Cold rolling process of aluminum-based silicon carbide coil stock

Abstract

The invention discloses a cold rolling process of an aluminum-based silicon carbide coil material. The cold rolling process comprises the following steps: carrying out surface treatment and coiling on a hot-rolled coil material; after the protective film is removed online, cold rolling-annealing I circulation is conducted, the single-pass rolling reduction of cold rolling is 5%-10%, the unit tension is 10%-30% of the yield strength of the material, the speed is smaller than or equal to 15 m / min, heat preservation is conducted for 1-2 h at the temperature of 430-480 DEG C in annealing I, and the heating and cooling rate is smaller than or equal to 10 DEG C / min; then edge cutting is carried out to remove edge cracks; the heating and cooling rate of the annealing II is smaller than or equal to 8 DEG C / min, and the heat preservation time is shorter than that of the annealing I; performing surface treatment after annealing II; and finally, finished product cold rolling is conducted, the single-pass rolling reduction is 5%-8%, and the speed is 5-10 m / min. By means of optimized multi-pass small rolling reduction rolling, staged temperature control annealing and tension control, the technical problem that the aluminum-based silicon carbide composite material is prone to cracking and strip breakage in the continuous cold rolling process is solved.

Description

Technical Field

[0001] This invention relates to the field of aluminum-based silicon carbide coil manufacturing technology, specifically to a cold rolling process for aluminum-based silicon carbide coils. Background Technology

[0002] Aluminum-based silicon carbide (SiCp / Al) composites are advanced materials with aluminum alloys as the matrix and silicon carbide particles as the reinforcing phase. This composite combines the ductility and toughness of metals with the high strength and high modulus of ceramics, exhibiting excellent properties such as high specific strength, high specific stiffness, low coefficient of thermal expansion, and good dimensional stability. These characteristics make it a promising candidate for applications in aerospace structural components, precision electronic packaging, and optical instrument support, where lightweighting, stiffness, and thermal stability are critical.

[0003] To achieve its engineering applications, it must be processed into wide-width coils. Currently, hot rolling is the plastic processing technology for producing such coils. This process involves heating aluminum-based silicon carbide ingots to a certain temperature (e.g., 450-500℃) and rolling them in multiple passes on a hot rolling mill to create a billet and roll it into a coil of a certain thickness. However, the difference in the coefficients of thermal expansion between silicon carbide particles and the aluminum matrix during high-temperature rolling can lead to interfacial stress concentration and easily induce microcracks under rolling forces. Furthermore, the hot-rolled sheets typically exhibit severe surface oxidation, and there is still room for improvement in the uniformity of the internal structure and dimensional accuracy.

[0004] To obtain coiled materials with higher precision, better quality, and superior performance, cold rolling is typically required after hot rolling. Existing cold rolling processes for aluminum-based silicon carbide composites are mostly limited to single-sheet, short-length production. This approach usually employs conservative process parameters, such as extremely low rolling speeds and minimal reduction per pass, to avoid cracking or breakage due to poor plasticity and rapid work hardening. This results in extremely low production efficiency and high costs.

[0005] Therefore, there is an urgent need to develop a cold rolling process that can achieve efficient, stable and continuous operation of aluminum-based silicon carbide coils. Summary of the Invention

[0006] The object of the present invention is to overcome at least one of the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the technical solution provided by the present invention is as follows.

[0008] A cold rolling process for aluminum-based silicon carbide coils includes the following steps performed sequentially: S01. The hot-rolled aluminum-based silicon carbide coil is surface-treated to remove the oxide layer and is then wound with a protective film. S02. After removing the protective film from the aluminum-based silicon carbide coil online, it is subjected to alternating cold rolling and annealing treatment I: In the cold rolling treatment, the reduction per pass is 5%~10%, the unit tension of the initial product is controlled at 10%~30% of the yield strength of the aluminum-based silicon carbide coil, and the rolling speed is ≤15m / min; In the annealing treatment I, the aluminum-based silicon carbide coil is heated to 430℃~480℃ and held for 1h~2h, and the heating and cooling rates are both ≤10℃ / min; S03. Trim the aluminum-based silicon carbide roll in the width direction to remove edge cracks; S04. The aluminum-based silicon carbide coil is subjected to alternating cold rolling and annealing treatment II: In annealing treatment II, the aluminum-based silicon carbide coil is heated to 430℃~480℃ and held for 1h~2h, the rolling speed is ≤15m / min, the heating and cooling rates are both ≤8℃ / min, and the holding time of annealing treatment II is shorter than that of annealing treatment I. S05. Perform surface treatment on the aluminum-based silicon carbide coil that has completed Annealing Treatment II to remove the oxide layer; S06. The surface-treated aluminum-based silicon carbide coil is cold-rolled until the target thickness is reached. During the cold rolling, the reduction per pass is 5% to 8%, and the rolling speed is controlled at 5m / min to 10m / min.

