A preparation method of an aluminum matrix composite material reinforced by vacuum reciprocating smelting assisted thin strip casting

Abstract

The present application belongs to the technical field of aluminum matrix composite material preparation, and particularly relates to a preparation method of reinforced aluminum matrix composite material by vacuum reciprocating smelting assisted thin strip casting and rolling. The method comprises the steps of aluminum matrix material preparation, ceramic / aluminum matrix composite powder vacuum ball milling, aluminum matrix and ceramic / aluminum matrix composite powder vacuum reciprocating smelting, thin strip casting and rolling, cast strip preliminary treatment, cast strip heat treatment, hot rolling, cold rolling and performance optimization. The aluminum alloy matrix rod with specific components is selected, the ceramic particle / aluminum matrix composite material powder with a mass fraction of 5% to 25% is prepared by vacuum ball milling, and the surface of the ceramic particle is completely attached with aluminum powder to ensure good wetting of the particle and the aluminum matrix. Subsequently, the thin strip casting and rolling, heat treatment, hot rolling and cold rolling and other treatments are performed. Finally, the ceramic / aluminum matrix composite material with the ceramic particles uniformly distributed on the matrix is prepared, which exhibits excellent tensile strength, elongation and wear resistance, and no grain boundary segregation phenomenon.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aluminum matrix composite material preparation, and particularly relates to a preparation method of aluminum matrix composite material reinforced by vacuum reciprocating smelting assisted thin strip casting and rolling. BACKGROUND

[0002] In the field of material science, composite materials with lightweight and high performance have become the key to driving technological development and industrial applications. Traditional single material performance cannot meet the complex and changing engineering requirements. Aluminum matrix composite material, with its good mechanical properties, low density and excellent electrical conductivity, has shown great potential in the fields of aerospace, vehicles, electronic packaging and national defense technology. Ceramic particle reinforced aluminum matrix composite material is a new type of composite material that adds ceramic particles to the aluminum matrix to improve the overall performance of the material, such as strength and wear resistance. However, traditional stirring casting, powder metallurgy and other preparation processes still have challenges in the uniform distribution of ceramic particles, interface bonding with the matrix and defect control. These problems not only affect the overall performance of the composite material, but also limit its development in high-end application fields.

[0003] Thin strip casting technology is a high-efficiency, short-process metal material preparation technology, which belongs to sub-rapid solidification. Applying thin strip casting technology to the preparation of ceramic / aluminum matrix composite material can fully utilize its continuous production characteristics and improve production efficiency. At the same time, the sub-rapid solidification effect in the thin strip casting process helps to refine the microstructure of the material and improve the overall performance of the material. Patent CN202311492267.2 discloses a method for preparing aluminum matrix composite material thin strip by continuous casting and rolling. The method is characterized by continuous feeding and continuous infiltration of the reinforced preform, and continuous forming of the aluminum matrix composite material thin strip under the action of rapid cooling and casting force. The patent relates to thin strip casting of aluminum matrix composite material, but does not mention specific processing methods for vacuum reciprocating smelting and ceramic particles, such as ball milling and vacuum smelting. Therefore, the overall performance of the aluminum matrix composite material prepared by the method cannot meet the current demand. SUMMARY

[0004] To solve the problems in the prior art, the application provides a preparation method of aluminum matrix composite material reinforced by vacuum reciprocating smelting assisted thin strip casting and rolling. The method combines the short process of thin strip casting technology with the precise control of vacuum reciprocating smelting technology, solving the problems of uneven distribution of ceramic particles in the aluminum matrix composite material, poor interface wettability between the matrix and ceramic particles, and high porosity.

[0005] The technical scheme of the application is as follows:

[0006] A preparation method of aluminum matrix composite material reinforced by vacuum reciprocating smelting assisted thin strip casting and rolling, comprising the following steps:

[0007] Step (1), aluminum-based material preparation: configure aluminum alloy base rod according to the set composition, which contains, by weight percentage, Mg 0.8~1.5%, Cu 0.15~4.9%, Si 0.4~0.8%, Mn 0.1~1.5%, Cr 0.04~0.35%, Zn 0.1~0.25%, Fe 0.35~0.7%, Ti 0.1~0.15%, N≤0.002%, O≤0.002%, and the balance of Al; the base material includes one or more of 6xxx series aluminum alloy, 2xxx series aluminum alloy, and 7xxx aluminum alloy;

[0008] Step (2), vacuum ball milling: vacuum ball mill the ceramic particles and Al powder to ensure that the surface of the ceramic particles is completely attached to the Al powder, so that the ceramic particles and aluminum powder are fully wetted, and the ceramic / aluminum-based composite powder with a mass fraction of 5~25% is prepared as a reinforcing phase; the ceramic particles provide a solidification heat transfer ratio of 30% or more;

