High-toughness corrosion-resistant aluminum-manganese alloy and preparation process thereof

Abstract

The invention discloses a high-toughness corrosion-resistant aluminum-manganese alloy and a preparation process thereof, and belongs to the technical field of aluminum alloy production. The high-toughness corrosion-resistant aluminum-manganese alloy comprises, by mass, 1.2%-1.5% of Mn, 0.4%-0.6% of Cu, 0.4%-0.7% of Si, 0.3%-0.8% of Ce, 0.1%-0.3% of Zr, 0.1%-0.2% of Cr and the balance Al and inevitable impurities, and the total amount of the impurities is smaller than or equal to 0.15%. The preparation process comprises the following specific steps: mixing all component raw materials, carrying out vacuum electromagnetic induction smelting, casting after smelting, carrying out multi-stage homogenization heat treatment, carrying out temperature gradient pre-extrusion and multi-directional rolling, carrying out cold rolling-annealing circular treatment and carrying out composite heat treatment to obtain the high-toughness corrosion-resistant aluminum-manganese alloy. Through element collaborative optimization and multi-stage process coupling, the tensile strength, elongation and corrosion resistance of the alloy are remarkably improved, and the aluminum-manganese alloy prepared through the method is good in comprehensive performance and suitable for the fields such as aerospace and new energy automobile battery shells which have strict requirements for the comprehensive performance of materials.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy production technology, specifically to a high-toughness and corrosion-resistant aluminum-manganese alloy and its preparation process. Background Technology

[0002] As a core component of new energy vehicles, the performance of power batteries directly affects the performance of the vehicles. The battery casing, as an important part of power batteries, plays a key role in the safety and stability of the batteries. Therefore, higher-performance materials are needed to manufacture battery casings to meet the needs of the rapidly developing new energy vehicle industry. Lithium batteries are chemically unstable and vulnerable to external forces such as puncture and compression, requiring rigid casing protection, which limits the widespread application of lithium batteries.

[0003] Chinese invention patent application CN118639064A discloses a preparation process for a corrosion-resistant, high-strength, and high-toughness aluminum alloy, which combines magnetic field-assisted melting with boron-nitrogen co-doped carbon nanotubes (BN / CNTs) reinforcement. However, this technology still has certain limitations: high Mg content (5.0-7.5wt%) easily leads to the precipitation of β(Al3Mg2) phase, which may affect long-term corrosion resistance; furthermore, the dispersion uniformity of BN / CNTs is difficult to control; boron-nitrogen co-doped carbon nanotubes are expensive; and the high-pressure casting process may lead to defects such as porosity and shrinkage in the as-cast structure.

[0004] Chinese invention patent application CN114182131A discloses a method for preparing high-strength, high-toughness, and corrosion-resistant 7085 aluminum-based composite materials, which combines in-situ nanoparticle reinforcement and rare earth coupling reinforcement. However, this technology still has the following shortcomings: First, the fluoride salt reaction system will generate fluorine-containing waste gas and waste residue, resulting in high environmental treatment costs; nanoparticles are prone to agglomeration at high contents, affecting the uniformity of dispersion; although high Zn and Cu contents improve strength, they will reduce plastic deformation capacity.

[0005] In summary, while existing technologies have achieved some breakthroughs in strength and corrosion resistance, problems remain: the use of high-cost elements leads to insufficient economic viability; unreasonable composition design makes it difficult to balance strength and corrosion resistance; and complex processes affect stability. These shortcomings limit the material's performance, preventing it from simultaneously meeting the comprehensive requirements of new energy vehicle power battery casings. Therefore, developing a method for preparing aluminum-manganese alloy materials that combines high toughness, excellent corrosion resistance, reasonable cost, and stable processing has become a key requirement for promoting the development of the new energy vehicle industry. Summary of the Invention

[0006] To address the shortcomings in the performance of aluminum-manganese alloy materials, the present invention aims to provide a high-toughness and corrosion-resistant aluminum-manganese alloy. The components and their mass percentages in the high-toughness and corrosion-resistant aluminum-manganese alloy are as follows: Mn 1.2-1.5%, Cu 0.4-0.6%, Si 0.4-0.7%, Ce 0.3-0.8%, Zr 0.1-0.3%, Cr 0.1-0.2%, with the balance being Al and unavoidable impurities, the total amount of impurities being ≤0.15%.

[0007] Another objective of this invention is to provide a method for preparing a high-toughness and corrosion-resistant aluminum-manganese alloy, which weakens the anisotropy of the texture and enhances the grain refinement effect under the action of deformation and multi-stage heat treatment, making the alloy structure and mechanical properties more uniform and improving the toughness and corrosion resistance of the aluminum-manganese alloy.

