Deformation treatment method for aluminum alloy forge piece
By combining hot deformation, solution quenching, cold pressing, and two-stage aging treatment, the problems of residual stress and performance imbalance in aluminum alloy forgings during processing were solved, achieving efficient production and performance improvement of forgings.
Patent Information
- Application Number
- CN202511124326.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-12
- Publication Date
- 2025-11-07
AI Technical Summary
In the current technology, the performance of aluminum alloy forgings is uneven before and after cold deformation, which leads to the scrapping of forgings, and the residual stress during cold deformation is difficult to control effectively.
By employing a combination of hot deformation treatment, solution quenching, cold pressing treatment, and two-stage aging treatment, and through the rational design of deformation amount and heat treatment parameters, the grain structure is refined, the cold pressing deformation amount is applied uniformly, residual stress is reduced, and the comprehensive mechanical properties of forgings are improved.
It effectively reduces the residual stress in aluminum alloy forgings, improves the overall mechanical properties of forgings, solves the problem of performance imbalance, and is suitable for large-scale industrial production.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of aluminum alloy material processing, and particularly relates to a deformation treatment method for an aluminum alloy forge piece. BACKGROUND
[0002] At present, the aviation manufacturing industry pursues the integration of aircraft structural parts, because this can not only greatly reduce the weight of the aircraft, greatly reduce the number of parts, shorten the assembly time and period, but also can improve the stability and reliability of the fuselage structure. Large aluminum alloy forgings with the characteristics of integration have the advantages of high material utilization, low organizational defects and good performance uniformity, and become the first choice for new aircraft load-bearing structural parts. At present, spray forming 7055 aluminum alloy is considered as the first choice for manufacturing large aluminum alloy forgings as a high-performance, low-cost high-strength aluminum alloy. As a heat-treatable strengthening alloy, it presents high comprehensive mechanical properties after solid solution and aging, but the deformation warping produced in the solid solution process also causes problems in the processing of the forgings.
[0003] In order to prevent the local deformation of the large aluminum alloy forgings due to the release of residual stress in the subsequent processing process, the processing allowance of the forgings has to be increased to provide space for shape correction. However, this is a negative feedback mechanism, that is, the increase of the processing allowance causes the increase of the effective thickness of the forgings, which eventually leads to the increase of the residual stress and the decrease of the mechanical properties. Through long-term implementation and verification, it is found that the residual stress can be effectively reduced by increasing the cold deformation (stretching or compression) after solid solution, which mainly overlaps the cold pressure stress field and the residual stress field by applying a permanent deformation of 1% to 5% to the large forgings, so that part of the residual stress is released due to plastic deformation, thereby achieving the purpose of reducing the residual stress. However, cold pressing is often performed after solid solution and quenching, and most engineers focus on the effect of cold deformation and the precise control of the cold deformation process, ignoring the influence on the performance of the forgings before and after cold deformation, which causes the difference in the oriented mechanical properties of the forgings, and even causes the forgings to be scrapped due to unbalanced performance.
[0004] The reason is that the aluminum alloy forging generates large residual stress after quenching, and in the manufacturing process, the internal energy distribution of the forging is changed instantaneously due to cutting, thereby causing dynamic balance of the internal stress field, and finally forming a non-uniform residual stress field in the forging and possibly generating large machining deformation. Therefore, in engineering, the residual stress in the forging is often eliminated by cold deformation, and under a cold pressing deformation amount of 1% to 5%, good stress elimination effect is shown. However, in the plastic deformation process, the microstructure of the material will change, and the mechanical properties such as strength, plasticity and toughness are sensitive to the change of the microstructure. At the same time, the deformation behavior will affect the aging precipitation, and in the aging process, the high-density dislocations generated by the external stress will accelerate the uniform precipitation of the second phase of the aluminum alloy along the crystal, so that the density of the precipitated phase increases and the overall tensile property changes. Therefore, the deformation treatment process considering the residual stress and performance matching can solve the problem. SUMMARY
[0005] The present application provides an aluminum alloy forging deformation treatment method, which considers the residual stress and performance matching of the forging to reduce the probability of rejection after deformation treatment of the forging.
