CNTs (at) Ti reinforced large-size aluminum-based composite part and preparation method thereof
By growing CNTs in situ on Ti particles and introducing CNTs@Ti enhanced phase into aluminum-based materials using the characteristics of Ti, the problem of difficulty in introducing and dispersing CNTs in stirred casting is solved, and the performance of composite materials is improved.
Patent Information
- Application Number
- CN202510341337.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2025-05-30
AI Technical Summary
During the stir-casting process, carbon nanotubes (CNTs) are difficult to uniformly introduce into aluminum-based materials, resulting in poor dispersion and difficulty in fully exerting the enhancement effect.
CNTs are grown in situ on Ti particles by chemical vapor deposition, and the CNTs@Ti reinforced phase is introduced into the aluminum-based material by utilizing the easy entry and good dispersion characteristics of Ti.
It effectively solves the problem of difficulty in introducing and dispersing CNTs in stirred casting, improves the performance of composite materials, and expands the scope of application of stirred casting.
Smart Images
Figure CN120060693A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of manufacturing aluminum-based composite parts, and relates to a CNTs@Ti reinforced large-size aluminum-based composite part and a preparation method thereof. Background Art
[0002] Aluminum-based materials include aluminum and its alloys (aluminum alloys). The composite materials of aluminum-based materials have superior properties such as high specific strength, good corrosion resistance, high thermal conductivity, low coefficient of thermal expansion, low resistivity, and strong damping capacity in industrial applications. Therefore, the composite materials of aluminum-based materials are important manufacturing materials for aircraft, aerospace, military, electric power, and ship parts. In addition, during the preparation process of the composite materials of aluminum-based materials, the fuel consumption and environmental pollution are relatively small, and they have excellent wear resistance, temperature creep resistance, and fatigue strength, and are excellent substitutes for replacing steel and cast iron parts.
[0003] Due to its special structure, excellent mechanical and thermodynamic properties, as well as advantages such as high aspect ratio, large specific surface area, and low density, carbon nanotubes (CNTs) can be used as an ideal reinforcing body to overcome the performance limitations of traditional materials, and can also be used as an ideal reinforcing phase to enhance the properties of aluminum-based materials. However, due to the strong van der Waals force, large specific surface area, and extremely high aspect ratio inside CNTs, it is extremely easy to agglomerate. The agglomerated state of entanglement will make it difficult for CNTs to be evenly distributed in the composite material. Especially during the stirring casting process, CNTs are extremely easy to agglomerate during the stirring process. And due to the extremely large surface tension of CNTs, it is already difficult to introduce CNTs into the Al melt through stirring casting, making it more challenging to have a high uniform dispersion of CNTs in the composite material. In the production of large-sized parts and large-scale production processes, stirring casting has unique advantages such as low cost and simple process flow, and is an indispensable method in metal part casting. Whether in the high-tech aerospace field or in civil fields such as the automotive and machinery industries, stirring casting has a large application value.
[0004] Therefore, it is necessary to provide a CNTs@Ti reinforced large-size aluminum-based composite part and a preparation method thereof to reduce the difficulty of introducing CNTs, optimize the uniformity and dispersion of the CNTs reinforcing phase introduced into the Al melt during the stirring casting process, so as to fully exert the reinforcing effect of CNTs in the parts prepared by stirring casting and improve the performance of the parts prepared by stirring casting. Summary of the Invention
[0005] To overcome the problems in the background art, in the present invention, CNTs are in-situ and uniformly grown on Ti particles by chemical vapor deposition (CVD). Since the specific gravity difference between Ti and Al is small, Ti can be easily introduced into the Al melt by stirring casting. Thus, the Ti particles can carry the CNTs grown in-situ on them into the Al melt, reducing the difficulty of introducing CNTs into the Al melt during the stirring casting process. At the same time, Ti is not prone to agglomeration during the stirring casting process and has good dispersibility. Therefore, by growing CNTs in-situ and uniformly on Ti particles, during the stirring casting process, the Ti can carry the CNTs into the Al melt and keep the CNTs relatively dispersed in the Al melt, making it easier to introduce the reinforcing phase and having better uniform dispersibility when preparing parts by stirring casting, enabling the CNTs to play a more reinforcing role and improving the performance of the parts prepared by stirring casting.
