A method for constructing a cold extrusion springback prediction model of a tantalum alloy hyperboloid component

Abstract

The present invention provides a method for predicting springback of a tantalum alloy hyperbolic member, a method for constructing a springback prediction model of a tantalum alloy hyperbolic member, and a computer-readable storage medium. The steps include: establishing a finite element model for cold extrusion forming of a tantalum alloy hyperbolic blank, establishing a finite element model for springback of the tantalum alloy hyperbolic blank, drawing longitudinal sectional views of the tantalum alloy hyperbolic blank before and after springback at various deformation amounts, establishing a rectangular coordinate system, calculating the change amount ⊿ of the center thickness of the tantalum alloy hyperbolic blank after springback at various deformation amounts, the radius of curvature of the upper curve on the longitudinal sectional view after springback ρ 12 , and the radius of curvature of the lower curve on the longitudinal sectional view after springback ρ 22 . By adopting this solution, not only can the springback amount of the tantalum alloy hyperbolic member be accurately predicted, but also the springback compensation can be effectively guided.

Description

Technical Field

[0001] The present invention belongs to the technical field of tantalum alloy forming, and particularly relates to a method for predicting springback of cold extrusion of a tantalum alloy hyperbolic member, a method for constructing a prediction model for springback of cold extrusion of a tantalum alloy hyperbolic member, and a computer-readable storage medium. Background Art

[0002] The metal precision cold extrusion forming technology, which belongs to the commonly used plastic forming methods, is a near-net forming technology that, at room temperature, applies pressure to a blank through a punch to make the metal flow reasonably to form a component with the required shape and properties. It has the advantages of high production efficiency, low cost, good surface quality, high material utilization rate, etc., and is widely used in the fields of aerospace, automotive industry, weaponry, etc.

[0003] Tantalum alloy components are usually prepared by a cold extrusion forming process. However, the work hardening effect is obvious during the plastic deformation process of tantalum alloy. At room temperature, when the deformation degree ≥ 30%, the tensile strength rises from about 350 MPa before deformation to (550 - 700) MPa, while the elongation after fracture decreases significantly (from 35% to about 11%). Therefore, it is necessary to use multi-pass forming to prepare tantalum alloy hyperbolic members. More critically, physical phenomena such as elastic-plastic deformation and complex dynamic contact between the blank and the die surface exist during the forming process of tantalum alloy. Coupled with the hyperbolic structure characteristics of the component, springback deformation inevitably occurs after forming and unloading, seriously affecting the assembly accuracy and service life of the product, and restricting the development of the precision cold extrusion forming technology of tantalum alloy components.

[0004] At present, the research on springback prediction and control mostly focuses on the forming process of sheet metals, including the springback of bending of structural parts such as U-shaped parts, V-shaped parts, or combinations of U-shaped and V-shaped parts. However, the existing springback control methods for sheet metal forming are not applicable to the cold extrusion forming of tantalum alloy hyperbolic members, and there is no research on the springback prediction of cold extrusion of tantalum alloy hyperbolic members except for empirical control. It is a technical problem in this field to quickly and accurately predict the springback of multi-pass forming of tantalum alloy components. Therefore, it is necessary to provide a calculation method for predicting the springback of cold extrusion of tantalum alloy hyperbolic members and establish a theoretical calculation model for springback, in order to improve the forming accuracy of tantalum alloy hyperbolic members and quickly and accurately predict the springback of cold extrusion of tantalum alloy hyperbolic members. Summary of the Invention

[0005] Aiming at the problem that the prior art cannot solve the problem of quickly and accurately predicting the springback of multi-pass forming of tantalum alloy components, the purpose of the present invention is to provide a method for predicting springback of cold extrusion of a tantalum alloy hyperbolic member, a method for constructing a prediction model for springback of cold extrusion of a tantalum alloy hyperbolic member, and a computer-readable storage medium, which can not only accurately predict the springback amount of a tantalum alloy hyperbolic member, but also effectively guide springback compensation.

[0006] To achieve the above object, the present invention adopts the following technical solutions.