[0009] Step (3), vacuum melting: place the aluminum alloy base rod prepared in step (1) into a vacuum melting furnace, and send the ceramic / aluminum-based composite powder prepared in step (2) into the furnace through a powder feeding mechanism, and vacuumize to 10 -3 Pa or less to remove impurities during the melting process; the temperature of the aluminum liquid is controlled to have a superheat of +25~65℃, and a bottom argon blowing gas deslagging and degassing treatment is set;

[0010] Step (4), reciprocating melting: after the solution temperature reaches 680~720℃, mechanically stir for 30min~60min, and then stand for 20min~30min to cool down, and reciprocate the melting for 3~6h in this way to remove gas and other impurities, and ensure that the ceramic particles are uniformly dispersed in the aluminum alloy melt and form a good interface wetting and bonding with the base;

[0011] Step (5), thin strip casting and rolling: start the casting and rolling machine and the water cooling system, and under the protection of inert gas Ar or N2, inject the uniform ceramic particle / aluminum alloy composite melt obtained after the reciprocating melting in step (4) into the flow distribution package lower water inlet, and from top to bottom into the molten pool composed of two rotating casting rolls and two side sealing plates, to ensure the smooth progress of the casting and rolling process and the stability of the cast strip quality; control the casting speed to be 30~50m / min, control the molten pool liquid level height to be 80~150mm, and control the cast strip thickness to be 3.0~15.0mm;

[0012] Step (6), cast strip preliminary treatment: cool the ceramic / aluminum-based composite material thin strip obtained in step (5) to room temperature, and then polish the surface to control the roughness to be Ra 2μm or more, and then use a wire cutting robot to segment;

[0013] Step (7), cast strip heat treatment: the ceramic / aluminum matrix composite material thin strip after step (6) treatment is solid solution treated at 450~550℃, the holding time is 1~8h, and then rapid cooling; the aging treatment temperature is 100~200℃, and the aging treatment time is 6~24h; the ceramic / aluminum matrix composite material thin strip after heat treatment is obtained, in which the ceramic particles are uniformly distributed in the matrix;

[0014] Step (8), hot rolling: the ceramic / aluminum matrix composite material thin strip after heat treatment is hot rolled, and the hot rolling temperature is set to 550~580℃, which is higher than the recrystallization temperature and lower than the melting temperature, so as to avoid cracking; through the hot rolling treatment, the grain is further refined, and the composite material organization and performance are significantly improved;

[0015] Step (9), cold rolling: on the basis of hot rolling, cold rolling treatment is carried out to obtain a ceramic / aluminum matrix composite material plate with a thickness of 0.2~0.3mm, and the surface quality is controlled between Ra 0.2μm and Ra 1.6μm;

[0016] Further, the preferred scheme of the above-mentioned preparation method of the vacuum reciprocating smelting assisted thin strip casting and rolling reinforced aluminum matrix composite material is that, in step (1), the 6xxx series aluminum alloy includes 6063, 6061, 6005 aluminum alloy, the 2xxx series aluminum alloy includes 2017, 2024, 2219 aluminum alloy, and the 7xxx series aluminum alloy includes 7075, 7050, 7005 aluminum alloy.

[0017] Further, the preferred scheme of the above-mentioned preparation method of the vacuum reciprocating smelting assisted thin strip casting and rolling reinforced aluminum matrix composite material is that, in step (2), the ceramic particles include SiC, TiC and TiB2, wherein the particle size of the ceramic particles is 3μm or less, the particle size of the Al powder is 30-50μm, and the ball milling time is 30h or more.

[0018] Further, the preferred scheme of the above-mentioned preparation method of the vacuum reciprocating smelting assisted thin strip casting and rolling reinforced aluminum matrix composite material is that, in step (4), the solution temperature is controlled to be 650℃ or more during the reciprocating smelting.

[0019] Further, the preferred scheme of the above-mentioned preparation method of the vacuum reciprocating smelting assisted thin strip casting and rolling reinforced aluminum matrix composite material is that, in step (7), the rapid cooling process after solid solution treatment includes water quenching, high-pressure water quenching and liquid-gas atomization medium quenching, so as to prevent adverse phase change or organization evolution during the cooling process.

[0020] Further, the preferred scheme of the above-mentioned preparation method of the ceramic / aluminum-based composite material by vacuum reciprocating smelting assisted thin strip casting is that, after the hot rolling in step (8), the mass fraction of the ceramic reinforcing particles in the ceramic / aluminum-based composite material hot-rolled plate substrate is 10-50%, the ceramic particles are uniformly distributed on the substrate, the ceramic particle size of the substrate is controlled to be 600-2000 nm, there is no grain boundary segregation phenomenon, and there is no shrinkage cavity around the ceramic.

