Ultrahigh-strength plastic three-dimensional multi-stage mixed heterogeneous titanium-based composite material and preparation method thereof

Abstract

This invention discloses an ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous titanium-based composite material and its preparation method. The method includes: 1. performing a flow friction coating treatment on titanium alloy powder and modified amorphous cracked carbon with high active sites; 2. performing a flow friction coating treatment on modified high active and highly dispersed boron source; 3. low-temperature short-time high-pulse current-assisted vacuum hot pressing sintering; 4. multiple non-constant rate hot deformation treatments. This invention uses modified amorphous cracked carbon with high active sites and modified high active and highly dispersed boron source as reinforcing phase precursors to sequentially coat a titanium alloy powder matrix. Combined with sintering and hot deformation treatments, a multi-level, multi-scale, and multi-heterogeneous phase structure is constructed in four dimensions to obtain a three-dimensional multi-level hybrid heterogeneous titanium-based composite material, which exhibits ultra-high strength and plasticity, with a tensile strength of 1430 MPa to 1605 MPa and an elongation of 7.5% to 9%.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composite material preparation technology, specifically relating to an ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous 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 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. With the rapid development of these industries, conventional titanium and titanium alloy materials are no longer sufficient to meet the urgent demands for higher strength and ductility in both civilian and military applications. Therefore, the design and fabrication of titanium-based composite materials are considered a crucial approach to obtaining powder metallurgy titanium-based materials with superior comprehensive performance, representing a significant development trend for titanium and titanium alloy materials.

[0003] Many researchers and technicians have used 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 suffer from problems such as large particle size, poor dispersibility, easy agglomeration, low activity, and difficulty in dissolution and diffusion. As a result, they accumulate in the titanium matrix shell, failing to fully exert their strengthening effect. Furthermore, these agglomerated large particles become crack sources during material re-deformation. Moreover, the agglomerated large particles also lead to dislocation pile-up and difficulty in coordinating deformation, ultimately resulting in a significant decrease in the elongation of the material, making it difficult to prepare high-strength and high-ductility titanium-based composites. For example, in currently popular graphene-reinforced titanium-based composites, graphene's tendency to agglomerate and its difficulty in achieving uniform dispersion lead to agglomeration and enrichment at the titanium matrix shell. During deformation, the extremely weak van der Waals forces between the graphene agglomerates cause crack initiation and a sharp decrease in elongation. Furthermore, the powder / shell size is often tens of micrometers, resulting in the enrichment of the reinforcing phase at the shell, failing to achieve the desired strengthening effect in most shell and intragranular locations. Some researchers have attempted to improve the strength-plasticity balance of titanium-based composites through core-shell and layered structures, but these methods still struggle to address the significant decrease in plasticity as strength increases. Currently, achieving ultra-high strength and plasticity remains a bottleneck in the design and fabrication of titanium-based composites. Summary of the Invention

[0004] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a method for preparing an ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous titanium-based composite material. This method uses highly active amorphous pyrolysis carbon obtained through modification and a highly active and highly dispersed boron source obtained through modification as reinforcing phase precursors, which are sequentially coated onto a titanium alloy powder matrix. Combined with sintering and hot deformation treatments, a multi-level, multi-scale, and multi-heterogeneous phase structure is constructed in four dimensions, resulting in a three-dimensional multi-level hybrid heterogeneous titanium-based composite material with ultra-high strength and plasticity.

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

[0006] Step 1: The titanium alloy powder is subjected to flow friction coating treatment with the modified amorphous pyrolysis carbon with high active sites to obtain a single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolysis carbon nanoparticles with high active sites.

[0007] Step 2: The single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolysis carbon nanoparticles with high active sites obtained in Step 1 is subjected to flow friction coating treatment with a highly active and highly dispersed boron source obtained after modification treatment to obtain multi-level core-shell structure titanium alloy powder coated with carbon and boron.

[0008] Step 3: The multi-level core-shell structure titanium alloy powder coated with carbon and boron obtained in Step 2 is subjected to low-temperature short-time large pulse current assisted vacuum hot pressing sintering to obtain a three-dimensional multi-level multi-scale heterogeneous phase structure billet; the three-dimensional multi-level multi-scale heterogeneous phase structure billet has an ultra-fine titanium boride fiber structure at the shell, a β titanium encapsulating α phase grain core-shell structure in the shell, and a nano-titanium carbide structure dispersed in the α phase;

[0009] Step 4: The three-dimensional multi-level multi-scale heterogeneous phase structure blank obtained in Step 3 is subjected to multiple non-constant rate hot deformation treatments to obtain a three-dimensional multi-level hybrid heterogeneous titanium-based composite material. The three-dimensional multi-level hybrid heterogeneous titanium-based composite material has a four-dimensional multi-level multi-scale multi-heterogeneous phase structure, including an ultrafine boride titanium fiber structure in the shell, a β titanium-encapsulated α phase grain lamellar structure in the shell, a three-dimensional multi-level multi-scale multi-heterogeneous phase structure with dispersed nano-titanium carbide structure in the α phase, and an interweaving of multi-level dislocation and dislocation cell structures. The tensile strength of the three-dimensional multi-level hybrid heterogeneous titanium-based composite material reaches 1430MPa~1605MPa, and the elongation reaches 7.5%~9%.