[0006] To achieve the above object, the present invention is realized through the following technical solutions:
[0007] On the one hand, the present invention provides a method for preparing a CNTs@Ti reinforced large-size aluminum matrix composite part, which is characterized in that: the preparation method includes the following steps:
[0008] (1) A uniform layer of nano-Co particles is deposited on the surface of Ti particles by the precipitation-deposition method to obtain a precursor powder. Then, by the chemical vapor deposition method under the catalysis of Co, CNTs are in-situ synthesized on the Ti particles to obtain a CNTs@Ti reinforcing phase;
[0009] (2) The CNTs@Ti reinforcing phase obtained in step (1) and an aluminum matrix material are mixed and cast by the stirring casting method to obtain a CNTs@Ti reinforced large-size aluminum matrix composite part.
[0010] Preferably, in step (1), the specific process of the precipitation-deposition method includes: Ti powder and Co(NO 3 ) 2 . 6H 2 O are added to water in a mass ratio of Ti:Co(NO 3 ) 2 . 6H 2 O = 40:1 to 40:6 to obtain a mixed liquid. Then, the mixed liquid is ultrasonically vibrated for 30 min to promote Co(NO 3 ) 2 . 6H 2O is fully dissolved. After the ultrasonic treatment is completed, the mixed liquid is stirred for 60 min. During the stirring process, 0.1 mol / L NaOH is added until the mixed liquid becomes neutral. Then, the stirring is stopped and the mixture is allowed to stand for 24 h. The mixed liquid is subjected to vacuum filtration to obtain a solid substance. The solid substance is vacuum dried at 60 °C for 12 h to obtain the precursor powder.
[0011] Preferably, in step (1), the specific process of chemical vapor deposition includes: introducing argon at a flow rate of 200 ml / min, heating the precursor powder to 400 °C and holding for 2 h, then heating the precursor powder to 450 °C and introducing hydrogen at a flow rate of 200 ml / min. After holding for 2 h, the introduction of hydrogen is stopped, and the precursor powder is continuously heated to 550 °C while adjusting the argon flow rate to 150 - 450 ml / min. At the same time, acetylene is introduced as a carbon source at a flow rate of 10 - 60 ml / min and held for 0.25 - 1 h. Finally, the introduction of acetylene is stopped and argon is continuously introduced to allow the chemical vapor deposition product to cool to room temperature in an argon atmosphere to prevent oxidation, obtaining the CNTs@Ti reinforcing phase.
[0012] Preferably, in step (2), the specific process of stir casting is as follows: under an argon atmosphere, the aluminum-based material is heated and melted, the CNTs@Ti reinforcing phase is wrapped with aluminum foil, and then the CNTs@Ti reinforcing phase wrapped with aluminum foil is added to the melt of the aluminum-based material. The mixture is mechanically stirred to make the CNTs@Ti reinforcing phase and the aluminum-based material mix evenly. Finally, the stirred mixture is cast into a mold and cooled to form a CNTs@Ti reinforced large-sized aluminum-based composite part.
[0013] Preferably, the heating temperature of the aluminum-based material is 700 - 740 °C.
[0014] Preferably, the mold is a metal mold, and the inner wall of the mold is coated with boron nitride.
[0015] Preferably, in step (2), the stirring speed is 800 rpm and the stirring time is 5 - 30 min.
[0016] Preferably, in step (2), the added mass of the CNTs@Ti reinforcing phase is 0.5% - 2% of the total mass of the reinforcing phase and the aluminum-based material.
[0017] On the other hand, the present invention provides a CNTs@Ti reinforced large-sized aluminum-based composite part, which is prepared by the above preparation method.
