Prediction method of folding defects in aluminum alloy forgings

Abstract

An embodiment of the present application provides a method for predicting folding defects in aluminum alloy forgings. The method includes: determining the die structure, billet shape, and size based on the aluminum alloy forging; constructing a three-dimensional model that reflects the complete structure of the die and billet based on the die structure and billet shape and size; importing the three-dimensional model into preset simulation software for pre-processing, wherein the pre-processing includes importing material constitutive relations, meshing, and setting forging parameters and boundary conditions; and analyzing the post-processing results output by the preset simulation software to predict the folding position of the aluminum alloy forging, wherein the post-processing results include folding angles, contact points, and metal flow vector diagrams. This method is used to accurately predict the occurrence and final folding position of folds.

Description

Technical Field

[0001] The present application relates to the technical field of forging technology, and in particular to a method for predicting folding defects of aluminum alloy forgings. Background Art

[0002] In modern industrial manufacturing, aluminum alloys are widely used in a wide range of key industries, including aerospace, automotive, and mechanical engineering, thanks to their outstanding comprehensive properties, including lightweight, high strength, and excellent corrosion resistance. However, they suffer from a relatively narrow forging temperature range, high crack sensitivity, strong adhesion between materials, good thermal conductivity, a high coefficient of friction, and poor fluidity. When complex aluminum alloy forgings are produced using high-temperature forging processes, these characteristics can easily lead to serious defects such as folding, cracking, and insufficient filling.

[0003] In the prior art, forging defects are addressed by using finite element analysis to reverse-trace the precision forging process to identify the areas to be optimized in the pre-forging. However, this forging defect location method is still somewhat blind to defect optimization and may result in optimization failure. Summary of the Invention

[0004] The embodiments of the present application provide a method for predicting folding defects in aluminum alloy forgings, so as to achieve the effect of accurately predicting the occurrence of folding and the final folding position.

[0005] In a first aspect, an embodiment of the present application provides a method for predicting folding defects of aluminum alloy forgings, comprising: determining a mold structure, a blank shape, and a size based on the aluminum alloy forging; constructing a three-dimensional model that can reflect the complete structure of the mold and the blank based on the mold structure and the blank shape and size; importing the three-dimensional model into a preset simulation software, defining the material properties of the mold and the blank, and meshing the three-dimensional model to obtain a discretized model; setting the forging parameters in the forging process in the preset simulation software, and determining the boundary conditions; importing the constitutive equation of the aluminum alloy material into the preset simulation software, and associating the constitutive equation with the material properties of the blank; based on the discretized model, combined with the forging parameters and boundary conditions, calling the constitutive equation to calculate the mechanical response of the aluminum alloy material in each unit to obtain a post-processing result; analyzing the post-processing result to predict the folding position of the aluminum alloy forging, wherein the post-processing result includes a folding angle, a contact point, and a metal flow vector diagram.

[0006] In one possible embodiment, the post-processing results output by the preset simulation software are analyzed, including: traversing the regional data set of the aluminum alloy forging through the folding angle command; for any regional data, constructing a folding angle calculation model and performing numerical calculation to obtain a calculation result; if the calculation result exceeds the first range and there is grid distortion, using the contact point to determine whether the mold and the blank at the grid position are not in full contact; if the mold and the blank at the grid position are not in full contact, determining whether there is a confluence phenomenon at the grid position through the metal flow vector diagram; if there is a confluence phenomenon at the grid position, determining that the grid position has folded.

[0007] In one possible implementation, after determining that a fold occurs at a grid position, the method further includes: selecting tracking points within a determined abnormal area according to preset rules; tracking the tracking points in real time, recording the position coordinates of each tracking point at different time steps, and forming continuous motion trajectory data; and determining the final position of the fold based on the final position coordinates of the tracking points after the forging simulation is completed.

[0008] In one possible implementation, the constitutive equation is:

[0009]

[0010] Where, represents the strain rate, σ represents the flow stress, T represents the absolute temperature, Q represents the activation energy, R represents the gas constant, A represents the material constant, α represents the stress level parameter, and n represents the stress exponent.

[0011] In one possible embodiment, the aluminum alloy forging is a suspension wire clamp product forging; accordingly, the method includes: determining by a measuring tool the volume of the suspension wire clamp product forging to be 1.13×10 6 mm 3 ; Cut a billet with a diameter of 80mm and a height of 290mm from the aluminum alloy bar at 130% of its volume, and use a 1600T press to apply pressure to the billet to prepare a suspension wire clamp product forging; select the flash groove according to the tonnage of the press, and determine the bridge height, bridge width, bin depth, bin width and fillet radius of the flash groove to determine the mold structure; construct a three-dimensional model of the suspension wire clamp product forging and the mold; intercept the three-dimensional model of the mold and 1 / 4 of the suspension wire clamp product forging, and import it into the preset simulation software for pre-processing; analyze the post-processing results output by the preset simulation software to predict the folding position of the suspension wire clamp product forging.

[0012] In one possible implementation, the bridge height is 8 mm, the bridge width is 16 mm, the pocket depth is 10 mm, the pocket width is 60 mm, and the fillet radius is 4 mm.

[0013] In one possible embodiment, the pre-processing includes: defining the material properties of the mold as H13 and the material properties of the blank as 6082 aluminum alloy; meshing the three-dimensional model to obtain a discretized model, wherein the number of meshes is 12,000 and the minimum mesh size is 1.14 mm; setting forging parameters during the forging process and determining boundary conditions; importing the constitutive equation of 6082 aluminum alloy and determining the material constant in the constitutive equation to be 8.0087×10 9 , the stress level parameter is 0.0238, the stress exponent is 6.4934, the activation energy is 145997 J / mol, and the gas constant is 8.31 J / (mol·K); based on the discretization model, combined with the forging parameters and boundary conditions, the constitutive equation is called to calculate the mechanical response of the aluminum alloy material in each unit, and the post-processing results are obtained.