[0006] The present application is implemented by the following technical scheme: an aluminum alloy forging deformation treatment method, comprising:
[0007] Hot deformation treatment: compressing the heated aluminum alloy forging to make the aluminum alloy forging uniformly deform;
[0008] Solution quenching treatment: solution quenching the aluminum alloy forging after the hot deformation treatment;
[0009] Cold pressing treatment: placing the aluminum alloy forging after the solution quenching treatment in a cold pressing cavity of a cold pressing die for cold pressing treatment;
[0010] Aging treatment: placing the aluminum alloy forging after the cold pressing in a heating furnace for aging treatment.
[0011] Further, in order to better implement the present application, the deformation amount in the hot deformation treatment process is 10%-70%, and the deformation speed is 2-10mm / s.
[0012] Further, in order to better implement the present application, the solution quenching treatment comprises the following steps:
[0013] First-stage solution treatment: placing the aluminum alloy forging in a heating furnace and heating to 400-480℃, and then holding for 3-8h;
[0014] Second-stage solution treatment: after the first-stage solution treatment, heating the aluminum alloy forging to 450-500℃ again by using the heating furnace, and then holding for 4-12h;
[0015] Quenching treatment: after the second stage of solid solution treatment, the aluminum alloy forging is taken out from the heating furnace and placed in warm water of 30-70 DEG C for quenching, and the warm water is stirred during quenching, and the quenching time is 20-120 min.
[0016] Further, in order to better realize the present application, the cold pressing treatment comprises the following steps:
[0017] First pass cold pressing: the aluminum alloy forging after solid solution quenching treatment is placed in the cold pressing cavity of the cold pressing die for pressing, and the degree of pressing is the nominal cold pressing amount, wherein the nominal cold pressing amount is a value obtained by multiplying the effective thickness size by any value in the deformation range of 1% to 5% in the cold compression process.
[0018] Second pass cold pressing: the aluminum alloy forging after the first pass cold pressing is pressed again, and the degree of pressing is the calculated cold pressing amount, wherein the calculated cold pressing amount is the sum of the first difference and the second difference, the first difference is the difference between the cold pressing springback amount and the nominal cold pressing amount, and the second difference is the difference between the actual cold pressing amount and the nominal cold pressing amount.
[0019] Further, in order to better realize the present application, the deformation amount of the cold pressing treatment is 1%-5%.
[0020] Further, in order to better realize the present application, the lubricant used in the cold pressing treatment is lubricating oil, which is uniformly applied to the aluminum alloy forging.
[0021] Further, in order to better realize the present application, the interval time between the solid solution quenching treatment and the cold pressing treatment is not more than 4-12h.
[0022] Further, in order to better realize the present application, the aging treatment is two-stage aging, comprising the following steps:
[0023] First stage aging: the aluminum alloy forging after the cold pressing treatment is placed in a heating furnace at 100 DEG C-140 DEG C, and is kept for 4-12h;
[0024] Second stage aging: the aluminum alloy forging after the first stage aging treatment is heated to 120 DEG C-180 DEG C, and is kept for 6-24h, and then is air cooled after the end.
[0025] Further, in order to better realize the present application, the interval time between the cold pressing treatment and the aging treatment is not more than 72h.
[0026] Further, in order to better realize the present application, the aluminum alloy forging is a 7055 aluminum alloy forging prepared by spray forming.
[0027] Compared with the prior art, the present application has the following beneficial effects:
[0028] The aluminum alloy forging deformation treatment method provided by the application first performs hot deformation treatment on the aluminum alloy forging before solid solution quenching treatment, refines the grain structure, and after solid solution quenching, uniformly applies a cold pressure deformation amount to each forging region, and then performs double-stage aging, so that the residual stress can be effectively reduced while the comprehensive mechanical properties of the forging are improved.
[0029] The application is particularly suitable for quenching residual stress elimination and performance control of spray-formed 7055 aluminum alloy forgings, that is, 7055 aluminum alloy forgings formed by spray forming. By reasonably designing the hot deformation amount, the cold pressure deformation amount and the heat treatment parameters, the quenching residual stress can be effectively reduced, the mechanical properties of the forging are improved, the processing deformation is effectively reduced, and the strength and toughness matching is optimized. The operation is simple, the effect is obvious, and it is suitable for large-scale industrialization promotion and application. DETAILED DESCRIPTION
[0030] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.