[0008] The preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy of the present invention specifically includes the following steps: (1) Mix the raw material components in proportion and perform vacuum electromagnetic induction melting to obtain molten alloy liquid.

[0009] (2) Cast the molten alloy liquid to obtain an aluminum-manganese alloy ingot.

[0010] (3) The ingot is subjected to multi-stage homogenization heat treatment to obtain a billet that has undergone multi-stage homogenization heat treatment.

[0011] (4) The billet that has undergone multi-stage homogenization heat treatment is subjected to temperature gradient pre-extrusion, temperature incremental rolling and hot cross rolling in sequence to obtain the plate.

[0012] (5) The plate is subjected to cold rolling-annealing cycle treatment to obtain aluminum-manganese alloy after cold rolling-annealing cycle treatment.

[0013] (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment to obtain a high-toughness and corrosion-resistant aluminum-manganese alloy.

[0014] Preferably, the pretreatment in step (1) of the present invention is: preheating the raw material at 150-250℃ for 1.5-2.5h.

[0015] Preferably, the vacuum electromagnetic induction melting in step (1) of the present invention specifically involves: drawing a vacuum to make the vacuum degree in the electromagnetic induction furnace ≤0.05Pa to ensure a low oxygen environment, then introducing argon gas to reach 0.03-0.05 MPa, and melting at 750-800℃ for 5~15 minutes.

[0016] Preferably, the multi-stage homogenization process in step (3) of the present invention adopts a gradient heating method. The first stage is held at 300-330℃ for 7-8h to pre-nucleate the Al3Zr phase. The second stage is held at 390-410℃ for 5-6h to promote the precipitation of the Al2Cu dispersed phase. The third stage is held at 510-530℃ for 7-8h to dissolve the coarse phase, and then air cooling is performed.

[0017] Preferably, the gradient preheating extrusion conditions in step (4) of the present invention are: the temperature at the end of the die cylinder is 460-480℃, increasing by 3-5℃ / 40mm along the extrusion direction, and the extrusion ratio is 5:1.

[0018] Preferably, in step (4) of the present invention, multi-directional rolling adopts gradient heating rolling and cross rolling, specifically: rolling 8% deformation along the rolling direction at 380℃, rolling 10% deformation along the rolling direction at 400℃, rolling 10% deformation along the rolling direction at 420℃, and rolling 12% deformation along the rolling direction at 440℃; then rolling 4 times at 350℃ with a cross rolling angle of 90°, each time with a deformation of 10%, and the interval between each cross rolling is <30s.

[0019] Preferably, the cold rolling-annealing cycle process in step (5) of the present invention is as follows: the sheet is cold rolled, after cold rolling deformation of 10%, it is annealed at 400°C for 2 hours, then cold rolled again, after cold rolling deformation of 14%, it is annealed at 400°C for 2 hours, then cold rolled again, after cold rolling deformation of 16%, it is annealed at 400°C for 2 hours, then cold rolled again, cold rolling deformation of 20%, and the cumulative cold rolling deformation is 60%.

[0020] Preferably, the composite heat treatment in step (6) of the present invention is as follows: first, solution treatment at 500℃ for 1h, water quenching, and then gradient aging treatment: the first stage is aging at 120-130℃ for 3.5-4h to form the GP region, and the second stage is aging at 160-180℃ for 7-8h. On the pre-precipitated Al3Zr nano-dispersions, the heterogeneous nucleation and synergistic precipitation of Al2Cu phase are promoted, thereby obtaining a fine and uniform precipitated phase distribution.

[0021] Mechanism of the invention: This invention achieves synergistic effects in optimizing the microstructure and improving the performance of aluminum-manganese alloys by combining the synergistic regulation of trace alloying elements with multi-stage thermomechanical processing. In terms of alloy design, the added rare earth elements Ce and Zr, along with transition elements Cu and Cr, form multi-scale strengthening phases: Ce purifies grain boundaries, Zr and Cr form thermally stable nanoscale Al3Zr and Al7Cr dispersed phases to pin grain boundaries and dislocations, Cu provides a solute source for subsequent aging precipitation, and the coarse Al6Mn phase formed by Mn regulates the strain distribution during deformation. In terms of process, multi-stage homogenization treatment first prepares an initial microstructure in which dispersed phases and saturated solid solutions coexist for subsequent processing; temperature gradient pre-extrusion forms an axial temperature field gradient, promoting a gradient distribution of dynamically recrystallized grains; multi-directional hot rolling and cold rolling-annealing cycles utilize the non-uniform deformation induced by the Mn-containing coarse phase to effectively disrupt the strong texture, and achieve strengthening through strain-induced precipitation of nano-θ' (Al2Cu) phase; the final staged aging process precisely controls the precipitation behavior of Cu element, obtaining a high-density nano-strengthening phase and a narrow precipitation-free zone. This invention, through the synergy of composition design and processing technology, uses elements as the carrier for the process, and the process maximizes the potential of elements, ultimately achieving an ideal microstructure with fine grains, weak texture, and multi-scale second phases coexisting, enabling the alloy to simultaneously possess comprehensive properties of high strength, high toughness, excellent corrosion resistance, and low anisotropy.