[0014] In one possible implementation, the forging parameters are set as follows: forging temperature of 490°C, extrusion speed of 200 mm / s, friction coefficient of 0.3, and die temperature of 250°C.

[0015] In one possible embodiment, the aluminum alloy forging is a rotary forging; accordingly, the method includes: determining the volume of the rotary forging to be 1.41×105mm3 by a measuring tool; cutting a hollow semi-circular arc special-shaped blank with an outer diameter of 45mm, an inner diameter of 35mm and a length of 75mm from an aluminum alloy bar at 140% of the volume, and applying pressure to the hollow semi-circular arc special-shaped blank using a 1000T press to prepare a rotary forging; selecting a flash groove according to the tonnage of the press, determining the bridge height, bridge width, bin depth, bin width and fillet radius of the flash groove to determine the mold structure; constructing a three-dimensional model of the rotary forging and the mold; importing the three-dimensional models of the mold and the rotary forging into a preset simulation software for pre-processing; and analyzing the post-processing results output by the preset simulation software to predict the folding position of the rotary forging.

[0016] In one possible implementation, the bridge portion has a height of 6 mm, a width of 14 mm, a depth of 8 mm, a width of 50 mm, and a fillet radius of 3 mm.

[0017] The method for predicting folding defects in aluminum alloy forgings, provided in an embodiment of the present application, achieves folding defect prediction by determining the die structure, billet shape, and dimensions based on the aluminum alloy forging, constructing a three-dimensional model, importing it into preset simulation software for comprehensive pre-processing, and conducting in-depth analysis of the post-processing results. By predicting folding defects in advance based on the aluminum alloy forging itself and using preset simulation software, it is possible to determine the location of folding and analyze the causes of folding, providing a theoretical basis for subsequent optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0019] Figure 1 A schematic flow chart of a method for predicting folding defects in aluminum alloy forgings provided in an embodiment of the present application;

[0020] Figure 2a A three-dimensional model of the suspension wire clamp product forging provided in an embodiment of the present application;

[0021] Figure 2b A simulation diagram of the pre-processing of the suspension wire clamp mold and 1 / 4 blank provided in the embodiment of the present application;

[0022] Figure 3a This is a diagram of the folding angle of the post-processing forging of the suspension wire clamp product provided in the embodiment of the present application;

[0023] Figure 3b A diagram of post-processing contact points of a forged suspension wire clamp product provided in an embodiment of the present application;

[0024] Figure 3c A mesh diagram showing post-processing of a forged suspension wire clamp product provided in an embodiment of the present application;

[0025] Figure 3d A metal flow vector diagram for the post-processing of the forging of the suspension wire clamp product provided in an embodiment of the present application;

[0026] Figure 4 A schematic diagram of tracking the initial folding point of the suspension wire clamp provided in an embodiment of the present application;

[0027] Figure 5 A schematic diagram of tracking the final folding point of the suspension wire clamp provided in an embodiment of the present application;

[0028] Figure 6 The actual product folding defect position of the suspension wire clamp provided in the embodiment of the present application;

[0029] Figure 7 A two-dimensional schematic diagram of various states during the folding process of the suspension wire clamp provided in an embodiment of the present application;

[0030] Figure 8 A planing diagram in a forging simulation of a suspension wire clamp provided in an embodiment of the present application;

[0031] Figure 9a A three-dimensional model of the rotary forging provided in an embodiment of the present application;

[0032] Figure 9b A simulation diagram of the rotary forging die and billet pre-treatment provided in an embodiment of the present application;

[0033] Figure 10a A diagram of the folding angle of a post-processing rotary forging provided in an embodiment of the present application;

[0034] Figure 10b A diagram of contact points for post-processing of a rotating body provided in an embodiment of the present application;

[0035] Figure 10c A post-processing mesh division diagram of a body of revolution provided in an embodiment of the present application;

[0036] Figure 10d A metal flow vector diagram for post-processing of a rotating body provided in an embodiment of the present application;

[0037] Figure 11 A tracking diagram of the initial folding point of the rotating body after post-processing provided in an embodiment of the present application;

[0038] Figure 12 The final folding pad tracking diagram of the rotary body post-processing provided in the embodiment of the present application;

[0039] Figure 13 The actual product folding defect position of the rotating body provided in the embodiment of the present application;

[0040] Figure 14 A two-dimensional schematic diagram of the folding state of the rotating body provided in an embodiment of the present application;

[0041] Figure 15 This is a planing view of the rotary forging simulation provided in an embodiment of the present application.

