A method for preparing an aluminum matrix composite thin strip by continuous casting

Abstract

This invention belongs to the field of aluminum-based composite material preparation technology, and relates to a continuous casting and rolling method for preparing aluminum-based composite material strips. The method involves preparing a reinforcing preform with a thickness not exceeding the roll gap distance in the aluminum-based composite material strip. Before preparing the aluminum-based composite material strip, the casting rolls are water-cooled and run at a set speed. Molten aluminum is injected into the molten pool, and the liquid level is controlled to a set value. Throughout the preparation process, the molten pool liquid level is maintained at the set value. The molten aluminum cools and solidifies upon contact with the roll surface of the casting rolls. Under the casting action of the two casting rolls, an aluminum alloy strip is formed and continuously output from the lower end of the roll gap. During the preparation process, the reinforcing preform moves from top to bottom at a set speed and is immersed in the molten aluminum pool. The molten aluminum penetrates into and fills the interior of the reinforcing preform. The reinforced preform, filled with molten aluminum, gradually solidifies as it moves to the roll gap until it is completely solidified. Then, under the casting force of the two casting rolls, it undergoes rolling deformation to form the aluminum-based composite material strip.

Description

Technical Field

[0001] This invention belongs to the field of aluminum-based composite material preparation technology, and relates to a method for continuous casting and rolling of aluminum-based composite material strips. Background Technology

[0002] Aluminum-based composite materials possess advantages such as low density, corrosion resistance, high strength, and high modulus. Driven by trends towards carbon reduction and lightweighting, they are widely used in high-end manufacturing fields such as aerospace, defense weaponry, and automotive. Aluminum-based composite sheet and strip materials are crucial raw materials for manufacturing core components such as aerospace vehicle skins, stringers, and weapon protective devices, with large quantities and urgent demand. Depending on the types of matrix and reinforcement, the preparation methods for aluminum-based composite materials mainly include powder metallurgy, stirred casting, jet deposition, in-situ composite methods, liquid infiltration, and additive manufacturing.

[0003] Powder metallurgy involves mechanically mixing aluminum powder with reinforcement and then hot-pressing and sintering to prepare composite materials. It offers advantages such as fine microstructure and minimal segregation, but the process is complex, aluminum powder is expensive, energy consumption is high, efficiency is low, and large-scale production is difficult. Stirred casting involves adding reinforcement to molten aluminum at high temperatures and achieving uniform dispersion through stirring before casting into ingots. Its advantages include the ability to use traditional casting processes, simple equipment operation, and high efficiency, but it suffers from severe segregation and uneven reinforcement dispersion. Spray deposition involves atomizing molten aluminum droplets and simultaneously spraying them with reinforcement under high-pressure airflow onto a substrate to form a composite material. This method is flexible and efficient, but suffers from defects such as non-density and porosity. In-situ composite methods involve introducing elements or compounds into the aluminum matrix to react and generate a reinforcing phase within the matrix, forming a composite material. Because the reinforcement is generated in situ, it offers advantages such as good compatibility, fine and uniform reinforcement, and simple processing. However, it has disadvantages such as the inability to artificially control the reinforcement and low design flexibility. Liquid infiltration involves first preparing a preform of reinforcement with a certain volume fraction of voids, then infiltrating molten aluminum into the preform to form a composite material. This method offers advantages such as uniform reinforcement distribution and high design flexibility. Additive manufacturing, on the other hand, involves melting, mixing, and solidifying the reinforcement with aluminum powder under high-energy heating methods such as lasers or electron beams, and then depositing the mixture layer by layer to create the composite material. This process suffers from problems such as porosity, high density, and high residual stress, and is still under research.

