Short-flow semi-solid closed extrusion-forging combined forming process for scroll disc of hydrogen circulating pump

Abstract

This application discloses a short-process semi-solid closed-loop extrusion forging composite forming process for a scroll disk for a hydrogen circulation pump, relating to the field of scroll disk forming technology for hydrogen circulation pumps. First, the aluminum alloy cylindrical material required for forming the scroll disk is determined; then, the aluminum alloy cylindrical material undergoes cold heading rough deformation, and the cold-headed aluminum alloy billet is heated and held at a certain temperature to obtain a semi-solid fine spherulite material; next, the semi-solid fine spherulite material is quickly placed into the cavity formed by the outer and lower molds, and the upper mold is controlled to press down to extrude and deform the semi-solid fine spherulite material and hold the pressure, thereby forming a semi-solid scroll disk; finally, the upper mold is raised and controlled to forge the semi-solid scroll disk, ultimately obtaining a scroll disk part for a hydrogen circulation pump that simultaneously possesses a semi-solid spherulite structure and a forged deformed structure. This application features a simple process, low forming force, high material utilization, high product density, and good mechanical properties.

Description

Technical Field

[0001] This application relates to the field of manufacturing technology for complex screw components, and in particular to a short-process semi-solid closed-loop extrusion forging composite forming process for a scroll disk used in hydrogen circulation pumps. Background Technology

[0002] Hydrogen circulation pumps are key components of fuel cell systems, and vortex hydrogen circulation pumps, with their unique advantages of high efficiency and low noise, have become one of the preferred types of hydrogen circulation pumps for automotive fuel cell systems.

[0003] As a typical multi-layered, thin-walled cup-like complex component, the scroll disk is a core part of the scroll hydrogen circulation pump, and has an extremely important impact on the performance of the hydrogen circulation system in hydrogen fuel cell vehicles. Meanwhile, with the continuous development of hydrogen fuel cell vehicle technology and related basic design infrastructure, the requirements for high performance, high reliability, and high functional efficiency of the corresponding scroll disk components are constantly increasing.

[0004] Traditional scroll disk parts are mainly produced through integral milling. However, integral milling of scroll disks involves significant material waste, cutting of metal fibers, reduced mechanical properties, lengthy milling processes, and low production efficiency. Although subsequent processes such as hot forging, liquid forging, liquid die casting, powder metallurgy, and back pressure forming have been developed, each of these forming processes has significant drawbacks. Solid forging suffers from high energy consumption, liquid forging has a short die life, liquid die casting has serious internal defects, powder metallurgy has lengthy processes, and back pressure forming has complex die structures. Summary of the Invention

[0005] To address the aforementioned technical problems, embodiments of this application provide a short-process semi-solid closed-loop extrusion forging composite forming process for a hydrogen circulation pump scroll disk. This process enables the preparation of a hydrogen circulation pump scroll disk part that simultaneously possesses a semi-solid spherulitic structure and a forged deformation structure.

[0006] To achieve the above objectives, embodiments of this application provide a short-process semi-solid closed-loop extrusion forging composite forming process for a scroll disk for a hydrogen circulation pump, comprising the following steps: S1, determining the material and dimensions of the aluminum alloy cylindrical material: S11, determining the material of the aluminum alloy cylindrical material as 6061 wrought aluminum alloy based on the material of the scroll disk part for the hydrogen circulation pump; S12, determining the diameter d of the aluminum alloy cylindrical material as d≥D / 2 based on the maximum axial projection circle diameter D of the scroll disk part for the hydrogen circulation pump and the preset axial upsetting deformation amount of 50%; S13, determining the height H of the aluminum alloy cylindrical material as H≤16V / (πD) based on the volume V of the scroll disk part for the hydrogen circulation pump and the diameter d of the aluminum alloy cylindrical material. 2S2. Semi-solid material preparation: S21. Obtain the aluminum alloy cylindrical material described in step S1; S22. Perform cold heading rough deformation of the aluminum alloy cylindrical material along the axial direction with a deformation amount of 50% to obtain a cold-headed aluminum alloy billet; S23. Place the cold-headed aluminum alloy billet in a resistance heating furnace and heat it to 630℃ and hold it for 10 minutes to obtain a semi-solid fine spherulite material with a diameter of 30~50μm and an average shape factor ≥0.6; S3. Semi-solid closed extrusion forging composite forming: S31. Quickly place the semi-solid fine spherulite material obtained in step S2 into the "U"-shaped mold cavity formed by the outer mold and the lower mold; S32. Control the upper mold to press down at a speed of 10mm / s and a pressing force of 50 tons. The load is applied to deform the semi-solid fine spherulitic material by compression, so that it fills the "U"-shaped cavity formed by the outer mold and the lower mold, forming a semi-solid vortex disk with a fine near-spherical microstructure; S33, the upper mold is raised and then controlled to press down at a speed of 100 mm / s and a load of 200 tons to forge the semi-solid vortex disk and hold the pressure for 5 minutes to obtain a vortex disk part for hydrogen circulation pump that has both a semi-solid spherulitic structure and a forged deformation structure; S34, the vortex disk part for hydrogen circulation pump is demolded: first, the upper mold is raised to separate the vortex disk part for hydrogen circulation pump from it, then the lower mold is lowered to separate the vortex disk part for hydrogen circulation pump from it, and finally the lower mold is raised again to eject the vortex disk part for hydrogen circulation pump.