[0009] As a preferred technical solution, in steps S01 and / or S05, the surface treatment includes chemical cleaning or physical polishing, and after the surface treatment is completed, it is dried at 60℃~80℃ for 10min~15min. Chemical cleaning involves using a 5%–8% alkaline solution at 45°C–60°C for 5–10 minutes; physical polishing uses a polishing machine to remove a thickness of 0.04 mm–0.06 mm on one side.

[0010] As a preferred technical solution, in step S02, the aluminum-based silicon carbide coil is transferred to annealing treatment I when the total deformation reaches 20%~25%; and / or The cold rolling process uses a four-roll reversible cold rolling mill with roll diameters of 400mm to 500mm and a roll surface roughness Ra ≤ 0.2μm. The interval between two adjacent cold rolling passes is ≤ 30 seconds. During the cold rolling process, the roll temperature is maintained at 20℃ to 40℃, and the cooling method is emulsion spraying.

[0011] As a preferred technical solution, in step S03, the width removed by the edge trimming process is controlled between 2mm and 10mm.

[0012] As a preferred technical solution, in step S03, the edge cutting is carried out by a disc shear. The blade angle of the disc shear is 75°~85°, the overlap of the upper and lower blades is 0.05mm~0.15mm, the gap between the upper and lower blades is 8%~12% of the thickness of the aluminum-based silicon carbide coil, and the shearing speed is controlled at 10m / min~30m / min.

[0013] As a preferred technical solution, in step S03, the edge cutting process adopts pulsed laser cutting, and the laser cutting is configured with a protective atmosphere; wherein, the laser wavelength is 1050nm~1090nm, the pulse frequency is 20kHz~50kHz, and the cutting speed is controlled at 30mm / s~80mm / s.

[0014] As a preferred technical solution, during the pulsed laser cutting process, an emulsion is also simultaneously sprayed into the cutting area. The spraying pressure of the emulsion is between 0.8 MPa and 1.5 MPa, and the spraying direction is at an angle ≤15° with the axis of the laser beam.

[0015] As a preferred technical solution, in step S04, the holding time of annealing treatment II is shortened by 5% to 10% compared with the holding time of annealing treatment I.

[0016] As a preferred technical solution, the volume fraction of silicon carbide in the aluminum-based silicon carbide coil is 10% to 25%, with the remainder being aluminum and aluminum alloys.

[0017] An aluminum-based silicon carbide coil, made by any of the above technical features, has a tensile strength ≥580 MPa, a yield strength ≥480 MPa, an elongation ≥5%, and an elastic modulus ≥110 GPa.

[0018] The advantages and beneficial effects of this invention are as follows: by alternating cold rolling and annealing processes, the total deformation is decomposed into multiple increments, enabling the base aluminum alloy to gradually coordinate with SiC deformation through mechanisms such as dislocation slip; in response to the changes in heat transfer characteristics and mechanical state of the material as it thins during rolling, the later-stage annealing process employs stricter temperature control and shorter holding time, thereby avoiding the thermal stress caused by excessively fast or long heating due to shortened heat penetration time, which could lead to excessive temperature difference between the surface and the core, or cause excessive grain growth and damage to the material's performance.

[0019] This invention uses laser beams and other methods to remove existing or potentially expanding edge damage areas, eliminating the risk that edge cracks will become fracture sources in subsequent rolling with larger deformation, thus ensuring the continuity of the long coil rolling process. Simultaneous spraying of emulsion can remove the localized high heat generated by laser cutting, inhibiting the expansion of the heat-affected zone and reducing the tendency for microcracks caused by thermal stress. At the same time, the liquid film formed by the emulsion has a certain lubricating and scouring effect on the cut edges, helping to remove slag, smooth the cut surface, prevent uneven thermal expansion from affecting the sheet shape accuracy, and reduce the coefficient of friction and rolling force. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below. It is to be understood that the specific embodiments described herein are merely illustrative of this application and not intended to limit it. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0021] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly or implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] This invention provides a cold rolling process for aluminum-based silicon carbide coils to overcome the technical problems of poor plasticity, rapid work hardening, and easy edge cracking or even strip breakage in traditional cold rolling of aluminum-based silicon carbide materials (SiCp / Al). This process enables efficient, stable, and continuous production from hot-rolled intermediate coils to ultra-thin finished coils. The process described in this invention is particularly suitable for aluminum-based composite material coils with a silicon carbide volume fraction between 10% and 25%, ultimately yielding coils with excellent thickness accuracy, shape quality, and mechanical properties.