[0018] The beneficial effects of the present invention:
[0019] 1. By using chemical vapor deposition, the present invention in-situ grows CNTs on the surface of Ti particles to fabricate the CNTs@Ti reinforcement phase. Taking advantage of the fact that Ti can easily enter the Al melt and has good dispersibility in the Al melt, during the stir casting process, Ti is introduced into the Al melt and evenly dispersed in the Al melt, so that Ti can bring CNTs into the Al melt and evenly disperse them in the Al matrix, effectively overcoming the problems that CNTs are difficult to introduce into the matrix metal and prone to agglomeration and uneven dispersion during the stir casting process, enabling CNTs to fully exert their strengthening effect and being conducive to effectively improving the properties of the composite material.
[0020] 2. By solving the problems that CNTs are difficult to introduce and unevenly dispersed in the matrix during the stir casting process, the present invention expands the applicable range of stir casting, enabling the unique advantages of stir casting for manufacturing large-volume parts, facilitating large-scale production, low cost, and simple process flow to be more fully exerted and utilized.
[0021] 3. The preparation method of the present invention can also be applied to the manufacture of aluminum matrix composites based on other series of aluminum alloys. While improving their strength and plasticity, the coefficient of thermal expansion will also be lower, showing wide applicability.
[0022] 4. The preparation method of the present invention has a simple process flow and low cost, and is suitable for large-scale industrial promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is the SEM image of the CNTs@Ti reinforcement phase in the present invention;
[0024] Figure 2 It is the TEM image of CNTs;
[0025] Figure 3 It is the microstructural image of the composite part prepared in Example 3 of the present invention;
[0026] Figure 4 It is the stress-strain curve graph of Example 4 and Comparative Example 1 of the present invention;
[0027] Figure 5 It is the physical image of the large-size aluminum matrix composite plate obtained by hot rolling the part prepared by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] The following further describes the present invention in detail with reference to the drawings and specific embodiments, but the protection scope of the present invention is not limited to the content described.
[0029] In the embodiments and comparative examples of the present invention, chemical reagents not specifically stated are all commercially available analytical pure reagents for experiments.
[0030] Example 1
[0031] In this embodiment, the CNTs@Ti reinforced aluminum matrix composite parts are prepared by the following method:
[0032] (1) Preparation of CNTs@Ti reinforcing phase: Ti powder and Co(NO 3 ) 2 . 6H 2 O are added to 150 ml of water at a mass ratio of Ti:Co(NO 3 ) 2 . 6H 2 O = 40:1 to obtain a mixed liquid, and then the mixed liquid is ultrasonically vibrated for 30 min to promote the complete dissolution of Co(NO 3 ) 2 . 6H 2 O. After the ultrasonic treatment, the mixed liquid is magnetically stirred for 60 min. During the stirring process, 0.1 mol / L NaOH is added until the solution becomes neutral. Then, the stirring is stopped. After the mixed liquid stands for 24 h, the mixed liquid is vacuum filtered to obtain a solid substance. Finally, the solid substance is vacuum dried at 60 °C for 12 h to obtain the precursor powder.
[0033] (2) The precursor powder is evenly spread in a porcelain boat and placed in a tubular furnace. Argon is introduced at a flow rate of 200 ml / min, and the precursor powder is heated to 400 °C and held for 2 h. Then, the precursor powder is heated to 450 °C and hydrogen is introduced at a flow rate of 200 ml / min. After holding for 2 h, the introduction of hydrogen is stopped. The precursor powder is continuously heated to 550 °C and the argon flow rate is adjusted to 150 ml / min. At the same time, acetylene is introduced as a carbon source at a flow rate of 10 ml / min and held for 0.25 h. Finally, the introduction of acetylene is stopped and argon is continuously introduced to allow the chemical vapor deposition product to cool to room temperature in an argon atmosphere to prevent oxidation, obtaining the CNTs@Ti reinforcing phase.
