High-strength plastic multistage hybrid heterogeneous structure titanium-based composite material and preparation method thereof

Abstract

The application discloses a high-strength and high-plasticity multi-level mixed heterogeneous structure titanium-based composite material and a preparation method thereof, and the method comprises the following steps: firstly, alumina nanoparticles and amorphous pyrolytic carbon are respectively subjected to activity adjustment and surface modification; secondly, the alumina nanoparticles with high defects and high activity are subjected to pre-coating treatment together with titanium-based powder; thirdly, the surface-modified high-activity amorphous pyrolytic carbon particles are subjected to low-energy ball milling coating together with the pre-coated alumina nanoparticles and the single-level core-shell structure titanium-based powder; and finally, high-strength and high-plasticity multi-level mixed heterogeneous structure titanium-based composite material is obtained through low-temperature short-time large-pulse current plasma sintering. In the application, the alumina nanoparticles and the amorphous pyrolytic carbon are used as the reinforcing phase precursors, and after the activity adjustment and the surface modification, the two are coated on the titanium-based powder in sequence to form the multi-level coated core-shell structure titanium-based powder, and a plurality of kinds of reinforcing phase mixed heterogeneous structures are generated in situ and solid-solution-diffused and precipitated through sintering, so that the strength and plasticity matching performance of the titanium-based composite material is significantly improved.

Description

A high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material and its preparation method Technical Field

[0001] This invention belongs to the field of metal matrix composite material preparation technology, specifically relating to a high-strength, high-plasticity, multi-level hybrid heterostructure titanium matrix composite material and its preparation method. Background Technology

[0002] Titanium and titanium alloys possess numerous advantages, including low density, high strength, high temperature resistance, low temperature resistance, corrosion resistance, non-magnetic properties, and a low coefficient of linear expansion. In particular, their specific strength is among the highest of all existing metallic materials. Secondly, they exhibit high corrosion resistance, especially in seawater and ammonia-containing media. Furthermore, titanium alloys have higher heat resistance than aluminum and magnesium alloys, leading to their widespread application in aerospace and other fields. Titanium alloys are one of the main structural materials for modern aircraft and engines, and their application level is a crucial indicator of the sophistication of weaponry and its combat readiness. In addition, the application of titanium alloys in mechanical engineering, biomedicine, marine engineering, chemical engineering, metallurgy, building materials, and general civilian industries is showing a year-on-year growth trend. Within the 400℃–500℃ temperature range, titanium alloys exhibit significantly superior specific creep strength, specific creep strength, and specific fatigue strength compared to heat-resistant stainless steel. With the rapid development of application industries, ordinary titanium and titanium alloy materials can no longer meet the urgent demands of civilian and military defense sectors for the superior comprehensive performance of titanium materials. The design and preparation of super titanium-based composite materials are considered an important way to obtain powder metallurgy titanium-based materials with superior comprehensive performance, and are an important development trend of titanium and titanium alloy materials.

[0003] Many researchers and technicians use titanium carbide, titanium silicide, titanium boride, diamond, graphene, carbon nanotubes, onion carbon, MAX ceramics, and intermetallic compounds as reinforcing phases in titanium-based composites. However, these traditional reinforcing phases often concentrate in the shell, leading to a sharp decrease in elongation while improving the strength of titanium-based composites, making it difficult to achieve a high strength-ductility balance in the preparation of titanium-based composites. Some technicians have also tried to improve the strength-ductility balance of titanium-based composites through the design of core-shell and layered structures, but the problem of a significant decrease in ductility with increased strength remains unresolved. Currently, achieving a high strength-ductility balance is a bottleneck in the design and preparation of titanium-based composites. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for preparing a high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material, addressing the shortcomings of the prior art. This method uses alumina nanoparticles and amorphous pyrolytic carbon as reinforcing phase precursors. After activity regulation and surface modification, both are sequentially coated onto titanium-based powder to form a multi-level coated core-shell structure. Densification and activation are achieved through low-temperature, short-time, high-pulse current plasma sintering, resulting in the in-situ generation and solid-solution diffusion precipitation of various types of reinforcing phase hybrid heterostructures, significantly improving the strength-plasticity matching performance of the titanium-based composite material.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing a high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material, characterized in that the method includes the following steps:

[0006] Step 1: Alumina nanoparticles and amorphous pyrolysis carbon are subjected to activity regulation and surface modification, respectively, to obtain alumina nanoparticles with high defects and high activity and surface-modified amorphous pyrolysis carbon particles with high activity.