[0021] Further, the preferred scheme of the above-mentioned preparation method of the ceramic / aluminum-based composite material by vacuum reciprocating smelting assisted thin strip casting is that, during the cold rolling in step (9), the roll gap of the cold rolling mill is adjusted to be 3.0-15.0 mm, and the cold rolling direction is the same as the casting direction.

[0022] Further, the preferred scheme of the above-mentioned preparation method of the ceramic / aluminum-based composite material by vacuum reciprocating smelting assisted thin strip casting is that, after the cold rolling in step (9), the ceramic particle size of the cold-rolled plate substrate is controlled to be 600-2000 nm and is uniformly distributed on the substrate, there is no grain boundary segregation phenomenon, the tensile strength of the composite material is improved by 20%, the elongation rate is 5-15%, the wear resistance is improved by more than 25%, and the microhardness is improved by more than 30%.

[0023] Further, in step (3), the number of pores on the solidification section of the thin strip plate in the vacuum smelting chamber is ≤6 / 10 mm 2 , and the pore size is ≤0.5 μm, and after the hot rolling and cold rolling in steps (8) and (9), the pores are completely pressed together.

[0024] The design idea of the present application is:

[0025] The present application combines the vacuum reciprocating smelting technology with the thin strip casting technology, aims to realize the uniform distribution of ceramic particles in the aluminum matrix, and significantly improve the comprehensive mechanical properties of the ceramic / aluminum-based composite material. The design idea of the method mainly has four aspects:

[0026] First, ceramic particles are used as reinforcing phases, and the vacuum ball milling mixing technology is used to ensure that the ceramic particles and the aluminum matrix are fully wetted and combined, laying a foundation for subsequent smelting and casting;

[0027] Second, the vacuum environment is reciprocatingly smelted, the vacuum degree and the temperature in the smelting chamber are strictly controlled, impurities in the smelting process are removed, the uniform dispersion of the ceramic particles in the aluminum alloy melt is ensured, and a good interface wetting and combination between the ceramic particles and the matrix is formed. This step is crucial for improving the comprehensive mechanical properties of the composite material;

[0028] Third, the parameters such as casting speed, molten pool liquid level height and casting strip thickness are accurately controlled in the casting process to obtain high-quality composite material thin strips, and the casting strips are preliminarily treated and heat-treated, so that the internal organization and performance of the ceramic / aluminum-based composite material are further regulated and controlled;

[0029] Fourth, through hot rolling and cold rolling treatment, ceramic particle uniformly distributed ceramic / aluminum-based composite material plate without grain boundary segregation and excellent mechanical properties is obtained.

[0030] This innovative method not only greatly expands the preparation category of ceramic / aluminum-based composite materials, but also opens up a new perspective for the research and development of ceramic particle reinforced aluminum-based composite materials, and has great application potential and industrial value. In order to meet the harsh requirements of aluminum-based composite materials on comprehensive performance in the fields of aviation and aerospace, automobile lightweight and building, etc.

[0031] Advantages and beneficial effects of the present application:

[0032] 1. The present application combines ceramic particle / aluminum-based composite powder with vacuum reciprocating melting technology to realize thin strip casting and rolling in a vacuum environment of ≤3000Pa (≤0.03 bar), and the prepared ceramic / aluminum-based composite material has excellent mechanical properties. Specifically, the tensile strength is improved by 20%, the elongation rate reaches 5-15% or higher, and the wear resistance is improved by more than 25%. These performance improvements are mainly due to the good combination of ceramic particles and aluminum matrix and the dispersion distribution. Compared with traditional casting, powder metallurgy and other processes, the ceramic particles are wrapped by aluminum alloy powder, the wettability of the ceramic particle and aluminum matrix interface is enhanced, the strengthening effect is more uniform, and the solidification defects are significantly eliminated. A large number of aluminum-based composite material researches are basically based on non-vacuum environment preparation, and there are often a large number of pore defects, which is due to the poor wettability of ceramic particles and aluminum matrix causing gas phase retention. Vacuum ball milling and vacuum reciprocating melting technology can fundamentally solve this problem;

[0033] 2. Ceramic particle / aluminum-based composite materials are generally prepared under normal pressure, and such technology generally deposits under normal pressure. The main problem is the agglomeration of ceramic particles and the existence of pores around. At present, there is no research on the preparation of ceramic / aluminum-based composite materials by combining vacuum ball milling of ceramic particle / aluminum-based composite powder with vacuum reciprocating melting technology to assist thin strip continuous casting. The ceramic / aluminum-based composite material of the present application is melted in a vacuum environment and protected by inert gas Ar, which effectively prevents the oxidation and pollution of the aluminum-based composite material melt and improves the purity of the metal.