[0024] In step S01, the hot-rolled aluminum-based silicon carbide coil undergoes surface treatment to remove the oxide layer formed during hot rolling and subsequent storage. Removing the oxide layer is a prerequisite for achieving good surface quality in subsequent cold rolling; otherwise, the oxide scale will be pressed into the substrate during rolling, forming surface defects and exacerbating roll wear. After surface treatment, a protective film (such as a plastic diaphragm or paper) is used for winding. The purpose is to prevent scratches (interlayer abrasions) on the smooth strip surface due to relative sliding between layers during winding and transportation.

[0025] In step S02, the coil processed in step S01 is uncoiled, and after the protective film is removed online, it enters a cycle of the first "cold rolling treatment" and "annealing treatment I". The cold rolling treatment uses a rolling method with a small reduction, low speed, and moderate tension. Aluminum-based silicon carbide materials have limited plastic reserves, and the hard silicon carbide particles severely hinder the continuous plastic flow of the aluminum matrix. Excessive single-pass reduction will cause stress concentration at the particle / matrix interface due to insufficient matrix-coordinated deformation, inducing microcracks. A smaller reduction decomposes the total deformation, allowing the matrix to gradually and coordinately accommodate hard particles in multiple passes through mechanisms such as dislocation slip and climb, alleviating stress concentration. The lower speed reduces the rate of deformation heat generation, which is beneficial for roll and strip temperature control, while providing more time for stress relaxation within the material. Moderate tension provides stable longitudinal tensile stress on the one hand, assisting in straight strip bite and stable rolling; on the other hand, excessive tension will apply additional tensile stress to the brittle material edges, increasing the risk of edge cracking.

[0026] When the cumulative cold rolling deformation reaches 20%~25%, the material's work hardening is relatively complete, and its plasticity is almost exhausted, necessitating intermediate annealing. The annealing temperature is set at 430℃~480℃, held for 1~2 hours, with both heating and cooling rates not exceeding 10℃ / min. This temperature range is higher than the recrystallization temperature of the aluminum matrix, sufficient to drive a full static recrystallization and recovery process. Crystal defects introduced by cold rolling, such as dislocations, are annihilated and rearranged during this process, forming new, distortion-free grains, thereby eliminating work hardening to a certain extent and restoring the material's plastic deformation capacity. Controlling the heating and cooling rates helps mitigate the thermal stress caused by the difference in thermal expansion coefficients between SiC particles and the aluminum matrix.

[0027] Step S03: After the initial cold rolling annealing cycle, the strip edges are in a "free edge" state and are subjected to complex stress states during rolling, making it difficult to avoid the formation of microcracks. This step involves trimming the edges in the width direction to actively remove these existing edge crack areas, eliminating the risk that they will become stress concentration sources and fracture initiation points in subsequent rolling with larger cumulative deformation.

[0028] In step S04, the trimmed coil continues to undergo alternating cycles of cold rolling and annealing treatment II. This step further thins the strip while optimizing for changes in material state. The temperature window in annealing treatment II remains 430℃~480℃, but the heating and cooling rates are more stringent, and the holding time is shorter than in annealing treatment I. After the preceding rolling and annealing, the strip thickness has been reduced. According to Fourier's law of thermal conductivity, the characteristic thermal diffusion time constant of a thin plate is proportional to the square of its thickness. Thinning means a shorter time for heat to transfer from the surface to the core, making the temperature across the entire cross-section more uniform, but also making it more sensitive to the rate of temperature change. Slower heating and cooling rates are used to further smooth out the cross-sectional temperature difference and minimize thermal stress under thin plate conditions. Shortening the holding time is to reduce the time required for the thin strip to reach thermal equilibrium and complete recrystallization. Excessive holding time may lead to excessive growth of recrystallized grains. According to the Hall-Petch relationship, coarse grains reduce material strength and may impair its plasticity, which is detrimental to subsequent final rolling.

[0029] After annealing treatment II is completed in step S05, a new oxide layer will form on the surface of the coil. Before entering the final product rolling, it must be removed by surface treatment again to ensure that the finished product is rolled on a clean metal surface to obtain a bright and defect-free final surface.

[0030] Step S06 involves the final cold rolling pass of the surface-treated coil until the target thickness is achieved. During this stage, the reduction per pass is further reduced to 5%–8%, and the rolling speed is controlled at 5–10 m / min. Near the finished thickness, the absolute thickness of the strip is very small, and any uneven deformation can easily lead to poor strip shape. Smaller reduction and more conservative speed settings facilitate precise response and adjustment of the rolling force and strip shape control system, ensuring high-precision thickness and straightness.

