Blanking and forging method and system for Al-Zn-Mg aluminum alloy cast ingot
By performing staged forging deformation on Al-Zn-Mg aluminum alloy ingots, the problems of porosity, shrinkage cavities, and coarse microstructure within the ingots were solved, achieving uniform microstructure and improved performance of the forgings, making them suitable for aerospace and transportation applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-06
- Publication Date
- 2026-03-10
AI Technical Summary
Al-Zn-Mg aluminum alloys are prone to hydrogen absorption during the smelting process, have a wide solidification temperature range, and a slow cooling rate, resulting in metallurgical defects such as loose shrinkage cavities, coarse grains, and compositional segregation in the ingots. Furthermore, the differences in microstructure severely affect their applications.
The method of high-temperature forging with small deformation, followed by low-temperature forging with large deformation, and finally high-temperature forging with large deformation is adopted. Upsetting and drawing deformation is used to eliminate porosity, shrinkage cavities and coarse structure defects in the ingot, thereby achieving uniformity of longitudinal, transverse and vertical structure and properties of the forging.
It eliminates porosity, shrinkage cavities, and coarse microstructure defects in the ingot, improves the overall performance of the forging, reduces anisotropy, and achieves uniformity of microstructure and improved performance.
Smart Images
Figure CN121624341A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of aluminum alloy hot working, and particularly relates to a method and system for cogging forging of Al-Zn-Mg aluminum alloy ingot. BACKGROUND
[0002] As a heat treatment strengthening alloy, Al-Zn-Mg aluminum alloy not only has good hot deformation performance, but also can obtain tensile strength higher than 500 MPa through dispersing MgZn2 nanophase. Meanwhile, Al-Zn-Mg aluminum alloy also has advantages such as low density, excellent weldability, good stress corrosion cracking resistance, etc., so that it becomes an indispensable key material in modern industry, especially in the fields of aerospace and transportation.
[0003] However, in the smelting process of Al-Zn-Mg aluminum alloy, the molten liquid is easy to absorb hydrogen, the solidification temperature range is wide, and the cooling rate is slow, which finally leads to the existence of metallurgical defects such as porosity shrinkage, coarse grains and composition segregation in the ingot. At the same time, due to the solidification temperature gradient, chemical composition segregation, cooling rate difference, etc., the Al-Zn-Mg aluminum alloy ingot also has organization differences such as surface fine grain zone, subsurface columnar grain zone, center equiaxed grain zone, etc., which causes large performance difference between the surface and the center of the ingot, and seriously restricts the application of Al-Zn-Mg aluminum alloy. SUMMARY
[0004] The application provides a method and system for cogging forging of Al-Zn-Mg aluminum alloy ingot, which selects Al-Zn-Mg aluminum alloy ingot as raw material, and eliminates the metallurgical defects such as porosity shrinkage and coarse structure in the Al-Zn-Mg aluminum alloy ingot through high-temperature small deformation forging, low-temperature large deformation forging and finally high-temperature large deformation forging, so as to realize the uniformity of the longitudinal, transverse and high direction organization and performance of the Al-Zn-Mg aluminum alloy forging. The technical scheme is as follows: In a first aspect, a method for cogging forging of Al-Zn-Mg aluminum alloy ingot is provided, which comprises: Step 1: performing upsetting-drawing deformation of the Al-Zn-Mg aluminum alloy ingot for 1-2 heating times at a preset temperature and a preset deformation amount; Step 2: performing upsetting-drawing deformation of the forging prepared in step 1 for 1-4 heating times at a preset temperature and a preset deformation amount; Step 3: performing upsetting-drawing deformation of the forging prepared in step 2 for 1-2 heating times at a preset temperature and a preset deformation amount, so as to obtain Al-Zn-Mg aluminum alloy forging with good uniformity of organization and performance; The preset temperature in step 1 and step 3 belongs to the same temperature range and is greater than the preset temperature in step 2; The preset deformation amount in step 2 and step 3 belongs to the same deformation amount range and is greater than the preset deformation amount in step 1.