[0007] Step 2: The high-defect and high-activity alumina nanoparticles obtained in Step 1 are pre-coated with titanium-based powder to obtain a single-level core-shell structure titanium-based powder with pre-coated alumina nanoparticles; the titanium-based powder is titanium powder or titanium alloy powder.

[0008] Step 3: The surface-modified highly active amorphous pyrolysis carbon particles obtained in Step 1 and the pre-coated alumina nanoparticles obtained in Step 2 are subjected to low-energy ball milling coating treatment to obtain multi-level coated core-shell structured titanium-based powder.

[0009] Step 4: The multi-level coated core-shell structure titanium-based powder obtained in Step 3 is subjected to low-temperature short-time high-pulse current plasma sintering to obtain a high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material; the tensile strength of the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material is 782MPa~826MPa, and the elongation is 8%~20%.

[0010] This invention uses alumina nanoparticles and amorphous pyrolytic carbon as reinforcing phase precursors. First, the activity of both is adjusted and the surface is modified to obtain alumina nanoparticles with high defects and high activity and surface-modified amorphous pyrolytic carbon particles with high activity. Then, they are sequentially coated on titanium-based powder to form a multi-level coated core-shell structure titanium-based powder. Low-temperature short-time high-pulse current plasma sintering promotes densification, strengthening reaction, atomic migration and precipitation, and in-situ generation and solid solution diffusion precipitation of various types of reinforcing phase hybrid heterostructures, which significantly improves the strength-plasticity matching performance of titanium-based composite materials.

[0011] The above-mentioned method for preparing a high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material is characterized in that the alumina nanoparticles in step one are γ-alumina with a particle size of less than 50 nm and a specific surface area of ​​greater than 100 m². 2 / g; the amorphous pyrolysis carbon is generated by the pyrolysis of organic gases or solids; the methods for activity regulation and surface modification are ultrasonic irradiation, friction, or plasma treatment. The γ-alumina preferably used in this invention has a fine particle size, a large specific surface area, high reactivity, and high porosity, which is beneficial for uniformly coating the surface of titanium-based powder and interacting, reacting, dissolving, diffusing, and precipitating with the titanium matrix; the amorphous pyrolysis carbon preferably used in this invention has high active sites, fine particle size, good dispersibility, and high porosity, which is beneficial for coating the surface of pre-coated alumina nanoparticles in a single-level core-shell structure of titanium-based powder, and reacting, dissolving, diffusing, and precipitating reinforcing phases with the titanium matrix; the activity regulation and surface modification methods of this invention improve the defects, reactivity, dispersion, and adhesion of alumina and amorphous pyrolysis carbon, which is beneficial for the smooth progress of subsequent pre-coating and coating processes.

[0012] The preparation method of the above-mentioned high-strength and high-plasticity multi-level hybrid heterostructure titanium-based composite material is characterized in that the average particle size of the titanium-based powder in step two is less than 200 μm; the mass of the highly defective and highly active alumina nanoparticles is less than 1% of the mass of the titanium-based powder. The titanium-based powder with a particle size of less than 200 μm preferred in this invention has a suitable specific surface area, achieving a uniform distribution of the reinforcing phase precursor on the surface of the titanium-based powder to obtain a core-shell structure with excellent performance; the mass of the highly defective and highly active alumina nanoparticles controls their distribution on the surface of the titanium-based powder, which is beneficial for obtaining excellent strength-plasticity matching; the wet solvent has good dispersibility, which is beneficial for obtaining good dispersion and coating performance.

[0013] The method for preparing a high-strength, high-plasticity, multi-level hybrid heterogeneous titanium-based composite material is characterized in that the mass of the surface-modified highly active amorphous pyrolysis carbon particles in step three is less than 1.0% of the mass of the titanium-based powder in step two; and the rotation speed of the low-energy ball milling coating treatment is less than 300 r / min. This low-energy ball milling speed effectively avoids deformation of the titanium-based powder.