[0007] This application has the following advantages over the prior art:

[0008] 1. The cold heading rough strain-induced semi-solid material preparation process in the embodiments of this application does not involve oxidation and the introduction of impurity phases caused by high-temperature overheating liquid during the preparation of semi-solid slurry in the liquid phase method. The prepared semi-solid material is pure and free of pollution.

[0009] 2. The embodiments of this application fully consider the size of the cold heading deformation amount that can effectively accumulate strain energy required for the preparation of semi-solid materials by cold heading rough strain-induced method, and the axial projection circle diameter of the aluminum alloy billet in the cold heading rough deformation form is less than or equal to the maximum axial projection circle diameter of the scroll disk part. This facilitates the acquisition of high-quality semi-solid fine spherulite materials, which can be directly placed into the mold cavity for scroll disk forming, avoiding the "secondary remelting" step of traditional semi-solid forming. This enables short-process, near-net-shape forming of scroll disks, and significantly improves material utilization.

[0010] 3. Compared with traditional cutting processes, the embodiments of this application can shorten the process flow, save production costs, and improve production efficiency. They also have the advantages of high material density of formed parts, superior mechanical properties compared to traditional semi-solid formed parts, and the ability to be heat-treated to further improve part performance. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a process flow diagram of an embodiment of this application;

[0013] Figure 2 This is a schematic diagram of the material dimension design process in an embodiment of this application;

[0014] Figure 3 This is a schematic diagram showing the shape and microstructure deformation of the material during the forming process of an embodiment of this application;

[0015] Figure 4 This is a schematic diagram of the demolding process of the semi-solid scroll disk formed in the embodiment of this application. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0018] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, they can refer to fixed connection, detachable connection, or integral connection; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0019] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] Reference Figures 1 to 3 The embodiments of this application provide a short-process semi-solid closed-loop extrusion forging composite forming process for a scroll disk for a hydrogen circulation pump, including the following steps:

[0021] S1. Determine the material and dimensions of aluminum alloy cylinder material 1-2:

[0022] S11. Based on the material of the scroll plate part 1-1 for the hydrogen circulation pump, the material of the aluminum alloy cylinder material 1-2 is determined to be 6061 wrought aluminum alloy.

[0023] S12. Based on the maximum axial projection circle diameter D of the scroll plate part 1-1 for the hydrogen circulation pump and the preset axial upsetting deformation amount of 50%, determine the diameter d of the aluminum alloy cylindrical material to be ≥ D / 2. It should be noted that this dimension is to ensure that, under the above upsetting deformation amount, the axial projection circle diameter D1 of the upset aluminum alloy cylindrical material 1-2 (i.e., the cold upsetting deformed aluminum alloy billet 2-1) is ≤ the maximum axial projection circle diameter D of the scroll plate part 1-1 for the hydrogen circulation pump.

[0024] S13. Based on the volume V of the scroll plate part 1-1 for the hydrogen circulation pump and the diameter d of the aluminum alloy cylindrical material 1-2, determine the height H of the aluminum alloy cylindrical material 1-2 to be ≤ 16V / (πD). 2 ) .

[0025] S2, Semi-solid material preparation:

[0026] S21. Obtain aluminum alloy cylindrical material 1-2 from step S1.

[0027] S22. The aluminum alloy cylindrical material 1-2 is subjected to cold heading deformation with a deformation amount of 50% along the axial direction to obtain the cold heading aluminum alloy billet 2-1. The axial projection circle diameter of the cold heading aluminum alloy billet 2-1 is denoted as D1, and the thickness is H / 2.

[0028] S23. Place the cold-forged aluminum alloy billet 2-1 into a resistance heating furnace 2-2 and heat it to 630℃ and hold it for 10 minutes to obtain a semi-solid fine spherulite material 2-3 with a diameter of 30~50μm and an average shape factor ≥0.6.

[0029] S3. Semi-solid closed-loop extrusion forging composite forming: It should be noted that this step is based on the mold. The mold includes an outer mold 3-1, a lower mold 3-2, and an upper mold 3-3. The outer mold 3-1, the lower mold 3-2, and the upper mold 3-3 together form a composite mold cavity, the shape of which is adapted to the shape of the scroll plate part 1-1 for the hydrogen circulation pump.