[0010] This invention uses titanium alloy powder as the titanium matrix raw material, and modified amorphous pyrolysis carbon with high active sites and modified highly active and highly dispersed boron source as reinforcing phase precursors. The modified amorphous pyrolysis carbon with high active sites has extremely fine particle size, near-spherical morphology, extremely high reactive sites and reactive diffusion ability, excellent dispersibility and excellent adhesion. The modified highly active and highly dispersed boron source has excellent dispersibility and adhesion properties. First, the titanium alloy powder and the modified amorphous pyrolysis carbon with high active sites are reacted... Friction coating is performed to uniformly disperse and adsorb onto the surface of titanium alloy powder, resulting in a single-level core-shell structure titanium alloy powder pre-coated with amorphous pyrolytic carbon nanoparticles with highly active sites. This powder is then subjected to friction coating with a modified, highly active, and highly dispersed boron source. This further uniformly coats the pre-coated amorphous pyrolytic carbon nanoparticles with the modified boron source, constructing a double-layered, multi-level core-shell structure titanium alloy powder coated with carbon and boron. Finally, a low-temperature, short-time, high-pulse current-assisted vacuum treatment is applied. In the hot-pressing sintering process, the inner carbon interacts with the titanium in the titanium matrix and diffuses into the titanium matrix, precipitating two levels of nanoscale titanium carbide within the grains or at grain boundaries. The outer boron source reacts with the titanium matrix and diffuses into the shell to grow ultrafine boron titanium fibers. Simultaneously, under the action of dissolved carbon and precipitated carbon, a β-titanium-encapsulated α-phase grain core-shell structure is obtained, resulting in a three-dimensional multi-level, multi-scale heterogeneous phase structure billet. Finally, through multiple non-constant rate hot deformation treatments, dislocation structures are generated, decayed, and stored within the three-dimensional multi-level, multi-scale, multi-heterogeneous phase structure, constructing a multi-level, multi-scale structure in four dimensions. A multi-heterogeneous phase structure was obtained to obtain a three-dimensional multi-level hybrid heterogeneous titanium matrix composite material. This three-dimensional multi-level hybrid heterogeneous titanium matrix composite material has a four-dimensional multi-level multi-scale multi-heterogeneous phase structure, including an ultra-fine boride titanium fiber structure in the shell, a β titanium encapsulating α phase grain lamellar structure in the shell, a dispersed nano-titanium carbide structure in the α phase, and the interweaving of multi-level dislocation and dislocation cell structures. This makes the three-dimensional multi-level hybrid heterogeneous titanium matrix composite material have ultra-high strength and plasticity, with a tensile strength of 1430MPa to 1605MPa and an elongation of 7.5% to 9%.

[0011] The preparation method of the above-mentioned ultra-high strength and ductility three-dimensional multi-level hybrid heterogeneous titanium-based composite material is characterized in that the titanium alloy powder in step one is a near-α titanium alloy or (α+β) titanium alloy, and the titanium alloy powder is composed of the following components by mass content: Al < 9%, V < 5%, Mo < 4%, Si < 0.3%, Zr < 4%, with the balance being Ti; the highly active site amorphous pyrolysis carbon obtained after modification treatment is a near-spherical amorphous and microcrystalline structure with an average particle size of less than 100 nm, and the amount added is less than 1% of the mass of the titanium alloy powder. This composition of titanium alloy powder is beneficial for constructing a hard β titanium-coated soft α titanium micro / nano dual-phase structure in the α titanium matrix, and the solid solution atoms increase the nucleation sites for carbon precipitation and limit its coarsening, creating conditions for dislocation storage and structural regulation; the preferred amount of highly active site amorphous pyrolysis carbon obtained after modification treatment in this invention makes the distribution of multi-level titanium carbide more reasonable, ensuring the distribution of titanium carbide while avoiding the decrease in elongation caused by the enrichment of titanium carbide at the shell.

[0012] The preparation method of the above-mentioned ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous titanium-based composite material is characterized in that the highly active and highly dispersed boron source obtained by modification treatment in step two is elemental boron or a boron-containing compound, and the amount added is less than 0.5% of the mass of the titanium alloy powder. The amount of highly active and highly dispersed boron source added by this modification treatment ensures that the product has a good elongation.

[0013] The preparation method of the above-mentioned ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous titanium-based composite material is characterized in that the modification treatment methods used for the highly active site amorphous pyrolysis carbon obtained after modification treatment in step one and the highly active and highly dispersed boron source obtained after modification treatment in step two are ultrasonic irradiation, plasma irradiation, or mechanical friction treatment, wherein the rotation speed of mechanical friction treatment is less than 300 r / min. This preferred treatment method ensures that the highly active site amorphous pyrolysis carbon obtained after modification treatment has extremely high active sites, reaction / diffusion activity, and dispersibility, and ensures that the modified boron source has excellent dispersibility and reaction activity, which is beneficial to enhancing the reaction of the remaining titanium and generating a large number of ultrafine boride titanium fibers in situ on the shell.