[0031] In some embodiments, to efficiently and flexibly remove the oxide layer, the surface treatment in steps S01 and / or S05 includes chemical cleaning or physical polishing. Chemical cleaning can use a 5%–8% alkaline solution (such as NaOH solution) at 45°C–60°C for 5–10 minutes to dissolve the alumina through chemical corrosion. Physical polishing can use equipment such as a flap wheel polisher to remove the oxide layer through mechanical grinding, with the thickness removed on one side controlled at 0.04 mm–0.06 mm. Insufficient removal will result in incomplete oxide layer removal, while excessive removal will lead to material waste and may introduce new surface inhomogeneities. After surface treatment, drying at 60°C–80°C for 10–15 minutes removes surface moisture to prevent residual water stains from causing corrosion or affecting rolling lubrication in subsequent processes.

[0032] In some embodiments, to precisely control the timing of the first annealing, step S02 sets the aluminum-based silicon carbide coil to undergo annealing treatment I when the total deformation reaches 20%~25%. If the deformation is less than 20%, the work hardening is insufficient, the annealing efficiency is low, and unnecessary heat treatment cycles are increased; if the deformation exceeds 25%, the work hardening of the material is too severe, the plasticity reserve is too low, and the risk of brittle cracking increases during the last rolling pass before annealing or when uncoiling after annealing.

[0033] In some embodiments, the cold rolling process in step S02 employs a four-roll reversible cold rolling mill. The roll diameter is preferably 400mm~500mm, and the roll surface roughness Ra≤0.2μm to ensure a smooth strip surface. The interval between two adjacent cold rolling passes is controlled within 30 seconds to reduce the strip's idle time in the mill, maintain the continuity of the rolling rhythm, and avoid uneven temperature distribution caused by short pauses. During cold rolling, the roll temperature is maintained at 20℃~40℃ using an emulsion spraying system. The emulsion's functions include, but are not limited to, cooling and removing the heat generated by rolling deformation, preventing uneven thermal expansion of the rolls from affecting the strip shape, controlling the strip temperature rise to prevent dynamic recovery softening; forming a fluid lubricating film between the rolls and the strip to reduce the coefficient of friction and rolling force; and flushing away small particles that detach during rolling to protect the strip surface.

[0034] In some embodiments, the width of the edge removal in step S03 is controlled between 2mm and 10mm. Removing too little may fail to completely remove the crack root; removing too much will result in a loss of yield. Edge removal can be performed using rotary shears or simulating laser cutting.

[0035] Specifically, the blade angle of the disc shear is set at 75°~85°, the overlap between the upper and lower blades is 0.05mm~0.15mm, and the gap is set at 8%~12% of the strip thickness.

[0036] Pulsed laser cutting. Utilizing near-infrared pulsed lasers with wavelengths of 1050nm~1090nm, frequencies of 20kHz~50kHz, and speeds of 30mm / s~80mm / s. Laser cutting is a non-contact process, free from mechanical stress, and is particularly suitable for materials that are already hardened or semi-hardened and sensitive to mechanical impact. A protective atmosphere (such as argon) is used in the cutting area to prevent high-temperature oxidation of the cut.

[0037] Furthermore, during pulsed laser cutting, an emulsion with a pressure of 0.8~1.5MPa is simultaneously sprayed into the cutting area, with the spray direction forming an angle ≤15° with the laser beam axis. The emulsion jet adheres closely to the laser's point of action, rapidly carrying away the high heat generated by laser processing, reducing the heat-affected zone (HAZ), and suppressing the tendency for microcracks caused by thermal stress. Simultaneously, the liquid film lubricates and washes away molten spatter (slag), helping to remove it and resulting in a smoother cut surface. Coaxial, small-angle spraying ensures the cooling medium is precisely applied to the high-temperature area, maximizing cooling efficiency while avoiding interference with the laser beam path or energy transmission.

[0038] In some embodiments, the holding time of annealing treatment II is shortened by 5% to 10% compared to annealing treatment I. As the strip thins, its specific surface area increases, resulting in faster heat dissipation and heating, and a correspondingly shorter recrystallization incubation period and completion time. Appropriately shortening the holding time is sufficient to ensure complete recrystallization while avoiding grain coarsening caused by overheating or excessively long holding times, thereby preserving the material's fine-grain strengthening potential while restoring plasticity.

[0039] In some embodiments, the entire process can be completed on an integrated continuous or semi-continuous production line. The production line, in sequence, may include: an uncoiler, a surface treatment unit, a mill inlet tension station, a four-high reversible cold rolling mill (equipped with a high-precision hydraulic AGC thickness control system), a mill outlet tension station, an online trimming device, a coiler, and an emulsion circulation cooling and filtration system throughout the line. The annealing process is carried out in a bell-type annealing furnace or a continuous pass-through annealing furnace.