[0034] 3、The application can effectively prevent oxidation and remove impurities such as gas through strict temperature control and mechanical stirring time in the process of vacuum reciprocating smelting, so as to ensure that the ceramic particles are uniformly dispersed in the aluminum melt. Meanwhile, through subsequent solid solution aging, hot rolling and cold rolling treatment, the pores can be further compressed, the density of the ceramic / aluminum matrix composite material can be improved, and the comprehensive mechanical properties thereof can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The application is a vacuum reciprocating smelting auxiliary thin strip casting ceramic particle reinforced aluminum matrix composite material process schematic diagram;

[0036] In the figure, 1 is a high vacuum pump set; 2 is a heating mechanism; 3 is a powder feeding mechanism; 4 is a stirring mechanism; 5 is an upper cover plate; 6 is a top rod; 7 is a crucible; 8 is a rotating casting roll; 9 is a gas cooling device; and 10 is a casting strip. DETAILED DESCRIPTION

[0037] The specific embodiments of the application will be further described in detail below in combination with the drawings and examples in the specification. The following examples are used to illustrate the application, but cannot be used to limit the scope of the application. Those skilled in the art can make various modifications or changes within the scope of the claims, which does not affect the essential content of the application.

[0038] The following examples use the process and device shown in Figure 1 , wherein the high vacuum pump set 1 is responsible for providing a high vacuum environment for the system, so that the smelting process is free of impurities; the heating mechanism 2 provides heat to make the aluminum matrix composite material reach a molten state; the powder feeding mechanism 3 is responsible for feeding ceramic particles; the stirring mechanism 4 promotes the full mixing of the aluminum liquid and the ceramic particles through stirring; the upper cover plate 5 closes the smelting area to prevent heat loss and external pollution; the top rod 6 is used to eject during pouring, so that the aluminum matrix composite solution flows out into the casting roll 8; the crucible 7 is used as a container for smelting the aluminum matrix composite material; the casting roll 8 makes the aluminum matrix composite material into a thin strip through rapid cooling and calendering; the gas cooling device 9 is used to cool the casting strip 10 to ensure the organization and performance of the thin strip; and the casting strip 10 is the ceramic particle reinforced aluminum matrix composite material thin strip finally prepared through the vacuum reciprocating smelting auxiliary thin strip casting, which has excellent mechanical properties. Example 1

[0039] The preparation method of the aluminum matrix composite material reinforced by the vacuum reciprocating smelting auxiliary thin strip casting in this embodiment comprises the following steps:

[0040] (1) Preparation of 6063 aluminum matrix material: 6063 aluminum alloy rods are prepared according to the set composition, which contains the following by weight percentage: Mg 0.8%, Si 0.5%, Mn 0.6%, Cr 0.1%, Zn 0.15%, Fe 0.4%, Ti 0.1%, N≤ 0.002%, O≤0.002%, with the balance being Al;

[0041] (2) Vacuum ball milling of SiC / 6063 composite powder: 5% SiC powder is used as a reinforcing material; SiC ceramic particles and Al powder are ball milled and mixed evenly for 30 hours to ensure that the surface of the ceramic particles is completely covered with Al powder, so that the ceramic particles and the aluminum liquid are fully wetted; wherein the particle size of the ceramic particles is 3μm, the particle size of the metal powder is 30μm, and the proportion of particles providing solidification heat transfer is 30%;

[0042] (3) Vacuum melting: Place the 6063 aluminum alloy rod and the ball-milled SiC / Al composite powder into a vacuum melting furnace and evacuate to 100°C. -5 Pa is used to remove impurities during the smelting process; the aluminum liquid temperature is controlled to be at a superheat of +25℃, and bottom argon blowing is used for slag removal and degassing; the number of pores on the solidification section of the thin strip is 6 per 10mm. 2 And the pore size is 0.5μm;

[0043] (4) Reciprocating melting: After the solution temperature reaches 680℃, mechanically stir for 30 min, then let it stand and cool for 20 min, and reciprocate melting for 3 h to remove impurities such as gas, so as to ensure that SiC ceramic particles are uniformly dispersed in the aluminum alloy melt and form good interface wetting and bonding with the matrix.

[0044] (5) Thin strip casting and rolling: Start the casting and rolling mill and water cooling system: Inject the uniform SiC / 6063 aluminum-based composite melt obtained after vacuum reciprocating melting into the lower water outlet of the flow package, and enter the molten pool composed of two rotating casting rolls and block side sealing plates from top to bottom. Control the casting speed to 30m / min, control the molten pool liquid level height to 80mm, and control the casting strip thickness to 3.0mm.

[0045] (6) Preliminary treatment of cast strip: The SiC / 6063 aluminum-based composite material strip obtained by thin strip casting and rolling is cooled to room temperature, and then the surface is polished. The roughness is controlled at Ra 2μm, and then it is segmented by wire cutting.