[0005] The temperature range to which the preset temperature in step 1 and step 3 belongs is determined according to the Al-Zn-Mg aluminum alloy forging temperature, which is generally not higher than 15℃ below the eutectic temperature (475℃) point; The deformation amount range to which the preset deformation amount in step 2 and step 3 belongs is determined according to the plastic deformation capacity (deformation amount < 70%) of the Al-Zn-Mg aluminum alloy and the temperature rise effect in the forging process.
[0006] In step 1, the forging temperature is 440℃~460℃, and the forging deformation amount is 30~45%, thereby reducing the risk of surface and core cracking of the Al-Zn-Mg aluminum alloy ingot during the first breakdown forging process, improving the operability of the breakdown forging, and laying a foundation for further forging with high density.
[0007] In step 2, the forging temperature is 400℃~420℃, and the forging deformation amount is 50~60%, so that the coarse eutectic structure at the triangular grain boundary in the Al-Zn-Mg aluminum alloy ingot can be significantly broken under the action of high lattice distortion, and the grains are further refined.
[0008] In step 3, the forging temperature is 440℃~460℃, and the forging deformation amount is 50~60%, in order to promote the dynamic recrystallization behavior of the Al-Zn-Mg aluminum alloy during the forging deformation process and reduce the anisotropy of the forged piece.
[0009] In step 3, the forging temperature is 440℃~460℃, and the forging deformation amount is 50~60%, in order to promote the dynamic recrystallization behavior of the Al-Zn-Mg aluminum alloy during the forging deformation process and reduce the anisotropy of the forged piece.
[0010] In step 3, the forging temperature is 440℃~460℃, and the forging deformation amount is 50~60%, in order to promote the dynamic recrystallization behavior of the Al-Zn-Mg aluminum alloy during the forging deformation process and reduce the anisotropy of the forged piece.
[0011] After the last forging is completed, the forged piece is air-cooled to room temperature, in order to reduce the residual stress in different regions of the Al-Zn-Mg aluminum alloy forging, increase the number of precipitated phases, and thereby ensure the comprehensive performance of the Al-Zn-Mg aluminum alloy.
[0012] Optionally, the Al-Zn-Mg aluminum alloy ingot is a 7A85 aluminum alloy ingot, a 7050 aluminum alloy ingot or a 7075 aluminum alloy ingot.
[0013] In a second aspect, a system for the Al-Zn-Mg aluminum alloy ingot breakdown forging method of any one of the first aspect is provided, comprising a hydraulic press, an anvil and a fixture, The hydraulic press is used for applying compressive stress to the Al-Zn-Mg aluminum alloy ingot, The anvil is used for supporting and transmitting compressive stress to the Al-Zn-Mg aluminum alloy ingot, The fixture is used for positioning, clamping and turning the Al-Zn-Mg aluminum alloy ingot during the forging process.
[0014] The present application has at least the following advantages: The Al-Zn-Mg aluminum alloy ingot breakdown forging method and system of the present application can improve the plastic deformation capacity of the Al-Zn-Mg aluminum alloy ingot, reduce the risk of surface and core cracking during the first breakdown forging process, gradually improve the density of the alloy ingot, and improve the further forging deformation capacity of the alloy.
[0015] In summary, the Al-Zn-Mg aluminum alloy ingot breakdown forging method and system of the present application can eliminate the metallurgical defects such as porosity and shrinkage cavity in the Al-Zn-Mg aluminum alloy ingot, realize the refinement of the longitudinal, transverse and high direction of the Al-Zn-Mg aluminum alloy forging, and improve the comprehensive performance and reduce the anisotropy of the forging. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 The microstructure of the 7A85 aluminum alloy breakdown forging prepared for the first embodiment of the present application is shown in the figure; Figure 2 The microstructure of the 7050 aluminum alloy breakdown forging prepared for the second embodiment of the present application is shown in the figure; Figure 3 The microstructure of the 7075 aluminum alloy breakdown forging prepared for the third embodiment of the present application is shown in the figure; Figure 4 The flowchart of the Al-Zn-Mg aluminum alloy ingot breakdown forging method of the present application is shown in the figure. DETAILED DESCRIPTION
[0017] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present application.
