Preparation method of high-strength and high-plasticity single-walled carbon nanotube aluminum-based composite material

Abstract

The invention relates to the technical field of 6-series aluminum-based composite materials, in particular to a preparation method of a high-strength and high-plasticity single-walled carbon nanotube aluminum-based composite material, which comprises the following steps: preparing an SWCNTs-SiC composite phase; s10, the SWCNTs-SiC composite phase prepared in the step S10 and 6-series aluminum alloy powder are mixed in proportion, ground and sieved, and a mixture is obtained; the mixture obtained in the step S20 is treated under a certain condition, and an intermediate alloy of the SWCNTs-SiC-6 series aluminum alloy is obtained; 6-series aluminum alloy ingots are melted and then added into the intermediate alloy obtained in the step S30 and AlTiB, stirring is conducted under the melting condition, and then cooling and casting are conducted under a certain condition; and S40, treating the product in the step S40 to obtain a finished product. The 6-series aluminum-based composite material prepared through the method has excellent comprehensive performance, the tensile strength ranges from 300 MPa to 390 MPa, and the ductility ranges from 9% to 15%.

Description

Technical Field

[0001] The invention relates to the technical field of 6-series aluminum-based composite materials, and in particular to a method for preparing a high-strength and plastic single-walled carbon nanotube aluminum-based composite material. Background Art

[0002] 6061 aluminum alloy belongs to the Al-Mg-Si alloy series. It is a medium-strength aluminum alloy that can be strengthened by heat treatment. It has good corrosion resistance, good toughness, good welding performance and processing performance.

[0003] The basic solid solubility, diffusion coefficient of the solid solution state and interface energy of Al-Mg-Si alloy are relatively small, which can reduce the coarsening of aluminum matrix composites and interface reaction, and is an ideal matrix material. Single-walled carbon nanotubes (SWCNTs) have the advantages of extremely high strength, good electrical conductivity, high fracture toughness, low thermal conductivity, etc., and are ideal reinforcements for aluminum matrix composites, which can effectively improve the plasticity of aluminum matrix composites. However, there are some difficulties in controlling the interface between single-walled carbon nanotubes and aluminum matrix, so that the reinforcement effect of carbon nanotubes is not fully utilized.

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

[0005] The present invention aims at the deficiencies in the prior art and provides the following technical solutions:

[0006] The method for preparing a high-strength and plastic single-walled carbon nanotube aluminum-based composite material comprises the following steps:

[0007] S10, preparing SWCNTs-SiC composite phase;

[0008] S20, mixing the SWCNTs-SiC composite phase obtained in step S10 with 6 series aluminum alloy powder in proportion, grinding, and sieving to obtain a mixture;

[0009] S30, treating the mixture obtained in step S20 under certain conditions to obtain a SWCNTs-SiC-6 series aluminum alloy master alloy;

[0010] S40, melting the 6 series aluminum alloy ingot and adding it to the master alloy and AlTiB obtained in step S30, stirring under a molten condition, and then cooling and casting under certain conditions;

[0011] S50, processing the product in step S40 to obtain a finished product.

[0012] As an improvement of the above technical solution, the formula applicable to the preparation method includes the following components in percentage by weight:

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

[0014] Among them, the composition of 6 series aluminum alloy is as follows:

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

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

[0017] S11, using silicon powder and SWCNTs as raw materials, ultrasonically dispersing to obtain a uniform mixture;

[0018] S12, adopting in-situ reaction sintering to prepare SWCNTs-SiC composite phase, the sintering temperature is 1000-1400°C;

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

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

[0021] As an improvement of the above technical solution, in step S30, the processing conditions of the mixture are:

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

[0023] As an improvement of the above technical solution, in step S40, the processing conditions after the 6 series aluminum alloy ingot is melted and added to the master alloy and AlTiB obtained in step S30 are:

[0024] Keep the temperature within the range of 710-770℃ for 10-45min, stir for 5-10min at a stirring speed of 20-75r / min, and then keep the temperature for 40-80min. After that, the alloy melt is cast when the melt temperature drops to 680-720℃ after gas refining.

[0025] As an improvement of the above technical solution, in step S50, the product is processed 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 temperature 500 ~ 550 ℃, keep warm for 1 ~ 3 hours, water cooling, and then aging treatment at 155 ~ 180 ℃, 8 ~ 12h and air cooling.