[0034] (3) Using an intermediate frequency induction melting furnace, 3000 g of pure aluminum is heated to complete melting in an argon atmosphere. The temperature of the melt is measured by a thermocouple to reach 740 °C. The CNTs@Ti reinforcing phase wrapped in aluminum foil is put into the Al melt (the added mass of the CNTs@Ti reinforcing phase is 0.5% of the total mass of the CNTs@Ti reinforcing phase and pure aluminum). The melt is mechanically stirred at a speed of 800 rpm for 5 min. After the stirring is completed, the melt is immediately cast into a steel mold sprayed with boron nitride for cooling and forming, obtaining the CNTs@Ti reinforced aluminum composite parts.
[0035] Various performance tests are carried out on the composite parts prepared in this embodiment, and the results are shown in Table 1.
[0036] Example 2
[0037] In this example, the CNTs@Ti reinforced aluminum matrix composite parts were prepared by the following method:
[0038] (1) Preparation of CNTs@Ti reinforcing phase: Ti powder and Co(NO 3 ) 2 . 6H 2 O were added to 150 ml of water at a mass ratio of Ti:Co(NO 3 ) 2 . 6H 2 O = 40:3 to obtain a mixed liquid, and then the mixed liquid was ultrasonically oscillated for 30 min to promote the complete dissolution of Co(NO 3 ) 2 . 6H 2 O. After ultrasonication, the mixed liquid was magnetically stirred for 60 min, and 0.1 mol / L NaOH was added during the stirring until the solution became neutral. Then, the stirring was stopped, and the mixed liquid was allowed to stand for 24 h. After that, the mixed liquid was vacuum filtered to obtain a solid substance, and finally, the solid substance was vacuum dried at 60 °C for 12 h to obtain the precursor powder.
[0039] (2) The precursor powder was evenly spread in a porcelain boat and placed in a tube furnace. Argon was introduced at a flow rate of 200 ml / min, and the precursor powder was heated to 400 °C and held for 2 h. Then, the precursor powder was heated to 450 °C and hydrogen was introduced at a flow rate of 200 ml / min and held for 2 h. After that, the introduction of hydrogen was stopped, and the precursor powder was continuously heated to 550 °C and the argon flow rate was adjusted to 300 ml / min. At the same time, acetylene was introduced as a carbon source at a flow rate of 30 ml / min and held for 1 h. Finally, the introduction of acetylene was stopped and argon was continuously introduced to prevent oxidation, and the chemical vapor deposition product was cooled to room temperature in an argon atmosphere to obtain the CNTs@Ti reinforcing phase.
[0040] (3) 3000 g of pure aluminum was heated to complete melting in an argon atmosphere using an intermediate frequency induction melting furnace, and the melt temperature was measured by a thermocouple to reach 720 °C. The CNTs@Ti reinforcing phase wrapped in aluminum foil was put into the Al melt (the added mass of the CNTs@Ti reinforcing phase was 1% of the total mass of the CNTs@Ti reinforcing phase and pure aluminum). The melt was mechanically stirred at 800 rpm for 30 min. After stirring, the melt was immediately cast into a steel mold sprayed with boron nitride for cooling and forming to obtain the CNTs@Ti reinforced aluminum composite parts.
[0041] Various performance tests were carried out on the composite parts prepared in this example, and the results are shown in Table 1.
[0042] Example 3
[0043] The CNTs@Ti reinforced aluminum matrix composite parts were prepared by the following method in this example:
[0044] (1) Preparation of CNTs@Ti reinforcing phase: Ti powder and Co(NO 3 ) 2 . 6H 2 O were added to 150 ml of water at a mass ratio of Ti:Co(NO 3 ) 2 . 6H 2 O = 40:6 to obtain a mixed liquid, and then the mixed liquid was ultrasonically oscillated for 30 min to promote the complete dissolution of Co(NO 3 ) 2 . 6H 2 O. After ultrasonic treatment, the mixed liquid was magnetically stirred for 60 min. During the stirring process, 0.1 mol / L NaOH was added until the solution became neutral, and then the stirring was stopped. After the mixed liquid was allowed to stand for 24 h, the mixed liquid was vacuum filtered to obtain a solid substance. Finally, the solid substance was vacuum dried at 60 °C for 12 h to obtain the precursor powder.