[0004] Overall, the aluminum-based composite materials prepared by the above methods are mostly bulk materials. To obtain aluminum-based composite strips, rolling is still required. However, aluminum-based composite materials have higher strength, greater deformation resistance, poor plasticity, and are prone to cracking than aluminum alloys. Thin strip rolling is difficult, production costs are high, energy consumption is high, and preparation efficiency is extremely low. There is an urgent need to develop a new and efficient method for preparing aluminum-based composite strips. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for continuous casting and rolling of aluminum-based composite material strips. By continuously conveying and impregnating the reinforcing preform, and under the action of rapid cooling and casting force, the continuous forming of aluminum-based composite material strips is achieved, reducing or eliminating the need for subsequent rolling processes, thereby reducing the process flow and improving the preparation efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for continuous casting and rolling of aluminum-based composite strip includes a pair of horizontally and parallelly placed casting rolls, with a set gap between the rolls and a water-cooling channel inside the rolls. It also includes a molten pool for containing molten aluminum, which is made of refractory material and metal frame. The molten pool is placed directly above the two casting rolls. The side of the molten pool parallel to the axis of the casting rolls is the side surface, and the side perpendicular to the axis of the casting rolls is the end surface. The lower ends of the two side surfaces are in contact with the roll surface, and the two end surfaces extend downward to the minimum gap and are in contact with the roll surface. The molten pool forms a cavity with an opening at the top, an opening at the bottom matching the size of the gap, and a closed perimeter.

[0008] The preparation method specifically includes the following steps:

[0009] The reinforcement in the aluminum matrix composite strip is made into a preform with a thickness not greater than the roll gap. Before preparing the aluminum matrix composite strip, the casting roll is water-cooled and runs at a set speed. The aluminum liquid is injected into the molten pool and the liquid level is controlled to the set value. The liquid level in the molten pool is kept at the set value throughout the preparation process. The aluminum liquid comes into contact with the roll surface of the casting roll and cools and solidifies. Under the casting and rolling action of the two casting rolls, an aluminum alloy strip is formed and continuously output from the lower end of the roll gap. The whole process reaches a stable state.

[0010] During the preparation process, the reinforcing preform moves from top to bottom at a set speed and is first immersed in the molten aluminum pool. The molten aluminum penetrates into the interior of the reinforcing preform and fills it completely. As the reinforcing preform, which is filled with molten aluminum, moves to the roll gap, it gradually solidifies until it is completely solidified. Then, it undergoes rolling deformation under the casting force of two casting rolls and is continuously fed downwards out of the roll gap under the friction of the casting rolls to form a thin strip of aluminum-based composite material, which is collected after cooling.

[0011] Furthermore, it also includes a pretreatment furnace arranged directly above the molten pool;

[0012] Before preparation, the pretreatment furnace is turned on and heated to the set temperature. During the preparation process, the reinforcing preform moves from top to bottom at a set speed and is heated to the pretreatment temperature by the pretreatment furnace. Then it is immersed in the molten aluminum pool. Under the wetting effect of the molten aluminum and the reinforcing preform, the molten aluminum penetrates into the interior of the reinforcing preform and fills it.

[0013] Furthermore, the reinforced preform is protected with inert gas during pretreatment heating.

[0014] Furthermore, the cooling water pressure of the water-cooling channel is 0.3MPa to 1MPa, and the cooling of the casting roll is started in advance and runs for more than 30 minutes, so that the roll surface temperature does not exceed 40°C during the entire aluminum-based composite material thin strip casting and rolling process.

[0015] Furthermore, the roller surface material of the casting roller is steel or copper alloy, the roller diameter ranges from 500mm to 1500mm, the roller gap is from 2mm to 8mm, and the roller surface is lubricated with graphite.

[0016] Furthermore, the reinforcing preform is one of the following: metallic material, non-metallic material, or hybrid material. The metallic reinforcing preform is a spatial network or layered structure composed of fibers, wires, foils, or strips of titanium alloy, steel-based alloy, nickel-based alloy, molybdenum alloy, or tungsten alloy. The non-metallic reinforcing preform is a spatially continuous porous or foam structure of ceramic fibers and particles, whiskers, carbon fibers, or graphene. The hybrid reinforcing preform possesses the characteristics of both metallic and non-metallic materials.

[0017] Furthermore, the thickness of the reinforcing preform is not greater than the roll gap, and its width should be consistent with the width of the aluminum-based composite material strip to be prepared. Its conveying speed is matched with the roll speed, and a traction belt is provided at the lower end of the reinforcing preform.