[0018] The features and illustrative embodiments of various aspects of the present application will be described below in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one of ordinary skill in the art that the present application can be practiced without some of these specific details. The following description of embodiments is merely exemplary in nature and is intended to provide a better description of the application. The present application is not limited to any particular setting or method set forth below, but covers any modifications, equivalents, and alternatives of structures, methods, devices, etc. without departing from the spirit of the present application. In the drawings and the following description, well-known structures and techniques are not shown to avoid unnecessary obscuring the present application.
[0019] It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict, and each embodiment can be mutually referenced and quoted.
[0020] The present application will be described in detail below in combination with the accompanying drawings and specific embodiments.
[0021] Based on this, the present application proposes an Al-Zn-Mg aluminum alloy ingot cogging forging method and system, which not only eliminates the metallurgical defects in the Al-Zn-Mg aluminum alloy ingot, but also ensures the uniformity of the structure and performance of the Al-Zn-Mg aluminum alloy forging in the longitudinal, transverse and high directions.
[0022] The implementation process of the present application is as follows: Step 1, 1~2 high-temperature small-deformation forging Al-Zn-Mg aluminum alloy ingot is used as the raw material, the Al-Zn-Mg aluminum alloy ingot is heated to 440℃~460℃ and kept for heat penetration to the core, and then it is discharged and transferred to the hydraulic machine within 10s~60s for upsetting-drawing forging deformation. Among them, the anvil and the tool clamp need to be preheated to 300℃~350℃ before forging, the forging speed is 10mm / s~15mm / s, the forging deformation is 30%~45%, and the final forging temperature is not lower than 360℃.
[0023] Step 2, Low-temperature forging with large deformation in 2-4 heats The Al-Zn-Mg aluminum alloy forgings obtained in step 1 are heated to 400℃~420℃ and held at that temperature until the core is thoroughly heated. They are then removed from the furnace and transferred to a hydraulic press within 10s~60s for upsetting and drawing forging deformation. Before forging, the die needs to be preheated to 300℃~350℃, the forging speed is 10mm / s~15mm / s, the forging deformation is 50%~60%, and the final forging temperature is not lower than 360℃.
[0024] Step 3: High-temperature forging with large deformation in 1-2 fires The forgings obtained in step 2 are first heated to 440℃~460℃ and held at that temperature until the core is thoroughly heated. Then, they are removed from the furnace and transferred to a hydraulic press within 10s~60s for upsetting and drawing forging deformation. Before forging, the die needs to be preheated to 300℃~350℃, the forging speed is 10mm / s~15mm / s, the forging deformation is 50%~60%, and the final forging temperature is not lower than 360℃.
[0025] Example 1 Step 1: Select a Φ600mm 7A85 aluminum alloy ingot as the raw material. First, heat the ingot to 455℃ and hold for 15 hours. Then, remove it from the furnace and transfer it to a 25MN high-speed forging mill for upsetting and drawing deformation in 45 seconds. Return the hot material to the furnace and hold it at 455℃ for another 8 hours. Then, remove it from the furnace and transfer it to a 25MN high-speed forging mill for upsetting and drawing deformation in 50 seconds. Before forging, preheat the hammer, anvil, and tooling fixture to 320℃. The forging speed is 10mm / s, the forging deformation is 35%, and the final forging temperature is 400℃.