[0045] (2) The precursor powder was evenly spread in a porcelain boat and placed in a tubular furnace. Argon was introduced at a flow rate of 200 ml / min, and the precursor powder was heated to 400 °C and held for 2 h. Then, the precursor powder was heated to 450 °C and hydrogen was introduced at a flow rate of 200 ml / min and held for 2 h. After that, the introduction of hydrogen was stopped, and the precursor powder was continuously heated to 550 °C and the argon flow rate was adjusted to 450 ml / min. At the same time, acetylene was introduced as a carbon source at a flow rate of 60 ml / min and held for 0.5 h. Finally, the introduction of acetylene was stopped and argon was continuously introduced to prevent oxidation, and the chemical vapor deposition product was cooled to room temperature in an argon atmosphere to obtain the CNTs@Ti reinforcing phase.
[0046] (3) 3000 g of pure aluminum was heated to complete melting in an argon atmosphere using an intermediate frequency induction melting furnace. The temperature of the melt was measured by a thermocouple to reach 720 °C. The CNTs@Ti reinforcing phase wrapped in aluminum foil was put into the Al melt (the added mass of the CNTs@Ti reinforcing phase was 2% of the total mass of the CNTs@Ti reinforcing phase and pure aluminum). The melt was mechanically stirred at a speed of 800 rpm for 15 min. After the stirring was completed, the melt was immediately cast into a steel mold sprayed with boron nitride for cooling and forming to obtain the CNTs@Ti reinforced aluminum composite parts.
[0047] Various performance tests were carried out on the composite parts prepared in this example, and the results are shown in Table 1.
[0048] Example 4
[0049] (1) Preparation of CNTs@Ti reinforcing phase: Add Ti powder and Co(NO 3 ) 2 . 6H 2 O into 150 ml of water at a mass ratio of Ti:Co(NO 3 ) 2 . 6H 2 O = 40:1 to obtain a mixed liquid, and then ultrasonically vibrate the mixed liquid for 30 min to promote the complete dissolution of Co(NO 3 ) 2 . 6H 2 O. After ultrasonication, magnetically stir the mixed liquid for 60 min, add 0.1 mol / L NaOH during the stirring process until the solution becomes neutral, then stop stirring. After the mixed liquid stands for 24 h, perform vacuum filtration on the mixed liquid to obtain a solid substance. Finally, vacuum dry the solid substance at 60 °C for 12 h to obtain the precursor powder.
[0050] (2) Uniformly spread the precursor powder in a porcelain boat and place it in a tubular furnace. Pass argon at a flow rate of 200 ml / min, heat the precursor powder to 400 °C and hold for 2 h, then heat the precursor powder to 450 °C and pass hydrogen at a flow rate of 200 ml / min, hold for 2 h. After that, stop passing hydrogen, continue to heat the precursor powder to 550 °C and adjust the argon flow rate to 300 ml / min, and simultaneously pass acetylene as a carbon source at a flow rate of 10 ml / min, hold for 0.5 h. Finally, stop passing acetylene and keep passing argon to prevent oxidation, and let the chemical vapor deposition product cool to room temperature in an argon atmosphere to obtain the CNTs@Ti reinforcing phase.
[0051] (3) Use an intermediate frequency induction melting furnace to heat 3000 g of pure aluminum to complete melting in an argon atmosphere. Measure the melt temperature with a thermocouple up to 700 °C, and put the CNTs@Ti reinforcing phase wrapped in aluminum foil into the Al melt (the added mass of the CNTs@Ti reinforcing phase is 2% of the total mass of the CNTs@Ti reinforcing phase and pure aluminum). Mechanically stir the melt at a speed of 800 rpm for 15 min. Immediately after the stirring is completed, pour the melt into a steel mold sprayed with boron nitride for cooling and forming to obtain the CNTs@Ti reinforced aluminum composite part.