[0007] In the present invention, the finally formed tantalum alloy is called a tantalum alloy hyperbolic member, and the tantalum alloy during the forming process is called a tantalum alloy hyperbolic blank.

[0008] A computer-readable storage medium stores a computer program thereon, characterized in that when a processor executes the program, the following steps are implemented:

[0009] An input unit for inputting the deformation amount x% of cold extrusion forming of a tantalum alloy hyperbolic blank;

[0010] An output unit for outputting calculation results;

[0011] A display unit for displaying data;

[0012] A data storage unit stores calculation models (I), (II), (III) and (IV) of the springback amount of cold extrusion of a tantalum alloy hyperbolic blank, where:

[0013] Change amount of the center thickness of the blank after springback of cold extrusion of a tantalum alloy hyperbolic member

[0014] ⊿t = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 +1.01185x 3 ×10 -6 (80≥x≥30)...(I);

[0015] Radius of curvature of the upper curve after springback

[0016] ρ 12 = 151.02333 + 0.045x (50≥x≥30).................................(II);

[0017] Radius of curvature of the upper curve after springback

[0018] ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 (80≥x≥50)......................(III);

[0019] Radius of curvature of the lower curve after springback

[0020] ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 -6.62037x 3×10 -5 (80 ≥ x ≥ 30).......(Ⅳ);

[0021] The control unit implements the following steps:

[0022] When the read input deformation x% satisfies 50 ≥ x ≥ 30, execute equations (Ⅰ), (Ⅱ) and (Ⅳ) and output the calculation result;

[0023] When the read input deformation x% satisfies 80 ≥ x ≥ 50, execute equations (Ⅰ), (Ⅲ) and (Ⅳ) and output the calculation result;

[0024] When the read input deformation x% satisfies x ≤ 30 or x ≥ 80, output "Error" or "Please check the input data".

[0025] A method for constructing a cold extrusion springback prediction model of a tantalum alloy hyperbolic member, characterized in that the steps sequentially include:

[0026] Step 1: Establish a finite element model for cold extrusion forming of a tantalum alloy hyperbolic blank based on the Abaqus platform;

[0027] Step 2: According to the finite element model for cold extrusion forming of the tantalum alloy hyperbolic blank obtained in Step 1, establish a springback finite element model of the tantalum alloy hyperbolic blank;

[0028] Step 3: Draw longitudinal sectional views of the tantalum alloy hyperbolic blank before and after springback at various deformation amounts, and establish a rectangular coordinate system;

[0029] Step 4: Combine the rectangular coordinate system obtained in Step 3, and calculate the change amount Δt of the center thickness of the tantalum alloy hyperbolic blank after springback at various deformation amounts (Δt = the center thickness t2 of the tantalum alloy blank after springback - the center thickness t1 of the tantalum alloy blank before springback), the radius of curvature ρ of the curve on the longitudinal sectional view after springback 12 , and the radius of curvature ρ of the lower curve on the longitudinal sectional view after springback 22 ;

[0030] Step 5: According to the data obtained in Step 4, construct the springback amount calculation models (Ⅰ), (Ⅱ), (Ⅲ), (Ⅳ). When the deformation amount x% satisfies 80 ≥ x ≥ 30, the change amount of the center thickness of the blank after springback

[0031] Δt = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 ......(Ⅰ);

[0032] When the deformation amount x% satisfies 50≥x≥30, the upper curve radius of curvature after springback

[0033] ρ 12 = 151.02333 + 0.045x............................................(Ⅱ);

[0034] When the deformation amount x% satisfies 80≥x≥50, the upper curve radius of curvature after springback

[0035] ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 ................................(Ⅲ);

[0036] When the deformation amount x% satisfies 80≥x≥30, the lower curve radius of curvature after springback

[0037] ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 ×10 -5 .................(Ⅳ);

[0038] To more accurately predict the springback amount of the tantalum alloy hyperboloid component, the springback finite element model includes a tantalum alloy hyperboloid blank springback model at 30% deformation amount, a tantalum alloy hyperboloid blank springback model at 40% deformation amount, a tantalum alloy hyperboloid blank springback model at 50% deformation amount, a tantalum alloy hyperboloid blank springback model at 60% deformation amount, a tantalum alloy hyperboloid blank springback model at 70% deformation amount, and a tantalum alloy hyperboloid blank springback model at 80% deformation amount..