[0022] Compared with the prior art, the present invention provides a high-toughness and corrosion-resistant aluminum-manganese alloy and its preparation process, which has the following beneficial effects: (1) This invention achieves significant improvement in tensile strength while maintaining the excellent corrosion resistance of Al-Mn alloy through multi-element synergistic optimization.

[0023] (2) The present invention uses gradient deformation process to make the grain size distribution more uniform and the anisotropy index is reduced by more than 40%.

[0024] (3) The present invention controls the size of the precipitated phase within the range of 5-20nm through a multi-stage heat treatment process, thereby achieving the best balance of strength, toughness and corrosion resistance.

[0025] (4) The aluminum-manganese alloy prepared by the present invention has good comprehensive performance and is particularly suitable for fields with strict requirements for the comprehensive performance of materials, such as high-strength corrosion-resistant structural parts for aerospace and battery casings for new energy vehicles. Attached Figure Description

[0026] Figure 1 This is a process flow diagram for the preparation of high-toughness and corrosion-resistant aluminum-manganese alloy.

[0027] Figure 2 This is a schematic diagram of the preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy of the present invention.

[0028] Figure 3The images shown are STEM and EDS-mapping images of the aluminum-manganese alloy prepared in Example 1 of this invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1 A preparation process for a high-toughness and corrosion-resistant aluminum-manganese alloy, the specific steps of which are as follows: (1) Weigh the raw materials according to the proportions in Table 1, preheat the raw materials in an oven at 200℃ for 2 hours, add the raw materials to the electromagnetic induction furnace in the order of Al, Zr, Cr, Mn, Cu, Si and Ce, evacuate the vacuum furnace to make the vacuum degree ≤0.05Pa, then introduce argon gas to reach 0.04MPa, and melt at 775℃ for 10 minutes to obtain liquid alloy.

[0031] (2) The liquid alloy liquid is poured into a 200mm×100mm×100mm metal mold to obtain an aluminum-manganese alloy ingot.

[0032] (3) The ingot is subjected to multi-stage homogenization heat treatment. The first stage is held at 315-320℃ for 7.5h, the second stage is held at 400-405℃ for 5.5h, and the third stage is held at 510-515℃ for 8h. Then it is air-cooled to obtain the billet after multi-stage homogenization heat treatment.

[0033] (4) The billet that has undergone multi-stage homogenization heat treatment is pre-extruded. The initial temperature at the end of the die cylinder is 470-475℃, and the temperature increases by 4℃ / 40mm along the extrusion direction. The extrusion ratio is 5:1 to ensure dynamic recrystallization and grain refinement. Then, the billet is rolled in sequence at 380℃ with 8% deformation, at 400℃ with 10% deformation, at 420℃ with 10% deformation, and at 440℃ with 12% deformation. Finally, the billet is rolled in 4 times at 350℃ with 90° cross rolling, each time with 10% deformation. The interval between each cross rolling is <30s to obtain the plate.

[0034] (5) The plate is subjected to cold rolling-annealing cycle treatment. After cold rolling deformation of 10%, the plate is annealed at 400℃ for 2 hours, then cold rolling deformation of 14% is annealed at 400℃ for 2 hours, then cold rolling deformation of 16% is annealed at 400℃ for 2 hours, and finally cold rolling deformation of 20% is obtained to obtain aluminum-manganese alloy after cold rolling-annealing cycle treatment.

[0035] (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment. First, it is solution treated at 500℃ for 1h, then water quenched, and then subjected to gradient aging treatment: the first stage is aging treatment at 125-130℃ for 3.5h, and the second stage is aging treatment at 165-170℃ for 7h, to obtain a high toughness and corrosion resistant aluminum-manganese alloy.

[0036] Table 1 Example 2 A preparation process for a high-toughness and corrosion-resistant aluminum-manganese alloy, the specific steps of which are as follows: (1) Weigh the raw materials according to the proportions in Table 2, preheat the raw materials in an oven at 150℃ for 2.5h, add the raw materials to the electromagnetic induction furnace in the order of Al, Zr, Cr, Mn, Cu, Si and Ce, evacuate the vacuum furnace to make the vacuum degree ≤0.05Pa, then introduce argon gas to reach 0.03MPa, and melt at 800℃ for 5min to obtain liquid alloy.