[0052] Perform stress-strain tests on the composite parts prepared in this example. The results are as Figure 4 shown, and the performance tests are shown in Table 1.
[0053] The microstructure of the composite material prepared in this example was observed, and the results are as Figure 3 shown.
[0054] Comparative Example 1
[0055] In this comparative example, CNTs@Ti reinforced aluminum matrix composite parts were prepared by the same method as in Example 4, except that: in this comparative example, the addition amount of the CNTs@Ti reinforcing phase was 3%.
[0056] The performance of the composite parts prepared in this example was tested, and the stress-strain obtained is as Figure 4 shown, and each performance test is shown in Table 1.
[0057] Comparative Example 2
[0058] In this comparative example, CNTs@Ti reinforced aluminum matrix composite parts were prepared by the same method as in Example 4, except that: in this comparative example, the addition amount of the CNTs@Ti reinforcing phase was 5%.
[0059] The performance of the composite parts prepared in this example was tested, and the results are shown in Table 1.
[0060] Comparative Example 3
[0061] In this comparative example, CNTs@Ti reinforced aluminum matrix composite parts were prepared by the same method as in Example 4, except that: in this comparative example, CNTs were directly added as the reinforcing phase.
[0062] The performance of the composite parts prepared in this example was tested, and the results are shown in Table 1.
[0063] Table 1
[0064]
[0065] It can be seen from Table 1 that as the addition amount of the CNTs@Ti reinforcing phase increases, the tensile strength of the composite parts prepared in Examples 1-4 shows an upward trend. Although the elongation fluctuates, the fluctuation range is small and they are relatively close to each other. In Comparative Examples 1 and 2, the elongation decreased significantly, and both its tensile strength and elongation decreased compared with the composite parts prepared in Example 4. This is because when the addition amount of the CNTs@Ti reinforcing phase is too much, a large number of CNTs cause serious agglomeration phenomena, which greatly deteriorates the mechanical properties of the composite parts. Therefore, the addition of too much CNTs@Ti reinforcing phase will have a counterproductive effect on the strengthening effect. As the amount of CNTs@Ti increases, the conductivity and thermal conductivity of Example 4 are still relatively good, and the coefficient of thermal expansion also decreases.
[0066] As can be seen from Table 1, the composite parts of Example 4 have improved tensile strength and elongation compared with Comparative Examples 1 and 2, indicating that the composite parts prepared by the preparation method of the present invention have relatively excellent comprehensive mechanical properties, good electrical conductivity, thermal conductivity and low coefficient of thermal expansion.
[0067] As can be seen from Table 1, the composite part in Comparative Example 3 has a low tensile strength and a high elongation. The properties of the composite part are similar to those of the non-reinforced aluminum-based material, and there is no obvious strengthening effect. It is proved that in Comparative Example 3, although the reinforcing phase is added, the reinforcing phase does not effectively play its reinforcing role, indicating that without the introduction of Ti, it is difficult for CNTs to be introduced into the Al melt by the stir casting method.
[0068] Through Figure 1 It can be seen that uniform CNTs can be in-situ synthesized on Ti under the catalysis of Co by chemical vapor deposition.
[0069] Through Figure 2 It can be seen that the in-situ synthesized CNTs have good morphology and uniform tube diameters, ensuring a good strengthening effect on the aluminum-based composite parts.
[0070] Through Figure 3 It can be seen that in the aluminum-based composite parts prepared by the preparation method of the present invention, the CNTs@Ti reinforcing phase is not only successfully introduced into the Al matrix, but also shows a relatively uniform dispersion state in the matrix.
[0071] Through Figure 5 It can be seen that using the aluminum-based composite parts prepared by the present invention as raw materials, aluminum-based composite profiles with larger sizes can be successfully prepared.
[0072] In summary, the present invention in-situ grows CNTs on Ti particles by chemical vapor deposition, uses CNTs@Ti as the reinforcing phase, and utilizes the characteristics that Ti is easy to enter the Al-based material and has good dispersion in the Al matrix. By driving CNTs with Ti, the problems of difficult introduction of CNTs into the Al matrix and poor uniform dispersion during the stir casting process are effectively solved, so that the reinforcing phase can fully play its reinforcing role and the aluminum-based composite parts have relatively excellent properties.