[0014] The method for preparing a high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material is characterized in that, in step four, the low-temperature, short-time, high-pulse current plasma sintering temperature is 800℃~1000℃, the sintering pressure is greater than 10MPa, and the holding time is less than 30min. The sintering of this invention is carried out at a relatively low temperature, which rapidly promotes densification, strengthening reaction, atomic migration, and precipitation. Moreover, under the aforementioned sintering temperature, time, and pressure, on the one hand, it ensures sintering densification and sufficient reaction diffusion, and on the other hand, it limits the ripening and coarsening of the titanium matrix microstructure and the reinforcing phase structure.

[0015] The above-mentioned method for preparing a high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material is characterized in that the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material in step four has a gradient multi-level, multi-scale interwoven hybrid structure of titanium carbide and titanium oxyaluminum distributed from the shell to the grains and grain boundaries within the shell.

[0016] In addition, the present invention also discloses a high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material, characterized in that it is prepared by the above-described method.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. This invention uses alumina nanoparticles and amorphous pyrolytic carbon as reinforcing phase precursors. After the activity of the two is adjusted and the surface is modified, they are sequentially coated on titanium-based powder to form a multi-level coated core-shell structure titanium-based powder. The powder is densified and activated by low-temperature short-time high-pulse current plasma sintering, resulting in the in-situ generation and solid solution diffusion precipitation of various types of reinforcing phase hybrid heterostructures, which significantly improves the strength-plasticity matching performance of titanium-based composite materials.

[0019] 2. Compared with traditional ordinary reinforcing phase precursors, this invention uses fine-sized, highly dispersible, and highly active γ-alumina nanoparticles and low-cost, highly dispersible, and highly active amorphous pyrolysis carbon as precursors for in-situ reaction and solid solution diffusion precipitation of reinforcing phases. It has significant advantages in terms of cost, dispersibility and adhesion, active sites and reactivity, and multi-scale and multi-level regulation, thus achieving a strong-plasticity matching performance of titanium-based composite materials.

[0020] 3. This invention employs ultrasonic, friction, or plasma treatment to regulate the activity and modify the surface of alumina nanoparticles and amorphous pyrolysis carbon, thereby improving the active sites, dispersibility, and porosity of alumina nanoparticles and amorphous pyrolysis carbon. This creates favorable conditions for the uniformity of coating of core-shell structured titanium-based powder, as well as for subsequent sintering diffusion reactions and the distribution control of multi-scale reinforcing phases.

[0021] 4. This invention first pre-coats high-defect and high-activity alumina nanoparticles onto titanium-based powder to obtain a single-level core-shell structure titanium-based powder. Then, surface-modified high-activity amorphous pyrolysis carbon particles are coated onto the single-level core-shell structure titanium-based powder to obtain a multi-level coated core-shell structure titanium-based powder. This structure allows the inner layer of alumina to rapidly interact and react with titanium and undergo solid solution diffusion during subsequent sintering, while the outer layer of high-activity pyrolysis carbon reacts and diffuses with titanium, forming a multi-scale, multi-level, core-shell gradient concentration structure, which is beneficial for improving the strength-plasticity matching of titanium-based composite materials.

[0022] 5. This invention constructs a multi-level coated core-shell structure of titanium-based powder. During the subsequent sintering process, a concentration gradient of elements such as aluminum, oxygen, and carbon is formed from the shell to the inside of the shell, which promotes the reaction with titanium and solid solution diffusion behavior. The resulting multi-level hybrid heterostructure titanium-based composite material has a gradient multi-level and multi-scale interwoven hybrid structure of titanium carbide and titanium-oxygen-aluminum from the shell to the grains and grain boundaries inside the shell, thus giving the titanium-based composite material an excellent strength-plasticity match.

[0023] 6. The present invention employs low-temperature, short-time, high-pulse current plasma sintering, which greatly promotes the diffusion and migration rate of the reinforcing phase precursor, thereby promoting its diffusion and distribution from the shell to the shell.

[0024] 7. The preparation method of the present invention is simple to operate, has low energy consumption, and is highly versatile, making it suitable for the preparation of high-strength titanium-based composite materials.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1a is a low-magnification scanning electron microscope image of the multi-level coated core-shell structured titanium-based powder prepared in Example 1 of the present invention.

[0027] Figure 1b is a high-magnification scanning electron microscope image of the multi-level coated core-shell structured titanium-based powder prepared in Example 1 of the present invention.

