispherical component P3.

[0053] Example 2

[0054] This embodiment provides a method for forming a deep conical component of an aluminum alloy welded plate. The mold used for the deep conical component of the aluminum alloy welded plate includes a pre-forming mold and a final forming mold. In this embodiment, the pre-forming mold has the same structure as the pre-forming mold used in Embodiment 1. The difference between the final forming mold used and the final forming mold used in Embodiment 1 is that the shape of the lower end of the second punch in this embodiment is changed from a hemispherical shape in Embodiment 1 to a deep conical shape.

[0055] The specific forming steps are as follows:

[0056] The first step is to prepare an aluminum alloy welded plate P0 using friction stir welding. The aluminum alloy welded plate P0 has a diameter of 480 mm and a thickness of 2.5 mm. The material used for preparation is an Al-Li alloy, specifically an annealed 2195 aluminum-lithium alloy plate. The friction stir welding parameters are: welding advance speed of 300 mm / min and welding rotation speed of 1200 rpm.

[0057] Step 2: Place the aluminum alloy welded plate P0 on the first concave mold and fix it with the first pressure ring. Cool the aluminum alloy welded plate P0 to below -180°C by immersion in liquid nitrogen. Apply pressure to the aluminum alloy welded plate P0 using the first punch to deform it, obtaining the first pre-formed rotating component P1, as shown below. Figure 2 As shown, the first preformed rotating component P1 is shaped like a washbasin; its depth h is 100 mm, and the diameter of the top opening is d, h / d = 0.75;

[0058] Step 3: The first preformed rotary component P1 is solution treated at 525℃ and kept at that temperature for 40 minutes. After being taken out and quickly water-quenched, the weld of the first preformed rotary component P1 is cut off and re-performed by friction stir welding to obtain the second preformed rotary component P2. The friction stir welding parameters are: welding advance speed of 300mm / min and welding rotation speed of 1200rpm.

[0059] Step 4: Place the second pre-formed rotary component P2 on the second die and fix it with the second pressure ring. At room temperature, use the second punch to press the second pre-formed rotary component P2 to deform it, obtaining the final formed rotary component P3, as shown. Figure 6 As shown, the main body shape of the final formed rotating component P3 is a deep cone.

[0060] Step 5: The final shaped rotary component P3 is subjected to artificial aging treatment. The artificial aging treatment includes: placing the final shaped rotary component P3 in an aging furnace, holding it at 155°C for 48 hours, and then removing it and air-cooling it to room temperature. The artificial aging treatment results in an average tensile strength of 480 MPa and an elongation of 8% for the weld of the hemispherical component P3.

[0061] Furthermore, it should be noted that although the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for forming a rotating component from an aluminum alloy welded plate, characterized in that, include: Step S1: Place the aluminum alloy welded plate on the preforming mold, and apply pressure to the preforming mold at -160 to -190°C to deform the aluminum alloy welded plate and obtain the first preformed rotating body component. Step S2: After solution treatment of the first preformed rotary component, the weld of the first preformed rotary component is cut off and re-welded to obtain the second preformed rotary component. Step S3: Place the second preformed rotary component on the final forming mold, and apply pressure to the final forming mold at room temperature to deform the second preformed rotary component, thereby obtaining a deeper final formed rotary component.

2. The method for forming a rotary component of aluminum alloy welded plates according to claim 1, characterized in that, The depth of the first pre-formed rotary component is h, and the depth of the final formed rotary component is H, wherein the ratio of h to (Hh) is not less than 2.

3. The method for forming a rotary component of aluminum alloy welded plates according to claim 2, characterized in that, The top opening diameter of the first preformed rotary component is d, and the top opening diameter of the final formed rotary component is D. The ratio of h to d is 0.5 to 0.95 times the ratio of H to D.

4. The method for forming a rotating aluminum alloy welded plate component according to claim 1, characterized in that, In step S1, the aluminum alloy welded plate is formed by friction stir welding. The rotation speed of the friction stir welding is 800-1200 rpm, and the welding advance speed is 200-600 mm / min.

5. The method for forming a rotary component of aluminum alloy welded plate according to claim 1, characterized in that, In step S2, the welding method used for the re-welding is friction stir welding, and the rotation speed of friction stir welding is 500-2000 rpm, and the welding advance speed is 200-1000 mm / min.

6. The method for forming a rotary component of aluminum alloy welded plate according to claim 1, characterized in that, In step S2, the solution treatment temperature is 450–550°C and the time is 30–60 min.

7. The method for forming a rotating aluminum alloy welded plate component according to claim 1, characterized in that, It also includes: step S4, artificially aging the final shaped rotary component.

8. The method for forming a rotary component of aluminum alloy welded plates according to claim 7, characterized in that, In step S4, the temperature of the artificial aging treatment is 150-180℃, and the time is 12-48h.

9. The method for forming a rotary component of aluminum alloy welded plates according to claim 1, characterized in that, In step S1, the aluminum alloy welded plate is made of annealed aluminum alloy.

10. The method for forming a rotary component of aluminum alloy welded plate according to claim 9, characterized in that, The annealed aluminum alloy includes one of the following: Al-Cu-Mg alloy, Al-Cu-Mn alloy, Al-Mg-Si alloy plate, Al-Zn-Mg-Cu alloy, and Al-Cu-Li alloy plate.

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