[0037] (2) The liquid alloy liquid is poured into a 200mm×100mm×100mm metal mold to obtain an aluminum-manganese alloy ingot.

[0038] (3) The ingot is subjected to multi-stage homogenization heat treatment. The first stage is held at 300-305℃ for 8 hours, the second stage is held at 390-395℃ for 6 hours, and the third stage is held at 520-525℃ for 7.5 hours. Then it is air-cooled to obtain the billet after multi-stage homogenization heat treatment.

[0039] (4) The billet that has undergone multi-stage homogenization heat treatment is pre-extruded. The initial temperature at the end of the die cylinder is 460-465℃, and the temperature increases by 3℃ / 40mm along the extrusion direction. The extrusion ratio is 5:1 to ensure dynamic recrystallization and grain refinement. Then, the billet is rolled in sequence at 380℃ with 8% deformation, at 400℃ with 10% deformation, at 420℃ with 10% deformation, and at 440℃ with 12% deformation. Finally, the billet is rolled in 4 times at 350℃ with 90° cross rolling, each time with 10% deformation. The interval between each cross rolling is <30s to obtain the plate.

[0040] (5) The sheet is subjected to cold rolling-annealing cycle treatment, specifically: the sheet is cold rolled, after cold rolling deformation of 10%, it is annealed at 400℃ for 2 hours, then cold rolled again, after cold rolling deformation of 14%, it is annealed at 400℃ for 2 hours, then cold rolled again, after cold rolling deformation of 16%, it is annealed at 400℃ for 2 hours, then cold rolled again, cold rolling deformation of 20%, and the cumulative cold rolling deformation is 60%.

[0041] (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment. First, it is solution treated at 500℃ for 1h, then water quenched, and then subjected to gradient aging treatment: the first stage is aging treatment at 120-125℃ for 4h, and the second stage is aging treatment at 160-165℃ for 8h, to obtain a high toughness and corrosion resistant aluminum-manganese alloy.

[0042] Table 2 Example 3 A preparation process for a high-toughness and corrosion-resistant aluminum-manganese alloy, the specific steps of which are as follows: (1) Weigh the raw materials according to the proportions in Table 3, preheat the raw materials in an oven at 250℃ for 1.5h, add the raw materials to the electromagnetic induction furnace in the order of Al, Zr, Cr, Mn, Cu, Si and Ce, evacuate the vacuum furnace to make the vacuum degree ≤0.05Pa, then introduce argon gas to reach 0.05MPa, and melt at 750℃ for 15min to obtain liquid alloy.

[0043] (2) The liquid alloy liquid is poured into a 200mm×100mm×100mm metal mold to obtain an aluminum-manganese alloy ingot.

[0044] (3) The ingot is subjected to multi-stage homogenization heat treatment. The first stage is held at 325-330℃ for 7 hours, the second stage is held at 405-410℃ for 5 hours, and the third stage is held at 525-530℃ for 7 hours. Then it is air-cooled to obtain the billet after multi-stage homogenization heat treatment.

[0045] (4) The billet that has undergone multi-stage homogenization heat treatment is pre-extruded. The initial temperature at the end of the die cylinder is 475-480℃, and the temperature increases by 5℃ / 40mm along the extrusion direction. The extrusion ratio is 5:1 to ensure dynamic recrystallization and grain refinement. Then, the billet is rolled in sequence at 380℃ with 8% deformation, at 400℃ with 10% deformation, at 420℃ with 10% deformation, and at 440℃ with 12% deformation. Finally, the billet is rolled in 4 times at 350℃ with 90° cross rolling, each time with 10% deformation. The interval between each cross rolling is <30s to obtain the plate.

[0046] (5) The plate is subjected to cold rolling-annealing cycle treatment. After cold rolling deformation of 10%, the plate is annealed at 400℃ for 2 hours, then cold rolling deformation of 14% is annealed at 400℃ for 2 hours, then cold rolling deformation of 16% is annealed at 400℃ for 2 hours, and finally cold rolling deformation of 20% is obtained to obtain aluminum-manganese alloy after cold rolling-annealing cycle treatment.

[0047] (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment. First, it is solution treated at 500℃ for 1h, then water quenched, and then subjected to gradient aging treatment: the first stage is aging treatment at 120-125℃ for 3.5h, and the second stage is aging treatment at 160-165℃ for 8h, to obtain a high toughness and corrosion resistant aluminum-manganese alloy.

