Method for predicting folding defects of aluminum alloy forgings

Abstract

The embodiment of the invention provides a method for predicting folding defects of an aluminum alloy forge piece. The method comprises the following steps: determining a die structure and blank shape and size according to an aluminum alloy forging; according to the mold structure and the shape and size of the blank, a three-dimensional model capable of reflecting the complete structure of the mold and the blank is constructed; importing the three-dimensional model into preset simulation software for pretreatment, wherein the pretreatment comprises importing a material constitutive relation, dividing grids and setting forging parameters and boundary conditions; a post-processing result output by the preset simulation software is analyzed to predict the folding position of the aluminum alloy forge piece, and the post-processing result comprises the folding angle, the contact point and the metal flow vector diagram. The method is used for achieving the effect of accurately predicting folding generation and final folding positions.

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 the field of modern industrial manufacturing, aluminum alloys have been widely used in many key industries such as aerospace, automobile manufacturing, and mechanical engineering due to their excellent comprehensive properties, such as light weight, high strength, and good corrosion resistance. However, their forging temperature range is relatively narrow, they are highly crack-sensitive, have strong adhesion between materials, and have good thermal conductivity, a large friction coefficient, and poor fluidity. When high-temperature forging processes are used to prepare aluminum alloy forgings with complex structures, these characteristics can easily lead to serious defects such as folding, cracking, and insufficient filling.

[0003] In the prior art, the processing of forging defects is to use the finite element analysis method to reversely track the precision forging to obtain the area to be optimized of the pre-forging. However, this forging defect location method is still somewhat blind to defect optimization and there is a possibility of optimization failure. Summary of the invention

[0004] The embodiment of the present application provides a method for predicting folding defects of 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 according to the aluminum alloy forging; constructing a three-dimensional model that can reflect the complete structure of the mold and the blank according to 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 forging parameters in the forging process in the preset simulation software, and determining boundary conditions; importing a 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, in combination 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 implementation, 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 a possible implementation, after determining that a fold occurs at a grid position, the method further includes: selecting tracking points in 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; after the forging simulation is completed, determining the final position of the fold according to the final position coordinates of the tracking points.

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

[0009]

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

[0011] In one possible implementation, the aluminum alloy forging is a suspension wire clamp product forging; accordingly, the method comprises: determining by a measuring tool that the volume of the suspension wire clamp product forging is 1.13×10 6 mm 3 ; Cut out 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 a possible implementation, the bridge height is 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.

[0013] In a possible implementation, 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 the forging parameters during the forging process and determining the boundary conditions; importing the constitutive equation of the 6082 aluminum alloy, and determining that the material constant in the constitutive equation is 8.0087×109, the stress level parameter is 0.0238, the stress exponent is 6.4934, the activation energy is 145997 KJ / mol, and the gas constant is 8.31 J / (mol·K); based on the discretized 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 to obtain the post-processing results.

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

[0015] In one possible embodiment, the aluminum alloy forging is a rotary forging; accordingly, the method includes: determining that the volume of the rotary forging is 1.41×105mm3 by a measuring tool; cutting out a hollow semi-circular arc 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 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 model of the mold and the rotary forging into a preset simulation software for pre-processing; analyzing the post-processing results output by the preset simulation software to predict the folding position of the rotary forging.

[0016] In a 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 aluminum alloy forging folding defect prediction method provided in the embodiment of the present application realizes the prediction of folding defects by determining the die structure, blank shape and size according to the aluminum alloy forging, constructing a three-dimensional model and importing it into the preset simulation software for comprehensive pre-processing, and deeply analyzing the post-processing results. Starting from the aluminum alloy forging itself, the folding defect is predicted in advance with the help of the preset simulation software, the location where the folding occurs can be determined, and the cause of the folding can be analyzed to provide 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 diagram of a process for predicting folding defects of aluminum alloy forgings provided in an embodiment of the present application;

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

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

[0022] Figure 3a A diagram of the post-processing folding angle of the suspension wire clamp product forging provided in an 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 division diagram for post-processing of a suspension wire clamp product forging 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 the 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 view 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 a rotating body forging provided in an embodiment of the present application;