[0039] As a preferred application solution of the present invention, the inner wall and the outer wall of the tantalum alloy hyperboloid blank are both in a hemispherical structure.

[0040] A cold extrusion springback prediction method for a tantalum alloy hyperboloid component, characterized in that the steps sequentially include:

[0041] Step A, for tantalum alloy bars of three specifications of φ40mm, φ50mm, and φ60mm, establish a cold extrusion forming finite element model based on the Abaqus platform, and respectively simulate cold extrusion forming at deformation amounts of 30%, 40%, 50%, 60%, 70%, and 80%;

[0042] Step B: Export the models obtained in Step A, define predefined field variables, set load boundary conditions, and perform springback simulations on tantalum alloy billets under different deformation amounts respectively.

[0043] Step C: Draw the longitudinal sectional views of the tantalum alloy hyperbolic billets before and after springback under all deformation amounts respectively, and establish a rectangular coordinate system.

[0044] Step D: Based on the obtained rectangular coordinate system, calculate the center thickness t1 and t2 of the tantalum alloy billet, and the curve curvature radius ρ 11 and ρ 12 of the upper curve on the longitudinal sectional view, as well as the curve curvature radius ρ 21 and ρ 22 of the lower curve on the longitudinal sectional view for the tantalum alloy billets before and after springback under each deformation amount.

[0045] Step E: According to the data obtained in Step D, draw the change diagram of the center thickness change amount ⊿t (⊿t = center thickness t2 of the tantalum alloy billet after springback - center thickness t1 of the tantalum alloy billet before springback), the change diagram of the upper curve curvature radius ρ 12 and the change diagram of the lower curve curvature radius ρ 22 for the tantalum alloy billets after springback under each deformation amount respectively, and fit the curves to obtain the calculation formula for the center thickness change amount ⊿t of the tantalum alloy billet after springback, the calculation formula for the upper curve curvature radius ρ 12 of the longitudinal sectional view after springback, and the calculation formula for the lower curve curvature radius ρ 22 of the longitudinal sectional view after springback, where:

[0046] When the deformation amount x% satisfies 80 ≥ x ≥ 30, the center thickness change amount

[0047] ⊿t = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 .............(Ⅰ);

[0048] When the deformation amount x% satisfies 50 ≥ x ≥ 30, the upper curve curvature radius

[0049] ρ 12 = 151.02333 + 0.045x...........................................(Ⅱ);

[0050] When the deformation amount x% satisfies 80 ≥ x ≥ 50, the upper curve curvature radius

[0051] ρ 12= 145.5735 + 0.29285x - 0.00277x 2 .................................(Ⅲ);

[0052] When the deformation amount x% satisfies 80 ≥ x ≥ 30, the lower curve radius of curvature after springback

[0053] ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 × 10 -5 .................(Ⅳ);

[0054] Step E, based on the obtained formula, predict the cold extrusion springback amount of the tantalum alloy hyperbolic component under the corresponding deformation amount.

[0055] Beneficial effects: Using the present invention can not only accurately and quickly predict the springback amount of the tantalum alloy hyperbolic component, but also effectively guide the springback compensation, solving the problem in the prior art that it is impossible to quickly and accurately predict the multi-pass forming springback of the tantalum alloy component. Comparing the experimental results after springback with the prediction results of the present invention, the change amount Δt of the center thickness of the tantalum alloy hyperbolic component is within the allowable error range, and the absolute value of the maximum difference between the experimental results and the prediction results of the upper and lower curve radii of curvature is not greater than 0.05 mm, and the prediction model and results are accurate and reliable. Description of the Drawings

[0056] Figure 1 is the springback finite element model of the tantalum alloy hyperbolic blank under the deformation amount of 30% - 80% in Example 3, wherein, (a) 30% deformation amount, (b) 40% deformation amount, (c) 50% deformation amount, (d) 60% deformation amount, (e) 70% deformation amount, (f) 80% deformation amount;

