Aluminum alloy forge piece blank structure capable of overcoming insufficient hardenability and design method of aluminum alloy forge piece blank structure

Abstract

The invention relates to the technical field of aeronautical manufacturing, and discloses an aluminum alloy forge piece blank structure capable of overcoming insufficient hardenability and a design method thereof.By conducting blank piece process allowance distribution, the initial blank structure design meets the allowance basic requirement during part design machining, then parametric modeling is conducted, and the blank piece process allowance is obtained; forming a digital simulation structure of the preliminary blank structure; the section thickness gradient design of the blank is carried out according to a digital simulation structure, the thickness reducing groove structure is added, and the section thickness gradient design enables the thickness distribution of the blank at different parts to be more reasonable. According to the method, it can be guaranteed that the maximum heat treatment thickness of an entity is within the hardenability limit thickness of the aluminum alloy material, the hardenability of the material in the quenching process is enhanced, it is guaranteed that the more uniform and thorough through quenching effect can be achieved in the quenching treatment process, the problem that due to insufficient hardenability of the aluminum alloy, the material performance is not uniform is solved, and the service life of the aluminum alloy is prolonged. The final product quality is effectively guaranteed, and the reliability and the service life of the product are improved.

Description

Technical Field

[0001] This invention relates to the field of aerospace manufacturing technology, and discloses an aluminum alloy forging blank structure and its design method for overcoming insufficient hardenability. Background Technology

[0002] In aerospace manufacturing, aluminum alloys are widely used in the design of various structural parts due to their lightweight, high strength, and good processing properties. Forgings, with their streamlined distribution, excellent microstructure, and improved properties after reforging, are particularly suitable for manufacturing important load-bearing structural components. In the production of aluminum alloy forgings, heat treatment of the blanks is usually performed to improve their mechanical properties; quenching is one of the key processes determining their final performance. Traditional aluminum alloy forging blanks have limits on hardenability; for example, the hardenability of 7050 aluminum alloy is around 203 mm, and that of 7A85 aluminum alloy is around 305 mm.

[0003] However, as aerospace structural design increasingly favors integrated structural design for weight reduction and better rigidity, the external dimensions of many important load-bearing structural components have become larger. The thickness of the forging blanks for these structural components often exceeds the limit, resulting in insufficient hardenability of the aluminum alloy, which may lead to uneven material properties and affect the quality of the final product. Summary of the Invention

[0004] The purpose of this invention is to provide a structure and design method for aluminum alloy forging blanks that overcomes insufficient hardenability, thereby avoiding the problem of uneven material properties caused by insufficient hardenability of aluminum alloys, effectively ensuring the quality of the final product, and improving the reliability and service life of the product.

[0005] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows: A method for designing the structure of aluminum alloy forging blanks to overcome insufficient hardenability includes: Based on the processing requirements of the designed parts, the process allowance of the blank of the designed parts is allocated to complete the preliminary blank structure design; Parametric modeling is performed based on the preliminary blank structure to form a digital simulation structure of the preliminary blank structure; The cross-sectional thickness gradient design of the blank is carried out based on the digital simulation structure, and a thickness reduction groove structure is added to the digital simulation structure so that the ratio of the maximum thickness value to the minimum thickness value of the blank along the thickness direction is less than a preset ratio threshold, thereby obtaining the optimized geometric features of the blank.

[0006] Furthermore, the preliminary blank structure design process also includes adapting the material flow lines so that the fiber direction of the preliminary blank structure is parallel to the principal stress direction.

[0007] Furthermore, the method for determining the preset ratio threshold includes: Based on the preliminary blank structure corresponding to the designed part, a thickness reduction groove structure of different sizes is opened in the machining allowance area of ​​the preliminary blank structure; Quenching tests were conducted on preliminary blank structures with different sized reduction groove structures. The tensile strength values ​​of the preliminary blank structures with reduction groove structures were analyzed and obtained. An analysis model for the tensile strength values ​​of the preliminary blank structures based on the ratio of the maximum thickness to the minimum thickness was constructed. Using the tensile strength limit value required by the design part as input, the analysis model is used to analyze and obtain a preset ratio threshold of the ratio of the maximum thickness value to the minimum thickness value corresponding to the tensile strength limit value.

[0008] Furthermore, after obtaining the geometric features of the blank, the optimized blank is analyzed using DEFORM simulation of the forging process to obtain the simulated values ​​of metal flow, temperature field, and stress field of the blank. The final blank structure that is determined to be the aluminum alloy forging blank structure is the one where the simulated values ​​of metal flow are within the preset flow value range, the maximum temperature in the temperature field is not greater than the preset temperature threshold, and the maximum stress in the stress field is not greater than the preset stress threshold.

[0009] Furthermore, the aluminum alloy is an Al-Cu, Al-Mg-Si, or Al-Zn-Mg aluminum alloy.