[0026] Step 2: The hot forging material obtained in Step 1 is returned to the furnace and held at 410℃ for 8 hours. Then, it is removed from the furnace and transferred to a 25MN high-speed forging mill for upsetting and drawing deformation in 47 seconds. (This process is repeated three times in the original text.) The hot material is returned to the furnace, held at 410℃ for 8 hours, removed from the furnace, and transferred to a 25MN high-speed forging mill for upsetting and drawing deformation in 53 seconds. (This process is repeated three times in the original text.) The hot material is returned to the furnace, held at 410℃ for 8 hours, removed from the furnace, and transferred to a 25MN high-speed forging mill for upsetting and drawing deformation in 41 seconds. Before forging, the hammer, anvil, and tooling fixture are preheated to 320℃. The forging speed is 10 mm / s, the forging deformation is 55%, and the final forging temperature is 370℃.
[0027] Step 3: The hot forging material obtained in Step 2 is returned to the furnace and held at 455℃ for 8 hours. Then, it is removed from the furnace and transferred to a 25MN high-speed forging mill for upsetting and drawing deformation in 57 seconds. The hot material is then returned to the furnace and held at 455℃ for another 8 hours. It is then removed from the furnace and transferred to a 25MN high-speed forging mill for upsetting and drawing deformation in 46 seconds. After air cooling to room temperature, a 7A85 aluminum alloy billet forging is obtained. Specifically, the hammer, anvil, and tooling fixture are preheated to 320℃ before forging. The forging speed is 10 mm / s, the forging deformation is 50%, and the final forging temperature is 395℃.
[0028] After solution treatment and aging, the 7A85 aluminum alloy forging prepared in this embodiment has tensile strengths of 534 MPa, 529 MPa, and 531 MPa in the longitudinal, transverse, and high directions at room temperature, respectively; yield strengths of 497 MPa, 484 MPa, and 487 MPa; and elongation of 10.4%, 9.4%, and 11.0%.
[0029] like Figure 1 The image shows the microstructure of the 7A85 aluminum alloy forging prepared in Example 1 of this invention. It can be seen that the longitudinal, transverse and height structures of the forging are relatively similar, and there are no metallurgical defects such as porosity, shrinkage cavities, inclusions, or coarse eutectic structures. Moreover, the grains in different directions are all fine.
[0030] Example 2 Step 1: Select a Φ400mm 7050 aluminum alloy ingot as the raw material. First, heat the ingot to 450℃ and hold for 12 hours. Then, remove it from the furnace and transfer it to a 16MN high-speed forging mill for upsetting and drawing deformation in 39 seconds. Return the hot material to the furnace and hold it at 450℃ for another 6 hours. Then, remove it from the furnace and transfer it to a 16MN high-speed forging mill for upsetting and drawing deformation in 46 seconds. Before forging, preheat the hammer, anvil, and tooling fixture to 310℃. The forging speed is 10mm / s, the forging deformation is 40%, and the final forging temperature is 410℃.
[0031] Step 2: The hot forging material obtained in Step 1 is returned to the furnace and held at 405℃ for 6 hours. Then, it is removed from the furnace and transferred to a 16MN high-speed forging mill for upsetting and drawing deformation in 43 seconds. The hot material is returned to the furnace and held at 405℃ for another 6 hours. Then, it is removed from the furnace and transferred to a 16MN high-speed forging mill for upsetting and drawing deformation in 39 seconds. Before forging, the hammer, anvil, and tooling fixture are preheated to 300℃. The forging speed is 10 mm / s, the forging deformation is 60%, and the final forging temperature is 365℃.
[0032] Step 3: The hot forging material obtained in Step 2 is returned to the furnace and held at 450℃ for 6 hours. Then, it is removed from the furnace and transferred to a 16MN high-speed forging mill for one upsetting and one drawing deformation over 47 seconds. After air cooling to room temperature, a 7050 aluminum alloy billet forging is obtained. Specifically, the hammer, anvil, and tooling fixture are preheated to 310℃ before forging, the forging speed is 10 mm / s, the forging deformation is 55%, and the final forging temperature is 390℃.