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

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

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

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

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

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

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

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

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

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

[0042] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0043] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0044] In order to clearly understand the technical solution of the present application, the solution of the prior art is first introduced in detail. Aluminum alloy forging has narrow temperature range, strong crack sensitivity, high adhesion, good thermal conductivity, large friction coefficient and poor fluidity. Therefore, when preparing aluminum alloy forgings with complex structures by high temperature forging, defects such as folding, cracking and insufficient filling are prone to occur. Folding is formed by the merging of metals during metal deformation. It can be formed by the merging of two (or more) strands of metal; it can also be formed by the rapid and large flow of a metal that brings the surface metal of the adjacent part to flow, and the two merge; it can also be formed by the local deformation of part of the metal and being pressed into another part of the metal. Folding is related to the shape of the raw materials and blanks, the design of the mold, the arrangement of the forming process, the lubrication conditions and the actual operation of forging. Folding not only reduces the bearing area of ​​the parts, but also often becomes a fatigue source due to the stress concentration here during work. For a long time, the elimination of local defects mainly depends on the theoretical knowledge and experience of designers, requiring on-site mold testing and mold repair, low efficiency and poor precision in mold and blank design, high production cost and long development cycle. In the prior art, the processing of forging defects is to use the finite element analysis method to reversely track the precision forging to obtain the area to be optimized of the pre-forging. However, this forging defect location method is still somewhat blind to defect optimization and there is a possibility of optimization failure.

[0045] In response to the above technical problems, the inventors came up with the idea of ​​constructing a three-dimensional model that can reflect the complete structure of the mold and the blank, and importing it into the preset simulation software for pre-processing, including importing the material constitutive relationship, dividing the grid, and setting the forging parameters and boundary conditions, and using the post-processing results output by the preset simulation software, including the folding angle, contact point, and metal flow vector diagram, to analyze the information, so as to effectively predict the folding position of the aluminum alloy forging. Starting from the aluminum alloy forging itself, the folding defect can be predicted in advance with the help of the preset simulation software, the location where the folding occurs can be determined, and the cause of the folding can be analyzed to provide a theoretical basis for subsequent optimization.

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

[0047] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. 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 The following is a flow chart of a method for predicting folding defects of aluminum alloy forgings provided in an embodiment of the present application. Figure 1 As shown, the method includes:

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

[0050] Specifically, for aluminum alloy forgings with complex structures, large volumes, and axisymmetry, professional measurement software is used to accurately measure their volumes. In order to ensure that there is sufficient material for the billet during forging, the billet size is usually determined based on a certain proportion of the forging volume, and suitable aluminum alloy bars are cut out as billets. The structure of the mold is determined based on the tonnage of the press used, and the appropriate flash groove is selected, and the parameters such as the flash groove bridge height, bridge width, bin depth, bin width, and fillet radius are set to construct the mold structure.

[0051] S102: Construct a three-dimensional model that can reflect 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 needs to be constructed to intuitively display the forging scene. Considering that the full model may result in excessive calculation when the forging volume is large, parts of the die and billet are intercepted to construct the 3D model.

[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 preset simulation software, the material types used for the mold and the blank are clearly defined. For example, for the mold, common materials such as H13 are used, and its hardness, thermal conductivity and elastic modulus are set; for the blank, common materials such as 6082 aluminum alloy are used, and its alloy composition, density and yield strength properties are defined. Among them, H13 is a hot working die steel.

[0055] Specifically, after the constructed three-dimensional model of the mold and blank is imported into the preset simulation software, the continuous three-dimensional model is divided into numerous tiny units by setting appropriate grid parameters. These tiny units constitute a discrete model, so that the preset simulation software can analyze each independent unit.

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

[0057] Among them, the setting of forging temperature affects the fluidity and deformation resistance of aluminum alloy materials. The extrusion speed determines how fast the billet deforms in the die. Too fast speed may cause internal stress concentration in the material, while too slow speed affects production efficiency. The friction coefficient reflects the friction between the billet and the die. Friction consumes energy and affects the direction of metal flow. Maintaining the appropriate temperature of the die can prevent the die from affecting its life or causing quality problems of forgings due to too high or too low temperature.