[0073] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.
Claims
1. A method for preparing a CNTs@Ti reinforced large-size aluminum-based composite part, characterized in that: The preparation method comprises the following steps: (1) A uniform layer of nano-Co particles is deposited on the surface of Ti particles by a precipitation-deposition method to obtain a precursor powder, and then CNTs are in situ synthesized on the Ti particles under the catalytic action of Co by a chemical vapor deposition method to obtain a CNTs@Ti reinforcement phase; (2) The CNTs@Ti reinforced phase obtained in step (1) and the aluminum-based material are mixed and cast by a stirring casting method to obtain a CNTs@Ti reinforced large-sized aluminum-based composite part.
2. The preparation method according to claim 1, characterized in that: In the step (1), the specific process of the precipitation-deposition method includes: mixing Ti powder and Co(NO3)2 . 6H2O with a mass ratio of Ti:Co(NO3)2 . 6H2O=40:1~40:6 is added to water to obtain a mixed liquid, and then the mixed liquid is ultrasonically shaken for 30 minutes to promote the reaction of Co(NO3)2 . 6H2O is fully dissolved. After the ultrasonication is completed, the mixed liquid is stirred for 60 minutes. During the stirring process, 0.1 mol / L NaOH is added until the mixed liquid is neutral. Then the stirring is stopped and the mixture is allowed to stand for 24 hours. The mixed liquid is vacuum filtered to obtain a solid substance. The solid substance is vacuum dried at 60°C for 12 hours to obtain a precursor powder.
3. The preparation method according to claim 1, characterized in that: In the step (1), the specific process of chemical vapor deposition includes: introducing argon at a flow rate of 200 ml / min, heating the precursor powder to 400°C and keeping it warm for 2 hours, then heating the precursor powder to 450°C and introducing hydrogen at a flow rate of 200 ml / min, after keeping it warm for 2 hours, stopping the introduction of hydrogen, continuing to heat the precursor powder to 550°C and adjusting the argon flow rate to 150 ml / min~450 ml / min, and at the same time introducing acetylene as a carbon source at a flow rate of 10 ml / min~60 ml / min, keeping it warm for 0.25h~1h, finally stopping the acetylene and keeping the argon flow, so that the chemical vapor deposition product is cooled to room temperature in the argon atmosphere to prevent oxidation, and obtaining a CNTs@Ti reinforcement phase.
4. The preparation method according to claim 1, characterized in that: In the step (2), the specific process of stirring casting is: after heating and melting the aluminum-based material under argon atmosphere, the CNTs@Ti reinforcing phase is wrapped with aluminum foil, and then the CNTs@Ti reinforcing phase wrapped with aluminum foil is added to the aluminum-based material melt, and the mixture is mechanically stirred to make the CNTs@Ti reinforcing phase and the aluminum-based material mixed evenly, and finally the stirred mixture is cast into a mold and cooled to form, so as to obtain a CNTs@Ti reinforced large-sized aluminum-based composite part.
5. The preparation method according to claim 4, characterized in that: The heating temperature of the aluminum-based material is 700-740°C.
6. The preparation method according to claim 4, characterized in that: The mold is a metal mold, and the inner wall of the mold is coated with boron nitride.
7. The preparation method according to claim 1, characterized in that: In the step (2), the stirring speed is 800 rpm and the stirring time is 5 to 30 min.
8. The preparation method according to claim 1, characterized in that: In the step (2), the mass of the CNTs@Ti reinforcement phase added is 0.5% to 2% of the total mass of the reinforcement phase and the aluminum-based material.
9. A CNTs@Ti reinforced large-size aluminum-based composite part, characterized in that: The CNTs@Ti reinforced large-size aluminum-based composite component is prepared by the preparation method described in any one of claims 1-8.