[0028] Figure 2 shows the tensile properties of the titanium-based composite materials prepared in Examples 1-3 and the titanium-based materials prepared in Comparative Examples 1-2 of this invention. Detailed Implementation

[0029] Example 1

[0030] This embodiment includes the following steps:

[0031] Step 1: Alumina nanoparticles and amorphous pyrolysis carbon are subjected to activity regulation and surface modification, respectively, to obtain alumina nanoparticles with high defects and high activity, and surface-modified highly active amorphous pyrolysis carbon particles; the alumina nanoparticles are γ-alumina with an average particle size of 10 nm and a specific surface area of ​​200 m². 2 / g; the amorphous pyrolyzed carbon is produced by the pyrolysis of carbon-containing gases; the method for activity regulation and surface modification is ultrasonic irradiation treatment for 3 hours;

[0032] Step 2: The high-defect and high-activity alumina nanoparticles obtained in Step 1 are subjected to a pre-coating treatment by low-energy ball milling with titanium powder having an average particle size of less than 100 μm. The low-energy ball milling speed is 150 r / min to 300 r / min, and the time is 3 h, to obtain a single-level core-shell structure titanium-based powder with pre-coated alumina nanoparticles; the mass of the high-defect and high-activity alumina nanoparticles is 0.3% of the mass of the titanium powder.

[0033] Step 3: The surface-modified highly active amorphous pyrolysis carbon particles obtained in Step 1 are subjected to low-energy ball milling coating treatment with the single-level core-shell structure titanium-based powder with pre-coated alumina nanoparticles obtained in Step 2 to obtain multi-level coated core-shell structure titanium-based powder; the mass of the surface-modified highly active amorphous pyrolysis carbon particles is 0.3% of the mass of the titanium powder in Step 2; the rotation speed of the low-energy ball milling coating treatment is 150 r / min to 250 r / min, and the time is 3 h;

[0034] Step 4: The multi-level coated core-shell structure titanium-based powder obtained in Step 3 is subjected to low-temperature short-time high-pulse current plasma sintering at a temperature of 800℃~1000℃, a sintering pressure of 20MPa~40MPa, and a holding time of 5min to obtain a high-strength and high-plasticity multi-level hybrid heterostructure titanium-based composite material.

[0035] Figures 1a and 1b are low-magnification and high-magnification scanning electron microscope (SEM) images of the multi-level coated core-shell structured titanium-based powder prepared in this embodiment, respectively. As can be seen from Figures 1a and 1b, highly active alumina and carbon nanoparticles are uniformly coated on the surface of titanium spheres in the multi-level coated core-shell structured titanium-based powder.

[0036] The tensile strength of the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material prepared in this embodiment is 783 MPa, and the elongation is 20%.

[0037] Testing revealed that the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material prepared in this embodiment possesses a gradient multi-level, multi-scale interwoven hybrid structure of titanium carbide and titanium oxyaluminum distributed from the shell to the grains and grain boundaries within the shell.

[0038] In step one of this embodiment, the amorphous pyrolysis carbon can also be generated by the pyrolysis of organic solids, and the methods of activity adjustment and surface modification can be replaced by friction or plasma treatment.

[0039] Example 2

[0040] The difference between this embodiment and Embodiment 1 is that the mass of the highly active amorphous pyrolysis carbon particles modified on the surface in step three is 0.5% of the mass of the titanium powder in step two.

[0041] The tensile strength of the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material prepared in this embodiment is 818 MPa, and the elongation is 12%.

[0042] Testing revealed that the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material prepared in this embodiment possesses a gradient multi-level, multi-scale interwoven hybrid structure of titanium carbide and titanium oxyaluminum distributed from the shell to the grains and grain boundaries within the shell.

[0043] Example 3

[0044] The difference between this embodiment and Embodiment 1 is that the mass of the highly active amorphous pyrolysis carbon particles modified on the surface in step three is 0.75% of the mass of the titanium powder in step two.

[0045] The tensile strength of the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material prepared in this embodiment is 826 MPa, and the elongation is 8.4%.

[0046] Testing revealed that the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material prepared in this embodiment possesses a gradient multi-level, multi-scale interwoven hybrid structure of titanium carbide and titanium oxyaluminum distributed from the shell to the grains and grain boundaries within the shell.