[0058] Specifically, in actual forging, the die is usually installed in a fixed way, which is reflected in the simulation as displacement constraints on certain parts of the die, making it unable to move in a specific direction. There is a contact relationship between the billet and the die, and the contact type needs to be defined, such as binding contact or friction contact.

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

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

[0062]

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

[0064] S106: Based on the discretization 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, according to 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 the post-processing results to predict the folding position of the aluminum alloy forging, wherein the post-processing results include the folding angle, the contact point, and the metal flow vector diagram.

[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~Sa5.

[0068] Sa1: Traversing the regional data set of aluminum alloy forgings through 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 folding angle command is started, the preset simulation software will automatically scan the regional data set of the entire aluminum alloy forging in sequence. This regional data set covers the relevant information of each tiny area in the forging model, including the deformation history, stress and strain state of the 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 data traversed, the preset simulation software will build a folding angle calculation model based on specific algorithms and physical principles. Taking into account the metal flow path, deformation degree and interaction with surrounding areas in the forging process, the folding angle value of the area under specific forging conditions can be obtained through numerical calculation through this model.

[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 the preset first range and there is a grid distortion phenomenon in the area, it indicates that there is an abnormality in the area. At this time, 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 the grid position, it means that there is a "cavity" or gap here, which is an important sign that folding defects are prone 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 display the flow direction and speed of aluminum alloy materials at different positions during the forging process.

[0078] Among them, by observing the metal flow vector diagram, if it is found that the top material flows downward and the bottom material flows upward at the same time, this phenomenon of two or more metals flowing in opposite directions is called the confluence phenomenon. The confluence phenomenon is an important feature of folding, because when metal flows in different directions converge here, if the mold cannot provide sufficient constraints, it is easy to cause metal accumulation and entanglement, and then form folding defects.

[0079] Specifically, once it is determined that the die and the blank are not in full contact at a certain grid position, the metal flow vector diagram is needed for further analysis. Near the grid position, observe the metal flow vector diagram. If it is found that the top material flows downward and the bottom material flows upward, it indicates that folds have occurred near the grid.

[0080] Sa5: If there is confluence at the grid position, it is determined that the grid position is 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 the incomplete contact between the mold and the blank, it can be determined that folding has occurred at this grid position.

[0082] In summary, by determining the die structure, billet shape and size according to the aluminum alloy forgings, and constructing a three-dimensional model to import the preset simulation software for comprehensive pre-processing, as well as in-depth analysis of the post-processing results, the prediction of folding defects is achieved. Starting from the aluminum alloy forgings themselves, the folding defects are predicted in advance with the help of preset simulation software, the location of the folding can be determined, and the cause of the folding can be analyzed to provide 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, in the abnormal area where folding has been determined, tracking points are selected according to preset rules. For example, a uniform distribution method can be used to select multiple tracking points at a certain interval in the abnormal area, or tracking points can be densely selected at key locations where flow changes drastically according to the complexity of metal flow in the area.

[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, when the forging simulation process is ongoing, the preset simulation software will track the selected tracking points in real time. For each tracking point, the software will record its position coordinates at different times according to the set time step. As the simulation time progresses, these position coordinates gradually form continuous motion trajectory data. These data intuitively show the movement path and changes of the tracking points during the forging process. By analyzing these motion trajectory data, we can clearly understand how the metal flows and eventually 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, when the entire forging simulation process is completed, the final position coordinates of each tracking point are obtained. By analyzing and integrating these final position coordinates, the final position of the fold in the aluminum alloy forging can be accurately determined. Since the tracking points are selected according to reasonable rules in the abnormal area where the fold has been determined to occur, their final position coordinates can accurately reflect the actual position 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. This provides a more accurate basis for taking targeted improvement measures for folding defects, such as optimizing mold design and adjusting forging process parameters, and helps to further improve the quality and production efficiency of aluminum alloy forgings.

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

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

[0093] Specifically, Figure 2a The three-dimensional model of the suspension wire clamp product forging provided in the embodiment of the present 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 was cut out from an aluminum alloy bar at 130% of its volume, and a 1600T press was 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 are cut out at 130% of the volume of the suspension wire clamp product forging. This product is designed using a 1600T press.