[0057] Figure 2 is the schematic diagram of the longitudinal section before and after springback of the tantalum alloy hyperbolic blank in Example 3 under a certain deformation amount, the curve (solid line) represents before springback, and the curve (dashed line) represents after springback;

[0058] Figure 3 is the upper curve radius of curvature ρ before springback of the tantalum alloy hyperbolic blank under different deformation amounts in Example 3 11 , the upper curve radius of curvature ρ after springback 12 , the lower curve radius of curvature ρ before springback 21 , the lower curve radius of curvature ρ after springback 22, Variation diagram of the center thickness ⊿t of the blank after springback, where (a) is the radius of curvature of the upper curve, (b) is the radius of curvature of the lower curve, and (c) is the variation ⊿t of the center thickness of the blank after springback;

[0059] Figure 4 It is a comparison diagram of the cold extrusion springback prediction results (theoretical results) and actual test results of the tantalum alloy hyperbolic component in Example 3, where (a) is the radius of curvature ρ of the upper curve after springback 12 , (b) is the radius of curvature ρ of the lower curve after springback 22 , (c) is the variation ⊿t of the center thickness of the blank after springback. Detailed implementation manners

[0060] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the description of the following embodiments is only used to help understand the principle and core idea of the present invention, and does not limit the protection scope of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, improvements made to the present invention without departing from the principle of the present invention also fall within the protection scope of the claims of the present invention.

[0061] Example 1

[0062] A computer-readable storage medium stores a computer program. When a processor executes the program, the following steps are implemented: an input unit for inputting the deformation amount x% of the cold extrusion forming of the tantalum alloy hyperbolic blank; an output unit for outputting calculation results; a display unit for displaying data;

[0063] A data storage unit stores the cold extrusion springback amount calculation models (I), (II), (III) and (IV) of the tantalum alloy hyperbolic blank, where:

[0064] The variation of the center thickness of the blank after cold extrusion springback of the tantalum alloy hyperbolic component

[0065] ⊿t = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 (80 ≥ x ≥ 30)...(I);

[0066] The radius of curvature of the upper curve after springback

[0067] ρ 12 = 151.02333 + 0.045x (50 ≥ x ≥ 30).................................(II);

[0068] The radius of curvature of the upper curve after springback

[0069] ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 (80 ≥ x ≥ 50)................(Ⅲ);

[0070] Radius of curvature of the lower curve after springback

[0071] ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 ×10 -5 (80 ≥ x ≥ 30)..(Ⅳ);

[0072] The control unit implements the following steps:

[0073] When the input deformation x% is read and satisfies 50 ≥ x ≥ 30, execute equations (Ⅰ), (Ⅱ) and (Ⅳ) and output the calculation results;

[0074] When the input deformation x% is read and satisfies 80 ≥ x ≥ 50, execute equations (Ⅰ), (Ⅲ) and (Ⅳ) and output the calculation results;

[0075] When the input deformation x% is read and satisfies x ≤ 30 or x ≥ 80, output "Error" or "Please check the input data".

[0076] Example 2

[0077] A method for constructing a cold extrusion springback prediction (computer) model of a tantalum alloy hyperbolic member, the steps sequentially include:

[0078] Step 1, establish a finite element model for the cold extrusion forming of a tantalum alloy hyperbolic blank based on the Abaqus platform;

[0079] Step 2, according to the finite element model for the cold extrusion forming of the tantalum alloy hyperbolic blank obtained in Step 1, establish a springback finite element model of the tantalum alloy hyperbolic blank;

[0080] Step 3, draw the longitudinal sectional views of the tantalum alloy hyperbolic blank before and after springback at various deformation amounts, and establish a rectangular coordinate system;

[0081] Step 4, in combination with the rectangular coordinate system obtained in Step 3, calculate the change amount Δt of the center thickness of the tantalum alloy hyperbolic blank after springback, the radius of curvature ρ of the upper curve on the longitudinal sectional view after springback 12 , and the radius of curvature ρ of the lower curve on the longitudinal sectional view after springback 22 ;

[0082] Step 5: According to the data obtained in Step 4, construct the springback amount calculation models of Equation (Ⅰ), Equation (Ⅱ), Equation (Ⅲ), and Equation (Ⅳ). When the deformation amount x% satisfies 80≥x≥30, the change amount of the center thickness of the blank after springback