[0018] Furthermore, the speed of the casting roll is adjusted according to the material, shape, thickness of the reinforcing preform and the material of the roll surface. The speed range of the reinforcing preform made of metal is 1m / min to 60m / min, of which the speed of the steel roll surface is 1m / min to 10m / min and the speed of the copper roll surface is 5m / min to 60m / min.

[0019] The roller speed range for non-metallic reinforced preforms is 1m / min to 20m / min, of which the roller speed for steel rollers is 1m / min to 5m / min and the roller speed for copper rollers is 3m / min to 20m / min.

[0020] The roller speed range is the same for hybrid materials and non-metallic reinforced preforms.

[0021] Furthermore, the rolling deformation of the metal-reinforced preform should be controlled to be no more than 60%, and the rolling deformation of the non-metallic-reinforced preform should be controlled to be between 20% and 40%.

[0022] Furthermore, the temperature of the molten pool is 650℃~900℃, the liquid level of the molten pool is not lower than 350mm, and its fluctuation range is ±2mm.

[0023] The beneficial effects of this invention are as follows:

[0024] Traditional aluminum-based composite strip manufacturing processes are lengthy and inefficient. Furthermore, aluminum-based composites have high deformation resistance, poor plasticity, and are prone to cracking, making strip rolling extremely difficult and resulting in low yield. The efficient and short-process manufacturing of aluminum-based composite strips has become a bottleneck in the industry.

[0025] The continuous casting and rolling method for preparing aluminum-based composite strips provided by this invention has the following advantages compared with traditional aluminum-based composite strip preparation processes:

[0026] (1) Aluminum-based composite material strips are continuously transported and impregnated through the reinforcing preform and continuously formed under rapid cooling and casting force. The preparation is completed in one process, which greatly shortens the product preparation process. It belongs to short process manufacturing. From casting to cooling and collection, the preparation cycle is ≤6h. Traditional ingots use multiple hot rolling, intermediate annealing, milling and other processes, and the preparation cycle is more than 20 days. The efficiency is significantly improved.

[0027] (2) The length of the continuous casting and rolling production line for aluminum-based composite thin strips is no more than 50m, while the length of the traditional production line, which includes casting, hot rolling, heat treatment, and machining processes, is no less than 300m, giving it a clear advantage in terms of space occupancy.

[0028] (3) In the continuous casting and rolling process of aluminum-based composite strip, the cumulative deformation of the reinforcing preform is small, the deformation resistance during the casting and rolling process is small, the strip is not easy to crack, and the yield is improved.

[0029] (4) Cooling casting rolls can achieve rapid solidification of aluminum liquid, with a cooling rate of over 100℃ / s, resulting in a large degree of supercooling, which can significantly refine the thin strip grains.

[0030] (5) Because the reinforcing preform has strong designability, the performance of the thin strip is enhanced, and the subsequent rolling deformation of the thin strip is small or no rolling is required. The design morphology of the reinforcing preform can be basically inherited to the thin strip product, so as to obtain aluminum matrix composite thin strip products with ideal performance.

[0031] (6) Compared with the traditional aluminum-based composite casting process, the introduction of rolling deformation in the casting and rolling process can reduce the defects of porosity, improve the density of thin strip products and optimize the grain structure.

[0032] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0034] Figure 1 This is a schematic diagram of a continuous casting and rolling method for preparing aluminum-based composite thin strips according to the present invention;

[0035] Figure 2 This is a schematic diagram of the solidification-rolling deformation of the aluminum-based composite material thin strip in the casting and rolling zone of the present invention. Detailed Implementation

[0036] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0037] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0038] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0039] Please see Figures 1-2 This is a method for continuous casting and rolling of aluminum-based composite thin strips. The method uses a pair of horizontally and parallel metal casting rolls with a set gap between the rolls and a water-cooling channel designed inside the metal casting rolls.

