Design method for extrusion forming process of thin-wall ultra-wide aluminum alloy profile

Abstract

The invention discloses a design method for an extrusion forming process of a thin-wall ultra-wide aluminum alloy profile. The design method comprises the following steps: designing structural parameters of a blank and an extrusion container; structural parameters of the extrusion die are designed; designing extrusion process parameters; establishing a material constitutive relation model; establishing a finite element simulation model, and checking stress and strain of the extrusion container and the extrusion die; checking the forming quality of the extruded profile; carrying out an extrusion forming test to verify the extrusion forming quality of the profile; shape dimension and surface quality testing and checking are carried out on the extruded profile; and carrying out microstructure and mechanical property testing and checking on the extruded profile, and feeding back optimized extrusion process parameters and structural parameters of the extrusion die according to each checking result. The problem that the thin-wall ultra-wide aluminum alloy profile cannot be integrally extruded at a time in an existing traditional extrusion technology is solved, the test quantity and the trial and error cost are reduced, and the production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of metal material plastic forming technology, specifically to a design method for extrusion forming process of thin-walled ultra-wide aluminum alloy profiles. Background Technology

[0002] Thin-walled, ultra-wide aluminum alloy profiles are widely used in the automotive, rail transportation, and aerospace industries, serving as an important type of load-bearing component. Typical applications include battery pack base plates for new energy vehicles, high-speed rail carriage wall panels, aircraft floors, and ship hull frames, indicating a huge market demand. However, due to their thin walls and wide widths, these profiles are difficult to form in a single step using traditional extrusion molding processes; therefore, they are typically manufactured using narrow-width profile welding.

[0003] Replacing the traditional single large-diameter billet with multiple small-diameter billets is one of the effective methods to reduce the extrusion ratio and extrusion pressure, enabling the one-time extrusion of thin-walled, ultra-wide profiles using low-tonnage extrusion equipment. However, due to the special structure of the extrusion cylinder and die, the metal flow pattern is more complex during high-temperature extrusion, making it difficult to control the forming quality of the profiles. At the same time, it also poses greater challenges to the strength and lifespan of the extrusion cylinder and die, and the process design and optimization methods are still immature. Summary of the Invention The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention provides a process design method for extruding thin-walled ultra-wide aluminum alloy profiles, solving the problem that existing extrusion technology cannot extrude thin-walled ultra-wide aluminum alloy profiles in one continuous process.

[0004] According to an embodiment of the present invention, a method for designing a thin-walled, ultra-wide aluminum alloy profile extrusion forming process is applicable to an extrusion forming system having an extrusion press, an extrusion cylinder, and an extrusion die. The extrusion cylinder has multiple loading holes for loading blanks, and the extrusion press is used to extrude the blanks in the extrusion cylinder through the extrusion die to form a profile product. The extrusion forming process design method includes: Design the structural parameters of the billet and extrusion cylinder based on the tonnage of the extruder and the cross-sectional dimensions of the final profile product; Design the structural parameters of the extrusion die based on the cross-sectional shape and dimensions of the final profile product; Design extrusion process parameters based on material properties, heat treatment standards, and process experience; High-temperature stress-strain curves of the extrusion cylinder, the extrusion die, and the billet were obtained through high-temperature tensile and high-temperature compression tests, and their material constitutive models were established respectively. A finite element simulation model is established to verify the stress and strain of the extrusion cylinder and the extrusion die, and the extrusion process parameters, the structural parameters of the extrusion die and the extrusion cylinder are optimized based on the verification results. The forming quality of the extruded profile is checked, and the extrusion process parameters and the structural parameters of the extrusion die are optimized based on the check results. Extrusion molding tests were conducted to verify the extrusion molding quality of the profile. The extruded profiles are tested and verified for shape, size and surface quality, and the extrusion process parameters and the structural parameters of the extrusion die are optimized based on the verification results. The microstructure and mechanical properties of the extruded profile are tested and verified, and the extrusion process parameters and the structural parameters of the extrusion die are optimized based on the verification results.

[0005] According to some embodiments of the present invention, the structural parameters of the billet and the extrusion cylinder include the diameter, number, and arrangement of the billet and the loading holes, as well as the spacing of the loading holes; The design of structural parameters for the billet and extrusion cylinder based on the extrusion press tonnage and the final profile cross-sectional dimensions includes: Set the diameter D of any of the blanks. i satisfy ≥B / 13, where B is the width of the final profile product and N is the number of blanks and loading holes.