[0040] The aluminum-based silicon carbide coils that this invention is suitable for processing contain silicon carbide in a volume fraction of 10% to 25%, with the remainder being aluminum and aluminum alloys, such as heat-treatable aluminum alloys like 6061 and 6092 as the matrix.

[0041] The present invention will be further explained and illustrated below with reference to the embodiments.

[0042] [Example 1] A cold rolling process for aluminum-based silicon carbide coils is disclosed for processing 6092 aluminum-based composite materials with a silicon carbide volume fraction of 17.5%. The objective is to roll hot-rolled coils with dimensions of 0.8mm × 220mm into finished products with dimensions of 0.3mm × 220mm. The specific steps are as follows: S01. The hot-rolled aluminum-based silicon carbide coil is physically polished. A flap wheel polisher is used to remove the surface oxide layer, with a thickness of approximately 0.05 mm removed on each side. After polishing, the coil is dried in an oven at 75°C for 12 minutes, and then wound together using a plastic diaphragm to prevent interlayer abrasion.

[0043] S02. After removing the protective film online, the coil enters the cold rolling process. A four-high reversible cold rolling mill (450mm roll diameter) with a roll surface roughness Ra=0.15μm is used for rolling. The single-pass reduction is controlled at 6%, the unit tension is set to 20% of the material's yield strength (approximately 300MPa), and the rolling speed is set to 12m / min. The interval between adjacent passes is approximately 20 seconds, and the rolls are cooled by emulsion spray to maintain the temperature at around 30℃. When the total deformation accumulates to 22%, cold rolling is stopped, and annealing treatment I begins. The coil is placed in an annealing furnace, heated to 450℃ at a rate of 8℃ / min, held at that temperature for 1.5 hours, and then furnace cooled to room temperature at a rate of 8℃ / min.

[0044] S03. After annealing, the coil is mechanically trimmed using a disc shear to remove edge cracks. The disc shear blade angle is 80°, the overlap between the upper and lower blades is 0.10mm, the gap is 10% of the current coil thickness (approximately 0.62mm), and the shearing speed is 20m / min. The width removed from each side is 4mm.

[0045] S04. After trimming, continue cold rolling to reduce the thickness, with the same process parameters as in S02. Then, perform Annealing II, heating to 440°C at a rate of 6°C / min, holding for 1.4 hours, and then furnace cooling at a rate of 6°C / min. The total deformation during cold rolling is controlled at approximately 22%.

[0046] S05. The coil material is physically polished again to remove the oxide layer formed by annealing, and then dried for later use.

[0047] S06. A low-speed rolling mode is adopted, with a single-pass reduction of 6% and the rolling speed reduced to 8m / min. The target thickness of 0.3mm is finally achieved through multiple passes.

[0048] The aluminum-based silicon carbide coil obtained in this embodiment has a thickness of 0.298±0.004mm and a flatness controlled below 5I. The continuous rolling process of the entire coil is stable, with no strip breakage and no new cracks after edge trimming. The tensile strength is 595MPa, the yield strength is 495MPa, the elongation is 5.8%, and the elastic modulus is 112GPa. The total process time from uncoiling to coiling (excluding annealing and heat preservation time) is approximately 4.5 hours.

[0049] [Example 2] A cold rolling process for aluminum-based silicon carbide coils is disclosed for processing 6061 aluminum-based composite materials with a silicon carbide volume fraction of 12%. The goal is to roll hot-rolled coils with dimensions of 1.0 mm × 300 mm into finished products with dimensions of 0.35 mm × 300 mm. The specific steps are as follows: S01. Chemical cleaning treatment is performed on the hot-rolled aluminum-based silicon carbide coil. The coil is immersed in a 6.5% NaOH alkaline solution and cleaned at 55°C for 8 minutes, then rinsed with clean water. After cleaning, the coil is dried online at 65°C for 13 minutes, and then wound up using a paper separator.

[0050] S02. After removing the protective film online, the coil enters the cold rolling process. A four-high reversible cold rolling mill (420mm roll diameter) with a roll surface roughness Ra=0.18μm is used for rolling. The single-pass reduction is controlled at 8%, the unit tension is set to 15% of the material's yield strength (approximately 280MPa), and the rolling speed is set to 10m / min. The interval between adjacent passes is approximately 25 seconds, and the rolls are cooled by emulsion spray to maintain the temperature at around 25℃. When the total deformation reaches 21%, cold rolling is stopped, and annealing treatment I begins. The coil is placed in an annealing furnace, heated to 460℃ at a rate of 9℃ / min, held for 1.2 hours, and then furnace cooled to room temperature at a rate of 9℃ / min.