[0040] The molten pool for containing molten aluminum is made by combining refractory materials with a metal frame. The molten pool is placed directly above two metal casting rolls. The side surface of the molten pool is parallel to the axis of the metal casting rolls, and the end surface is perpendicular to the axis of the metal casting rolls. The lower ends of the two side surfaces are in contact with the roll surface, and the two end surfaces extend downward to the minimum roll gap and are in contact with the roll surface. The molten pool forms a cavity with an opening at the top, a roll gap at the bottom, and closed sides.

[0041] The reinforcement is made into a preform with a thickness not greater than the roll gap and a certain width. Before preparation, the metal casting roll is water-cooled and run at a set roll speed. The reinforcement pretreatment furnace is opened and heated to the set temperature. The aluminum liquid is injected into the molten pool and the liquid level is controlled to the set value. The aluminum liquid comes into contact with the roll surface and cools and solidifies. Under the casting and rolling action of the two rolls, an aluminum alloy strip is formed and continuously output from the lower end of the roll gap. The whole process reaches a stable state.

[0042] During the preparation process, the reinforcing preform moves from top to bottom at a certain speed, is heated to the pretreatment temperature in a pretreatment furnace, and then immersed in the molten aluminum pool. Under the wetting effect of the molten aluminum and the reinforcing preform, the molten aluminum penetrates into the interior of the reinforcing preform and fills it. When the reinforcing preform filled with molten aluminum moves to a certain distance above the roll gap, the molten aluminum inside begins to solidify under the cooling effect and moves towards the roll gap at the same time. When it moves to a closer distance above the roll gap, it completely solidifies and undergoes a certain amount of rolling deformation under the casting and rolling force of the two rolls. At the same time, under the friction force of the casting rolls, it is continuously fed downwards out of the roll gap to form a thin strip of aluminum-based composite material. After cooling, it is collected. Throughout the process, the liquid level in the molten pool is maintained at a certain set value.

[0043] Key references Figure 1 In the continuous casting and rolling process of aluminum-based composite strips that realizes the above method, the metal casting roll surface structure is made of materials with high thermal conductivity such as steel and copper alloys of a certain thickness. The roll diameter is generally 500mm to 1500mm, the roll gap is generally 2mm to 8mm, and the roll surface is lubricated with materials such as graphite.

[0044] In the continuous casting and rolling process of aluminum-based composite strips using the above method, the metal casting rolls are cooled by high-pressure water with a cooling water pressure of 0.3MPa to 1MPa. The cooling of the metal casting rolls should be started in advance and run for more than 30 minutes, and the roll surface temperature should not exceed 40°C during the entire aluminum-based composite strip casting and rolling process.

[0045] In the continuous casting and rolling process of aluminum-based composite strips using the above method, the roll speed of the metal casting roll is adjusted according to the material, shape, thickness of the reinforcing preform, and the roll surface material. The roll speed range for the metal reinforcing preform is 1 m / min to 60 m / min, with steel rolls having a speed of 1 m / min to 10 m / min and copper rolls having a speed of 5 m / min to 60 m / min. The roll speed range for the non-metallic reinforcing preform is 1 m / min to 20 m / min, with steel rolls having a speed of 1 m / min to 5 m / min and copper rolls having a speed of 3 m / min to 20 m / min. The roll speed range for the mixed material is the same as that for the non-metallic reinforcing preform.

[0046] In the continuous casting and rolling process of aluminum-based composite strips using the above method, the reinforcing preform can be made of metallic, non-metallic, or hybrid materials. The metallic reinforcing preform is a spatial network or layered structure composed of fibers, wires, foils, or strips of metallic materials such as titanium alloys, steel-based alloys, nickel-based alloys, molybdenum alloys, and tungsten alloys. The non-metallic reinforcing preform is a spatially continuous porous or foam structure prepared from ceramic fibers and particles, whiskers, carbon fibers, graphene, etc. The hybrid reinforcing preform possesses characteristics of both materials. The thickness of the reinforcing preform is no greater than the roll gap, and its width should be consistent with the width of the aluminum-based composite strip to be prepared. Its conveying speed is matched with the roll speed. To ensure the positional accuracy of the reinforcing preform during operation, a traction belt can be installed at the lower end of the reinforcing preform.