[0006] According to some embodiments of the present invention, the step of designing the structural parameters of the billet and the extrusion cylinder based on the extrusion press tonnage and the final profile product cross-sectional dimensions further includes: Define the radial distance d between any point on the edge of any loading hole and the edge of the extrusion cylinder liner. ti ≥D ti / 10, where D ti This represents the diameter of the corresponding loading hole.

[0007] According to some embodiments of the present invention, the step of designing the structural parameters of the billet and the extrusion cylinder based on the extrusion press tonnage and the final profile product cross-sectional dimensions further includes: The diameter of the loading holes can be the same or different, and the arrangement can be linear or non-linear.

[0008] According to some embodiments of the present invention, the step of designing the structural parameters of the billet and the extrusion cylinder based on the extrusion press tonnage and the final profile product cross-sectional dimensions further includes: Set the minimum spacing d between two adjacent loading holes. min ≥D min / 10, where D min The diameter is the smaller of the two adjacent loading holes.

[0009] According to some embodiments of the present invention, obtaining the high-temperature stress-strain curves of the extrusion cylinder, the extrusion die, and the billet through high-temperature tensile and high-temperature compression tests, and establishing their material constitutive relationship models respectively, includes: The temperatures for the high-temperature tensile test and the high-temperature compression test of the extrusion cylinder and the extrusion die are set to 350~600℃.

[0010] According to some embodiments of the present invention, obtaining the high-temperature stress-strain curves of the extrusion cylinder, the extrusion die, and the billet through high-temperature tensile and high-temperature compression tests, and establishing their material constitutive relationship models respectively, includes: The high-temperature compression test temperature of the billet was set at 300~550℃, and the strain rate was set at 0.001~10s. -1 .

[0011] According to some embodiments of the present invention, the step of establishing a finite element simulation model, checking the stress and strain of the extrusion cylinder and the extrusion die, and optimizing the extrusion process parameters, the structural parameters of the extrusion die and the extrusion cylinder based on the check results includes: The constitutive relation models of each material are imported into the finite element software to perform stress-strain verification of the extrusion cylinder and extrusion die, and fatigue life is predicted and verified based on the results.

[0012] According to some embodiments of the present invention, extrusion process parameters are designed based on material properties, heat treatment standards, and process experience, including: The extrusion process parameters include, but are not limited to, billet temperature, extrusion barrel temperature, die temperature, and extrusion speed.

[0013] According to some embodiments of the present invention, the step of checking the forming quality of the extruded profile and optimizing the extrusion process parameters, the extrusion die, and the structural parameters of the extrusion cylinder based on the check results includes: Finite element simulation is used to predict the flow velocity and stress-strain distribution of metal.

[0014] The extrusion molding process design method according to embodiments of the present invention has at least the following beneficial effects: This paper addresses the unique characteristics of multi-bulb extrusion forming and fully considers the applicable applications of thin-walled, wide-width aluminum alloy profile extrusion. It rationally designs and verifies the structural parameters of the billets, extrusion cylinders, and extrusion dies, as well as the extrusion process parameters. This improves the service conditions of extrusion tooling such as the extrusion cylinder and extends its service life. By replacing the traditional single large-diameter billet with multiple small-diameter billets, the extrusion ratio and extrusion pressure are reduced. This enables the one-time integral extrusion of aluminum alloy profiles with a wall thickness of less than 3mm and a width of more than 1000mm on extrusion equipment with a capacity of less than 10,000 tons. This solves the problem that existing traditional extrusion technologies cannot extrude thin-walled, ultra-wide-width aluminum alloy profiles in a single operation. It provides a design concept for the one-time integral extrusion forming process of thin-walled, ultra-wide-width aluminum alloy profiles, reduces the amount of experimentation and trial-and-error costs, and improves production efficiency.