[0033] After solution treatment and aging, the 7050 aluminum alloy forging prepared in this embodiment has tensile strengths of 517 MPa, 510 MPa, and 524 MPa in the longitudinal, transverse, and high directions at room temperature, respectively; yield strengths of 434 MPa, 417 MPa, and 435 MPa; and elongation of 10.0%, 13.0%, and 12.5%.
[0034] like Figure 2 The image shows the microstructure of the 7050 aluminum alloy forging prepared in Example 2 of this invention. It can be seen that the forging is free from metallurgical defects such as porosity, shrinkage cavities, and inclusions. The coarse eutectic structure on the original grain boundaries is broken, and the differences in the longitudinal, transverse, and vertical structures are small, with fine grains in different directions.
[0035] Example 3 Step 1: Select a Φ300mm 7075 aluminum alloy ingot as the raw material. First, heat the ingot to 450℃ and hold for 8 hours. Then, remove it from the furnace and transfer it to a 16MN high-speed forging mill for upsetting and drawing deformation in 40 seconds. Before forging, preheat the hammer, anvil, and tooling fixture to 330℃. The forging speed is 10mm / s, the forging deformation is 35%, and the final forging temperature is 400℃.
[0036] Step 2: The hot forging material obtained in Step 1 is returned to the furnace and held at 410℃ for 4 hours. Then, it is removed from the furnace and transferred to a 16MN high-speed forging mill for upsetting and drawing deformation in 46 seconds. (This process is repeated three times in the original text.) The hot material is returned to the furnace, held at 410℃ for another 4 hours, removed from the furnace, and transferred to a 16MN high-speed forging mill for upsetting and drawing deformation in 37 seconds. (This process is repeated three times in the original text.) The hot material is returned to the furnace, held at 410℃ for another 4 hours, removed from the furnace, and transferred to a 16MN high-speed forging mill for upsetting and drawing deformation in 50 seconds. Before forging, the hammer, anvil, and tooling fixture are preheated to 330℃. The forging speed is 10 mm / s, the forging deformation is 55%, and the final forging temperature is 370℃.
[0037] Step 3: The hot forging material obtained in Step 2 is returned to the furnace and held at 450℃ for 4 hours. It is then removed from the furnace and transferred to a 16MN high-speed forging mill for one upsetting and one drawing deformation over 37 seconds. After air cooling to room temperature, a 7050 aluminum alloy billet forging is obtained. Specifically, the hammer, anvil, and tooling fixture are preheated to 330℃ before forging. The forging speed is 10 mm / s, the forging deformation is 55%, and the final forging temperature is 375℃.
[0038] After solution treatment and aging, the 7075 aluminum alloy forgings prepared in this embodiment have tensile strengths of 488 MPa, 482 MPa, and 478 MPa in the longitudinal, transverse, and high directions at room temperature, respectively; yield strengths of 407 MPa, 388 MPa, and 383 MPa; and elongation of 13.5%, 16.0%, and 18.5%.
[0039] like Figure 3 The image shows the microstructure of the 7075 aluminum alloy forging prepared in Example 3 of this invention. It can be seen that the forging is free from metallurgical defects such as porosity, shrinkage cavities, and inclusions. The coarse eutectic structure on the original grain boundaries is almost completely broken. The differences in the longitudinal, transverse, and vertical structures are small, and the grains in different directions are all fine.
[0040] This invention discloses a method for forging Al-Zn-Mg aluminum alloy ingots. By first performing high-temperature, low-deformation upset-drawing forging on the Al-Zn-Mg aluminum alloy ingots, then performing low-temperature, high-deformation upset-drawing forging, and finally performing high-temperature, high-deformation upset-drawing forging, metallurgical defects such as porosity, shrinkage cavities, and coarse microstructure in the Al-Zn-Mg aluminum alloy ingots are eliminated. This method achieves refinement of the longitudinal, transverse, and height-oriented microstructure of the Al-Zn-Mg aluminum alloy forgings and improves their overall performance, while reducing the anisotropy of the forgings.
