Preparation method of high-strength and ductile single-walled carbon nanotube aluminum matrix composite material

Abstract

This invention relates to the field of 6-series aluminum-based composite materials, and particularly to a method for preparing high-strength, high-ductility single-walled carbon nanotube (SWCNTs) aluminum-based composite materials, comprising the following steps: preparing a SWCNTs-SiC composite phase; mixing, grinding, and sieving the SWCNTs-SiC composite phase obtained in step S10 with 6-series aluminum alloy powder in a certain proportion to obtain a mixture; treating the mixture obtained in step S20 under certain conditions to obtain a SWCNTs-SiC-6-series aluminum alloy master alloy; melting a 6-series aluminum alloy ingot, then adding AlTiB and the SWCNTs-SiC-6-series aluminum alloy master alloy obtained in step S30, stirring under molten conditions, and then cooling and casting under certain conditions; and treating the product in step S40 to obtain the finished product. The 6-series aluminum-based composite material prepared by the above method has excellent comprehensive properties, with a tensile strength of 300~390MPa and an elongation of 9~15%.

Description

Technical Field

[0001] This invention relates to the field of 6-series aluminum-based composite materials technology, and more particularly to a method for preparing high-strength, high-plasticity single-walled carbon nanotube aluminum-based composite materials. Background Technology

[0002] 6061 aluminum alloy belongs to the Al-Mg-Si alloy system. It is a medium-strength aluminum alloy that can be strengthened by heat treatment. It has good corrosion resistance, as well as good toughness, weldability and machinability.

[0003] Al-Mg-Si alloys have relatively low basic solid solubility, diffusion coefficient in the solid solution state, and interfacial energy, which can reduce microstructure coarsening and interfacial reactions in aluminum matrix composites, making them ideal matrix materials. Single-walled carbon nanotubes (SWCNTs) possess advantages such as extremely high strength, good electrical conductivity, high fracture toughness, and low thermal conductivity, making them ideal reinforcements for aluminum matrix composites and effectively improving their plasticity. However, controlling the interface between SWCNTs and the aluminum matrix presents some challenges, preventing the reinforcing effect of carbon nanotubes from being fully realized.

[0004] Therefore, it is necessary to design a method for preparing high-strength and high-ductility 6-series aluminum-based composite materials. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides the following technical solution:

[0006] A method for preparing high-strength, high-ductility, single-walled carbon nanotube aluminum-based composite materials includes the following steps:

[0007] S10. Preparation of SWCNTs-SiC composite phase;

[0008] S20. The SWCNTs-SiC composite phase obtained in step S10 is mixed with 6-series aluminum alloy powder in a certain proportion, ground, and sieved to obtain a mixture.

[0009] S30. The mixture obtained in step S20 is processed under certain conditions to obtain SWCNTs-SiC-6 series aluminum alloy intermediate alloy.

[0010] S40. Melt the 6-series aluminum alloy ingot, then add AlTiB and the SWCNTs-SiC-6-series aluminum alloy master alloy obtained in step S30, stir under molten conditions, and then cool down and cast under certain conditions.

[0011] S50. Process the product from step S40 to obtain the finished product.

[0012] As an improvement to the above technical solution, the formulation applicable to this preparation method includes the following components in weight percentages:

[0013] 0.1wt%~0.5wt% of SWCNTs-SiC-6, 0.1wt%-1wt% of AlTiB and 98.5wt%~99.8wt% of 6-series aluminum alloys;

[0014] The composition of 6-series aluminum alloys is as follows:

[0015] 0.6wt%~1.2wt% Mg, 0.4wt%~1.3wt% Si, 0.15wt%~0.4wt% Cu, 0.5wt%~1.0wt% Fe, 0.15wt%~1.0wt% Mn, 0.20wt%~0.25wt% Zn, 0.04wt%~0.4wt% Cr, 0.10wt%~0.15wt% Ti, with the balance being Al.

[0016] As an improvement to the above technical solution, in step S10, the preparation method of the SWCNTs-SiC composite phase includes the following steps:

[0017] S11. Using silicon powder and SWCNTs as raw materials, a uniform mixture is obtained by ultrasonic dispersion.

[0018] S12. SWCNTs-SiC composite phase was prepared by in-situ reaction sintering at a sintering temperature of 1000-1400℃.