[0046] (7) Heat treatment of cast strip: Solution treatment is performed at 450℃ for 1 hour, followed by water quenching for rapid cooling; the aging treatment temperature is 100℃ and the aging treatment time is 6 hours; after heat treatment, SiC / 6063 aluminum matrix composite material with SiC particles uniformly distributed in the matrix is ​​obtained; (8) Hot rolling: The heat-treated SiC / 6063 aluminum matrix composite strip is hot rolled, and the hot rolling temperature is set at 550℃, which is higher than the recrystallization temperature and lower than the melting temperature to avoid cracking; through hot rolling treatment, the grains are further refined, and the structure and properties of the composite material are significantly improved; the mass fraction of ceramic reinforcing particles in the hot-rolled ceramic / aluminum matrix composite plate is 20%, the ceramic particles are uniformly distributed in the matrix, and the size of the ceramic particles in the matrix is ​​controlled at 800nm;

[0047] (9) Cold rolling: Cold rolling is carried out on the basis of hot rolling. The roll gap of the cold rolling mill is adjusted to 5mm. The cold rolling direction is the same as the casting rolling direction to obtain a 0.2mm SiC / 6063 aluminum-based composite material plate. The surface quality is controlled within Ra 0.2μm. After cold rolling, the size of the ceramic particles in the cold-rolled plate matrix is ​​controlled at 600nm.

[0048] In this embodiment, the SiC / 6063 aluminum-based composite material exhibits uniform SiC ceramic particles distributed on the matrix without grain boundary segregation. The composite material shows a 20% increase in tensile strength, a 5% increase in elongation, a 25% increase in wear resistance, and a 30% increase in microhardness. Example 2

[0049] This embodiment discloses a method for preparing a vacuum reciprocating melting-assisted thin strip casting and rolling reinforced aluminum matrix composite material, characterized by comprising the following steps:

[0050] (1) Preparation of 2024 aluminum matrix material: Prepare 2024 aluminum alloy bars according to the set composition, which contains the following by weight percentage: Mg 1.2%, Si 0.4%, Mn 0.3%, Cr 0.04%, Zn 0.15%, Fe 0.5%, Ti 0.15%, N≤ 0.002%, O≤0.002%, with the balance being Al;

[0051] (2) Vacuum ball milling of SiC / 2024 composite powder: 10% SiC powder is used as a reinforcing material; SiC ceramic particles and Al powder are ball milled and mixed evenly for 40 hours to ensure that the surface of the ceramic particles is completely covered with Al powder, so that the ceramic particles and the aluminum liquid are fully wetted; wherein the particle size of the ceramic particles is 3μm, the particle size of the metal powder is 30μm, and the proportion of particles providing solidification heat transfer is 30%;

[0052] (3) Vacuum melting: Place the 2024 aluminum alloy rod and the ball-milled SiC / Al composite powder into a vacuum melting furnace and evacuate to 100°C. -3Pa, to remove impurities in the smelting process; the superheat of the molten aluminum is controlled at +45℃, and the bottom argon blowing is set for deslagging and degassing treatment; the number of pores on the solidification section of the thin strip plate is 6 per 10 mm 2 , and the pore size is 0.5 μm;

[0053] (4) Reciprocal smelting: after the solution temperature reaches 700℃, mechanical stirring is performed for 40 min, and then standing and cooling is performed for 30 min, and reciprocal smelting is performed for 5 h, so as to remove gas and other impurities, and to ensure that the SiC ceramic particles are uniformly dispersed in the aluminum alloy melt, and form a good interface wetting and bonding with the matrix;

[0054] (5) Thin strip casting and rolling: the casting and rolling machine and the water cooling system are started: the uniform SiC / 2024 aluminum matrix composite melt obtained after vacuum reciprocal smelting is injected into the water inlet of the flow package, and then enters the molten pool composed of two rotating casting rolls and side sealing plates from top to bottom, the casting speed is controlled at 40 m / min, the molten pool liquid level is controlled at 120 mm, and the casting strip thickness is controlled at 4.0 mm;

[0055] (6) Preliminary treatment of the casting strip: the SiC / 2024 aluminum matrix composite material thin strip obtained by casting and rolling is cooled to room temperature, and then surface polishing is performed, the roughness is controlled to be greater than Ra 2 μm, and then segmentation is performed by using wire cutting;

[0056] (7) Heat treatment of the casting strip: solid solution treatment is performed at 500℃, and the holding time is 5 h, and then water quenching is adopted for rapid cooling; the aging treatment temperature is 150℃, and the aging treatment time is 10 h; after heat treatment, the SiC / 2024 aluminum matrix composite material is obtained, in which the SiC particles are uniformly distributed in the matrix;