[0083] ⊿t = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 ......(Ⅰ);

[0084] When the deformation amount x% satisfies 50≥x≥30, the radius of curvature of the upper curve after springback

[0085] ρ 12 = 151.02333 + 0.045x........................................(Ⅱ);

[0086] When the deformation amount x% satisfies 80≥x≥50, the radius of curvature of the upper curve after springback

[0087] ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 ..............................(Ⅲ);

[0088] When the deformation amount x% satisfies 80≥x≥30, the radius of curvature of the lower curve after springback

[0089] ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 ×10 -5 .............(Ⅳ);

[0090] Among them, the springback finite element model includes the tantalum alloy hyperboloid blank springback model at 30% deformation amount, the tantalum alloy hyperboloid blank springback model at 40% deformation amount, the tantalum alloy hyperboloid blank springback model at 50% deformation amount, the tantalum alloy hyperboloid blank springback model at 60% deformation amount, the tantalum alloy hyperboloid blank springback model at 70% deformation amount, and the tantalum alloy hyperboloid blank springback model at 80% deformation amount.

[0091] In a preferred application solution, the inner wall and the outer wall of the tantalum alloy hyperboloid blank are both of hemispherical structure.

[0092] Example 3

[0093] A cold extrusion springback prediction method for tantalum alloy hyperbolic components, the steps sequentially include:

[0094] Step A, for tantalum alloy bars with three specifications of φ40mm, φ50mm, and φ60mm, establish a cold extrusion forming finite element model based on the Abaqus platform, and respectively simulate cold extrusion forming at deformation amounts of 30%, 40%, 50%, 60%, 70%, and 80%.

[0095] Step B, export the models obtained in Step A, define predefined field variables, set load boundary conditions, and respectively perform springback simulations on tantalum alloy billets at different deformation amounts.

[0096] Step C, respectively draw the longitudinal sectional views of the tantalum alloy hyperbolic billets before and after springback for all deformation amounts, and establish a rectangular coordinate system.

[0097] Step D, based on the obtained rectangular coordinate system, respectively calculate the center thickness t1 and t2 of the tantalum alloy billet before and after springback for each deformation amount, and the curvature radii ρ 11 and ρ 12 of the upper curve on the longitudinal sectional view, as well as the curvature radii ρ 21 and ρ 22 of the lower curve on the longitudinal sectional view;

[0098] Step E, according to the data obtained in Step D, respectively draw the change diagram of the center thickness change amount ⊿t (⊿t = t2 - t1) of the tantalum alloy billet after springback for each deformation amount, the change diagram of the upper curve curvature radius ρ 12 change diagram, and the change diagram of the lower curve curvature radius ρ 22 change diagram, and fit the curves to obtain the calculation formula for the center thickness change amount ⊿t of the tantalum alloy billet after springback, the calculation formula for the upper curve curvature radius ρ 12 of the longitudinal sectional view after springback, and the calculation formula for the lower curve curvature radius ρ 22 of the longitudinal sectional view after springback, where:

[0099] When the deformation amount x% satisfies 80 ≥ x ≥ 30, the center thickness change amount of the billet after springback

[0100] ⊿t = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 .....(Ⅰ);

[0101] When the deformation amount x% satisfies 50 ≥ x ≥ 30, the upper curve curvature radius after springback

[0102] ρ 12= 151.02333 + 0.045x............................................(Ⅱ);

[0103] When the deformation amount x% satisfies 80 ≥ x ≥ 50, the curvature radius of the upper curve after springback

[0104] ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 ................................(Ⅲ);

[0105] When the deformation amount x% satisfies 80 ≥ x ≥ 30, the curvature radius of the lower curve after springback

[0106] ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 ×10 -5 .......(Ⅳ);

[0107] Step E, predict the cold extrusion springback amount of the tantalum alloy hyperboloid component under the corresponding deformation amount based on the obtained formula.