[0031] Example 1
[0032] A large-scale long-beam type spray-formed 7055 aluminum alloy die forging with a specification of 3397mm x 354mm x 150mm after hot forming (it is noted that hot forming refers to compression of the thickened forging, the compression amount is 10%, and the deformation speed is 2mm / s) is placed in a heating furnace for solid solution treatment, double-stage solid solution treatment is performed, the solid solution system is 430℃ x 6h + 480℃ x 8h (that is, the forging is first heated to 430℃ in the heating furnace and kept for 6h, and then the forging is heated to 480℃ and kept for 8h), after keeping, it is quickly quenched in warm water with a temperature of 50℃, and stirring is maintained during the quenching process. Then the quenched die forging is placed in a cold pressing die for the first pass of cold pressing, the second pass of cold pressing is performed after the first pass of cold pressing is completed, the cold pressing amount is 2.5%, and then the die forging is placed in a heating furnace for double-stage aging treatment, the aging system is 140℃ x 6h + 180℃ x 10h (that is, the forging is first placed in a heating furnace at 140℃ for 6h, and then the forging is placed in a heating furnace at 180℃ for 10h), and the interval between cold pressing and aging is not more than 72h. The residual stress test value and the conventional mechanical properties are shown in Table 1 below.
[0033] Comparative Example 1
[0034] A large-scale long beam type injection molded 7055 aluminum alloy forging having a size of 3397 mm x 354 mm x 150 mm after hot forming was put into a heating furnace to perform solution treatment, and two-stage solution treatment was performed at a solution treatment regime of 430°C x 6h + 480°C x 8h. After the heat preservation, the forging was rapidly quenched in warm water having a temperature of 50°C, and stirring was maintained during the quenching. After the solution treatment, the forging was put into a heating furnace to perform two-stage aging treatment at an aging regime of 140°C x 6h + 180°C x 10h, and the interval between the cold pressing and the aging treatment was not more than 72h. The residual stress test values and the general mechanical properties are shown in Table 1 below.
[0035] Comparative Example 2
[0036] A large-scale long beam type injection molded 7055 aluminum alloy forging having a size of 3397 mm x 354 mm x 150 mm after hot forming was put into a heating furnace to perform solution treatment, and two-stage solution treatment was performed at a solution treatment regime of 430°C x 6h + 480°C x 8h. After the heat preservation, the forging was rapidly quenched in warm water having a temperature of 50°C, and stirring was maintained during the quenching. Then, the quenched forging was put into a cold pressing mold to perform cold pressing at a cold pressing amount of 5%, and the forging was again put into a heating furnace to perform two-stage aging treatment at an aging regime of 140°C x 6h + 180°C x 10h, and the interval between the cold pressing and the aging treatment was not more than 72h. The residual stress test values and the general mechanical properties are shown in Table 1 below.
[0037] Example 2
[0038] A large-scale long beam type injection molded 7055 aluminum alloy forging having a size of 3397 mm x 354 mm x 150 mm after hot forming (Note that the hot forming refers to compression of the thickened forging at a compression amount of 10% and a deformation speed of 2mm / s) was put into a heating furnace to perform solution treatment, and two-stage solution treatment was performed at a solution treatment regime of 430°C x 6h + 480°C x 8h (i.e., the forging was first heated to 430°C in the heating furnace and heat preserved for 6h, and then the forging was heated to 480°C and heat preserved for 8h). After the heat preservation, the forging was rapidly quenched in warm water having a temperature of 50°C, and stirring was maintained during the quenching. Then, the quenched forging was put into a cold pressing mold to perform first pass cold pressing, and second pass cold pressing was performed after the first pass cold pressing was completed, at a cold pressing amount of 1%. The forging was again put into a heating furnace to perform two-stage aging treatment at an aging regime of 140°C x 6h + 180°C x 10h (i.e., the forging was first heat preserved for 6h in a heating furnace at 140°C, and then the forging was heat preserved for 10h in a heating furnace at 180°C). The interval between the cold pressing and the aging treatment was not more than 72h. The residual stress test values and the general mechanical properties are shown in Table 1 below.