[0047] In the continuous casting and rolling process of aluminum-based composite strips that implements the above method, the reinforcing preform needs to be preheated in a pretreatment furnace before entering the molten aluminum pool to improve the wettability of the reinforcing preform material with the molten aluminum. The pretreatment time and temperature are specifically determined according to the material of the reinforcing preform. The pretreatment process can be protected with inert gas according to the material and surface performance requirements.

[0048] In the continuous casting and rolling process of aluminum-based composite strips that implements the above method, the reinforcing preform is continuously conveyed into the molten aluminum pool at a roller speed v for continuous infiltration. The temperature of the molten aluminum pool is generally 650℃~900℃ depending on the composition of the aluminum alloy matrix, the material and morphology of the reinforcing preform, and the liquid level height H of the molten aluminum pool is generally not less than 350mm, depending on the composition of the aluminum matrix, the material and morphology of the reinforcing preform, and its fluctuation range is ±2mm.

[0049] Key references Figure 2In the continuous casting and rolling process of aluminum-based composite strips using the above method, under the premise of a fixed roll diameter, the cooling capacity of the casting roll is controlled by adjusting the cooling water pressure and roll speed, thereby adjusting the solidification endpoint height. Under the action of the casting force F, different rolling deformation amounts of 2Δh / (2Δh+t)×100% are obtained. For the reinforcing preform of metallic materials, the deformation amount does not exceed 60%, and for the reinforcing preform of non-metallic materials, the deformation amount is controlled between 20% and 40%. After casting and rolling, the aluminum-based composite strip is obtained by cooling and collection. Here, Δh is the single-sided rolling deformation height, and t is the aluminum strip thickness.

[0050] Example 1

[0051] A method for continuous casting and rolling of titanium alloy fiber reinforced aluminum matrix composite strips, wherein the following steps are taken during the preparation process: (1) Water-cooled copper rollers with a diameter of 500 mm and a roller gap of 4 mm are selected for casting, and graphite lubrication is used; (2) The cooling water pressure is set to 0.8 MPa, and cooling is started 30 min in advance; (3) The roller speed is set to 10 m / min; (4) The reinforcing preform is a multi-layer structure woven from continuous titanium alloy fibers, with TC4 titanium alloy fibers having a diameter of 100 μm. The titanium alloy fibers are distributed in a 0°-90° cross pattern in a single layer plane, with a parallel spacing of 500 μm between fibers and a layer spacing of 500 μm, for a total of 9 layers. The thickness of the reinforcing preform is 4 mm and the width is 500 mm; (5) Argon gas protection is applied to the reinforcing preform. Preheating treatment, treatment temperature 560±5℃, treatment time 10min; (6) 5083 aluminum alloy is selected for the aluminum matrix, the aluminum liquid temperature is set to 780℃, and the liquid level height is 400±2mm; (7) The running speed of the titanium alloy fiber reinforced preform is 10m / min, and the reinforced preform enters the molten pool to fully contact and wet the aluminum liquid; (7) The aluminum liquid inside the reinforced preform solidifies under the cooling action of the casting roll, and undergoes rolling deformation under the action of the casting rolling force of the casting roll. Adjust the cooling capacity to control the solidification endpoint height and ensure that the rolling deformation is controlled at about 10%; (8) The titanium alloy fiber reinforced aluminum matrix composite strip with a specification of 500mm×4mm is continuously output from the lower end of the roll gap, and is subsequently cooled and collected.