[0108] Taking tantalum alloy Ta-2.5W (bar) as an example for further illustration. Among them, the yield strength σ of tantalum alloy Ta-2.5W s is 232 MPa, the elastic modulus E is 160 GPa, the Poisson's ratio is 0.35, the diameter is φ50 mm, the convex die curvature radius SR is 150.1 mm, and the concave die curvature radius SR is 131.88 mm. Assuming that the tantalum alloy blank undergoes elastoplastic deformation and the convex and concave dies do not deform. The specific steps are as follows:

[0109] (1) Select tantalum alloy bars with a specification of φ50 mm, establish a cold extrusion forming finite element model based on the Abaqus platform, and perform cold extrusion deformations with deformation amounts of 30%, 40%, 50%, 60%, 70%, and 80% respectively to obtain six models in the extrusion state (under load);

[0110] (2) Export the tantalum alloy hyperboloid forming parts (models) with each deformation amount in step (1), define predefined field variables, set load boundary conditions on the forming parts (also called tantalum alloy blanks), and perform springback simulations of the tantalum alloy blanks with different deformation amounts to obtain Figure 1 the springback finite element models shown, that is, after unloading the load, the schematic diagrams of each model are shown in Figure 1 ;

[0111] (3) Based on the model obtained in step 1 and the springback finite element model obtained in step (2), draw the longitudinal sectional views of the tantalum alloy billet before and after springback under each deformation amount, and establish a rectangular coordinate system, as Figure 2 shown;

[0112] (4) Based on the obtained rectangular coordinate system, calculate the center thickness t1 and t2 of the tantalum alloy billet before and after springback of the tantalum alloy hyperbolic billet under 30% deformation amount, 40% deformation amount, 50% deformation amount, 60% deformation amount, 70% deformation amount, and 80% deformation amount respectively, and the curvature radii ρ 11 and ρ 12 of the upper curve on the longitudinal sectional view, as well as the curvature radii ρ 21 and ρ 22 of the lower curve on the longitudinal sectional view. The corresponding data are shown in Table 1,

[0113] Table 1 Center thickness, upper curve curvature radius, and lower curve curvature radius of the tantalum alloy hyperbolic billet before and after springback under different deformation amounts

[0114]

[0115] (5) According to the obtained data, draw the change amount ⊿t of the center thickness of the tantalum alloy billet after springback, the change diagrams of the upper curve curvature radius before and after springback, and the change diagrams of the lower curve curvature radius before and after springback of the tantalum alloy billet under 30% deformation amount, 40% deformation amount, 50% deformation amount, 60% deformation amount, 70% deformation amount, and 80% deformation amount respectively, as Figure 3 shown,

[0116] Further fit the curves to obtain the theoretical calculation formulas for the change amount ⊿t of the center thickness of the tantalum alloy billet after springback, the upper curve curvature radius ρ 12 and the lower curve curvature radius ρ 22 after springback under each deformation amount as follows;

[0117] When the deformation amount x% satisfies 80≥x≥30, the change amount of the center thickness of the billet after springback

[0118] ⊿t = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 ......(Ⅰ);

[0119] When the deformation amount x% satisfies 50≥x≥30, the upper curve curvature radius after springback

[0120] ρ 12= 151.02333 + 0.045x.........................................(Ⅱ);

[0121] When the deformation amount x% satisfies 80 ≥ x ≥ 50, the curvature radius of the upper curve after springback

[0122] ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 ..............................(Ⅲ);

[0123] When the deformation amount x% satisfies 80 ≥ x ≥ 30, the curvature radius of the lower curve after springback

[0124] ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 × 10 -5 ......(Ⅳ);

[0125] (6) Based on the formulas obtained in step (5), predict the cold extrusion springback amount of the tantalum alloy hyperbolic component under the corresponding deformation amount. For example: during the production process, when the punch curvature radius SR is 150.1 mm and the die curvature radius SR is 131.88 mm, to predict the springback amount of the tantalum alloy hyperbolic blank under a 45% deformation amount, it can be calculated only according to formula (Ⅰ), formula (Ⅱ) and formula (Ⅳ); to predict the springback amount of the tantalum alloy hyperbolic blank under a 75% deformation amount, it can be calculated only according to formula (Ⅰ), formula (Ⅲ) and formula (Ⅳ).