[0048] Table 3 Example 4 A preparation process for a high-toughness and corrosion-resistant aluminum-manganese alloy, the specific steps of which are as follows: (1) Weigh the raw materials according to the proportions in Table 4, preheat the raw materials in an oven at 200℃ for 2 hours, add the raw materials to the electromagnetic induction furnace in the order of Al, Zr, Cr, Mn, Cu, Si and Ce, evacuate the vacuum furnace to make the vacuum degree ≤0.05Pa, then introduce argon gas to reach 0.04MPa, and melt at 775℃ for 10 minutes to obtain liquid alloy.

[0049] (2) The liquid alloy liquid is poured into a 200mm×100mm×100mm metal mold to obtain an aluminum-manganese alloy ingot.

[0050] (3) The ingot is subjected to multi-stage homogenization heat treatment. The first stage is held at 310-315℃ for 7.5h, the second stage is held at 400-405℃ for 5.5h, and the third stage is held at 520-525℃ for 7.5h. Then it is air-cooled to obtain the billet after multi-stage homogenization heat treatment.

[0051] (4) The billet that has undergone multi-stage homogenization heat treatment is pre-extruded. The initial temperature at the end of the die cylinder is 470-475℃, and the temperature increases by 4℃ / 40mm along the extrusion direction. The extrusion ratio is 5:1 to ensure dynamic recrystallization and grain refinement. Then, the billet is rolled in sequence at 380℃ with 8% deformation, at 400℃ with 10% deformation, at 420℃ with 10% deformation, and at 440℃ with 12% deformation. Finally, the billet is rolled in 4 times at 350℃ with 90° cross rolling, each time with 10% deformation. The interval between each cross rolling is <30s to obtain the plate.

[0052] (5) The plate is subjected to cold rolling-annealing cycle treatment. After cold rolling deformation of 10%, the plate is annealed at 400℃ for 2 hours, then cold rolling deformation of 14% is annealed at 400℃ for 2 hours, then cold rolling deformation of 16% is annealed at 400℃ for 2 hours, and finally cold rolling deformation of 20% is obtained to obtain aluminum-manganese alloy after cold rolling-annealing cycle treatment.

[0053] (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment. First, it is solution treated at 500℃ for 1h, then water quenched, and then subjected to gradient aging treatment: the first stage is aging treatment at 120-125℃ for 4h, and the second stage is aging treatment at 175-180℃ for 7h, to obtain a high toughness and corrosion resistant aluminum-manganese alloy.

[0054] Table 4 like Figure 3 As shown, in the left ADF image, there are coarse blocky or irregularly shaped phases as well as a large number of fine, diffusely distributed nanoscale phases. Combined with EDS-mapping analysis, as shown in Figure (a2), Mn element is highly enriched in some areas. These areas correspond to the coarse phase in the left ADF image, which is consistent with the characteristics of Al6Mn phase. As shown in Figures (a1), (a3), and (a4), Al is widely and uniformly distributed as a matrix element. Mg and Cu elements are relatively dispersed and uniformly distributed, without showing obvious concentrated enrichment areas.

[0055] Comparative Example 1 A preparation process for an aluminum-manganese alloy, the specific steps of which are as follows: (1) Weigh the raw materials according to the proportions in Table 5, preheat the raw materials in an oven at 200℃ for 2 hours, add the raw materials to the electromagnetic induction furnace in the order of Al, Cr, Mn, Cu and Si, evacuate the vacuum furnace to make the vacuum degree ≤0.05Pa, then introduce argon gas to reach 0.04MPa, melt at 775℃ for 10 minutes to obtain liquid alloy.

[0056] (2) The liquid alloy liquid is poured into a 200mm×100mm×100mm metal mold to obtain an aluminum-manganese alloy ingot.

[0057] (3) The ingot is subjected to multi-stage homogenization heat treatment. The first stage is held at 315-320℃ for 7.5h, the second stage is held at 400-405℃ for 5.5h, and the third stage is held at 510-515℃ for 8h. Then it is air-cooled to obtain the billet after multi-stage homogenization heat treatment.

[0058] (4) The billet that has undergone multi-stage homogenization heat treatment is pre-extruded. The initial temperature at the end of the die cylinder is 470-475℃, and the temperature increases by 4℃ / 40mm along the extrusion direction. The extrusion ratio is 5:1 to ensure dynamic recrystallization and grain refinement. Then, the billet is rolled in sequence at 380℃ with 8% deformation, at 400℃ with 10% deformation, at 420℃ with 10% deformation, and at 440℃ with 12% deformation. Finally, the billet is rolled in 4 times at 350℃ with 90° cross rolling, each time with 10% deformation. The interval between each cross rolling is <30s to obtain the plate.