[0042] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0043] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0044] To clearly understand the technical solutions of this application, we first provide a detailed introduction to the existing solutions. Aluminum alloys suffer from a narrow forging temperature range, high crack sensitivity, high adhesion, good thermal conductivity, high friction coefficient, and poor fluidity. Consequently, complex aluminum alloy forgings produced through high-temperature forging are prone to defects such as folding, cracking, and insufficient filling. Folding occurs when metals merge together during deformation. It can occur when two (or more) strands of metal merge; it can also occur when a rapid, high-volume flow of a strand of metal carries the surface metal of an adjacent portion with it, causing the two to merge; or it can occur when a portion of metal is locally deformed and pressed into another portion of metal. Folding is related to the shape of the raw material and billet, die design, forming process arrangement, lubrication conditions, and actual forging operations. Folding not only reduces the bearing area of ​​the part but also often becomes a source of fatigue during operation due to stress concentration at this location. For a long time, eliminating localized defects has relied primarily on the theoretical knowledge and experience of designers, requiring on-site die trials and die repairs. This results in inefficient and inaccurate die and billet design, high production costs, and long development cycles. In the prior art, forging defects are addressed by using finite element analysis to reverse-trace the precision forging process to identify the areas to be optimized in the pre-forging. However, this forging defect location method is still somewhat blind to defect optimization and may result in optimization failure.

[0045] To address the above technical issues, the inventors came up with the idea of ​​constructing a three-dimensional model that reflects the complete structure of the mold and billet, and importing it into pre-processing software. This includes importing the material constitutive relationship, dividing the mesh, and setting forging parameters and boundary conditions. The pre-processing results, which include information such as folding angles, contact points, and metal flow vector diagrams output by the pre-processing software, are then analyzed to effectively predict the folding location of aluminum alloy forgings. By using the pre-processing software to predict folding defects in the aluminum alloy forging itself, the location of the fold can be determined, and the cause of the folding can be analyzed, providing a theoretical basis for subsequent optimization.

[0046] Based on the above creative findings, the inventor proposed the technical solution of this application.

[0047] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0048] Figure 1 Schematic diagram of the process of predicting folding defects of aluminum alloy forgings provided in the embodiment of the present application. Figure 1 As shown, the method includes:

[0049] S101: Determine the die structure, billet shape and size based on the aluminum alloy forging.

[0050] Specifically, for complex, large, and axisymmetric aluminum alloy forgings, specialized measurement software is used to accurately determine their volume. To ensure sufficient material for forging, the billet size is typically determined based on a certain proportion of the forging volume, and appropriate aluminum alloy bar stock is cut to serve as the blank. The die structure is determined by the tonnage of the press used. The die structure is constructed by selecting an appropriate flash groove, setting parameters such as the flash groove bridge height, bridge width, chamber depth, chamber width, and fillet radius.

[0051] S102: Construct a three-dimensional model that reflects the complete structure of the mold and the blank according to the mold structure and the shape and size of the blank.

[0052] Specifically, after obtaining the die structure and billet shape and size information, a 3D model is constructed to visually represent the forging scene. Considering that a complete model can be computationally intensive for large forgings, a 3D model is constructed by cutting out portions of the die and billet.

[0053] S103: Importing the three-dimensional model into a preset simulation software, defining the material properties of the mold and the blank, and meshing the three-dimensional model to obtain a discretized model.

[0054] Specifically, in the pre-set simulation software, specify the material types used for the mold and the blank. For example, for the mold, a common material such as H13 is used, with its hardness, thermal conductivity, and elastic modulus set; for the blank, a common material such as 6082 aluminum alloy is used, with its alloy composition, density, and yield strength properties defined. H13 is a hot work die steel.

[0055] Specifically, after importing the completed three-dimensional model of the mold and blank into the preset simulation software, the continuous three-dimensional model is divided into many tiny units by setting appropriate grid parameters. These tiny units constitute a discrete model, allowing the preset simulation software to analyze each independent unit.

[0056] S104: Setting forging parameters in the forging process in the preset simulation software and determining boundary conditions.

[0057] The forging temperature setting affects the fluidity and deformation resistance of the aluminum alloy. The extrusion speed determines how quickly the billet deforms in the die. Excessively high speeds can lead to internal stress concentrations, while too low speeds can affect production efficiency. The friction coefficient reflects the friction between the billet and the die, which consumes energy and affects metal flow. Maintaining the appropriate die temperature prevents overheating or underheating, which can shorten the die's lifespan and lead to quality issues in the forged parts.

[0058] Specifically, in actual forging, dies are typically fixed in place. This is reflected in simulations as displacement constraints on certain parts of the die, preventing them from moving in specific directions. Contact exists between the blank and the die, requiring the definition of a contact type, such as binding or frictional contact.

[0059] S105: Importing the constitutive equation of the aluminum alloy material into the preset simulation software, and associating the constitutive equation with the material properties of the blank.

[0060] Among them, the mechanical behavior of aluminum alloy materials under complex forging conditions is described by their constitutive equation.

[0061] Specifically, the constitutive equation of the aluminum alloy material is imported into the preset simulation software, and the parameters in the equation are closely associated with the defined material properties of the billet, so that the preset simulation software can simulate its mechanical response under different forging conditions based on the actual material properties of the billet. The constitutive equation is:

[0062]

[0063] Where, represents the strain rate, σ represents the flow stress, T represents the absolute temperature, Q represents the activation energy, R represents the gas constant, A represents the material constant, α represents the stress level parameter, and n represents the stress exponent.

[0064] S106: Based on the discretized model, combined with forging parameters and boundary conditions, the constitutive equation is called to calculate the mechanical response of the aluminum alloy material in each unit to obtain the post-processing results.

[0065] Specifically, for each tiny unit in the discretized model, the constitutive equation is used to calculate the mechanical response of the aluminum alloy material in the unit, such as flow stress, based on the actual working conditions such as temperature and strain rate at the unit's location. The post-processing results are obtained by calculating and integrating the mechanical responses of all units.

[0066] S107: Analyze post-processing results to predict the folding position of the aluminum alloy forging, wherein the post-processing results include folding angles, contact points, and metal flow vector diagrams.