[0051] S03. The annealed coil is then edge-trimmed using pulsed laser cutting to remove edge cracks. The laser wavelength is 1064nm, the pulse frequency is 40kHz, and the cutting speed is controlled at 50mm / s. Argon gas is used as a protective atmosphere during the cutting process. Simultaneously with laser cutting, an emulsion at a pressure of 1.0MPa is sprayed into the cut area at a 10° angle to the laser beam axis. A 6mm wide section is removed from each side.

[0052] S04. After trimming, continue cold rolling to reduce the thickness, with the same process parameters as in S02. Then, perform Annealing II, heating to 455°C at a rate of 7°C / min, holding for 1.1 hours, and then furnace cooling at a rate of 7°C / min. The total deformation during cold rolling is controlled at approximately 22%.

[0053] S05. The coiled material is chemically cleaned again to remove the oxide layer formed during annealing, and then dried for later use.

[0054] S06. A low-speed rolling mode is adopted, with a single-pass reduction of 7% and the rolling speed reduced to 6m / min. The target thickness of 0.35mm is finally achieved through multiple passes.

[0055] The aluminum-based silicon carbide coil obtained in this embodiment has a thickness of 0.348±0.005mm and a flatness controlled below 6I. The continuous rolling process of the entire coil is stable, and no strip breakage occurs. The tensile strength is 605MPa, the yield strength is 500MPa, the elongation is 6.5%, and the elastic modulus is 115GPa. The total process time from unwinding to coil winding is approximately 5.2 hours.

[0056] [Example 3] A cold rolling process for aluminum-based silicon carbide coils is disclosed for processing customized aluminum-based composite materials with a silicon carbide volume fraction of 22%. The goal is to roll hot-rolled coils with dimensions of 0.9mm × 200mm into finished products with dimensions of 0.28mm × 200mm. The specific steps are as follows: S01. The hot-rolled aluminum-based silicon carbide coil is physically polished. A flap wheel polisher is used to remove the surface oxide layer, with a thickness of approximately 0.045 mm removed on each side. After polishing, the coil is dried in an oven at 70°C for 15 minutes, and then wound together using a plastic diaphragm.

[0057] S02. After removing the protective film online, the coil enters the cold rolling process. A four-high reversible cold rolling mill (480mm roll diameter) with a roll surface roughness Ra=0.12μm is used for rolling. The single-pass reduction is controlled at 9%, the unit tension is set to 25% of the material's yield strength (approximately 320MPa), and the rolling speed is set to 14m / min. The interval between adjacent passes is approximately 15 seconds, and the rolls are cooled by emulsion spray to maintain the temperature at around 35℃. When the total deformation reaches 24%, cold rolling is stopped, and annealing treatment I begins. The coil is placed in an annealing furnace, heated to 470℃ at a rate of 10℃ / min, held for 1.8 hours, and then furnace cooled to room temperature at a rate of 10℃ / min.

[0058] S03. After annealing, the coil is mechanically trimmed using a disc shear to remove edge cracks. The disc shear blade angle is 78°, the overlap between the upper and lower blades is 0.12mm, the gap is 9% of the current coil thickness (approximately 0.68mm), and the shearing speed is 15m / min. The width removed from each side is 8mm.

[0059] S04. After trimming, continue cold rolling for thinning, with the same process parameters as in S02. Then, perform Annealing II, heating to 465°C at a rate of 8°C / min, holding for 1.6 hours, and then furnace cooling at a rate of 8°C / min. The total deformation during cold rolling is controlled at approximately 23%.

[0060] S05. Perform physical polishing on the coiled material again to remove the oxide layer formed by annealing, and then dry it for later use.

[0061] S06. A low-speed rolling mode is adopted, with a single-pass reduction of 5.5% and the rolling speed reduced to 9m / min. The target thickness of 0.28mm is finally achieved through multiple passes.

[0062] The aluminum-based silicon carbide coil obtained in this embodiment has a thickness of 0.279±0.006mm and a flatness controlled below 4I. The subsequent rolling process was stable, with no strip breakage. The tensile strength is 620MPa, the yield strength is 520MPa, the elongation is 5.2%, and the elastic modulus is 118GPa. The total process time from uncoiling to coil winding is approximately 5.8 hours.

[0063] [Example 4] A cold rolling process for aluminum-based silicon carbide coils is disclosed for processing aluminum-based composite materials with a silicon carbide volume fraction of 18%. The objective is to roll hot-rolled coils with dimensions of 1.2mm × 200mm into finished products with dimensions of 0.4mm × 200mm. The specific steps are as follows: S01. Chemical cleaning treatment is performed on the hot-rolled aluminum-based silicon carbide coil. The coil is immersed in a 7.5% NaOH alkaline solution and cleaned at 50°C for 6 minutes, then rinsed with clean water. After cleaning, the coil is dried in an oven at 80°C for 10 minutes, and then wound up using a plastic diaphragm.