[0059] (5) The plate is subjected to cold rolling-annealing cycle treatment. After cold rolling deformation of 10%, the plate is annealed at 400℃ for 2 hours, then cold rolling deformation of 14% is annealed at 400℃ for 2 hours, then cold rolling deformation of 16% is annealed at 400℃ for 2 hours, and finally cold rolling deformation of 20% is obtained to obtain aluminum-manganese alloy after cold rolling-annealing cycle treatment.

[0060] (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment. First, it is solution treated at 500℃ for 1h, then water quenched, and then subjected to gradient aging treatment: the first stage is aging treatment at 125-130℃ for 3.5h, and the second stage is aging treatment at 165-170℃ for 7h to obtain aluminum-manganese alloy.

[0061] Table 5 In this comparative example, Ce and Zr were not added. Without the grain-refining and strengthening effects of Ce and Zr, the grains will be coarser, resulting in decreased strength and elongation, increased corrosion rate, and significantly increased susceptibility to stress corrosion cracking.

[0062] Comparative Example 2 A preparation process for an aluminum-manganese alloy, the specific steps of which are as follows: (1) Weigh the raw materials according to the proportions in Table 6, preheat the raw materials in an oven at 200℃ for 2 hours, add the raw materials to the electromagnetic induction furnace in the order of Al, Zr, Cr, Mn, Cu, Si and Ce, evacuate the vacuum furnace to make the vacuum degree ≤0.05Pa, then introduce argon gas to reach 0.04MPa, and melt at 775℃ for 10 minutes to obtain liquid alloy.

[0063] (2) The liquid alloy liquid is poured into a 200mm×100mm×100mm metal mold to obtain an aluminum-manganese alloy ingot.

[0064] (3) The ingot is subjected to a single temperature homogenization treatment, and is kept at 500℃ for 8 hours. Then the billet is taken out and air-cooled.

[0065] (4) The billet that has undergone multi-stage homogenization heat treatment is pre-extruded. The initial temperature at the end of the die cylinder is 470-475℃, and the temperature increases by 4℃ / 40mm along the extrusion direction. The extrusion ratio is 5:1 to ensure dynamic recrystallization and grain refinement. Then, the billet is rolled in sequence at 380℃ with 8% deformation, at 400℃ with 10% deformation, at 420℃ with 10% deformation, and at 440℃ with 12% deformation. Finally, the billet is rolled in 4 times at 350℃ with 90° cross rolling, each time with 10% deformation. The interval between each cross rolling is <30s to obtain the plate.

[0066] (5) The plate is subjected to cold rolling-annealing cycle treatment. After cold rolling deformation of 10%, the plate is annealed at 400℃ for 2 hours, then cold rolling deformation of 14% is annealed at 400℃ for 2 hours, then cold rolling deformation of 16% is annealed at 400℃ for 2 hours, and finally cold rolling deformation of 20% is obtained to obtain aluminum-manganese alloy after cold rolling-annealing cycle treatment.

[0067] (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment. First, it is solution treated at 500℃ for 1h, then water quenched, and then subjected to gradient aging treatment: the first stage is aging treatment at 125-130℃ for 3.5h, and the second stage is aging treatment at 165-170℃ for 7h to obtain aluminum-manganese alloy.

[0068] Table 6 This comparative example uses a single-temperature homogenization treatment instead of a three-stage gradient homogenization treatment, which results in uneven distribution of the second phase and a decrease in alloy properties.

[0069] Comparative Example 3 A preparation process for an aluminum-manganese alloy, the specific steps of which are as follows: (1) Weigh the raw materials according to the proportions in Table 7, preheat the raw materials in an oven at 200℃ for 2 hours, add the raw materials to the electromagnetic induction furnace in the order of Al, Zr, Cr, Mn, Cu, Si and Ce, evacuate the vacuum furnace to make the vacuum degree ≤0.05Pa, then introduce argon gas to reach 0.04MPa, and melt at 775℃ for 10 minutes to obtain liquid alloy.

[0070] (2) The liquid alloy liquid is poured into a 200mm×100mm×100mm metal mold to obtain an aluminum-manganese alloy ingot.

[0071] (3) The ingot is subjected to multi-stage homogenization heat treatment. The first stage is held at 315-320℃ for 7.5h, the second stage is held at 400-405℃ for 5.5h, and the third stage is held at 510-515℃ for 8h. Then the billet is taken out and air-cooled.

[0072] (4) The billet that has undergone multi-stage homogenization heat treatment is extruded at a temperature of 470-475℃ with an extrusion ratio of 5:1; then it is rolled in sequence at 380℃ with 8% deformation, at 400℃ with 10% deformation, at 420℃ with 10% deformation, and at 440℃ with 12% deformation; and then rolled in unidirectional direction 4 times at 400℃ with 10% deformation each time, with an interval of <30s between each rolling to obtain the plate.