[0028] Beneficial effects of the present invention:

[0029] The SWCNTs-SiC composite phase added in the present invention is used as a reinforcing phase to improve the strength of the composite material; AlTi5B is used as a refiner. The 6-series aluminum-based composite material prepared by the method provided by the present invention has excellent comprehensive performance. 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 the present invention can effectively regulate the interface structure, forming an interface structure that can effectively transfer loads, adjust stress distribution, deflect and passivate cracks, have a certain amount of dislocation storage energy, and be stable. By modifying the surface of single-walled carbon nanotubes with nanoparticles, the interface bonding between the reinforcement and the aluminum matrix can be improved, and higher strength can be obtained while ensuring high plasticity, so as to prepare a high-strength and high-plasticity 6-series aluminum-based composite material. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0032] Figure 2 This is the SEM morphology of the SWCNTs-SiC composite phase after the reaction. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] There are some difficulties in controlling the interface between existing single-walled carbon nanotubes and aluminum substrates, which means that the reinforcing effect of carbon nanotubes is not fully utilized.

[0035] To solve the above problems, the present invention provides a technical solution to the above technical problems.

[0036] Embodiment 1

[0037] It should be noted that, in this embodiment, the aluminum-based composite material comprises a SWCNTs-SiC composite phase and a 6061 aluminum alloy.

[0038] Among them, the SWCNTs-SiC composite phase is 0.1wt%, and AlTiB is 0.5wt%; the aluminum matrix composition: 6061 aluminum alloy (99.4wt%), including Mg0.83%, Si0.42wt%, Cu0.34wt%, Fe0.63wt%, Mn0.16wt%, Zn0.26wt%, Cr0.36wt%, Ti0.14wt%, and the balance is Al.

[0039] The preparation method thereof comprises the following steps:

[0040] S10, mixing 1 wt% SWCNTs-SiC powder and an aluminum matrix component (6061 aluminum alloy (99 wt%) powder), and cold pressing at a pressure of 400 MPa for 1 min to obtain a SWCNTs-SiC-6061 aluminum alloy master alloy;

[0041] S20, then adding the 6061 aluminum alloy ingot into a graphite crucible, heating it in a resistance furnace until it is melted, and then adding a refiner AlTiB and a SWCNTs-SiC-6061 aluminum alloy master alloy;

[0042] S30, keeping the alloy melt at 760°C for 40 minutes, stirring for 10 minutes, with a stirring speed of 50 rpm, and keeping the melt at 70 minutes. Finally, after degassing and refining, the alloy melt is cast when the melt temperature drops to 660°C.

[0043] S40, hot extrusion deformation at 450℃, extrusion speed of 5m / min, extrusion ratio of 3:1, heat treatment process: solution temperature of 550℃ for 2 hours, water cooling, and then aging treatment at 180℃ for 8h;

[0044] S50, obtaining a finished product.

[0045] Comparative Example 1

[0046] It should be noted that, in this comparative example, the aluminum-based composite material composition includes 6061 aluminum alloy (99.5wt%), of which Mg is 0.83%, Si is 0.52wt%, Cu is 0.34wt%, Fe is 0.63wt%, Mn is 0.16wt%, Zn is 0.26wt%, Cr is 0.36wt%, Ti is 0.14wt%, and the balance is Al.

[0047] The preparation method thereof comprises the following steps:

[0048] S10, adding a 6061 aluminum alloy ingot into a graphite crucible, heating it in a resistance furnace until it is melted, and then adding a refiner AlTiB;

[0049] S20, keeping the alloy melt at 760°C for 40 minutes, stirring for 10 minutes, with a stirring speed of 50 rpm, and then keeping the melt at 70 minutes. Finally, after degassing and refining, the alloy melt is cast when the melt temperature drops to 660°C.

[0050] S30, hot extrusion deformation at 450℃, extrusion speed of 5m / min, extrusion ratio of 3:1, heat treatment process: solution temperature of 550℃ for 2 hours, water cooling, and then aging treatment at 180℃ for 8h;

[0051] S40, obtaining a finished product.

[0052] Embodiment 2

[0053] It should be noted that, in this embodiment, the aluminum-based composite material comprises a SWCNTs-SiC composite phase and a 6082 aluminum alloy.

[0054] Among them, the SWCNTs-SiC composite phase is 0.1wt%, and AlTiB is 0.5wt%; the aluminum matrix composition is 6082 aluminum alloy (99.4wt%), 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.

[0055] The preparation method thereof comprises the following steps:

[0056] S10, mixing 1 wt % SWCNTs-SiC powder with an aluminum matrix component (6082 aluminum alloy (99 wt %) powder), and cold pressing at a pressure of 400 MPa for 1 min to obtain a SWCNTs-SiC-6082 aluminum alloy master alloy;

[0057] S20, adding a 6082 aluminum alloy ingot into a graphite crucible, heating it in a resistance furnace until it is melted, and then adding a refiner AlTiB and a SWCNTs-SiC-6082 aluminum alloy master alloy;

[0058] S30, keeping the alloy melt at 760°C for 40 minutes, stirring for 10 minutes, with a stirring speed of 50 rpm, and then keeping the melt at 70 minutes. Finally, after degassing and refining, the alloy melt is cast when the melt temperature drops to 660°C.