[0064] S02. After removing the protective film online, the coil enters the cold rolling process. A four-high reversible cold rolling mill (500mm roll diameter) with a roll surface roughness Ra=0.20μm is used for rolling. The single-pass reduction is controlled at 7%, the unit tension is set to 28% of the material's yield strength (approximately 310MPa), and the rolling speed is set to 8m / min. The interval between adjacent passes is approximately 30 seconds, and the rolls are cooled by emulsion spray to maintain the temperature at around 40℃. When the total deformation accumulates to 20%, cold rolling is stopped, and annealing treatment I begins. The coil is placed in an annealing furnace, heated to 435℃ at a rate of 6℃ / min, held for 1.0 hour, and then furnace cooled to room temperature at a rate of 6℃ / min.

[0065] S03. The annealed coil is then edge-trimmed using pulsed laser cutting to remove edge cracks. The laser wavelength is 1080nm, the pulse frequency is 25kHz, and the cutting speed is controlled at 70mm / s. Argon gas is used as a protective atmosphere during the cutting process. Simultaneously with laser cutting, an emulsion at a pressure of 1.4MPa is sprayed into the cut area at a 5° angle to the laser beam axis. A 3mm wide section is removed from each side.

[0066] S04. After trimming, continue cold rolling to reduce the thickness, with the same process parameters as in stage S02. Then, perform Annealing II, heating to 430°C at a rate of 5°C / min, holding for 0.95 hours, and then furnace cooling at a rate of 5°C / min. The total deformation of cold rolling is controlled at approximately 21%.

[0067] S05. The coiled material is chemically cleaned again to remove the oxide layer formed during annealing, and then dried for later use.

[0068] S06. A low-speed rolling mode is adopted, with a single-pass reduction of 7.5% and the rolling speed reduced to 5m / min. The target thickness of 0.4mm is finally achieved through multiple passes.

[0069] The aluminum-based silicon carbide coil obtained in this embodiment has a thickness of 0.398±0.005mm and a flatness controlled below 5I. The continuous rolling process of the entire coil is stable, without cracking or breakage. The tensile strength is 585MPa, the yield strength is 485MPa, the elongation is 6.0%, and the elastic modulus is 113GPa. The total process time from unwinding to coil winding is approximately 6.5 hours.

[0070] [Comparative Example 1] Aluminum-based silicon carbide coils were prepared using a traditional hot rolling process. A 6092 aluminum-based silicon carbide ingot with a silicon carbide volume fraction of 17.5% was heated to 480°C and directly rolled from a 20mm thick ingot into a 0.8mm thick coil through multiple hot rolling passes. After rolling, simple straightening and cleaning were performed; no subsequent cold rolling was carried out.

[0071] The resulting coil surface was severely oxidized, appearing dark gray. Thickness accuracy was poor, fluctuating by more than ±0.03 mm. The sheet shape was poor, exhibiting obvious waviness. Due to the combined effects of thermal and rolling stresses during hot rolling, visible cracks were present at the edges. The tensile strength was 510 MPa, the yield strength was 420 MPa, the elongation was only 3.5%, and the elastic modulus was 108 GPa.

[0072] [Comparative Example 2] A cold rolling process for aluminum-based silicon carbide coils is similar to that in Example 1, but in the cold rolling processes of S02 and S04, the single-pass reduction is increased to 18%, while the other parameters remain unchanged.

[0073] After the first pass of the first cold rolling, obvious macroscopic cracks appeared on the edge of the strip. During the second rolling pass, the cracks propagated rapidly, causing the strip to break in the mill and making it impossible to continue subsequent processes.

[0074] [Comparative Example 3] A cold rolling process for aluminum-based silicon carbide coils is basically the same as that in Example 2, but the cooling rate is increased to 30°C / min in annealing treatments I and II.

[0075] After the first annealing, the material's plasticity was somewhat restored, allowing it to continue rolling. However, after the second annealing, during the finished product rolling stage, the strip frequently experienced edge cracking and broke when rolled to a thickness of approximately 0.4 mm.

[0076] [Comparative Example 4] A cold rolling process for aluminum-based silicon carbide coils, with steps similar to those in Example 3, but without the SO3 edge trimming step.

[0077] Visible microcracks were present at the edge of the strip after the first cold rolling and annealing cycle was completed.