[0030] S31. Quickly place the semi-solid fine spherulite material 2-3 obtained in step S2 into the "U"-shaped mold cavity formed by the outer mold 3-1 and the lower mold 3-2.

[0031] S32. Control the upper mold to compress and deform the semi-solid fine spherulite material 2-3 at a pressing speed of 10 mm / s and a pressing load of 50 tons, so that it fills the "U"-shaped mold cavity formed by the outer mold 3-1 and the lower mold 3-2, forming a semi-solid vortex disk 3-4 with a fine near-spherical microstructure.

[0032] S33, after raising the upper mold 3-3, control it to press down at a speed of 100 mm / s and a load of 200 tons to achieve forging deformation of the semi-solid scroll disk 3-4 and hold the pressure for 5 minutes to obtain the scroll disk part 3-5 for hydrogen circulation pump that has both semi-solid spherulitic structure and forged deformation structure.

[0033] S34, Demolding of scroll plate parts for hydrogen circulation pumps (3-5):

[0034] First, raise the upper mold 3-3 to separate the hydrogen circulation pump scroll plate 3-5 from it. Then, lower the lower mold 3-2 to separate the hydrogen circulation pump scroll plate 3-5 from it. Finally, raise the lower mold 3-3 again to eject the hydrogen circulation pump scroll plate 3-5.

[0035] The specific working principle of the ejection of the scroll disk component 3-5 for the hydrogen circulation pump after forming in this application is as follows:

[0036] Reference Figure 4As shown, after the scroll plate component 3-5 for the hydrogen circulation pump is formed, the upper mold 3-3 is raised first. Since the contact area between the scroll plate component 3-5 and the upper mold 3-3 is significantly smaller than the contact area between the scroll plate component 3-5 and the "U"-shaped cavity formed by the outer mold 3-1 and the lower mold 3-2, the scroll plate component 3-5 remains within the "U"-shaped cavity formed by the outer mold 3-1 and the lower mold 3-2, thus separating the upper mold 3-3 from the scroll plate component 3-5. Next, the lower mold 3-2 is lowered. Because the outermost ring of the scroll plate component 3-5 is limited by the internal structure of the outer mold 3-1, the scroll plate component 3-5 remains inside the outer mold 3-1 when the lower mold 3-2 descends, thus separating from the lower mold 3-2. Finally, the lower mold 3-2 is raised again to eject the formed hydrogen circulation pump scroll plate part 3-5 from inside the outer mold 3-1.

[0037] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A short process semi-solid closed type extrusion-forging combined forming process for a scroll plate for a hydrogen circulation pump, characterized by, The method comprises the following steps: S1, determining the material and size of the aluminum alloy cylinder material: S11, determining the material of the aluminum alloy cylinder material as 6061 deformed aluminum alloy according to the material of the scroll disc part for the hydrogen circulation pump; S12, determining the diameter d of the aluminum alloy cylinder material as ≥D / 2 according to the maximum axial projection circle diameter D of the scroll disc part for the hydrogen circulation pump and the preset axial upsetting deformation amount of 50%; S13. Determine the height H of the aluminum alloy cylindrical material ≤ 16V / (πD 2 ) based on the volume V of the scroll part for the hydrogen circulating pump and the diameter d of the aluminum alloy cylindrical material. S2, semi-solid material preparation: S21, obtaining the aluminum alloy cylinder material in step S1; S22, performing cold upsetting deformation on the aluminum alloy cylinder material along the axial direction by 50% to obtain a cold upsetting deformed aluminum alloy blank; S23, placing the cold upsetting deformed aluminum alloy blank into a resistance heating furnace to heat to 630°C for 10 min, and obtaining semi-solid fine-grain material with a grain size of 30-50 μm and an average shape factor ≥0.6; S3, semi-solid closed extrusion and forging composite forming: S31, quickly placing the semi-solid fine-grain material obtained in step S2 into a "U"-shaped die cavity formed by the outer die and the lower die; S32, controlling the upper die to realize extrusion deformation on the semi-solid fine-grain material at a pressing speed of 10 mm / s and a pressing load of 50 tons, so that after the semi-solid fine-grain material fills the "U"-shaped die cavity formed by the outer die and the lower die, a semi-solid scroll disc with fine near-spherical microstructure is formed; S33, lifting the upper die and then controlling it to press at a pressing speed of 100 mm / s and a pressing load of 200 tons, realizing forging deformation on the semi-solid scroll disc and holding pressure for 5 min, and obtaining a scroll disc part for the hydrogen circulation pump which simultaneously has semi-solid grain structure and forged deformed structure; S34, demolding of the scroll disc part for the hydrogen circulation pump: firstly lifting the upper die to separate the scroll disc part for the hydrogen circulation pump from the upper die, then lowering the lower die to separate the scroll disc part for the hydrogen circulation pump from the lower die, and finally lifting the lower die again to eject the scroll disc part for the hydrogen circulation pump.

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