[0059] S40, hot extrusion deformation at 450℃, extrusion speed of 5m / min, extrusion ratio of 3:1, heat treatment process: solution temperature of 550℃ for 2 hours, water cooling, and then aging treatment at 180℃ for 8h;

[0060] S50, obtaining a finished product.

[0061] Comparative Example 2

[0062] 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.

[0063] The preparation method thereof comprises the following steps:

[0064] S10, adding a 6082 aluminum alloy ingot into a graphite crucible, heating it in a resistance furnace until it is melted, and then adding a refiner AlTiB;

[0065] S20, keeping the alloy melt at 760°C for 40 minutes, stirring for 10 minutes, with a stirring speed of 50 rpm, and then keeping the melt at 70 minutes. Finally, after degassing and refining, the alloy melt is cast when the melt temperature drops to 660°C.

[0066] S30, hot extrusion deformation at 450℃, extrusion speed of 5m / min, extrusion ratio of 3:1, heat treatment process: solution temperature of 550℃ for 2 hours, water cooling, and then aging treatment at 180℃ for 8h;

[0067] S40, obtaining a finished product.

[0068] The ingots obtained in the above two embodiments and two comparative examples were processed into tensile specimens according to the room temperature tensile test method for metal materials in GB / T228-2002, and the mechanical properties of the specimens of different implementation examples were tested on a tensile testing machine.

[0069] The specific parameters are shown in Table 1:

[0070] Group Tensile strength(MPa) Elongation(%) Embodiment 1 308 9.7 Comparative Example 1 289 8.6 Embodiment 2 335 12.4 Comparative Example 2 310 15.2

[0071] It can be seen from Table 1 that when the SWCNTs-SiC composite phase is not added, the tensile properties of the obtained ingot are significantly lower, while when the SWCNTs-SiC composite phase is added, the tensile properties of the obtained ingot are significantly improved.

[0072] It can be seen that the aluminum-based composite material provided by the present invention has high comprehensive performance, can be assembled by adjusting the composition and process, and has broad application prospects.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them.

[0074] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0075] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 present invention. The present invention is therefore not limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a high-strength and plastic single-walled carbon nanotube aluminum-based composite material, characterized in that: The following steps are involved: S10, preparing SWCNTs-SiC composite phase; S20, mixing the SWCNTs-SiC composite phase obtained in step S10 with 6 series aluminum alloy powder in proportion, grinding, and sieving to obtain a mixture; S30, treating the mixture obtained in step S20 under certain conditions to obtain a SWCNTs-SiC-6 series aluminum alloy master alloy; S40, melting the 6 series aluminum alloy ingot and adding it to the SWCNTs-SiC-6 series aluminum alloy master alloy and AlTiB obtained in step S30, stirring under a molten condition, and then cooling and casting under certain conditions; S50, processing the product in step S40 to obtain a finished product.

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

3. The method for preparing the high-strength and plastic single-walled carbon nanotube aluminum-based composite material according to claim 1, characterized in that: In step S10, the method for preparing the SWCNTs-SiC composite phase includes the following steps: S11, using silicon powder and SWCNTs as raw materials, ultrasonically dispersing to obtain a uniform mixture; S12, adopting in-situ reaction sintering to prepare SWCNTs-SiC composite phase, the sintering temperature is 1000-1400°C; S13. After the temperature drops to room temperature, the SWCNTs-SiC composite phase is obtained.

4. The method for preparing the high-strength and plastic 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 the 6-series aluminum alloy powder, ball-milled, and then sieved with a sieve.

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

6. The method for preparing the high-strength and plastic single-walled carbon nanotube aluminum-based composite material according to claim 1, characterized in that: In step S40, the 6-series aluminum alloy ingot is melted and added to the SWCNTs-SiC-6-series aluminum alloy master alloy and AlTiB obtained in step S30, and the processing conditions are as follows: Keep the temperature within the range of 710-770℃ for 10-45min, stir for 5-10min at a stirring speed of 20-75r / min, and then keep the temperature for 40-80min. After that, the alloy melt is cast when the melt temperature drops to 680-720℃ after gas refining.

7. The method for preparing the high-strength and plastic 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 temperature 500 ~ 550 ℃, keep warm for 1 ~ 3 hours, water cooling, and then aging treatment at 155 ~ 180 ℃, 8 ~ 12h and air cooling.

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