[0096] S303: Select the flash groove according to the tonnage of the press, determine the bridge height, bridge width, bin depth, bin width and fillet radius of the flash groove, so as to 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 height and width of the bridge determine the resistance of the metal flowing out of the cavity, the depth and width of the bin are used to collect excess metal, and the setting of the fillet radius can reduce stress concentration and ensure the smoothness of metal flow. By reasonably determining these parameters, a mold structure suitable for forging of suspension wire clamp products can be constructed.

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

[0100] Specifically, after determining the die structure and billet size, the 3D modeling software is used to build the 3D model of the suspension wire clamp product forging and die. During the modeling process, the shape and size of the suspension wire clamp product forging are accurately drawn according to the actual design drawings and measurement data, including its complex structural features, such as lugs, wire grooves and other parts. For the die, its cavity, flash groove and other key components are modeled in detail. By building a 3D model, the position and deformation of the billet in the die during the forging process can be intuitively displayed.

[0101] S305: intercept the three-dimensional model of the die and the 1 / 4 suspension wire clamp product forging, and import it into the preset simulation software for pre-processing.

[0102] Among them, due to the large volume of the suspension wire clamp product forging, if the entire model is simulated and analyzed, the calculation amount will be too large, consuming a lot of time and computing resources. Therefore, in order to improve the calculation efficiency and ensure the accuracy of the simulation results, the method of intercepting 1 / 4 of the model is adopted. Figure 2b The simulation diagram of the suspension wire clamp mold and 1 / 4 blank pre-treatment 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, the 3D models of the die and the 1 / 4 suspension wire clamp product forging are intercepted through specific commands and operations. Then, the intercepted models are imported into the preset simulation software for pre-processing operations, including Sb1~Sb5:

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

[0105] Among them, H13 is a high-quality steel widely used in hot working dies, with good thermal strength, toughness, hardenability and thermal fatigue resistance. During the forging process, the high-temperature billet will continuously exert pressure and heat on the die. These characteristics of H13 material enable it to withstand high temperature and high pressure and maintain the shape and dimensional stability of the die. For the billet, 6082 aluminum alloy is used, which has the characteristics of high strength, good machinability and corrosion resistance, and is suitable for manufacturing suspension wire clamp product forgings.

[0106] Sb2: The three-dimensional model is meshed to obtain a discretized model, in which the number of meshes is 12000 and the minimum mesh size is 1.14 mm.

[0107] Specifically, after the constructed three-dimensional models of the die and the 1 / 4 suspension wire clamp product forging are imported into the simulation software, a meshing operation is performed.

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

[0109] 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.

[0110] Specifically, the forging temperature is set to 490°C, which is within the suitable forging temperature range of 6082 aluminum alloy, which 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 internal stress concentration of the material due to too fast 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 die 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 too high temperature or uneven heat transfer between the billet and the mold due to too low temperature.

[0111] Sb4: The constitutive equation of 6082 aluminum alloy was imported, and the material constant in the constitutive equation was determined to be 8.0087×109, the stress level parameter was 0.0238, the stress exponent was 6.4934, the activation energy was 145997KJ / mol, and the gas constant was 8.31J / (mol·K).

[0112] Among them, the constitutive equation is:

[0113]

[0114] In the formula, represents strain rate, σ represents flow stress, T represents absolute temperature, Q represents activation energy, R represents gas constant, A represents material constant, α represents stress level parameter, and n represents 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 billet under different forging conditions based on the actual material properties of the billet.