[0010] Furthermore, the cross-sectional shape of the thickness reduction groove is circular, rectangular, or polygonal.

[0011] To achieve the above-mentioned technical effects, the present invention also provides an aluminum alloy forging blank structure that overcomes insufficient hardenability, wherein the aluminum alloy forging blank structure is obtained by the aforementioned aluminum alloy forging blank structure design method.

[0012] Furthermore, the preset ratio threshold is 3.

[0013] Compared with the prior art, the beneficial effects of the present invention are: the present invention can ensure that the maximum heat treatment thickness of the solid is within the hardenability limit thickness of the aluminum alloy material, enhance the hardenability of the material during the quenching process, ensure a more uniform and thorough hardenability effect during the quenching process, avoid the problem of uneven material properties caused by insufficient hardenability of aluminum alloy, effectively guarantee the quality of the final product, and improve the reliability and service life of the product. Attached Figure Description

[0014] Figure 1 This is a flowchart of the aluminum alloy forging blank structure design method in Example 1; Figure 2 This is a schematic diagram of the front structure of the aluminum alloy forging blank in Example 1 or 2; Figure 3This is a schematic diagram of the back structure of the aluminum alloy forging blank in Example 1 or 2; Figure 4 This is a flowchart of the aluminum alloy forging blank structure design method in Example 2; Among them, 1. aluminum alloy forging blank structure; 2. thickness reduction groove. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0016] Example 1 See Figures 1 to 3 A method for designing the structure of aluminum alloy forging blanks to overcome insufficient hardenability, comprising: Based on the processing requirements of the designed parts, the process allowance of the blank of the designed parts is allocated to complete the preliminary blank structure design; Parametric modeling is performed based on the preliminary blank structure to form a digital simulation structure of the preliminary blank structure; The cross-sectional thickness gradient design of the blank is carried out based on the digital simulation structure, and a thickness reduction groove 2 structure is added to the digital simulation structure so that the ratio of the maximum thickness value to the minimum thickness value of the blank along the thickness direction is less than a preset ratio threshold, thereby obtaining the optimized geometric features of the blank.

[0017] In this embodiment, by reasonably allocating the process allowance of the blank, the preliminary blank structure design meets the basic allowance requirements for machining the designed parts. Then, parametric modeling is carried out based on the preliminary blank structure to form a digital simulation structure of the preliminary blank structure. Based on the digital simulation structure, the cross-sectional thickness gradient design of the blank is carried out, and a thickness reduction groove 2 structure is added. The cross-sectional thickness gradient design can make the thickness distribution of the blank in different parts more reasonable, ensuring that the maximum heat treatment thickness of the solid is within the hardenability limit thickness of the aluminum alloy material, enhancing the hardenability of the material during the quenching process, ensuring a more uniform and thorough hardenability effect during the quenching process, avoiding the problem of uneven material properties caused by insufficient hardenability of the aluminum alloy, effectively ensuring the quality of the final product, and improving the reliability and service life of the product.

[0018] Based on the same inventive concept, this embodiment also provides an aluminum alloy forging blank structure to overcome insufficient hardenability, wherein the aluminum alloy forging blank structure 1 is obtained by the aluminum alloy forging blank structure design method described above.

[0019] The aluminum alloy in this embodiment can be an Al-Cu, Al-Mg-Si, or Al-Zn-Mg alloy. The cross-sectional shape of the thickness reduction groove 2 can be circular, rectangular, polygonal, or other design configurations.

[0020] Example 2 See Figures 2 to 4 This embodiment takes the blank structure design of a certain type of Al-Mg-Si aluminum alloy forging as an example to describe in detail the blank structure design method of the present invention. The specific design method flow is as follows: Step 1: Allocate the process allowance of the blank of the designed part according to the processing requirements of aluminum alloy forging, and adapt the material flow lines so that the fiber direction of the preliminary blank structure is parallel to the principal stress direction, thus completing the preliminary blank structure design. In this embodiment, by rationally allocating the process allowance of the blank, the preliminary blank structure design meets the basic allowance requirements for machining the designed parts. When adapting the material flow lines according to the requirements of the designed parts, the direction of the principal stress that the parts will bear during actual use is fully considered, and the fiber direction of the blank is made parallel to it to maximize the material performance, improve fatigue life and damage tolerance, and achieve the best match between material performance and stress requirements. Making the fiber direction parallel to it can maximize the material performance and reduce the problem of uneven stress distribution caused by unreasonable stress distribution.

[0021] Step 2: Perform parametric modeling based on the preliminary blank structure to form a digital simulation structure of the preliminary blank structure.