[0067] Specifically, after the preset simulation software is completed, a series of post-processing results will be output, and the folding position of the aluminum alloy forging will be analyzed and predicted through steps Sa1 to Sa5.

[0068] Sa1: Traverse the regional data set of aluminum alloy forgings using the Fold Angle command.

[0069] Among them, in the preset simulation software, the folding angle command is a tool specifically used to detect the folding angle conditions of various areas in the aluminum alloy forging model.

[0070] Specifically, when the fold angle command is activated, the preset simulation software automatically scans the entire aluminum alloy forging to generate a regional data set. This regional data set contains relevant information about every tiny area in the forging model, including the deformation history, stress and strain state of that area during the forging process.

[0071] Sa2: For any area data, construct a folding angle calculation model and perform numerical calculations to obtain the calculation results.

[0072] Specifically, for each area of ​​data traversed, the preset simulation software constructs a fold angle calculation model based on specific algorithms and physical principles. Taking into account the metal flow path, degree of deformation, and interaction with surrounding areas during the forging process, this model performs numerical calculations to determine the fold angle value for that area under specific forging conditions.

[0073] Sa3: If the calculation result exceeds the first range and there is mesh distortion, the contact point is used to determine whether the mold and the blank are not in full contact at the mesh position.

[0074] Among them, the distortion of the grid means that during the forging process, the metal deformation in this area is more severe and exceeds the normal range.

[0075] Specifically, when the calculated folding angle value exceeds a pre-set first range and there is grid distortion in that area, it indicates an abnormality in that area. At this point, the contact point function in the preset simulation software is used to determine whether the mold and the blank are in full contact at the corresponding grid position. If the mold and the blank are not in full contact at that grid position, it indicates the presence of a "cavity" or gap, which is a key sign that folding defects are likely to occur.

[0076] Sa4: If the mold and blank are not in complete contact at the grid position, the metal flow vector diagram is used to determine whether there is confluence at the grid position.

[0077] Among them, the metal flow vector diagram can intuitively show the flow direction and speed of aluminum alloy materials at different positions during the forging process.

[0078] Observing the metal flow vector diagram, if you notice that the top material is flowing downward while the bottom material is flowing upward, this phenomenon of two or more metal streams flowing in opposite directions is called confluence. Confluence is a key characteristic of folding. When metal flows from different directions converge at this point, if the mold does not provide sufficient restraint, it can easily lead to metal accumulation and entanglement, resulting in folding defects.

[0079] Specifically, once it's determined that the die and blank are not fully contacting at a particular grid location, further analysis is performed using the metal flow vector diagram. Observe the metal flow vector diagram near that grid location. If you see material flowing downward at the top and upward at the bottom, this indicates a fold near that grid location.

[0080] Sa5: If there is confluence at a grid location, the grid location is determined to be folded.

[0081] Specifically, when the metal flow vector diagram confirms that there is a confluence phenomenon at a certain grid position, combined with factors such as the abnormal folding angle and incomplete contact between the mold and the blank, it can be determined that a fold has occurred at that grid position.

[0082] In summary, by determining the die structure, billet shape, and dimensions based on the aluminum alloy forging, constructing a 3D model, importing it into pre-configured simulation software for comprehensive pre-processing, and conducting in-depth analysis of the post-processing results, folding defect prediction was achieved. By using pre-configured simulation software to predict folding defects based on the aluminum alloy forging itself, the location of folding can be determined and the cause of folding analyzed, providing a theoretical basis for subsequent optimization.

[0083] After a fold is determined to occur at a certain grid position through analysis, in order to more accurately determine the final position of the fold and understand the dynamic process of fold formation, the method further includes:

[0084] S201: Selecting tracking points in the determined abnormal area according to preset rules.

[0085] Specifically, within the abnormal region where folding has been determined, tracking points are selected according to pre-set rules. For example, multiple tracking points can be selected at regular intervals within the abnormal region using a uniform distribution, or tracking points can be densely selected at key locations where flow changes are drastically, depending on the complexity of the metal flow in that region.

[0086] S202: Track the tracking points in real time, record the position coordinates of each tracking point at different time steps, and form continuous motion trajectory data.

[0087] Specifically, as the forging simulation progresses, the preset simulation software tracks selected tracking points in real time. For each tracking point, the software records its position coordinates at different times, according to a set time step. As the simulation progresses, these position coordinates gradually form a continuous motion trajectory. This data intuitively demonstrates the movement path and changes of the tracking point during the forging process. By analyzing this motion trajectory data, we can clearly understand how the metal flows and ultimately forms folds.

[0088] S203: After the forging simulation is completed, the final position of the fold is determined according to the final position coordinates of the tracking point.

[0089] Specifically, after the entire forging simulation is complete, the final position coordinates of each tracking point are obtained. By analyzing and integrating these final position coordinates, the final location of the fold in the aluminum alloy forging can be accurately determined. Because the tracking points are selected according to reasonable rules within the abnormal area determined to have folded, their final position coordinates accurately reflect the actual location of the fold in the forging.

[0090] In summary, the method of determining the final position of the fold by tracking points can locate the fold more accurately than simply relying on the initial folding judgment results. It provides a more accurate basis for subsequent targeted improvement measures for folding defects, such as optimizing mold design and adjusting forging process parameters, which helps to further improve the quality and production efficiency of aluminum alloy forgings.

[0091] The present application provides a method for predicting folding defects of aluminum alloy forgings that are suspension wire clamp products. The method includes:

[0092] S301: The volume of the suspension wire clamp forging is determined by measuring tools to be 1.13×10 6 mm 3 .