[0057] (8) Hot rolling: the SiC / 2024 aluminum matrix composite material thin strip after heat treatment is subjected to hot rolling, and the hot rolling temperature is set to 560℃, which is higher than the recrystallization temperature and lower than the melting temperature, so as to avoid cracking; through the hot rolling treatment, the grains are further refined, and the organization and performance of the composite material are significantly improved; the mass fraction of ceramic strengthening particles in the ceramic / aluminum matrix composite hot rolled plate is 20%, the ceramic particles are uniformly distributed on the matrix, and the size of the ceramic particles in the matrix is controlled to be 1000 nm;

[0058] (9) Cold rolling: on the basis of hot rolling, cold rolling treatment is performed, the roll gap of the cold rolling mill is adjusted to 10 mm, the cold rolling direction is the same as the casting and rolling direction, and a 0.2 mm SiC / 2024 aluminum matrix composite plate is obtained, and the surface quality is controlled to be between Ra 0.8 μm; after cold rolling treatment, the size of the ceramic particles in the cold rolled plate matrix is controlled to be 800 nm.

[0059] The SiC / 2024 aluminum matrix composite prepared in the embodiment has the SiC ceramic particles uniformly distributed on the matrix without grain boundary segregation. The tensile strength of the composite is increased by 20%, the elongation rate reaches 10%, the wear resistance is increased by 25%, and the microhardness is increased by 30%. Example 3

[0060] The embodiment relates to a preparation method of an aluminum matrix composite reinforced by thin strip casting with the aid of vacuum reciprocating smelting, and the method comprises the following steps.

[0061] The embodiment relates to a preparation method of an aluminum matrix composite reinforced by thin strip casting with the aid of vacuum reciprocating smelting, and the method comprises the following steps.

[0062] (1) 6061 aluminum matrix material preparation: 6061 aluminum alloy rods are prepared according to a set composition, and the composition contains, in percentage by weight, Mg 0.1%, Si 0.6%, Mn 0.7%, Cr 0.2%, Zn 0.15%, Fe 0.5%, Ti 0.12%, N less than or equal to 0.002%, and O less than or equal to 0.002%; and the balance is Al;

[0063] (2) TiC / 6061 composite powder vacuum ball milling: 20% TiC powder is prepared as a reinforcing material; TiC ceramic particles and Al powder are ball milled and uniformly mixed, the ball milling time is 40 h, the surface of the ceramic particles is completely attached to Al powder, and the ceramic particles and the aluminum liquid are fully wetted; the particle size of the ceramic particles is 3 microns, the particle size of the metal powder is 40 microns, and the particle size provides a solidification heat transfer ratio of 30%;

[0064] (3) Vacuum smelting: the 6061 aluminum alloy rods and the ball-milled TiC / Al composite powder are placed into a vacuum smelting furnace, vacuum is extracted to 10 -3 Pa to remove impurities in the smelting process; the temperature of the aluminum liquid is controlled to have a superheat of +65 DEG C, the bottom argon blowing is set for deslagging and degassing treatment; the number of pores on the solidification section of the thin strip plate is 5 / 10 mm 2 , and the pore size is 0.5 microns;

[0065] (4) Reciprocating smelting: mechanical stirring is performed for 60 min when the solution temperature reaches 720 DEG C, and then the solution is statically cooled for 30 min, and the reciprocating smelting is performed for 6 h to remove gas and other impurities, so that the TiC ceramic particles are uniformly dispersed in the aluminum alloy melt, and a good interface wetting and combination is formed between the TiC ceramic particles and the matrix;

[0066] (5) Thin strip casting: the water cooling system and the casting mill are started: the uniform TiC / 6061 aluminum matrix composite melt obtained after the vacuum reciprocating smelting is injected into the water outlet of the flow distribution package, and then the melt enters the melt pool composed of two rotating casting rolls and a block side sealing plate from top to bottom, the casting speed is controlled to be 50 m / min, the melt pool liquid level height is controlled to be 150 mm, and the casting strip thickness is controlled to be 5.0 mm.

[0067] (6) Casting strip preliminary processing: the casting and rolling of TiC / 6061 aluminum matrix composite material thin strip to room temperature, and then the surface is polished, the roughness is controlled to be Ra 2 μm, and then the line cutting is used for segmentation;

[0068] (7) Casting strip heat treatment: solid solution treatment is carried out at 550 ℃, the holding time is 8 h, and then the water quenching process is used for rapid cooling; the aging treatment temperature is 200 ℃, and the aging treatment time is 24 h; after heat treatment, the TiC / 6061 aluminum matrix composite material is obtained, in which the TiC particles are uniformly distributed in the matrix;