[0015] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a flowchart of the extrusion forming process design method for thin-walled ultra-wide aluminum alloy profiles according to the present invention; Figure 2 This is a schematic diagram of the extrusion cylinder of the present invention; Figure 3 This is a flowchart illustrating a specific embodiment of the thin-walled ultra-wide aluminum alloy profile extrusion forming process design method of the present invention. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0019] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0020] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0022] Currently, using multiple small-diameter billets instead of the traditional single large-diameter billet is one of the effective methods to reduce the extrusion ratio and extrusion pressure, enabling the one-time extrusion of thin-walled ultra-wide profiles using low-tonnage extrusion equipment. However, due to the special structure of the extrusion cylinder and die, the flow pattern of metal is more complex during high-temperature extrusion, making it difficult to control the forming quality of the profile. At the same time, it also poses greater challenges to the strength and lifespan of the extrusion cylinder and die, and the process design and optimization methods are still immature.

[0023] Therefore, this invention proposes a design method for the extrusion forming process of thin-walled ultra-wide aluminum alloy profiles, which solves the problem that existing extrusion technology cannot extrude thin-walled ultra-wide aluminum alloy profiles in one go, and provides a design idea for the integrated extrusion forming process of thin-walled ultra-wide aluminum alloy profiles.

[0024] The thin-walled ultra-wide aluminum alloy profile extrusion forming process design method of the present invention is applicable to an extrusion forming system having an extruder, an extrusion cylinder and an extrusion die, wherein the extrusion cylinder is provided with multiple loading holes 110 for loading blanks, and the extruder is used to extrude the blanks in the extrusion cylinder through the extrusion die to form profile products.

[0025] like Figure 1 The extrusion molding process design method of the present invention includes, but is not limited to, the following steps: Step S100: Design the structural parameters of the billet and extrusion cylinder based on the tonnage of the extruder and the cross-sectional dimensions of the final profile product; Step S200: Design the structural parameters of the extrusion die based on the cross-sectional shape and dimensions of the final profile product; Step S300: Design extrusion process parameters based on material properties, heat treatment standards, and process experience; Step S400: Obtain the high-temperature stress-strain curves of the extrusion cylinder, extrusion die, and billet through high-temperature tensile and high-temperature compression tests, and establish their material constitutive relationship models respectively; Step S500: Establish a finite element simulation model, check the stress and strain of the extrusion cylinder and extrusion die, and optimize the extrusion process parameters, extrusion die and extrusion cylinder structural parameters based on the check results; Step S600: Verify the forming quality of the extruded profile, and optimize the extrusion process parameters and the structural parameters of the extrusion die based on the verification results; Step S700: Conduct extrusion molding tests to verify the quality of profile extrusion molding; Step S800: Conduct shape, size and surface quality tests on the extruded profiles and optimize the extrusion process parameters and extrusion die structural parameters based on the verification results; Step S900: Conduct microstructure and mechanical property tests on the extruded profiles and optimize the extrusion process parameters and extrusion die structural parameters based on the verification results.

[0026] The structural parameters of the billet and extrusion cylinder include the diameter, number, and arrangement of the billet and the loading holes 110, as well as the spacing of the loading holes 110. The billet selected in this invention is an aluminum alloy billet. Furthermore, the diameters of the loading holes 110 can be set to be the same or different.

[0027] This invention completes the design of the billet and extrusion cylinder structure dimensions through step S100, specifically: determining the required aluminum alloy billet, the diameter, number, and arrangement of the loading holes 110, initially determining the spacing of the loading holes 110, and designing the structural dimensions of the extrusion cylinder. Step S100 of the present invention further includes: Step S101: Set the diameter D of any blank. i satisfy ≥B / 13, where B is the width of the final profile product and N is the number of blanks and loading holes 110.

[0028] Step S102: Set the radial distance d between any point on the edge of any feeding hole 110 and the edge of the extrusion cylinder liner 100. ti ≥D ti / 10, where D ti For the diameter of the corresponding loading hole 110, such as Figure 2 As shown.

[0029] Step S103: Set the minimum spacing d between two adjacent loading holes 110 min ≥D min / 10, where D min The diameter of the smaller of two adjacent loading holes 110, such as Figure 2 As shown.

[0030] The present invention completes the mold design through step S200, specifically: based on the cross-sectional shape of the profile product and considering metal flow, the extrusion mold structure and size are designed.

[0031] In step S300, the extrusion process parameters are initially designed based on the properties of aluminum alloy materials, heat treatment standards, and process experience. The extrusion process parameters include, but are not limited to, billet temperature, extrusion barrel temperature, die temperature, and extrusion speed.