[0093] Specifically, Figure 2a This is a three-dimensional model of the suspension wire clamp product forging provided in the embodiment of this application. Figure 2a As shown in the figure, the suspension wire clamp product is axisymmetric, with a complex structure and a large volume. The volume of the suspension wire clamp product forging is measured by measuring tools to be 1.13×10 6 mm 3 .

[0094] S302: A billet with a diameter of 80 mm and a height of 290 mm is cut from an aluminum alloy bar at 130% of its volume, and a 1600T press is used to apply pressure to the billet to prepare a suspension wire clamp product forging.

[0095] Specifically, 6082 aluminum alloy bars with a diameter of 80 mm and a height of 290 mm were cut out at 130% of the volume of the suspension wire clamp product forging. This product design uses a 1600T press.

[0096] S303: Select a flash groove according to the tonnage of the press, determine the bridge height, bridge width, chamber depth, chamber width and fillet radius of the flash groove, and determine the mold structure.

[0097] Specifically, the flash groove is selected according to the tonnage of the press, and the bridge height of the flash groove is determined to be 8 mm, the bridge width is 16 mm, the bin depth is 10 mm, the bin width is 60 mm, and the fillet radius is 4 mm.

[0098] The bridge's height and width determine the resistance to metal flowing out of the cavity, while the chamber's depth and width collect excess metal. The fillet radius reduces stress concentration and ensures smooth metal flow. By properly determining these parameters, a die structure suitable for forging suspension wire clamps can be constructed.

[0099] S304: Construct a 3D model of the forging and die of the suspension wire clamp product.

[0100] Specifically, after determining the die structure and billet dimensions, 3D modeling software was used to construct a 3D model of the suspension wire clamp forging and die. During the modeling process, the shape and dimensions of the suspension wire clamp forging were precisely mapped based on the actual design drawings and measurement data, including its complex structural features such as lugs and wire troughs. The die cavity, flash grooves, and other key components were modeled in detail. This 3D model visually demonstrates the position and deformation of the billet in the die during the forging process.

[0101] S305: Capture the 3D models of the die and the 1 / 4 suspension wire clamp product forgings and import them into the preset simulation software for pre-processing.

[0102] Due to the large size of the suspension wire clamp forging, simulating the entire model would be computationally intensive, consuming significant time and resources. Therefore, to improve computational efficiency while ensuring the accuracy of the simulation results, a 1 / 4 model cutoff was employed. Figure 2b The simulation diagram of the pre-processing of the suspension clamp mold and 1 / 4 blank provided in the embodiment of the present application is as follows: Figure 2b As shown, 1 is the upper mold of the suspension wire clamp, 2 is the suspension wire clamp blank, and 3 is the lower mold of the suspension wire clamp.

[0103] Specifically, in the 3D modeling software, specific commands and operations are used to intercept the 3D models of the die and the 1 / 4 suspension wire clamp product forging. The intercepted models are then imported into the preset simulation software for pre-processing operations, including Sb1 to Sb5:

[0104] Sb1: Define the material properties of the mold as H13 and the material properties of the blank as 6082 aluminum alloy.

[0105] H13 is a high-quality steel widely used in hot work dies, boasting excellent hot strength, toughness, hardenability, and thermal fatigue resistance. During the forging process, the hot billet continuously exerts pressure and heat on the die. These properties of H13 allow it to withstand high temperatures and pressures, maintaining the die's shape and dimensional stability. 6082 aluminum alloy is used as the billet, due to its high strength, excellent machinability, and corrosion resistance, making it suitable for the manufacture of suspension wire clamp forgings.

[0106] Sb2: Mesh the three-dimensional model to obtain a discretized model, where the number of meshes is 12,000 and the minimum mesh size is 1.14 mm.

[0107] Specifically, the three-dimensional models of the constructed mold and the 1 / 4 suspension wire clamp product forging are imported into the simulation software, and then meshing operations are performed.

[0108] Sb3: Set the forging parameters during the forging process and determine the boundary conditions.

[0109] The forging parameters are set as follows: forging temperature of 490°C, extrusion speed of 200 mm / s, friction coefficient of 0.3 and die temperature of 250°C.

[0110] Specifically, the forging temperature is set to 490°C, which is within the suitable forging temperature range of 6082 aluminum alloy. It can make the aluminum alloy material have good fluidity and facilitate shaping in the mold. The extrusion speed is set to 200mm / s, which can not only ensure production efficiency, but also avoid excessive stress concentration inside the material due to excessive speed, or affect the production cycle due to too slow speed. The friction coefficient is set to 0.3, which reflects the degree of friction between the billet and the mold surface. Friction consumes energy and affects the flow direction and speed of the metal. The mold temperature is set to 250°C. Maintaining the appropriate temperature of the mold helps to stabilize the forging process and prevent the mold from softening due to excessively high temperature or uneven heat transfer between the billet and the mold due to too low temperature.

[0111] Sb4: Import the constitutive equation of 6082 aluminum alloy and determine the material constant in the constitutive equation to be 8.0087×10 9 , the stress level parameter is 0.0238, the stress exponent is 6.4934, the activation energy is 145997 J / mol, and the gas constant is 8.31 J / (mol·K).

[0112] Among them, the constitutive equation is:

[0113]

[0114] Where, represents the strain rate, σ represents the flow stress, T represents the absolute temperature, Q represents the activation energy, R represents the gas constant, A represents the material constant, α represents the stress level parameter, and n represents the stress exponent.