[0041] The above description merely illustrates embodiments of the present invention and is quite specific and detailed; however, it should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Furthermore, any parts of the present invention not described in detail are conventional techniques.
Claims
1. A method of cogging an Al-Zn-Mg aluminum alloy ingot, characterized by, The method comprises: Step 1: subjecting an Al-Zn-Mg aluminum alloy ingot to upsetting-drawing deformation at a preset temperature and a preset deformation amount for 1-2 heating times; Step 2: subjecting the forged piece prepared in step 1 to upsetting-drawing deformation at a preset temperature and a preset deformation amount for 1-4 heating times; Step 3: subjecting the forged piece prepared in step 2 to upsetting-drawing deformation at a preset temperature and a preset deformation amount for 1-2 heating times to obtain an Al-Zn-Mg aluminum alloy forged piece with good uniformity in structure and performance; wherein the preset temperature in step 1 and step 3 belongs to the same temperature range and is greater than the preset temperature in step 2; the preset deformation amount in step 2 and step 3 belongs to the same deformation amount range and is greater than the preset deformation amount in step 1.
2. The method of claim 1, wherein the Al-Zn-Mg aluminum alloy ingot is forged by a method comprising: In step 1, the forging temperature is 440-460 DEG C, and the forging deformation amount is 30-45%. 3. The method of claim 1, wherein the Al-Zn-Mg aluminum alloy ingot is forged by a method comprising: heating the Al-Zn-Mg aluminum alloy ingot to a temperature of 450°C to 550°C; and forging the Al-Zn-Mg aluminum alloy ingot at a temperature of 450°C to 550°C. In step 2, the forging temperature is 400-420 DEG C, and the forging deformation amount is 50-60%.
4. The method of claim 1, wherein the Al-Zn-Mg aluminum alloy ingot is forged by a method comprising: heating the Al-Zn-Mg aluminum alloy ingot to a temperature of 450 to 550°C; and forging the Al-Zn-Mg aluminum alloy ingot at a temperature of 450 to 550°C. In step 3, the forging temperature is 440-460 DEG C, and the forging deformation amount is 50-60%.
5. The method of claim 1, wherein the Al-Zn-Mg aluminum alloy ingot is forged by a method comprising: heating the Al-Zn-Mg aluminum alloy ingot to a temperature of 450 to 550°C; and forging the Al-Zn-Mg aluminum alloy ingot at a temperature of 450 to 550°C. The breakdown forging equipment is a hydraulic machine, and the forging speed is 10-15 mm / s.
6. The method of claim 1, wherein the Al-Zn-Mg aluminum alloy ingot is forged by a cogging process. In each heating time, the hammer anvil and the tool clamp are used to assist the upsetting-drawing deformation of the Al-Zn-Mg aluminum alloy ingot, and the hammer anvil and the tool clamp need to be preheated to 300-350 DEG C before forging, the transfer time of the Al-Zn-Mg aluminum alloy after being discharged is 10-60 s, and the final forging temperature is not lower than 360 DEG C.
7. The method of claim 1, wherein the Al-Zn-Mg aluminum alloy ingot is forged by a cogging process. After the last heating forging is completed, the forged piece is air-cooled to room temperature.
8. The method of claim 1, wherein the Al-Zn-Mg aluminum alloy ingot is characterized by, The Al-Zn-Mg aluminum alloy ingot is a 7A85 aluminum alloy ingot, a 7050 aluminum alloy ingot or a 7075 aluminum alloy ingot.
9. A system for the Al-Zn-Mg aluminum alloy ingot breakdown forging method according to any one of claims 1 to 8, characterized by, It comprises: a hydraulic machine, a hammer anvil and a tool clamp, the hydraulic machine is used to apply compressive stress to the Al-Zn-Mg aluminum alloy ingot, the hammer anvil is used to support and transfer the compressive stress to the Al-Zn-Mg aluminum alloy ingot, the tool clamp is used for positioning, clamping and turning of the Al-Zn-Mg aluminum alloy ingot during forging.