[0116] Sb5: Based on the discretization 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 meshed discretized model, combined with the set forging parameters and determined boundary conditions, the software calls the imported and parameterized constitutive equation of 6082 aluminum alloy. 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, strain, etc., according to the actual working conditions of the unit. By calculating and integrating the mechanical responses of all units, the post-processing results are finally 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 a folding angle distortion area appears 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 the present application. Figure 3a As shown, during the forging process, the folding angle distortion occurs on the inner side of the suspension wire 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 a grid division diagram for the post-processing of the suspension wire clamp product forging provided in the embodiment of the present application. Figure 3c As shown in the figure, 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 the present application. Figure 3b As shown, the green dot indicates the contact between the blank and the upper die. It can be seen that the inner side of the hanging wire clip ear does not contact the upper die, so 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. Figure 3dThis is a metal flow diagram of the post-processing forging of the suspension wire clamp product provided in the embodiment of the present application. Figure 3d As shown in the figure, we can see that the material at the top of the ear flows downwards and the material at the bottom flows upwards. Therefore, we can judge that folding occurs at this position.

[0122] Specifically, the locations where folds occur are tracked. Figure 4 A schematic diagram of tracking the initial folding point of the suspension wire 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 wire clamp provided in the embodiment of the present application. Figure 5 As shown, the fold was traced to the end of forging and found to stay in the top area of ​​the lug. Figure 6 This is the actual product folding defect position of the suspension wire clamp provided in the embodiment of the present application. Figure 6 As shown, folds in the same direction appear at the top of the lugs.

[0123] Figure 7 The arrow direction in the figure is the metal flow direction. During the forging process, the material is filled upward, but the material is near the flash groove. Figure 7 At a in Figure (a), due to the absence of support, the material tilts toward the flash groove. When the top of the blank contacts the upper die, Figure 7 At point b in Figure (a), a "cavity" is formed inside, such as Figure 7 The c in Figure (b) is the inner side of the ear of the forged suspension wire clamp. As the upper die continues to press down, the material at the top flows downward and the material at the bottom flows upward. The two streams of material converge to produce severe folds. The folds are as follows: Figure 7 As shown in point d in Figure (c). Figure 8 The planing view 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 wire clamp folding. Figure 8 Figure (b) is a schematic diagram of the intermediate state of the suspension wire clamp folding. 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, adjusting forging process parameters, etc., which will help to further improve the quality and production efficiency of aluminum alloy forgings.

[0125] The embodiment of the present application also provides a method for predicting folding defects of an aluminum alloy forging that is a rotating body forging, the method comprising:

[0126] S401: The volume of the rotating forging is determined by measuring tools 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 arc shaped billet 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 arc shaped billet to prepare a rotary forging.

[0129] Specifically, based on the measured volume of the rotating forging, the material loss during the forging process is fully considered, and the blank is guaranteed to have enough material to fill the mold cavity, so the blank volume is determined by 140% of the forging volume. After careful calculation, the aluminum alloy bar of appropriate specifications is selected, and the cutting equipment is used to cut out the hollow semi-circular special-shaped blank with an outer diameter of 45mm, an inner diameter of 35mm and a length of 75mm. Subsequently, the cut hollow semi-circular special-shaped blank is placed on a 1000T press for forging.

[0130] S403: Select the flash groove according to the tonnage of the press, determine the bridge height, bridge width, bin depth, bin width and fillet radius of the flash groove, so as to 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 height and width of the bridge determine the resistance of the metal flowing out of the cavity, the depth and width of the bin are used to collect excess metal, and the setting of the fillet radius can reduce stress concentration and ensure the smoothness of metal flow. By reasonably determining these parameters, a mold structure suitable for forging of suspension wire clamp products can be constructed.

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

[0134] Specifically, after the mold structure and billet size are determined, the three-dimensional model of the rotating forging and the mold is constructed with the help of modeling software. In the modeling process, the shape and size of the rotating forging are accurately outlined based on the actual design drawings and measured data, such as the unique hollow semicircular arc shape and other key parts. For the mold, its cavity, flash groove and other core components are 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, first pre-forging the product into shape, and then adding the steel sheet to form it after the final forging. Figure 9b The simulation diagram of the rotary forging die and blank pre-treatment 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 is divided into 15000, the minimum mesh size is 1.42 mm, and the constitutive equation is

[0138]