[0019] S13. After the temperature drops to room temperature, the SWCNTs-SiC composite phase is obtained.

[0020] As an improvement to the above technical solution, the SWCNTs-SiC composite phase is mixed with 6-series aluminum alloy powder, then ball-milled and sieved.

[0021] As an improvement to the above technical solution, in step S30, the processing conditions for the mixture are as follows:

[0022] Cold press for 1-3 minutes at a pressure of 100-400 MPa.

[0023] As an improvement to the above technical solution, in step S40, the processing conditions for stirring under molten conditions and then cooling and casting under certain conditions are as follows:

[0024] Hold the mixture at 710-770℃ for 10-45 minutes, then stir at a stirring speed of 20-75 r / min for 5-10 minutes, and then hold it at 710-770℃ for 40-80 minutes. After the alloy melt is refined by gas, it is poured when the melt temperature drops to 680-720℃.

[0025] As an improvement to the above technical solution, the product processing procedure in step S50 is as follows:

[0026] S51. Hot processing: Extrusion ratio is 3~5, extrusion speed is 3~5m / min, and extrusion temperature is 400~475℃;

[0027] S52. Heat treatment: Solution treatment at 500~550℃, hold for 1~3 hours, water cooling, followed by aging treatment at 155~180℃ for 8~12 hours, and then air cooling.

[0028] The beneficial effects of this invention are:

[0029] The SWCNTs-SiC composite phase added in this invention serves as a reinforcing phase, improving the strength of the composite material; AlTi5B acts as a refining agent. The 6-series aluminum-based composite material prepared by the method provided in this invention exhibits excellent comprehensive properties. Experiments have shown that the tensile strength of the aluminum-based composite material is 300~390MPa, and the elongation is 9~15%.

[0030] The manufacturing method provided by this invention can effectively control the interface structure to form a stable interface structure that can effectively transfer loads, regulate stress distribution, deflect and passivate cracks, and store some fault energy. By modifying the surface of single-walled carbon nanotubes with nanoparticles, the interfacial bonding between the reinforcement and the aluminum matrix can be improved, achieving higher strength while ensuring high plasticity, thus preparing a high-strength and high-plasticity 6-series aluminum-based composite material. Attached Figure Description

[0031] Figure 1 The XRD pattern of the SWCNTs-SiC composite phase after the reaction;

[0032] Figure 2 The SEM morphology of the SWCNTs-SiC composite phase after the reaction is shown. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] There are some difficulties in controlling the interface between existing single-walled carbon nanotubes and aluminum substrates, which prevents the reinforcing effect of carbon nanotubes from being fully utilized.

[0035] To address the above problems, this invention provides a technical solution to solve the aforementioned technical issues. Example

[0036] It should be noted that, in this embodiment, the aluminum-based composite material consists of SWCNTs-SiC composite phase and 6061 aluminum alloy.

[0037] The composition of the SWCNTs-SiC composite phase is 0.1 wt%, and the composition of AlTiB is 0.5 wt%. The aluminum matrix composition is 6061 aluminum alloy (99.4 wt%), of which Mg is 0.83%, Si is 0.42 wt%, Cu is 0.34 wt%, Fe is 0.63 wt%, Mn is 0.16 wt%, Zn is 0.26 wt%, Cr is 0.36 wt%, Ti is 0.14 wt%, and the balance is Al.

[0038] Its preparation method includes the following steps:

[0039] S10. Mix 1 wt% of SWCNTs-SiC powder with aluminum matrix (6061 aluminum alloy (99 wt%) powder) and cold press at 400 MPa for 1 min to obtain SWCNTs-SiC-6061 aluminum alloy master alloy.

[0040] S20. Then, the 6061 aluminum alloy ingot is added to the graphite crucible and heated in the resistance furnace until it melts. Then, the refining agent AlTiB and SWCNTs-SiC-6061 aluminum alloy master alloy are added.

[0041] S30. The above alloy melt is kept at 760℃ for 40 minutes and then stirred for 10 minutes at a stirring speed of 50 rpm. It is kept at 70 minutes. Finally, the above alloy melt is degassed and refined, and the melt temperature is reduced to 660℃ before casting.

[0042] S40, 450℃ hot extrusion deformation, extrusion speed 5m / min, extrusion ratio 3:1, heat treatment process is: solution temperature 550℃ for 2 hours, water cooling, and then aging treatment at 180℃ for 8 hours.