[0052] Example 2

[0053] A method for continuous casting and rolling of SiC particle-reinforced aluminum matrix composite strips, wherein the following steps are taken during the preparation process: (1) Water-cooled steel rolls with a diameter of 850 mm and a roll gap of 3 mm are selected for the casting rolls, and graphite lubrication is used; (2) The cooling water pressure is set to 0.8 MPa, and the cooling is turned on 30 min in advance; (3) The roll speed is set to 2 m / min; (4) The SiC particles are subjected to oxygen-controlled high-temperature calcination treatment, and a SiO2 wetting layer is formed on the particle surface. The reinforcing preform is made of the treated SiC particles to form a porous structure with a particle diameter of 10-20 μm, a volume fraction of 20%, a thickness of 3 mm, and a width of 500 mm; (5) The reinforcing preform is preheated. , Processing temperature 500±5℃, processing time 30min; (6) 2024 aluminum alloy is selected for the aluminum matrix, the aluminum liquid temperature is set to 760℃, and the liquid level height is 600±2mm; (7) The running speed of the reinforcing preform is 2m / min, the reinforcing preform enters the molten pool and fully contacts and wets the aluminum liquid; (7) The aluminum liquid inside the reinforcing preform solidifies under the cooling action of the casting roll, and undergoes rolling deformation under the action of the casting rolling force of the casting roll. The cooling capacity is adjusted to control the solidification endpoint height, and the rolling deformation is controlled at about 30%; (8) The SiC particle reinforced aluminum matrix composite strip with a specification of 500mm×3mm is continuously output from the lower end of the roll gap, and is subsequently cooled and collected.

[0054] Example 3

[0055] A method for continuous casting and rolling of thin strips of nickel-based alloy wire mesh + Al2O3 whisker reinforced aluminum matrix composite material. In the preparation process: (1) water-cooled steel rollers with a diameter of 850 mm and a roller gap of 5 mm are selected for casting rolls and graphite lubrication is used; (2) the cooling water pressure is set to 0.8 MPa and the cooling is turned on 30 min in advance; (3) the roller speed is set to 5 m / min; (4) a multi-layer wire mesh structure is prepared by weaving nickel-based alloy wire with a diameter of 0.2 mm. The nickel-based alloy wires in the single layer plane are distributed in a 45°-45° cross pattern, with a parallel spacing of 1 mm between alloy wires and a layer spacing of 1 mm. There are a total of 6 layers, with a thickness of 5 mm and a width of 500 mm for the reinforcing preform. Al2O3 whiskers are uniformly coated on the surface of the nickel-based alloy wire mesh structure and the reinforcing preform is prepared after drying. (5) The reinforced preform is preheated with argon protection at a temperature of 560±5℃ for 10 minutes. (6) The aluminum matrix is ​​made of 5083 aluminum alloy, the aluminum liquid temperature is set at 800℃, and the liquid level is 400±2mm. (7) The running speed of the reinforced preform is 5m / min. The reinforced preform enters the molten pool and fully contacts and wets the aluminum liquid. (7) The aluminum liquid inside the reinforced preform solidifies under the cooling action of the casting roll and undergoes rolling deformation under the casting force of the casting roll. The cooling capacity is adjusted to control the solidification endpoint height and ensure that the rolling deformation is controlled at about 20%. (8) A nickel-based alloy wire mesh + Al2O3 whisker reinforced aluminum matrix composite strip with a specification of 500mm×5mm is continuously output from the lower end of the roll gap, cooled and collected afterward.