[0069] (8) Hot rolling: the hot rolling is carried out on the heat treated TiC / 6061 aluminum matrix composite material thin strip, the hot rolling temperature is set to be 580 ℃, which is higher than the recrystallization temperature and lower than the melting temperature, so as to avoid cracking; through the hot rolling treatment, the grains are further refined, and the composite material organization and performance are significantly improved; the mass fraction of ceramic strengthening particles in the ceramic / aluminum matrix composite material hot rolling plate is 50%, the ceramic particles are uniformly distributed on the matrix, and the size of the ceramic particles in the matrix is controlled to be 1500 nm;

[0070] (9) Cold rolling: on the basis of hot rolling, the cold rolling treatment is carried out, the roll gap of the cold rolling mill is adjusted to be 15.0 mm, the cold rolling direction is the same as the casting and rolling direction, the 0.3 mm TiC / 6061 aluminum matrix composite material plate is obtained, and the surface quality is controlled to be between Ra 1.6 μm; after the cold rolling treatment, the size of the ceramic particles in the cold rolling plate matrix is controlled to be 1000 nm.

[0071] The finally prepared TiC / 6061 aluminum matrix composite material in the embodiment has the following characteristics: the TiC ceramic particles are uniformly distributed on the matrix, there is no grain boundary segregation phenomenon, the tensile strength of the composite material is improved by 20%, the elongation rate reaches 15%, the wear resistance is improved by 25%, and the microhardness is improved by 30%. Example 4

[0072] The preparation method of the aluminum matrix composite material in the embodiment is different from that in example 1 in that the used matrix material is 7075 aluminum alloy, and the composition is as follows: Mg 1.5%, Si 0.8%, Mn 0.1%, Cr 0.18%, Zn 0.25%, Fe 0.7%, Ti 0.15%, N≤0.002%, O≤0.002%, and the balance is Al. 10% SiC powder is used as the reinforcing material, the particle size of the SiC powder is 2 μm, the particle size of the metal powder is 50 μm, the SiC powder and the 7075 aluminum alloy powder are ball milled and stirred uniformly, the ball milling time is 35 h, and the reciprocating melting time is 6 h. Example 5

[0073] The embodiment is a preparation method of an aluminum-based composite material reinforced by vacuum reciprocating smelting and assisted by thin strip casting and rolling, which is different from that of the embodiment 2 in that the base material used is 7075 aluminum alloy, and the composition is: Mg 1.5%, Si 0.3%, Mn 0.1%, Cr 0.18%, Zn 0.12%, Fe 0.7%, Ti 0.1%, N≤0.002%, O≤0.002%, and the balance is Al; 25% SiC powder is used as the reinforcing material, the particle size of the SiC powder is 2 μm, and the particle size of the metal powder is 40 μm. The SiC powder and the 7075 aluminum alloy powder are ball-milled and stirred uniformly, the ball-milling time is 30 h, the ball-milling speed is 300 r / min, and the ball-milling is stopped for 3 h; the reciprocating smelting time is 3 h. Embodiment 6

[0074] The embodiment is a preparation method of an aluminum-based composite material reinforced by vacuum reciprocating smelting and assisted by thin strip casting and rolling, which is different from that of the embodiment 3 in that the base material used is 6063 aluminum alloy. 25% TiC powder is used as the reinforcing material, the particle size of the TiC powder is 2 μm, and the particle size of the metal powder is 50 μm. The TiC powder and the 6063 aluminum alloy powder are ball-milled and stirred uniformly, the ball-milling is stopped for 30 min after 3 h of ball-milling, the ball-milling is stopped for 20 min after 2 h of ball-milling, and the ball-milling is stopped for 10 min after 1 h of ball-milling, and the operation mode is repeated, the ball-milling time is 40 h, and the reciprocating smelting time is 3 h.