[0043] S50, the finished product is obtained.

[0044] Comparative Example 1

[0045] It should be noted that in this comparative example, the aluminum-based composite material composition includes 6061 aluminum alloy (99.5 wt%), of which Mg is 0.83%, Si is 0.52 wt%, Cu is 0.34 wt%, Fe is 0.63 wt%, Mn is 0.16 wt%, Zn is 0.26 wt%, Cr is 0.36 wt%, Ti is 0.14 wt%, and the balance is Al.

[0046] Its preparation method includes the following steps:

[0047] S10. Add 6061 aluminum alloy ingots to a graphite crucible, heat in a resistance furnace until melted, and then add the refining agent AlTiB.

[0048] S20. The above alloy melt is kept at 760°C for 40 minutes and then stirred for 10 minutes at a stirring speed of 50 rpm. Then it is kept at 70 minutes. Finally, the above alloy melt is degassed and refined, and the melt temperature is reduced to 660°C before casting.

[0049] S30, hot extrusion deformation at 450℃, extrusion speed of 5m / min, extrusion ratio of 3:1, heat treatment process is: solution temperature of 550℃ for 2 hours, water cooling, and then aging treatment at 180℃ for 8 hours;

[0050] S40, the finished product is obtained. Example

[0051] It should be noted that, in this embodiment, the aluminum-based composite material consists of SWCNTs-SiC composite phase and 6082 aluminum alloy.

[0052] The composition of the SWCNTs-SiC composite phase is 0.1 wt%, and the composition of AlTiB is 0.5 wt%. The aluminum matrix composition is 6082 aluminum alloy (99.4 wt%), of which Mg is 0.73%, Si is 0.93 wt%, Cu is 0.05 wt%, Fe is 0.20 wt%, Mn is 0.68 wt%, Zn is 0.15 wt%, Cr is 0.18 wt%, Ti is 0.04 wt%, and the balance is Al.

[0053] Its preparation method includes the following steps:

[0054] S10. Mix 1 wt% of SWCNTs-SiC powder with aluminum matrix (6082 aluminum alloy (99 wt%) powder) and cold press at 400 MPa for 1 min to obtain SWCNTs-SiC-6082 aluminum alloy intermediate alloy.

[0055] S20. Add 6082 aluminum alloy ingots to a graphite crucible, heat it in a resistance furnace until it melts, and then add the refining agent AlTiB and SWCNTs-SiC-6082 aluminum alloy master alloy.

[0056] S30. The above alloy melt is kept at 760°C for 40 minutes and then stirred for 10 minutes at a stirring speed of 50 rpm. Then it is kept at 70 minutes. Finally, the above alloy melt is degassed and refined, and the melt temperature is reduced to 660°C before casting.

[0057] S40, 450℃ hot extrusion deformation, extrusion speed 5m / min, extrusion ratio 3:1, heat treatment process: solution temperature 550℃ for 2 hours, water cooling, and then aging treatment at 180℃ for 8 hours;

[0058] S50, the finished product is obtained.

[0059] Comparative Example 2

[0060] It should be noted that in this comparative example, the aluminum-based composite material composition includes 6082 aluminum alloy (100wt%), of which Mg is 0.73%, Si is 0.93wt%, Cu is 0.05wt%, Fe is 0.20wt%, Mn is 0.68wt%, Zn is 0.15wt%, Cr is 0.18wt%, Ti is 0.04wt%, and the balance is Al.

[0061] Its preparation method includes the following steps:

[0062] S10. Add 6082 aluminum alloy ingots to a graphite crucible, heat in a resistance furnace until melted, and then add the refining agent AlTiB.

[0063] S20. The above alloy melt is kept at 760°C for 40 minutes and then stirred for 10 minutes at a stirring speed of 50 rpm. Then it is kept at 70 minutes. Finally, the above alloy melt is degassed and refined, and the melt temperature is reduced to 660°C before casting.

[0064] S30, hot extrusion deformation at 450℃, extrusion speed of 5m / min, extrusion ratio of 3:1, heat treatment process is: solution temperature of 550℃ for 2 hours, water cooling, and then aging treatment at 180℃ for 8 hours;

[0065] S40, the finished product is obtained.