[0039] Example 3
[0040] The large-scale long beam type 7055 aluminum alloy die forging with a specification of 3397 mm x 354 mm x 150 mm after hot forming (it is to be noted that the hot forming refers to compression of the thickened forging, the compression amount is 70%, and the deformation speed is 10 mm / s) is placed into a heating furnace for solid solution treatment, double-stage solid solution treatment is performed, the solid solution system is 480℃ x 8h + 500℃ x 12h (that is, the forging is first heated to 480℃ and kept for 8h in the heating furnace, and then the forging is heated to 500℃ and kept for 12h), after keeping, the forging is rapidly placed into warm water with a water temperature of 30℃ for quenching, stirring is kept during the quenching process. Then the quenched die forging is placed into a cold pressing die for first pass cold pressing, after the first pass cold pressing, second pass cold pressing is performed, the cold pressing amount is 3%, after cold pressing, the die forging is again placed into a heating furnace, double-stage aging treatment is performed, the aging system is 100℃ x 4h + 120℃ x 6h (that is, the forging is first placed in a heating furnace at 100℃ for 4h, and then the forging is placed in a heating furnace at 120℃ for 6h), the interval time between cold pressing and aging is not more than 72h.
[0041] The above merely describes specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
[0042] Table 1 tensile properties and residual stress values under different process routes
[0043]
[0044] Note: the above conventional tensile test direction is L direction, and the fracture toughness test direction is L-T direction.
Claims
1. A method for the deformation treatment of an aluminum alloy wrought article, characterized in that, The method comprises the following steps: hot deformation treatment: compressing the heated aluminum alloy forge piece to make the aluminum alloy forge piece deform uniformly; solution quenching treatment: solution quenching the aluminum alloy forge piece after the hot deformation treatment; first cold pressing: placing the aluminum alloy forge piece after the solution quenching treatment in a cold pressing cavity of a cold pressing die to press, and the degree of pressing is a nominal cold pressing amount, wherein the nominal cold pressing amount is a value obtained by multiplying an arbitrary value in the range of 1%-5% and an effective thickness dimension in a cold compression recovery process; second cold pressing: pressing the aluminum alloy forge piece after the first cold pressing again, and the degree of pressing is a calculated cold pressing amount, wherein the calculated cold pressing amount is a sum of a first difference and a second difference, the first difference is a difference between a cold pressing springback amount and the nominal cold pressing amount, and the second difference is a difference between an actual cold pressing amount and the nominal cold pressing amount; aging treatment: placing the aluminum alloy forge piece after the cold pressing in a heating furnace to perform the aging treatment.
2. The method according to claim 1, wherein: the deformation amount in the hot deformation treatment is 10%-70%, and the deformation speed is 2-10 mm / s.
3. The method for deformation treatment of aluminum alloy forgings according to claim 1, characterized in that, The solution quenching treatment comprises the following steps: first-stage solution treatment: placing the aluminum alloy forge piece in a heating furnace to heat to 400-480℃, and then keeping the temperature for 3-8 h; second-stage solution treatment: after the first-stage solution treatment, heating the aluminum alloy forge piece to 450-500℃ again by using the heating furnace, and then keeping the temperature for 4-12 h; quenching treatment: after the second-stage solution treatment, taking the aluminum alloy forge piece out of the heating furnace and placing it in warm water of 30-70℃ to perform the quenching treatment, stirring the warm water during the quenching treatment, and the quenching time is 20-120 min.
4. The method according to claim 1, wherein: the first cold pressing and the second cold pressing form a cold pressing treatment of the aluminum alloy forge piece, and the deformation amount of the cold pressing treatment is 1%-5%.
5. The method according to claim 4, wherein: the lubricant used in the cold pressing treatment is lubricating oil, which is uniformly applied on the aluminum alloy forge piece.
6. The method according to claim 5, wherein: the interval time between the solution quenching treatment and the cold pressing treatment is not more than 4-12 h.
7. The method of claim 1, wherein the aluminum alloy wrought article is a plate. The aging treatment is two-stage aging, comprising the following steps: first-stage aging: placing the aluminum alloy forge piece after the cold pressing treatment in a heating furnace at 100℃-140℃, and keeping the temperature for 4-12 h; second-stage aging: heating the aluminum alloy forge piece after the first-stage aging treatment to 120℃-180℃, keeping the temperature for 6-24 h, and then air cooling.
8. The method according to claim 1, wherein: the interval time between the cold pressing treatment and the aging treatment is not more than 72 h.
9. The method according to claim 1, wherein: the aluminum alloy forge piece is a 7055 aluminum alloy forge piece prepared by spray forming.