[0115] Specifically, the constitutive equation and its corresponding parameters are accurately imported into the preset simulation software, so that the software can accurately simulate the mechanical response of the blank under different forging conditions based on the actual material properties of the blank.

[0116] Sb5: Based on the discretized model, combined with forging parameters and boundary conditions, the constitutive equation is called to calculate the mechanical response of the aluminum alloy material in each unit to obtain the post-processing results.

[0117] Specifically, based on the pre-meshed discretized model, combined with the set forging parameters and defined boundary conditions, the software invokes the imported and parameterized constitutive equations for 6082 aluminum alloy. For each tiny element in the discretized model, the constitutive equations are used to calculate the mechanical response of the aluminum alloy within that element, such as flow stress and strain, based on the actual working conditions at that element's location. By calculating and integrating the mechanical responses of all elements, the post-processing results are ultimately obtained.

[0118] S306: Analyze the post-processing results output by the preset simulation software to predict the folding position of the suspension wire clamp product forging.

[0119] Among them, the post-processing results include folding angles, contact points, and metal flow vector diagrams.

[0120] For example, after the pre-processing operation is completed, the post-processing result is opened, and the folding angle command is first turned on to check whether there is a folding angle distortion area in the product area during the forging process.

[0121] Figure 3a This is a diagram of the post-processing folding angle of the suspension wire clamp product forging provided in the embodiment of this application. Figure 3a As shown in the figure, during the forging process, the folding angle distortion occurs on the inner side of the suspension clamp ear, and the value of this area is greater than 270°, which indicates that folding may occur in this area. Figure 3c This is the mesh division diagram for the post-processing of the suspension wire clamp product forging provided in the embodiment of this application. Figure 3c As shown, the mesh inside the suspension clamp ear is distorted. Then open the contact point naming, Figure 3b This is a diagram of the post-processing contact points of the suspension wire clamp product forging provided in the embodiment of this application. Figure 3b As shown, the green dot indicates contact between the blank and the upper die. You can see that the inner side of the suspension clip's lug is not in contact with the upper die, resulting in a "cavity" there. This gap creates the conditions for folding. Finally, open the metal flow vector diagram to view the metal flow direction. Figure 3dThis is the metal flow vector diagram of the post-processing of the suspension wire clamp product forging provided in the embodiment of this application. Figure 3d As shown in the figure, we can see that the material at the top of the ear is flowing downwards, while the material at the bottom is flowing upwards. Therefore, we can conclude that there is a fold at this location.

[0122] Specifically, the location where the fold occurs is tracked. Figure 4 This is a schematic diagram of tracking the initial folding point of the suspension clamp provided in an embodiment of the present application. Figure 5 This is a schematic diagram of tracking the final folding point of the suspension clamp provided in the embodiment of the present application. Figure 5 As shown, the fold was found to remain in the top area of ​​the lug when traced to the end of forging. Figure 6 This is the actual product folding defect location of the suspension wire clamp provided in the embodiment of this application. Figure 6 As shown, folds in the same direction appear on the top of the lugs.

[0123] Figure 7 The arrow in the figure is the direction of metal flow. During the forging process, the material is filled upwards, but when it reaches the flash groove, the material is filled upwards. Figure 7 At a in Figure (a), since there is no support, the material tilts toward the flash groove. When the top of the blank contacts the upper die, as shown in Figure 7 At point b in Figure (a), a "cavity" is formed inside, such as Figure 7 As the upper die continues to press down, the material at the top flows downward and the material at the bottom flows upward, and the two streams converge to produce severe folds, as shown in the figure (c). Figure 7 As shown in point d in Figure (c). Figure 8 The planing diagram in the forging simulation of the suspension wire clamp provided in the embodiment of the present application is as follows: Figure 8 As shown, Figure 8 Figure (a) is a schematic diagram of the initial state of the suspension clamp folding. Figure 8 Figure (b) is a schematic diagram of the intermediate state of the folding of the suspension clamp. Figure 8 Figure (c) is a schematic diagram of the final state of the suspension clamp after folding.

[0124] In summary, the method of determining the final position of the fold by tracking points can locate the fold more accurately, providing a more accurate basis for subsequent targeted improvement measures for folding defects, such as optimizing mold design and adjusting forging process parameters, which will help to further improve the quality and production efficiency of aluminum alloy forgings.

[0125] The present application also provides a method for predicting folding defects in aluminum alloy forgings that are bodies of revolution. The method includes:

[0126] S401: The volume of the rotating forging is determined to be 1.41×10 5 mm 3 .

[0127] Specifically, Figure 9a The three-dimensional model of the rotating body forging provided in the embodiment of the present application. Figure 9a As shown in the figure, the rotating body is divided into two parts: the main body and the semicircular arc stainless steel sheet. It is an axisymmetric product. The volume of the rotating body forging is determined by measuring tools to be 1.41×10 5 mm 3 .

[0128] S402: A hollow semi-circular special-shaped blank with an outer diameter of 45 mm, an inner diameter of 35 mm, and a length of 75 mm is cut out from an aluminum alloy bar at 140% of its volume, and a 1000T press is used to apply pressure to the hollow semi-circular special-shaped blank to prepare a rotary forging.

[0129] Specifically, based on the measured volume of the rotating forging, and taking into account material loss during the forging process and ensuring sufficient material to fill the mold cavity, the billet volume was determined as 140% of the forging volume. After careful calculation, aluminum alloy bars of appropriate specifications were selected. Using cutting equipment, hollow semi-circular shaped billets with an outer diameter of 45mm, an inner diameter of 35mm, and a length of 75mm were cut. The cut hollow semi-circular shaped billets were then placed on a 1000T press for forging.