[0073] (5) The plate is subjected to cold rolling-annealing cycle treatment. After cold rolling deformation of 10%, the plate is annealed at 400℃ for 2 hours, then cold rolling deformation of 14% is annealed at 400℃ for 2 hours, then cold rolling deformation of 16% is annealed at 400℃ for 2 hours, and finally cold rolling deformation of 20% is obtained to obtain aluminum-manganese alloy after cold rolling-annealing cycle treatment.

[0074] (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment. First, it is solution treated at 500℃ for 1h, then water quenched, and then subjected to gradient aging treatment: the first stage is aging treatment at 125-130℃ for 3.5h, and the second stage is aging treatment at 165-170℃ for 7h, to obtain a high toughness and corrosion resistant aluminum-manganese alloy.

[0075] Table 7 The comparative example suffers from coarse and uneven grains, significant anisotropy, and decreased alloy properties due to the lack of gradient heating during extrusion, the use of unidirectional rolling, and excessively high temperatures.

[0076] Comparative Example 4 A preparation process for an aluminum-manganese alloy, the specific steps of which are as follows: (1) Weigh the raw materials according to the proportions in Table 1, preheat the raw materials in an oven at 200℃ for 2 hours, add the raw materials to the electromagnetic induction furnace in the order of Al, Zr, Cr, Mn, Cu, Si and Ce, evacuate the vacuum furnace to make the vacuum degree ≤0.05Pa, then introduce argon gas to reach 0.04MPa, and melt at 775℃ for 10 minutes to obtain liquid alloy.

[0077] (2) The liquid alloy liquid is poured into a 200mm×100mm×100mm metal mold to obtain an aluminum-manganese alloy ingot.

[0078] (3) The ingot is subjected to a single temperature homogenization treatment, and is kept at 500℃ for 8 hours. Then the billet is taken out and air-cooled.

[0079] (4) The billet that has undergone multi-stage homogenization heat treatment is initially heated to 470-475℃ at the end of the die cylinder, and the temperature increases by 4℃ / 40mm along the extrusion direction. The extrusion ratio is 5:1 to ensure dynamic recrystallization and grain refinement. Then, it is rolled in sequence at 380℃ with 8% deformation, at 400℃ with 10% deformation, at 420℃ with 10% deformation, and at 440℃ with 12% deformation. Finally, it is rolled in 4 times at 350℃ with 90° cross rolling, each time with 10% deformation. The interval between each cross rolling is <30s to obtain the plate.

[0080] (5) The plate is subjected to composite heat treatment. First, it is solution treated at 500℃ for 1 hour, then water quenched, and then subjected to gradient aging treatment: the first stage is aging treatment at 125-130℃ for 3.5 hours, and the second stage is aging treatment at 165-170℃ for 7 hours to obtain a high toughness and corrosion resistant aluminum-manganese alloy.

[0081] Table 8 Even though this comparative alloy contains strengthening elements such as Ce and Zr, the lack of cold rolling and subsequent annealing processes prevents the optimization of the precipitation behavior of Ce and Zr strengthening phases through deformation heat treatment, resulting in poor dispersion distribution and size control, which further weakens the strength and hardness of the alloy.

[0082] The aluminum-manganese alloys prepared in Examples 1-4 and Comparative Examples 1-4 were tested for their properties, and the results are shown in Table 9.

[0083] Table 9 The aluminum-manganese alloy described in this invention exhibits significantly improved overall performance due to the addition of key elements such as Ce and Zr. Ce effectively enhances toughness and corrosion resistance by inhibiting grain growth and promoting the formation of a dense composite oxide film; Zr, by forming a nanoscale Al3Zr dispersed phase, strongly hinders dislocation movement and enhances the strengthening effect. This invention employs a gradient extrusion process to promote dynamic recrystallization to refine grains, combined with a cross-rolling process to reduce texture and further optimize microstructure uniformity; subsequently, cold rolling introduces work hardening, followed by annealing to eliminate internal stress and refine grains, achieving a synergistic improvement in strength and toughness. According to the performance data of high-toughness and corrosion-resistant aluminum-manganese alloy plates prepared by different processes in Table 9, Examples 1-4 are significantly superior to Comparative Examples 1-4 in terms of tensile strength, elongation, and corrosion resistance, confirming the positive effects of multi-element composite addition (Ce, Zr, etc.) on grain refinement and corrosion resistance, as well as the significant optimization effect of gradient homogenization, gradient extrusion, and multi-stage rolling synergistic treatment on microstructure. In addition, the homogenization treatment with gradual heating and the gradient aging process effectively establish a temperature gradient, which greatly reduces internal stress and thus enhances the toughness and corrosion resistance of aluminum-manganese alloy.