[0139] In the formula, represents strain rate, σ represents flow stress, T represents absolute temperature, Q represents activation energy 145997 KJ / mol, R represents gas constant 8.31 J / (mol·K), A represents material constant 8.0087×109, α represents stress level parameter 0.0238, and n represents 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, Fig.10a This is a diagram of the post-processing folding angle of the rotating body forging provided in the embodiment of the present application. Fig.10aAs shown, during the forging process, 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. Fig.10c This is a post-processing grid division diagram of the rotating body provided in the embodiment of the present application. Fig.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, Fig.10b This is a diagram of the post-processing contact points of the rotating body provided in the embodiment of the present application. Fig.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. Fig.10d The metal flow vector diagram of the rotary body post-processing provided in the embodiment of the present application. Fig.10d As shown, the region has a stepped morphology and the metal converges on the inner side. Therefore, it can be determined that folding occurs at this location and point tracking is performed at this location. Fig.11 The initial folding point tracking diagram of the rotating body post-processing provided in the embodiment of the present application is Fig.12 This is a tracking diagram of the final folding pad after the rotary body processing provided in the embodiment of the present application. Fig.12 As shown, tracking to the end of forging revealed that the fold remained inside the groove. Fig.13 The actual product folding defect position of the rotating body provided in the embodiment of the present application. Fig.13 As shown, folding occurs at the same location. Fig.14 A 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 semicircular arc steel sheet, the pre-forging blank and the upper die have areas that need to be filled, such as Fig.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 Fig.14 As shown in Figure (b) e, as the upper die continues to press down, the material flow on both sides of the step position produces severe folds, where the arrow direction is the metal flow direction, and the resulting folds are as follows Fig.14 As shown at h in Figure (c). Fig.15 This is a planing diagram in the rotary forging simulation provided in the embodiment of the present application. Fig.15 As shown, Fig.15 Figure (a) is a schematic diagram of the initial state of the folding of the rotating body. Fig.15 Figure (b) is a schematic diagram of the intermediate state of the rotating body folding. Fig.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, adjusting forging process parameters, etc., 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 conceive of 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, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for predicting folding defects of aluminum alloy forgings, characterized in that: include: Determine the die structure, blank shape and size according to the aluminum alloy forging; According to the mold structure and the shape and size of the blank, a three-dimensional model that can reflect the complete structure of the mold and the blank is constructed; 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 in 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 a folding angle command; For any area data, a folding angle calculation model is constructed and numerical calculation is 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 full contact at the grid position; If the mold and the blank at the grid position are not in complete contact, judging 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 determined abnormal area, tracking points are selected 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; 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, characterized in that: The constitutive equation is: In the formula, represents strain rate, σ represents flow stress, T represents absolute temperature, Q represents activation energy, R represents gas constant, A represents material constant, α represents stress level parameter, and n represents stress exponent.

5. The method according to claim 1, characterized in that The aluminum alloy forging is a suspension wire clamp product forging; Accordingly, the method comprises: The volume of the suspension clamp product forging was determined by measuring tools 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; Select the flash groove according to the tonnage of the press, determine the bridge height, bridge width, bin depth, bin width and fillet radius of the flash groove, so as 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 height of the bridge portion is 8 mm, the width of the bridge portion is 16 mm, the depth of the bin portion is 10 mm, the width of the bin portion is 60 mm, and the fillet radius is 4 mm.

7. The method according to claim 5, characterized in that The pre-treatment comprises: The material property of the mold is defined as H13, and the material property of the blank is defined as 6082 aluminum alloy; The three-dimensional model is meshed to obtain a discretized model, wherein the number of meshes is 12000 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 145997KJ / mol, and the gas constant is 8.31J / (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 are set as follows: forging temperature is 490°C, extrusion speed is 200 mm / s, friction coefficient is 0.3 and die temperature is 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 rotary forging was determined by measuring tools to be 1.41×10 5 mm 3 ; Cutting out a hollow semi-circular arc shaped billet with an outer diameter of 45 mm, an inner diameter of 35 mm and a length of 75 mm from an aluminum alloy bar stock at 140% of the volume, and applying pressure to the hollow semi-circular arc shaped billet using a 1000T press to prepare the rotary body forging; Select the flash groove according to the tonnage of the press, determine the bridge height, bridge width, bin depth, bin width and fillet radius of the flash groove, so as 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 rotating body 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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