[0130] S403: Select a flash groove according to the tonnage of the press, determine the bridge height, bridge width, chamber depth, chamber width and fillet radius of the flash groove, and determine the mold structure.

[0131] Specifically, the rotary forging is designed using a 1000T press, and the flash groove is selected according to the tonnage of the press, and the bridge height is determined to be 6mm, the bridge width is 14mm, the bin depth is 8mm, the bin width is 50mm, and the fillet radius is 3mm.

[0132] The bridge's height and width determine the resistance to metal flowing out of the cavity, while the chamber's depth and width collect excess metal. The fillet radius reduces stress concentration and ensures smooth metal flow. By properly determining these parameters, a die structure suitable for forging suspension wire clamps can be constructed.

[0133] S404: Construct a three-dimensional model of the rotating forging and die.

[0134] Specifically, after determining the mold structure and billet dimensions, modeling software was used to construct a 3D model of the rotating forging and mold. During the modeling process, the shape and dimensions of the rotating forging, such as the unique hollow semicircular shape and other key features, were precisely outlined based on actual design drawings and measured data. For the mold, the cavity, flash groove, and other core components were modeled.

[0135] S405: Import the three-dimensional models of the die and the rotating body forging into the preset simulation software for pre-processing.

[0136] Specifically, due to the simple structure and small size of the rotating forging, the complete model is imported into the preset simulation software for pre-processing. There is a semi-circular arc steel sheet on the top of the rotating forging, which is designed to be completed in two forgings. The product is first pre-forged to form, and then the steel sheet is added after the final forging. Figure 9b The simulation diagram of the rotary forging die and billet pre-processing provided in the embodiment of the present application is as follows: Figure 9b As shown, 4 is the upper mold of the rotating body, 5 is the rotating body blank, and 6 is the lower mold of the rotating body.

[0137] Specifically, the blank material is determined to be 6082 aluminum alloy, the mold material is H13, the material properties are imported into the 3D model, the mesh size is divided into 15000, the minimum mesh size is 1.42mm, and the constitutive equation is

[0138]

[0139] Where, represents strain rate, σ represents flow stress, T represents absolute temperature, Q represents activation energy 145997 J / mol, R represents gas constant 8.31 J / (mol·K), and A represents material constant 8.0087×10 9 , α represents the stress level parameter 0.0238, and n represents the stress exponent 6.4934.

[0140] Specifically, the forging parameters were set to include a forging temperature of 490°C, an extrusion speed of 200 mm / s, a friction coefficient of 0.3, and a die temperature of 250°C.

[0141] S406: Analyze the post-processing results output by the preset simulation software to predict the folding position of the rotary forging.

[0142] Specifically, after the pre-processing operation is completed, open the post-processing results, first turn on the folding angle command, and observe whether there is a folding angle distortion area in the product area during the forging process.

[0143] For example, Figure 10a This is a diagram of the post-processing folding angle of the rotary forging provided in the embodiment of the present application. Figure 10aAs shown in the figure, during the forging process, the folding angle distortion occurs at the bottom of the groove of the rotating body, and the value of this area is greater than 270°, which indicates that folding may occur in this area. Figure 10c This is the post-processing grid division diagram of the rotation body provided in the embodiment of the present application. Figure 10c As shown in the figure, the mesh at the bottom of the groove of the rotating body is distorted. Then open the contact point command, Figure 10b This is a diagram of the post-processing contact points of the rotating body provided in the embodiment of the present application. Figure 10b As shown, the blue point indicates the contact between the blank and the lower die. It can be seen that there is no contact with the lower die in this area. There is a "cavity" here, and this gap creates conditions for folding. Finally, open the metal flow vector diagram to view the metal flow direction of the material. Figure 10d The metal flow vector diagram of the rotary body post-processing provided in the embodiment of the present application. Figure 10d As shown, this area has a stepped morphology and the metal converges on the inner side. Therefore, it can be determined that a fold occurs at this location and point tracking is performed at this location. Figure 11 This is the initial folding point tracking diagram for the post-processing of the rotating body provided in the embodiment of the present application. Figure 12 This is the final folding pad tracking diagram for the post-processing of the rotating body provided in the embodiment of the present application. Figure 12 As shown, the fold was found to remain inside the groove when traced to the end of forging. Figure 13 The actual product folding defect position of the rotating body provided in the embodiment of this application. Figure 13 As shown, folds occur at the same location. Figure 14 The two-dimensional schematic diagram of the folding state of the rotating body provided in the embodiment of the present application. In the final forging, due to the presence of the semi-circular arc steel sheet, the pre-forging blank and the upper die have areas that need to be filled, such as Figure 14 As shown in f in Figure (a), the material at the top of the inner rotating body flows here, and a "cavity" appears inside the inner rotating body groove as shown in Figure 14 As shown in Figure (b) e, as the upper mold continues to press down, the material flow on both sides of the step position produces severe folds, where the arrow direction is the direction of metal flow, and the folds produced are as follows Figure 14 As shown at h in Figure (c). Figure 15 This is a planing diagram in the rotary forging simulation provided in the embodiment of the present application. Figure 15 As shown, Figure 15 Figure (a) is a schematic diagram of the initial state of the folding of the rotating body. Figure 15 Figure (b) is a schematic diagram of the intermediate state of the rotating body folding. Figure 15 Figure (c) is a schematic diagram of the final state of the rotating body after folding.