[0047] Comparative Example 1

[0048] The difference between this comparative example and Example 1 is that no alumina nanoparticles and amorphous pyrolysis carbon are added, and there is no subsequent corresponding mixing step.

[0049] The titanium-based material prepared in this comparative example was tested and found to have a tensile strength of 437 MPa and an elongation of 24.3%.

[0050] Comparative Example 2

[0051] The difference between this comparative example and Example 1 is that only alumina nanoparticles with high defects and high activity are coated, without adding highly active amorphous pyrolysis carbon particles with surface modification.

[0052] The titanium-based material prepared in this comparative example was tested and found to have a tensile strength of 659 MPa and an elongation of 18.7%.

[0053] Figure 2 shows the tensile properties of the titanium-based composite materials prepared in Examples 1-3 and Comparative Examples 1-2. As can be seen from Figure 2, the titanium-based composite materials prepared in Examples 1-3 exhibit better elongation while improving strength, indicating that the titanium-based composite materials prepared by the method of the present invention have high strength-plasticity matching properties.

[0054] Example 4

[0055] The difference between this embodiment and Embodiment 1 is as follows: the amount of alumina added in step two is 0.5% of the mass of titanium powder; the mass of the highly active amorphous pyrolysis carbon particles modified on the surface in step three is 0.5% of the mass of titanium powder in step two; and the heat preservation time in step four is 10 min.

[0056] The high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material prepared in this embodiment has a tensile strength of 850 MPa and an elongation of 10%.

[0057] Testing revealed that the high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material prepared in this embodiment possesses a gradient multi-level, multi-scale interwoven hybrid structure of titanium carbide and titanium oxyaluminum distributed from the shell to the grains and grain boundaries within the shell.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a high-strength, high-ductility, multi-level hybrid heterostructure titanium-based composite material, characterized in that, The method includes the following steps: Step 1, alumina nanoparticles and amorphous pyrolysis carbon are subjected to activity regulation and surface modification, respectively, to obtain alumina nanoparticles with high defects and high activity, and surface-modified highly active amorphous pyrolysis carbon particles; the alumina nanoparticles are γ-alumina with a particle size of less than 50 nm and a specific surface area of ​​greater than 100 m². 2 / g; the amorphous pyrolysis carbon is generated by the pyrolysis of organic gases or solids; the method of activity regulation and surface modification is ultrasonic irradiation, friction or plasma treatment; Step 2: the high-defect and high-activity alumina nanoparticles obtained in Step 1 are pre-coated with titanium-based powder to obtain a single-level core-shell structure titanium-based powder with pre-coated alumina nanoparticles; the titanium-based powder is titanium powder or titanium alloy powder; the average particle size of the titanium-based powder is less than 200 μm; the mass of the high-defect and high-activity alumina nanoparticles is less than 1% of the mass of the titanium-based powder; Step 3: the surface-modified high-activity amorphous pyrolysis carbon particles obtained in Step 1 are ball-milled with the single-level core-shell structure titanium-based powder with pre-coated alumina nanoparticles obtained in Step 2. The coating process yields multi-level coated core-shell structured titanium-based powder; the mass of the surface-modified highly active amorphous pyrolysis carbon particles is less than 1.0% of the mass of the titanium-based powder in step two; the rotation speed of the low-energy ball milling coating process is less than 300 r / min; step four: the multi-level coated core-shell structured titanium-based powder obtained in step three is subjected to low-temperature short-time high-pulse current plasma sintering to obtain a high-strength, high-plasticity, multi-level hybrid heterostructured titanium-based composite material; the low-temperature short-time high-pulse current plasma sintering temperature is 800℃~1000℃, the sintering pressure is greater than 10MPa, and the holding time is less than 30min; the tensile strength of the high-strength, high-plasticity, multi-level hybrid heterostructured titanium-based composite material is 782MPa~826MPa, and the elongation is 8%~20%.

2. The method for preparing a high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material according to claim 1, characterized in that, The high-strength, high-plasticity, multi-level hybrid heterostructure titanium-based composite material described in step four has a gradient multi-level, multi-scale interwoven hybrid structure of titanium carbide and titanium oxyaluminum distributed from the shell to the grains and grain boundaries within the shell.

3. A high-strength, high-plasticity, multi-level hybrid heterogeneous titanium-based composite material, characterized in that, Prepared by the method described in claim 1 or 2.

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