[0126] Result verification: Using tantalum alloy Ta-2.5W (bar) as the original blank, cold extrusion forming of the tantalum alloy hyperbolic component is carried out (punch curvature radius SR150.1mm, die curvature radius SR131.88mm), and extrusion is carried out according to the deformation amounts of 30%, 40%, 50%, 60%, 70%, and 80% respectively. After each extrusion process, the springback amount (test result value) is measured at a fixed point. The springback numerical values are shown in Table 2; the springback amounts corresponding to each deformation amount are calculated according to the formulas corresponding to the solutions in Example 2 or Example 3 (theoretical result values), and the results are shown in Table 2. More specifically, the "theoretical result" in Table 2 is the calculation result based on Formulas (Ⅰ) to (Ⅳ), and the "test result" is obtained by measuring the central thickness of the blank at each deformation amount using a micrometer and measuring the curvature radius of the upper curve and the curvature radius of the lower curve after springback using a coordinate measuring instrument when the deformation amount is 30% to 80%; the error calculation formula for the central thickness change amount ⊿t: │theoretical result - test result│ / test result * 100, (where │theoretical result - test result│ represents the absolute value of the difference between the two); the calculation formula for the difference in the curvature radius of the upper curve: theoretical result - test result; the calculation formula for the difference in the curvature radius of the lower curve: theoretical result - test result.

[0127] Table 2 Comparison of theoretical result values and test result values

[0128]

[0129] Comparing the test results with the theoretical results, it can be seen that the maximum error of the central thickness change amount ⊿t does not exceed 10%, meeting the error requirements allowed in this field. The absolute values of the maximum differences in the curvature radii of the upper and lower curves are both not greater than 0.05mm, proving that the theoretical prediction model is accurate and can effectively predict the springback amount.

Claims

1. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the processor executes the program, the following steps are implemented: An input unit for inputting the deformation amount x% of the cold extrusion forming of the tantalum alloy hyperboloid blank; An output unit for outputting the calculation result; A display unit for displaying data; A data storage unit storing the calculation models of the springback amount of the tantalum alloy hyperboloid blank, namely formulas (Ⅰ), (Ⅱ), (Ⅲ) and (Ⅳ), where: The change amount of the center thickness of the blank after the cold extrusion springback of the tantalum alloy hyperboloid component Δt = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 (80 ≥ x ≥ 30)...(Ⅰ); The radius of curvature of the upper curve after springback ρ 12 = 151.02333 + 0.045x (50 ≥ x ≥ 30).....................................(Ⅱ); The radius of curvature of the upper curve after springback ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 (80 ≥ x ≥ 50)..........................(Ⅲ); The radius of curvature of the lower curve after springback ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 × 10 -5 (80 ≥ x ≥ 30)......(Ⅳ); A control unit implementing the following steps: When the input deformation amount x% read satisfies 50≥x≥30, execute formulas (Ⅰ), (Ⅱ) and (Ⅳ) and output the calculation result; When the input deformation amount x% read satisfies 80≥x≥50, execute formulas (Ⅰ), (Ⅲ) and (Ⅳ) and output the calculation result; When the input deformation amount x% read satisfies x≤30 or x≥80, output "Error" or "Please check the input data".