[0084] In summary, this invention achieves its goals by coupling multiple processes, such as precise multi-element proportioning with gradient homogenization, gradient extrusion, multi-stage rolling, cold rolling-annealing cycles, and composite heat treatment (e.g., ...). Figure 2 This process achieves grain refinement, uniform microstructure, dispersed distribution of reinforcing phases, and formation of a dense oxide film, resulting in high-strength, high-toughness, and high-corrosion-resistant aluminum-manganese alloy materials. These materials are suitable for industrial fields with high requirements for comprehensive material performance and provide a feasible solution for the preparation of related components.

[0085] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-toughness, corrosion-resistant aluminum-manganese alloy, characterized in that, The components and their mass percentages in the high-toughness and corrosion-resistant aluminum-manganese alloy are as follows: Mn 1.2-1.5%, Cu 0.4-0.6%, Si 0.4-0.7%, Ce 0.3-0.8%, Zr 0.1-0.3%, Cr 0.1-0.2%, with the balance being Al and unavoidable impurities, and the total amount of impurities ≤0.15%.

2. The preparation process of a high-toughness and corrosion-resistant aluminum-manganese alloy according to claim 1, characterized in that, Specifically, the following steps are included: (1) Mix and pretreat each raw material component according to the proportion, and then perform vacuum electromagnetic induction melting to obtain molten alloy liquid; (2) Cast the molten alloy liquid to obtain an aluminum-manganese alloy ingot; (3) The ingot is subjected to multi-stage homogenization heat treatment to obtain a billet that has undergone multi-stage homogenization heat treatment; (4) The billet that has undergone multi-stage homogenization heat treatment is subjected to temperature gradient pre-extrusion, temperature incremental rolling and hot cross rolling in sequence to obtain the plate. (5) The sheet metal is subjected to cold rolling-annealing cycle treatment to obtain an aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment; (6) The aluminum-manganese alloy that has undergone cold rolling-annealing cycle treatment is subjected to composite heat treatment to obtain a high-toughness and corrosion-resistant aluminum-manganese alloy.

3. The preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy according to claim 2, characterized in that, The pretreatment described in step (1) is to preheat the raw material at 150-250℃ for 1.5-2.5 hours.

4. The preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy according to claim 2, characterized in that, The vacuum electromagnetic induction melting described in step (1) is specifically as follows: evacuate the vacuum furnace to a vacuum degree ≤ 0.05 Pa, then introduce argon gas to reach 0.03~0.05 MPa, and then melt at 750~800℃ for 5~15 min.

5. The preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy according to claim 2, characterized in that, In step (3), the multi-stage homogenization process adopts a gradient heating method. The first stage is held at 300-330℃ for 7-8 hours, the second stage is held at 390-410℃ for 5-6 hours, and the third stage is held at 510-530℃ for 7-8 hours, followed by air cooling.

6. The preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy according to claim 2, characterized in that, In step (4), the gradient preheating extrusion conditions are: the temperature at the end of the die cylinder is 460-480℃, increasing by 3-5℃ / 40mm along the extrusion direction, and the extrusion ratio is 5:

1.

7. The preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy according to claim 2, characterized in that, In step (4), multi-directional rolling adopts gradient heating rolling and cross rolling, specifically: rolling 8% deformation along the rolling direction at 380℃, rolling 10% deformation along the rolling direction at 400℃, rolling 10% deformation along the rolling direction at 420℃, and rolling 12% deformation along the rolling direction at 440℃; then rolling 4 times at 350℃ with a cross rolling angle of 90°, each time with a deformation of 10%, and the interval between each cross rolling is <30s.

8. The preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy according to claim 2, characterized in that, In step (5), the cold rolling-annealing cycle is as follows: the sheet is cold rolled, and after cold rolling deformation of 10%, it is annealed at 400℃ for 2 hours, then cold rolled again, after cold rolling deformation of 14%, it is annealed at 400℃ for 2 hours, then cold rolled again, after cold rolling deformation of 16%, it is annealed at 400℃ for 2 hours, then cold rolled again, and the cold rolling deformation is 20%.

9. The preparation process of the high-toughness and corrosion-resistant aluminum-manganese alloy according to claim 2, characterized in that, The composite heat treatment described in step (6) is as follows: first, solution treatment at 500℃ for 1 hour, water quenching, followed by gradient aging treatment: the first stage is aging at 120-130℃ for 3.5-4 hours, and the second stage is aging at 160-180℃ for 7-8 hours.

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