[0056] This invention enables the continuous preparation of aluminum-based composite material strips, reducing the preparation process and improving preparation efficiency. It also has advantages such as strong heritability of reinforcement design, dense material, and refined microstructure.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for continuous casting and rolling of aluminum-based composite material thin strips, characterized in that: It includes a pair of horizontally and parallel casting rolls with a set gap between them and a water-cooling channel inside the rolls. It also includes a molten pool made of refractory material and a metal frame to hold molten aluminum. The molten pool is located directly above the two casting rolls. The side of the molten pool parallel to the axis of the casting rolls is the side surface, and the side perpendicular to the axis of the casting rolls is the end surface. The lower ends of the two side surfaces are in contact with the roll surface, and the two end surfaces extend downward to the minimum gap and are in contact with the roll surface. The molten pool forms a cavity with an opening at the top, an opening at the bottom matching the size of the gap, and a closed perimeter. The preparation method specifically includes the following steps: The reinforcement in the aluminum matrix composite strip is made into a preform with a thickness not greater than the roll gap. Before preparing the aluminum matrix composite strip, the casting roll is water-cooled and runs at a set speed. The aluminum liquid is injected into the molten pool and the liquid level is controlled to the set value. The liquid level in the molten pool is kept at the set value throughout the preparation process. The aluminum liquid comes into contact with the roll surface of the casting roll and cools and solidifies. Under the casting and rolling action of the two casting rolls, an aluminum alloy strip is formed and continuously output from the lower end of the roll gap. The whole process reaches a stable state. During the preparation process, the reinforcing preform moves from top to bottom at a set speed and is first immersed in the molten aluminum pool. The molten aluminum penetrates into the interior of the reinforcing preform and fills it. As the reinforcing preform, which is filled with molten aluminum, moves to the roll gap, it gradually solidifies until it is completely solidified. Then, it undergoes rolling deformation under the casting force of two casting rolls and is continuously fed downwards out of the roll gap under the friction force of the casting rolls to form a thin strip of aluminum-based composite material. It also includes a pretreatment furnace located directly above the molten pool; Before preparation, the pretreatment furnace is turned on and heated to the set temperature. During the preparation process, the reinforcing preform moves from top to bottom at a set speed and is heated to the pretreatment temperature through the pretreatment furnace. Then it is immersed in the molten aluminum pool. Under the wetting effect of the molten aluminum and the reinforcing preform, the molten aluminum penetrates into the interior of the reinforcing preform and fills it. The thickness of the reinforcing preform is no greater than the roll gap, and its width is consistent with the width of the aluminum-based composite material strip to be prepared. Its conveying speed is matched with the roll speed, and a traction belt is provided at the lower end of the reinforcing preform. The thickness of the reinforcing preform is 3mm to 5mm, and the thickness of the aluminum-based composite material strip is the same as that of the reinforcing preform. The cooling water pressure of the water cooling channel is 0.3MPa ~ 1MPa, and the cooling of the casting roll is turned on in advance and runs for more than 30 minutes, and the roll surface temperature does not exceed 40°C during the entire aluminum-based composite material thin strip casting and rolling process. The surface material of the casting roll is steel or copper alloy, the roll diameter ranges from 500mm to 1500mm, the roll gap is 3mm to 5mm, and the reinforcing preform is one of metal, non-metal, or mixed materials. The speed of the casting roll is adjusted according to the material, shape, thickness of the reinforcing preform and the material of the roll surface. The speed range of the reinforcing preform made of metal is 1m / min ~ 60m / min, of which the speed of the steel roll surface is 1m / min ~ 10m / min and the speed of the copper roll surface is 5m / min ~ 60m / min. The roller speed range for non-metallic reinforced preforms is 1m / min to 20m / min, of which the roller speed for steel rollers is 1m / min to 5m / min and the roller speed for copper rollers is 3m / min to 20m / min. The roller speed range is the same for hybrid materials and non-metallic reinforced preforms.

2. The method for continuous casting and rolling of aluminum-based composite material thin strips according to claim 1, characterized in that: The reinforced preform is protected with inert gas during pretreatment heating.

3. The method for continuous casting and rolling of aluminum-based composite material thin strips according to claim 1, characterized in that: The surface of the casting roll is lubricated with graphite.

4. The method for continuous casting and rolling of aluminum-based composite material thin strips according to claim 3, characterized in that: Metallic reinforcing preforms are spatial network and layered structures composed of fibers, wires, foils or strips of titanium alloys, steel-based alloys, nickel-based alloys, molybdenum alloys or tungsten alloys. Non-metallic reinforcing preforms are spatially continuous porous or foam structures of ceramic fibers and particles, whiskers, carbon fibers or graphene. Hybrid reinforcing preforms possess characteristics of both metallic and non-metallic materials.

5. The method for continuous casting and rolling of aluminum-based composite material thin strips according to claim 1, characterized in that: The rolling deformation of metal reinforced preforms shall be controlled to be no more than 60%, and the rolling deformation of non-metal reinforced preforms shall be controlled to be between 20% and 40%.

6. The method for continuous casting and rolling of aluminum-based composite material thin strips according to claim 1, characterized in that: The temperature of the molten pool is 650℃~900℃, the liquid level of the molten pool is not lower than 350mm, and its fluctuation range is ±2mm.

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