Claims

1. A method for preparing a vacuum reciprocating melting-assisted thin strip casting-rolling reinforced aluminum matrix composite material, characterized in that, Includes the following steps: Step (1) Preparation of aluminum-based materials: Prepare aluminum alloy matrix rods according to the set composition, which contains the following components by weight percentage: Mg 0.8~1.8%, Si 0.4~0.8%, Cu 0.15~4.9%, Mn 0.1~1.5%, Cr 0.04~0.35%, Zn 0.1~0.25%, Fe 0.35~0.7%, Ti 0.1~0.15%, N≤ 0.002%, O≤0.002%, with the balance being Al; Step (2), Vacuum ball milling: The ceramic particles and Al powder are mixed by vacuum ball milling to ensure that the surface of the ceramic particles is completely covered with Al powder, so that the ceramic particles and aluminum powder are fully wetted, and a ceramic / aluminum-based composite powder with a mass fraction of 5-25% is prepared as a reinforcing phase; the ceramic particles provide a solidification heat transfer ratio of more than 30%; the ceramic particles include SiC, TiC, and TiB2, wherein the particle size of the ceramic particles is less than 3μm, the particle size of the Al powder is 30-50μm, and the ball milling time is more than 30h; Step (3), Vacuum Melting: The aluminum alloy matrix rod prepared in step (1) is placed in a vacuum melting furnace, and the ceramic / aluminum-based composite powder prepared in step (2) is fed in through a powder feeding mechanism. The vacuum is then evacuated to 10. -3 The pressure is below 10 Pa to remove impurities from the smelting process; the aluminum melt temperature is controlled to be +25~65℃ superheat, and bottom argon blowing is used for slag removal and degassing; in the vacuum melting chamber, the number of pores on the solidification section of the thin strip is ≤6 / 10mm. 2 And the pore size is ≤0.5μm; Step (4), reciprocating melting: After the melt temperature reaches 680~720℃, mechanically stir for 30min~60min, then let it stand to cool down for 20min~30min. Repeat this reciprocating melting for 3~6h to remove impurities, ensure that ceramic particles are evenly dispersed in the aluminum alloy melt, and form good interface wetting and bonding with the matrix. Step (5), thin strip casting and rolling: turn on the casting and rolling mill and the water cooling system. Under the protection of inert gas Ar or N2, inject the uniform ceramic particles / aluminum alloy composite melt obtained after reciprocating melting in step (4) into the lower water outlet of the flow package. It enters the molten pool consisting of two rotating casting rolls and two side sealing plates from top to bottom. Control the casting speed to 30~50m / min, control the molten pool liquid level height to 80~150mm, and control the casting strip thickness to 3.0~15.0mm. Step (6) Preliminary treatment of the cast strip: The ceramic / aluminum composite material strip obtained in step (5) is cooled to room temperature, and then the surface is polished. The roughness is controlled to be above Ra 2μm. Then, it is segmented using a wire cutting robot. Step (7), heat treatment of the cast strip: The ceramic / aluminum matrix composite strip after step (6) is solution treated at 450~550℃ for 1~8h, and then rapidly cooled; the aging treatment temperature is 100~200℃ and the aging treatment time is 6~24h; after heat treatment, a ceramic / aluminum matrix composite strip with ceramic particles uniformly distributed in the matrix is ​​obtained. Step (8) Hot rolling: The heat-treated ceramic / aluminum composite strip is hot rolled at a temperature of 550~580℃, which is higher than the recrystallization temperature and lower than the melting temperature to avoid cracking. Through hot rolling, the grains are further refined and the structure and properties of the composite material are significantly improved. Step (9), cold rolling: cold rolling is carried out on the basis of hot rolling to obtain ceramic / aluminum-based composite material plates with a thickness of 0.2~0.3mm, and the surface quality is controlled between Ra 0.2μm~Ra 1.6μm.

2. The method for preparing a vacuum reciprocating melting-assisted thin strip casting and rolling reinforced aluminum matrix composite material according to claim 1, characterized in that, Step (4) During reciprocating melting, the temperature of the melt is controlled to be above 650℃.

3. The method for preparing a vacuum reciprocating melting-assisted thin strip casting and rolling reinforced aluminum matrix composite material according to claim 1, characterized in that, Step (7) The rapid cooling process after solution treatment includes high-pressure water quenching and liquid-gas atomization medium quenching.

4. The method for preparing a vacuum reciprocating melting-assisted thin strip casting and rolling reinforced aluminum matrix composite material according to claim 1, characterized in that, After hot rolling in step (8), the mass fraction of ceramic reinforcing particles in the hot-rolled ceramic / aluminum composite material matrix is ​​10~50%, the ceramic particles are evenly distributed on the matrix, the size of the matrix ceramic particles is controlled at 600~2000nm, there is no grain boundary segregation phenomenon, and no shrinkage cavities around the ceramic.

5. The method for preparing a vacuum reciprocating melting-assisted thin strip casting and rolling reinforced aluminum matrix composite material according to claim 1, characterized in that, During step (9) cold rolling, adjust the roll gap of the cold rolling mill to 3.0~15.0mm, and the cold rolling direction is the same as the casting and rolling direction.

6. The method for preparing a vacuum reciprocating melting-assisted thin strip casting and rolling reinforced aluminum matrix composite material according to claim 1, characterized in that, After cold rolling in step (9), the size of the ceramic particles in the cold-rolled plate matrix is ​​controlled at 600~2000nm, and they are evenly distributed on the matrix without grain boundary segregation.

7. The method for preparing a vacuum reciprocating melting-assisted thin strip casting and rolling reinforced aluminum matrix composite material according to claim 1, characterized in that, In step (3), within the vacuum melting chamber, the number of pores on the solidification section of the thin strip is ≤6 / 10mm. 2 And the pore size is ≤0.5μm. After hot rolling and cold rolling deformation in steps (8) and (9), all the pores are pressed together.

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