[0032] In step S400, the temperatures for the high-temperature tensile and high-temperature compression tests of the extrusion cylinder and extrusion die are set to 350~600℃, the temperature for the high-temperature compression test of the billet is set to 300~550℃, and the strain rate is 0.001~10s. -1 .

[0033] In step S500, the constitutive relation models of each material are imported into the finite element software to perform stress-strain verification of the extrusion cylinder and extrusion die, and the fatigue life is predicted and verified based on the results.

[0034] In step S600, finite element simulation is used to predict the metal flow velocity and stress-strain distribution.

[0035] After determining the final extrusion process parameters, the structural parameters of the billet and extrusion cylinder, and the structural parameters of the extrusion die, the extrusion forming process design for thin-walled ultra-wide aluminum alloy profiles was completed.

[0036] The present invention will be described in detail below with two examples: Example 1: This example uses a 6063 aluminum alloy profile with a width of 1300mm and a minimum wall thickness of 2mm as an example to illustrate the technical solution of the present invention. Figure 3 As shown, it includes the following steps: S1. Billet and Extrusion Cylinder Structural Parameter Design: Using N aluminum alloy billets of the same diameter, each loading hole (110mm diameter) will also have the same diameter. The billet diameter meets the following requirements. ≥1300 / 13mm=100mm, the minimum distance d between two adjacent loading holes 110 min ≥D min / 10, the radial distance d between any point on the edge of any feeding hole 110 and the edge of the extrusion cylinder. ti ≥D ti / 10; where D min =D ti The diameter of the loading hole 110 satisfies D. min =D ti >D i .

[0037] S2. Die Design: Based on the cross-sectional shape of the profile product and considering metal flow, design the structure and dimensions of the extrusion die; S3. Preliminary design of extrusion process parameters: The temperature of aluminum alloy billet, extrusion cylinder and extrusion die is 400~550℃, and the extrusion speed is 0.1~4mm / s; S4. High-temperature stress-strain curves of the extrusion cylinder, extrusion die, and billet were obtained through high-temperature tensile and high-temperature compression tests. Constitutive models of the materials were then established. The tensile / compression test temperatures for the extrusion cylinder and extrusion die were 350–600℃, and the compression test temperature for the aluminum alloy billet was 400–550℃, with strain rates ranging from 0.001 to 10 s⁻¹. -1 ; S5. Establish a finite element model, import the material constitutive relation model into the finite element software, carry out stress and strain verification of the extrusion cylinder and extrusion die, and predict and verify its fatigue life based on the results. Optimize the extrusion process parameters and tooling parameters based on the verification results. The tooling parameters include the extrusion cylinder structural parameters and the extrusion die structural parameters.

[0038] S6. Use finite element simulation to predict metal flow rate and stress-strain distribution, and check the forming quality of extruded profiles. Optimize extrusion process parameters and extrusion die parameters based on the check results. S7. Conduct extrusion molding tests to verify the quality of profile extrusion molding; S8. Perform shape, size and surface quality tests on the extruded profiles obtained in step S7, and optimize the extrusion process parameters and extrusion die parameters based on the verification results. S9. Conduct mechanical property and microstructure tests on the extruded profiles obtained in step S7, verify the profile microstructure and properties, and optimize the extrusion process parameters and extrusion die parameters based on the verification results; S10. Determine the final extrusion process parameters and tooling parameters, and complete the extrusion forming process design for thin-walled ultra-wide aluminum alloy profiles.

[0039] If four aluminum alloy billets of the same diameter are used, then the billet diameter satisfies D. i ≥25mm, minimum distance d between two adjacent loading holes 110 min ≥D min / 10, the radial distance d between any point on the edge of any loading hole 110 and the edge of the extrusion cylinder liner 100. ti ≥D ti / 10, where D min =D ti >25mm.

[0040] Example 2 This embodiment uses a 7075 aluminum alloy profile with a width of 910mm as an example to illustrate the technical solution of the present invention. The aluminum alloy profile has a thin-walled structure on one edge, and includes the following steps: A1. Billet and Extrusion Cylinder Structural Dimension Design: N-1 aluminum alloy billets of the same diameter are used, with one billet of a smaller diameter corresponding to the thin-walled structure side. The billet diameter meets the following requirements. ≥910 / 13mm=70mm, the minimum distance d between two adjacent loading holes 110 min ≥D min / 10, D min The diameter of the loading hole 110 corresponding to the smallest diameter billet; the radial distance d between any point on the edge of any loading hole 110 and the edge of the extrusion cylinder. ti ≥D ti / 10, D ti This refers to the diameter of the corresponding loading hole 110.