[0078] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention 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 protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A cold rolling process for aluminum-based silicon carbide coils, characterized in that, This includes the following steps performed sequentially: S01. The hot-rolled aluminum-based silicon carbide coil is surface-treated to remove the oxide layer and is then wound with a protective film. S02. After removing the protective film from the aluminum-based silicon carbide coil online, it is subjected to alternating cold rolling and annealing treatment I: In the cold rolling treatment, the reduction per pass is 5% to 10%, the unit tension is controlled at 10% to 30% of the yield strength of the aluminum-based silicon carbide coil, and the rolling speed is ≤15m / min; In the annealing treatment I, the aluminum-based silicon carbide coil is heated to 430℃ to 480℃ and held for 1h to 2h, and the heating and cooling rates are both ≤10℃ / min; S03. Trim the aluminum-based silicon carbide coil in the width direction to remove edge cracks; S04. The aluminum-based silicon carbide coil after edge trimming is subjected to alternating cold rolling and annealing treatment II: In the annealing treatment II, the aluminum-based silicon carbide coil is heated to 430℃~480℃ and held for 1h~2h, the rolling speed is ≤15m / min, the heating and cooling rates are both ≤8℃ / min, and the holding time of the annealing treatment II is shorter than the holding time of the annealing treatment I. S05. Perform surface treatment on the aluminum-based silicon carbide coil that has completed Annealing Treatment II to remove the oxide layer; S06. The surface-treated aluminum-based silicon carbide coil is cold-rolled until the target thickness is reached. In the cold rolling, the reduction per pass is 5% to 8%, and the rolling speed is controlled at 5m / min to 10m / min.

2. The cold rolling process for aluminum-based silicon carbide coils according to claim 1, characterized in that, In step S01 and / or step S05, the surface treatment includes chemical cleaning or physical polishing, and after the surface treatment is completed, it is dried at 60℃~80℃ for 10min~15min. The chemical cleaning uses an alkaline solution with a concentration of 5% to 8% and is performed at a temperature of 45°C to 60°C for 5 to 10 minutes. The physical polishing uses a polishing machine, and the thickness removed on one side of the polished surface is 0.04 mm to 0.06 mm.

3. The cold rolling process for aluminum-based silicon carbide coils according to claim 1, characterized in that, In step S02, the aluminum-based silicon carbide coil is transferred to the annealing treatment I when the total deformation reaches 20% to 25%.

4. The cold rolling process for aluminum-based silicon carbide coils according to claim 1, wherein the cold rolling process adopts a four-roll reversible cold rolling mill, the roll diameter is 400mm~500mm, the roll surface roughness Ra≤0.2μm; the single-pass reduction is 5%~10%, the interval between two adjacent cold rolling passes is ≤30 seconds; the roll temperature is maintained at 20℃~40℃ during the cold rolling process, and the cooling method is emulsion spraying.

5. The cold rolling process for aluminum-based silicon carbide coils according to claim 1, characterized in that, In step S03, the width removed during the edge trimming process is controlled between 2mm and 10mm.

6. The cold rolling process for aluminum-based silicon carbide coils according to claim 5, characterized in that, In step S03, the edge trimming is performed using a circular shear. The blade angle of the circular shear is between 75° and 85°, the overlap between the upper and lower blades is between 0.05mm and 0.15mm, the gap between the upper and lower blades is 8% to 12% of the thickness of the aluminum-based silicon carbide coil, and the shearing speed is controlled between 10m / min and 30m / min.

7. The cold rolling process for aluminum-based silicon carbide coils according to claim 5, characterized in that, In step S03, the edge trimming process uses pulsed laser cutting, and the laser cutting is configured with a protective atmosphere; wherein, the laser wavelength is 1050nm~1090nm, the pulse frequency is 20kHz~50kHz, and the cutting speed is controlled at 30mm / s~80mm / s.

8. The cold rolling process for aluminum-based silicon carbide coils according to claim 7, characterized in that, During the pulsed laser cutting process, an emulsion is simultaneously sprayed into the cutting area. The spraying pressure of the emulsion is between 0.8 MPa and 1.5 MPa, and the spraying direction is at an angle ≤15° with the axis of the laser beam.

9. The cold rolling process for aluminum-based silicon carbide coils according to claim 1, characterized in that, In step S04, the holding time of annealing treatment II is shortened by 5% to 10% compared with the holding time of annealing treatment I.

10. An aluminum-based silicon carbide coil obtained by the cold rolling process of any one of claims 1 to 9, characterized in that, The volume fraction of silicon carbide in the aluminum-based silicon carbide coil is 10%~25%, with the balance being aluminum and aluminum alloys; the tensile strength of the aluminum-based silicon carbide coil is ≥580MPa, the yield strength is ≥480MPa, the elongation is ≥5%, and the elastic modulus is ≥110GPa.