2. A method for constructing a cold extrusion springback prediction model of a tantalum alloy hyperbolic member, characterized in that The steps sequentially include: Step 1: Establish a finite element model for the cold extrusion forming of the tantalum alloy hyperboloid blank based on the Abaqus platform; Step 2: Establish a springback finite element model of the tantalum alloy hyperboloid blank according to the finite element model for the cold extrusion forming of the tantalum alloy hyperboloid blank obtained in Step 1; Step 3: Draw the longitudinal sectional views of the tantalum alloy hyperboloid blank before and after springback at each deformation amount, and establish a rectangular coordinate system; Step 4: Combine the rectangular coordinate system obtained in Step 3 to calculate the change in the center thickness ⊿t of the tantalum alloy hyperboloid blank after springback under various deformation amounts (⊿t = the center thickness t2 of the tantalum alloy blank after springback - the center thickness t1 of the tantalum alloy blank before springback), the radius of curvature ρ of the upper curve in the longitudinal section diagram after springback 12 , and the radius of curvature ρ of the lower curve in the longitudinal section diagram after springback 22 ; Step 5: According to the data obtained in Step 4, construct the springback amount calculation models of formulas (Ⅰ), (Ⅱ), (Ⅲ), (Ⅳ). When the deformation amount x% satisfies 80≥x≥30, the change amount of the center thickness of the blank after springback ⊿t = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 ................(Ⅰ); When the deformation amount x% satisfies 50≥x≥30, the radius of curvature of the upper curve after springback ρ 12 = 151.02333 + 0.045x................................................(Ⅱ); When the deformation amount x% satisfies 80≥x≥50, the radius of curvature of the upper curve after springback ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 .....................................(Ⅲ); When the deformation amount x% satisfies 80≥x≥30, the radius of curvature of the lower curve after springback ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 × 10 -5 .....................(Ⅳ).

3. The method according to claim 2, wherein: The springback finite element model includes the springback models of the tantalum alloy hyperboloid blank at 30% deformation amount, 40% deformation amount, 50% deformation amount, 60% deformation amount, 70% deformation amount, and 80% deformation amount.

4. The method according to claim 3, wherein: The inner wall and outer wall of the tantalum alloy hyperboloid blank are both hemispherical structures.

5. A method for predicting the springback of a tantalum alloy hyperbolic component during cold extrusion, characterized in that The steps sequentially include: Step A: For tantalum alloy bars with three specifications of φ40mm, φ50mm, and φ60mm, establish a finite element model for cold extrusion forming based on the Abaqus platform, and respectively simulate cold extrusion forming at 30% deformation amount, 40% deformation amount, 50% deformation amount, 60% deformation amount, 70% deformation amount, and 80% deformation amount; Step B: Export the models obtained in Step A at each deformation amount, define predefined field variables, set load boundary conditions, and respectively perform springback simulations of the tantalum alloy blank at different deformation amounts; Step C: Draw the longitudinal sectional views of the tantalum alloy hyperboloid blank before and after springback at all deformation amounts, and establish a rectangular coordinate system; Step D: Based on the obtained rectangular coordinate system, calculate the center thickness t1 and t2 of the tantalum alloy billet before and after springback of the tantalum alloy hyperboloid billet under each deformation amount, and the curve curvature radius ρ 11 and ρ 12 , and the curve curvature radius ρ 21 and ρ 22 ; Step E: According to the data obtained in Step D, respectively plot the variation diagram of the center thickness variation Δt of the tantalum alloy billet after springback under each deformation amount, the variation diagram of the upper curve radius of curvature ρο, 12 the variation diagram of the lower curve radius of curvature ρ 22 o, and fit the curves to obtain the calculation formula for the center thickness variation Δt of the tantalum alloy billet after springback, the calculation formula for the upper curve radius of curvature ρο of the longitudinal section diagram after springback, 12 and the calculation formula for the lower curve radius of curvature ρ 22 o of the longitudinal section diagram after springback, where: When the deformation amount x% satisfies 80 ≥ x ≥ 30, the change amount of the center thickness of the blank after springback Δt = -0.01988 + 0.00464x - 1.21659x 2 ×10 -4 + 1.01185x 3 ×10 -6 ................(Ⅰ); When the deformation amount x% satisfies 50 ≥ x ≥ 30, the curvature radius of the upper curve after springback ρ 12 = 151.02333 + 0.045x................................................(Ⅱ); When the deformation amount x% satisfies 80 ≥ x ≥ 50, the curvature radius of the upper curve after springback ρ 12 = 145.5735 + 0.29285x - 0.00277x 2 .....................................(Ⅲ); When the deformation amount x% satisfies 80 ≥ x ≥ 30, the curvature radius of the lower curve after springback ρ 22 = 138.24476 - 0.43546x + 0.01009x 2 - 6.62037x 3 × 10 -5 ....................(Ⅳ); Step E, predicting the cold extrusion springback amount of the tantalum alloy hyperbolic component under the corresponding deformation amount based on the obtained formula.

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