[0041] A2. Mold Design; A3. Preliminary design of extrusion process parameters: The temperature of aluminum alloy billet, extrusion cylinder and extrusion die is 400~500℃, and the extrusion speed is 0.1~4mm / s; A4. High-temperature stress-strain curves of the extrusion cylinder, extrusion die, and aluminum alloy billet were obtained through tensile and compression tests, and a material constitutive model was established. The tensile / compression test temperatures for the extrusion cylinder and extrusion die materials were 350–600℃, and the compression test temperature for the aluminum alloy billet was 400–500℃, with strain rates ranging from 0.001 to 10 s⁻¹. -1 ; A5. Establish a finite element model, import the material constitutive relation model into the finite element software, carry out stress and strain verification of the extrusion cylinder and extrusion die, and predict and verify its fatigue life based on the results. Optimize the extrusion process parameters and tooling parameters based on the verification results. A6. Use finite element simulation to predict metal flow velocity and stress-strain distribution, and verify the forming quality of extruded profiles. Optimize extrusion process parameters and extrusion die parameters based on the verification results. A7. Conduct extrusion molding tests to verify the quality of profile extrusion molding; A8. Conduct shape, size and surface quality tests on the extruded profiles obtained in step A7, and optimize the extrusion process parameters and extrusion die parameters based on the verification results; A9. Conduct mechanical property and microstructure tests on the extruded profiles obtained in step A7, verify the profile microstructure and properties, and optimize the extrusion process parameters and tooling parameters based on the verification results; A10. Determine the final extrusion process parameters and extrusion die parameters, and complete the extrusion forming process design for thin-walled ultra-wide aluminum alloy profiles.

[0042] For example, if four aluminum alloy blanks are used, with three blanks having a diameter of D1 and the blank diameter corresponding to the thin-walled profile being D2, then the following conditions must be met: 3D1 + D2 ≥ 70 mm, and D1 > D2. The minimum distance d between two adjacent loading holes 110 is... min ≥D min / 10, D min The diameter of the loading hole 110 corresponding to the diameter D2 of the billet, D min >D2; The radial distance d between any point on the edge of any extrusion cylinder loading hole 110 and the edge of the extrusion cylinder liner 100. ti ≥D ti / 10, D ti >D2.

[0043] The beneficial effects of this invention are: (1) By replacing the traditional single large-diameter billet with multiple small-diameter billets, the extrusion ratio and extrusion pressure are reduced, thereby enabling the extrusion equipment with a wall thickness of less than 3mm and a width of more than 1000mm to extrude aluminum alloy profiles in one go within a 10,000-ton range, solving the problem that the existing traditional extrusion technology cannot extrude thin-walled ultra-wide aluminum alloy profiles in one go. (2) In view of the complex process of multi-bill co-extrusion forming and the harsh service conditions caused by the special extrusion cylinder structure, the applicable objects of thin-walled wide aluminum alloy profile extrusion are fully considered. The billet size, extrusion cylinder and mold structure and forming process parameters are reasonably designed and checked, which is conducive to improving the forming quality and the service conditions of extrusion tooling such as extrusion cylinder, increasing service life and reducing operating costs. (3) It provides a design idea for the one-time integral extrusion forming process of thin-walled ultra-wide aluminum alloy profiles, reduces the amount of testing and trial and error costs, and improves production efficiency.