[0144] In summary, the method of determining the final position of the fold by tracking points can locate the fold more accurately, providing a more accurate basis for subsequent targeted improvement measures for folding defects, such as optimizing mold design and adjusting forging process parameters, which will help to further improve the quality and production efficiency of aluminum alloy forgings.

[0145] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A method for predicting folding defects of aluminum alloy forgings, characterized in that: include: Determining the die structure, blank shape and size according to the aluminum alloy forging; Constructing a three-dimensional model reflecting the complete structure of the mold and the blank according to the mold structure and the shape and size of the blank; Importing the three-dimensional model into a preset simulation software, defining the material properties of the mold and the blank, and meshing the three-dimensional model to obtain a discretized model; Setting forging parameters during the forging process in the preset simulation software and determining boundary conditions; Importing the constitutive equation of the aluminum alloy material into the preset simulation software, and associating the constitutive equation with the material properties of the blank; Based on the discretization model, combined with the forging parameters and the boundary conditions, the constitutive equation is called to calculate the mechanical response of the aluminum alloy material in each unit to obtain a post-processing result; The post-processing results are analyzed to predict the folding position of the aluminum alloy forging, wherein the post-processing results include folding angles, contact points, and metal flow vector diagrams.

2. The method according to claim 1, characterized in that The analyzing the post-processing results output by the preset simulation software includes: Traversing the regional data set of the aluminum alloy forging by using a fold angle command; For any area data, a folding angle calculation model is constructed and numerical calculations are performed to obtain the calculation results; If the calculation result exceeds the first range and there is grid distortion, using the contact point to determine whether the mold and the blank are not in complete contact at the grid position; If the mold and the blank at the grid position are not in complete contact, determining whether there is a confluence phenomenon at the grid position by using the metal flow vector diagram; If a confluence phenomenon exists at the grid position, it is determined that a fold occurs at the grid position.

3. The method according to claim 2, characterized in that After determining that the grid position is folded, the method further includes: In the identified abnormal area, tracking points are selected according to preset rules; Track the tracking points in real time, record the position coordinates of each tracking point at different time steps, and form continuous motion trajectory data; After the forging simulation is finished, the final position of the fold is determined according to the final position coordinates of the tracking point.

4. The method according to claim 1, wherein The constitutive equation is: Where, represents the strain rate, σ represents the flow stress, T represents the absolute temperature, Q represents the activation energy, R represents the gas constant, A represents the material constant, α represents the stress level parameter, and n represents the stress exponent.

5. The method according to claim 1, wherein The aluminum alloy forging is a suspension wire clamp product forging; Accordingly, the method comprises: The volume of the suspension clamp forging was determined to be 1.13×10 6 mm 3 ; Cutting a billet with a diameter of 80 mm and a height of 290 mm from an aluminum alloy bar at 130% of the volume, and applying pressure to the billet using a 1600T press to prepare the suspension wire clamp product forging; Selecting a flash groove according to the tonnage of the press, determining the bridge height, bridge width, chamber depth, chamber width, and fillet radius of the flash groove to determine the mold structure; Constructing a three-dimensional model of the suspension wire clamp product forging and the die; Cutting off the three-dimensional model of the die and 1 / 4 of the suspension wire clamp product forging, and importing it into the preset simulation software for pre-processing; The post-processing results output by the preset simulation software are analyzed to predict the folding position of the suspension wire clamp product forging.

6. The method according to claim 5, characterized in that The bridge portion height is 8 mm, the bridge portion width is 16 mm, the bin portion depth is 10 mm, the bin portion width is 60 mm, and the fillet radius is 4 mm.

7. The method according to claim 5, characterized in that The pre-treatment includes: The material property of the mold is defined as H13, and the material property of the blank is defined as 6082 aluminum alloy; Meshing the three-dimensional model to obtain a discretized model, wherein the number of meshes is 12,000 and the minimum mesh size is 1.14 mm; Setting the forging parameters during the forging process and determining the boundary conditions; The constitutive equation of the 6082 aluminum alloy is introduced, and the material constant in the constitutive equation is determined to be 8.0087×10 9 , the stress level parameter is 0.0238, the stress exponent is 6.4934, the activation energy is 145997 J / mol, and the gas constant is 8.31 J / (mol·K); Based on the discretization model, combined with the forging parameters and the boundary conditions, the constitutive equation is called to calculate the mechanical response of the aluminum alloy material in each unit to obtain a post-processing result.

8. The method according to claim 7, characterized in that The forging parameters were set as follows: forging temperature of 490°C, extrusion speed of 200 mm / s, friction coefficient of 0.3 and die temperature of 250°C.

9. The method according to claim 1, characterized in that The aluminum alloy forging is a body of revolution forging; Accordingly, the method comprises: The volume of the rotating forging was determined to be 1.41×10 5 mm 3 ; Cutting a hollow semi-circular arc shaped blank with an outer diameter of 45 mm, an inner diameter of 35 mm, and a length of 75 mm from an aluminum alloy bar at 140% of the volume, and applying pressure to the hollow semi-circular arc shaped blank using a 1000T press to prepare the rotary forging; Selecting a flash groove according to the tonnage of the press, determining the bridge height, bridge width, chamber depth, chamber width, and fillet radius of the flash groove to determine the mold structure; Constructing a three-dimensional model of the rotary forging and the die; Importing the three-dimensional models of the die and the rotary forging into the preset simulation software for pre-processing; The post-processing results output by the preset simulation software are analyzed to predict the folding position of the rotary forging.

10. The method according to claim 9, characterized in that The bridge portion has a height of 6 mm, a width of 14 mm, a depth of 8 mm, a width of 50 mm, and a fillet radius of 3 mm.

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