[0022] Step 3: Based on the digital simulation structure, design the cross-sectional thickness gradient of the blank and add a thickness reduction groove 2 structure to the digital simulation structure so that the ratio of the maximum thickness value to the minimum thickness value of the blank along the thickness direction is less than a preset ratio threshold, thereby obtaining the optimized geometric features of the blank. In this embodiment, the method for determining the preset ratio threshold includes: 3.1 Based on the preliminary blank structure corresponding to the designed part, thickness reduction grooves 2 of different sizes are opened in the machining allowance area of ​​the preliminary blank structure; 3.2 Conduct quenching tests on preliminary blank structures with different sizes of thickness reduction groove 2, analyze and obtain the tensile strength value of the preliminary blank structure with thickness reduction groove 2, and construct an analysis model for the tensile strength value of the preliminary blank structure based on the ratio of the maximum thickness to the minimum thickness. 3.3 Using the tensile strength limit value required by the design part as input, the analysis model is used to analyze and obtain a preset ratio threshold of the ratio of the maximum thickness value to the minimum thickness value corresponding to the tensile strength limit value.

[0023] As described in this embodiment, the preset ratio threshold is 3:1.

[0024] Step 4: After obtaining the geometric features of the blank, use DEFORM to simulate the forging process and conduct finite element analysis on the optimized blank to obtain the simulated metal flow values, temperature field, and stress field of the blank. The final blank structure determined is the aluminum alloy forging blank structure 1, where the simulated metal flow values ​​are within a preset flow value range (in this embodiment, the simulated metal flow values ​​are less than 50%), the maximum temperature in the temperature field is not greater than a preset temperature threshold (in this embodiment, 423°C), and the maximum stress in the stress field is not greater than a preset stress threshold (in this embodiment, -281MPa). Figure 2 , Figure 3 As shown, where Figure 2 This is a schematic diagram of the front structure of the aluminum alloy forging blank structure 1 obtained in this embodiment. Figure 3 This is a schematic diagram of the back structure of the aluminum alloy forging blank model 1.

[0025] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing the structure of aluminum alloy forging blanks to overcome insufficient hardenability, characterized in that, include: Based on the processing requirements of the designed parts, the process allowance of the blank of the designed parts is allocated to complete the preliminary blank structure design; Parametric modeling is performed based on the preliminary blank structure to form a digital simulation structure of the preliminary blank structure; The cross-sectional thickness gradient design of the blank is carried out based on the digital simulation structure, and a thickness reduction groove structure is added to the digital simulation structure so that the ratio of the maximum thickness value to the minimum thickness value of the blank along the thickness direction is less than a preset ratio threshold, thereby obtaining the optimized geometric features of the blank.

2. The method for designing the structure of aluminum alloy forging blanks according to claim 1, characterized in that, The preliminary blank structure design process also includes adapting the material flow lines so that the fiber direction of the preliminary blank structure is parallel to the principal stress direction.

3. The method for designing the structure of aluminum alloy forging blanks according to claim 1, characterized in that, The method for determining the preset ratio threshold includes: Based on the preliminary blank structure corresponding to the designed part, a thickness reduction groove structure of different sizes is opened in the machining allowance area of ​​the preliminary blank structure; Quenching tests were conducted on preliminary blank structures with different sized reduction groove structures. The tensile strength values ​​of the preliminary blank structures with reduction groove structures were analyzed and obtained. An analysis model for the tensile strength values ​​of the preliminary blank structures based on the ratio of the maximum thickness to the minimum thickness was constructed. Using the tensile strength limit value required by the design part as input, the analysis model is used to analyze and obtain a preset ratio threshold of the ratio of the maximum thickness value to the minimum thickness value corresponding to the tensile strength limit value.

4. The method for designing the structure of aluminum alloy forging blanks according to claim 1, characterized in that, After obtaining the geometric features of the blank, the finite element analysis of the optimized blank is carried out using DEFORM to simulate the forging process, and the simulated values ​​of metal flow, temperature field and stress field of the blank are obtained. The final blank structure that is determined to be the aluminum alloy forging blank structure is the one where the simulated values ​​of metal flow are within the preset flow value range, the maximum temperature in the temperature field is not greater than the preset temperature threshold and the maximum stress in the stress field is not greater than the preset stress threshold.

5. The method for designing the structure of aluminum alloy forging blanks according to claim 1, characterized in that, The aluminum alloy is an Al-Cu, Al-Mg-Si, or Al-Zn-Mg aluminum alloy.

6. The method for designing the structure of aluminum alloy forging blanks according to claim 1, characterized in that, The cross-sectional shape of the thickness reduction groove is circular, rectangular, or polygonal.

7. A blank structure for aluminum alloy forgings that overcomes insufficient hardenability, characterized in that, The aluminum alloy forging blank structure is obtained by the aluminum alloy forging blank structure design method according to any one of claims 1-6.

8. The aluminum alloy forging blank structure for overcoming insufficient hardenability according to claim 7, characterized in that, The preset ratio threshold is 3.

Images