[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0045] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for designing a thin-walled, ultra-wide aluminum alloy profile extrusion forming process, characterized in that, An extrusion forming system is applicable to an extrusion press, an extrusion cylinder, and an extrusion die, wherein the extrusion cylinder has multiple loading holes for loading blanks, the extrusion press is used to extrude the blanks in the extrusion cylinder through the extrusion die to form profile products, and the extrusion forming process design method includes: Design the structural parameters of the billet and extrusion cylinder based on the tonnage of the extruder and the cross-sectional dimensions of the final profile product; Design the structural parameters of the extrusion die based on the cross-sectional shape and dimensions of the final profile product; Design extrusion process parameters based on material properties, heat treatment standards, and process experience; High-temperature stress-strain curves of the extrusion cylinder, the extrusion die, and the billet were obtained through high-temperature tensile and high-temperature compression tests, and their material constitutive models were established respectively. A finite element simulation model is established to verify the stress and strain of the extrusion cylinder and the extrusion die, and the extrusion process parameters, the structural parameters of the extrusion die and the extrusion cylinder are optimized based on the verification results. The forming quality of the extruded profile is checked, and the extrusion process parameters and the structural parameters of the extrusion die are optimized based on the check results. Extrusion molding tests were conducted to verify the extrusion molding quality of the profile. The extruded profiles are tested and verified for shape, size and surface quality, and the extrusion process parameters and the structural parameters of the extrusion die are optimized based on the verification results. The microstructure and mechanical properties of the extruded profile are tested and verified, and the extrusion process parameters and the structural parameters of the extrusion die are optimized based on the verification results.

2. The extrusion molding process design method according to claim 1, characterized in that, The structural parameters of the billet and extrusion cylinder include the diameter, number, and arrangement of the billet and the loading holes, as well as the spacing between the loading holes; The design of structural parameters for the billet and extrusion cylinder based on the extrusion press tonnage and the final profile cross-sectional dimensions includes: Set the diameter D of any of the blanks. i satisfy ≥B / 13, where B is the width of the final profile product and N is the number of blanks and loading holes.

3. The extrusion molding process design method according to claim 2, characterized in that, The step of designing the structural parameters of the billet and extrusion cylinder based on the extrusion press tonnage and the final profile product cross-sectional dimensions also includes: Define the radial distance d between any point on the edge of any feeding hole and the edge of the extrusion cylinder liner. ti ≥D ti / 10, where D ti This represents the diameter of the corresponding loading hole.

4. The extrusion molding process design method according to claim 2, characterized in that, The step of designing the structural parameters of the billet and extrusion cylinder based on the extrusion press tonnage and the final profile product cross-sectional dimensions also includes: The diameter of the loading holes can be the same or different, and the arrangement can be linear or non-linear.

5. The extrusion molding process design method according to claim 2, characterized in that, The step of designing the structural parameters of the billet and extrusion cylinder based on the extrusion press tonnage and the final profile product cross-sectional dimensions also includes: Set the minimum spacing d between two adjacent loading holes. min ≥D min / 10, where D min The diameter is the smaller of the two adjacent loading holes.

6. The extrusion molding process design method according to claim 1, characterized in that, The high-temperature stress-strain curves of the extrusion cylinder, the extrusion die, and the billet are obtained through high-temperature tensile and high-temperature compression tests, and their material constitutive relationship models are established respectively, including: The temperatures for the high-temperature tensile test and the high-temperature compression test of the extrusion cylinder and the extrusion die are set to 350~600℃.

7. The extrusion molding process design method according to claim 1, characterized in that, The high-temperature stress-strain curves of the extrusion cylinder, the extrusion die, and the billet are obtained through high-temperature tensile and high-temperature compression tests, and their material constitutive relationship models are established respectively, including: The high-temperature compression test temperature of the billet was set at 300~550℃, and the strain rate was set at 0.001~10s. -1 .

8. The extrusion molding process design method according to claim 1, characterized in that, The establishment of a finite element simulation model to verify the stress and strain of the extrusion cylinder and extrusion die, and the optimization of the extrusion process parameters, the structural parameters of the extrusion die and the extrusion cylinder based on the verification results, includes: The constitutive relation models of each material are imported into the finite element software to perform stress-strain verification of the extrusion cylinder and extrusion die, and fatigue life is predicted and verified based on the results.

9. The extrusion molding process design method according to claim 1, characterized in that, Based on material properties, heat treatment standards, and process experience, the extrusion process parameters are designed, including: The extrusion process parameters include, but are not limited to, billet temperature, extrusion barrel temperature, die temperature, and extrusion speed.

10. The extrusion molding process design method according to claim 1, characterized in that, The process of verifying the forming quality of the extruded profile and optimizing the extrusion process parameters, the extrusion die, and the structural parameters of the extrusion cylinder based on the verification results includes: Finite element simulation is used to predict the flow velocity and stress-strain distribution of metal.

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