[0066] The ingots obtained in the two embodiments and two comparative examples were processed into tensile specimens according to GB / T228-2002 Metallic Materials, Tensile Testing at Room Temperature, and the mechanical properties of the specimens in different embodiments were tested on a tensile testing machine.

[0067] The specific parameters are shown in Table 1:

[0068] As shown in Table 1, the tensile properties of the ingots were significantly lower when the SWCNTs-SiC composite phase was not added, while the tensile properties of the ingots were significantly improved when the SWCNTs-SiC composite phase was added.

[0069] Therefore, the aluminum-based composite material provided by this invention has high comprehensive performance and can be assembled by adjusting the composition and process, and has broad application prospects.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

[0071] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing high-strength, high-plasticity single-walled carbon nanotube aluminum-based composite materials, characterized in that, Includes the following steps: S10. Preparation of SWCNTs-SiC composite phase; S20. The SWCNTs-SiC composite phase obtained in step S10 is mixed with 6-series aluminum alloy powder in a certain proportion, ground, and sieved to obtain a mixture. S30. The mixture obtained in step S20 is processed under certain conditions to obtain SWCNTs-SiC-6 series aluminum alloy intermediate alloy. S40. Melt the 6-series aluminum alloy ingot, then add AlTiB and the SWCNTs-SiC-6-series aluminum alloy master alloy obtained in step S30, stir under molten conditions, and then cool down and cast under certain conditions. S50. Process the product from step S40 to obtain the finished product.

2. The method for preparing the high-strength, ductile single-walled carbon nanotube aluminum-based composite material according to claim 1, characterized in that: The formulation to which this preparation method is applicable includes the following components in weight percentages: 0.1wt%~0.5wt% of SWCNTs-SiC-6, 0.1wt%-1wt% of AlTiB and 98.5wt%~99.8wt% of 6-series aluminum alloys; The composition of 6-series aluminum alloys is as follows: 0.6wt%~1.2wt% Mg, 0.4wt%~1.3wt% Si, 0.15wt%~0.4wt% Cu, 0.5wt%~1.0wt% Fe, 0.15wt%~1.0wt% Mn, 0.20wt%~0.25wt% Zn, 0.04wt%~0.4wt% Cr, 0.10wt%~0.15wt% Ti, with the balance being Al.

3. The method for preparing the high-strength, high-plasticity single-walled carbon nanotube aluminum-based composite material according to claim 1, characterized in that: In step S10, the preparation method of the SWCNTs-SiC composite phase includes the following steps: S11. Using silicon powder and SWCNTs as raw materials, a uniform mixture is obtained by ultrasonic dispersion. S12. SWCNTs-SiC composite phase was prepared by in-situ reaction sintering at a sintering temperature of 1000-1400℃. S13. After the temperature drops to room temperature, the SWCNTs-SiC composite phase is obtained.

4. The method for preparing the high-strength, ductile single-walled carbon nanotube aluminum-based composite material according to claim 1, characterized in that: In step S20, the SWCNTs-SiC composite phase is mixed with 6-series aluminum alloy powder, then ball-milled and sieved.

5. The method for preparing the high-strength, high-plasticity single-walled carbon nanotube aluminum-based composite material according to claim 1, characterized in that: In step S30, the processing conditions for the mixture are as follows: Cold press for 1-3 minutes at a pressure of 100-400 MPa.

6. The method for preparing the high-strength, ductile single-walled carbon nanotube aluminum-based composite material according to claim 1, characterized in that: In step S40, the processing conditions for stirring under molten conditions and then cooling and casting under certain conditions are as follows: Hold the mixture at 710-770℃ for 10-45 minutes, then stir at a stirring speed of 20-75 r / min for 5-10 minutes, and then hold it at 710-770℃ for 40-80 minutes. After the alloy melt is refined by gas, it is poured when the melt temperature drops to 680-720℃.

7. The method for preparing the high-strength, high-plasticity single-walled carbon nanotube aluminum-based composite material according to claim 1, characterized in that: In step S50, the product is processed as follows: S51. Hot processing: Extrusion ratio is 3~5, extrusion speed is 3~5m / min, and extrusion temperature is 400~475℃; S52. Heat treatment: Solution treatment at 500~550℃, hold for 1~3 hours, water cooling, followed by aging treatment at 155~180℃ for 8~12 hours, and then air cooling.

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