[0014] The preparation method of the above-mentioned ultra-high strength and plastic three-dimensional multi-level hybrid heterogeneous titanium-based composite material is characterized in that the temperature of the low-temperature short-time large pulse current assisted vacuum hot pressing sintering in step three is 800℃~1100℃, and the sintering pressure is greater than 10MPa.

[0015] The preparation method of the above-mentioned ultra-high strength and plastic three-dimensional multi-level hybrid heterogeneous titanium-based composite material is characterized in that the temperature of the multiple non-constant rate hot deformation treatment in step four is 700℃~1000℃, the number of times is more than 3, the deformation amount of each pass is less than 15%, the total deformation amount is more than 50%, and a micro-cold deformation treatment is performed after the multiple non-constant rate hot deformation treatment, and the deformation amount of the micro-cold deformation treatment is less than 5%.

[0016] In addition, the present invention also discloses an ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous 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 highly active amorphous pyrolysis carbon obtained through modification and highly active and highly dispersed boron source obtained through modification as reinforcing phase precursors, which are sequentially coated on a titanium alloy powder matrix. Combined with sintering, hot deformation, and cold deformation treatments, a multi-level, multi-scale, and multi-heterogeneous phase structure is constructed in four dimensions to obtain a three-dimensional multi-level mixed heterogeneous titanium matrix composite material. This three-dimensional multi-level mixed heterogeneous titanium matrix composite material has ultra-high strength and plasticity, with a tensile strength of 1430MPa to 1605MPa and an elongation of 7.5% to 9%.

[0019] 2. Compared with traditional ordinary reinforcing phase precursors, the reinforcing phase precursors used in this invention include amorphous cracked carbon with high active sites obtained through modification and a boron source with high activity and high dispersion obtained through modification. Both have extremely fine particle size, near-spherical morphology, extremely high reactive sites and reactive diffusion ability, excellent dispersibility and excellent adhesion to the surface of titanium alloys, and are inexpensive. They have significant advantages in terms of cost, dispersibility (and adhesion), active sites (reactivity) and multi-scale and multi-level control.

[0020] 3. The present invention adopts a "two-step flow friction coating method" to first coat the surface of titanium powder with amorphous cracked carbon with highly active sites obtained by modification treatment, and then further coat it with a highly active and highly dispersed boron source obtained by modification treatment, thereby constructing a multi-level core-shell structure titanium alloy powder with double-layer coating of carbon and boron. The powder with this structure creates favorable conditions for the graded diffusion reaction and precipitation of carbon and boron in the subsequent sintering process.

[0021] 4. This invention employs low-temperature, short-time, high-pulse current-assisted vacuum hot pressing sintering, which allows the carbon in the inner layer and the boron source in the outer layer to interact with the titanium matrix, thereby constructing a three-dimensional, multi-level, multi-scale heterogeneous phase structure billet with an ultrafine titanium boride fiber structure at the shell, a core-shell structure of α-phase grains wrapped in β-titanium inside the shell, and a nano-distributed titanium carbide structure within the α-phase.

[0022] 5. This invention employs multiple non-constant rate hot deformation treatments and micro-cold deformation treatments to construct a multi-level dislocation structure in a three-dimensional multi-level multi-scale multi-heterogeneous phase structure. This results in the interweaving of a three-dimensional multi-level multi-scale multi-heterogeneous phase structure, a shell with ultrafine titanium boride fiber structure, an inner shell with β titanium encapsulating α phase grain lamellar structure, and a nano-dispersed titanium carbide structure within the α phase, along with multi-level dislocation and dislocation cell structures. This gives the three-dimensional multi-level hybrid heterogeneous titanium-based composite material ultra-high strength and plasticity.

[0023] 6. The method of constructing three-dimensional multi-level multi-scale multi-heterogeneous phase structures and multi-level dislocation and fault cell structures in this invention is also applicable to other highly active carbon sources and boron sources as reinforcements.

[0024] 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

[0025] Figure 1 Scanning electron microscope (SEM) image of a single-level core-shell structure titanium alloy powder pre-coated with amorphous pyrolytic carbon nanoparticles with pre-coated high-activity sites, prepared in Example 1 of this invention.

[0026] Figure 2a The energy spectrum of Ti element in the single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolysis carbon nanoparticles with high active sites prepared in Example 1 of the present invention is shown.

[0027] Figure 2b The energy spectrum of V in the single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolytic carbon nanoparticles with high active sites prepared in Example 1 of this invention is shown.

[0028] Figure 2c The energy spectrum of Al in the single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolytic carbon nanoparticles with high active sites prepared in Example 1 of this invention is shown.

[0029] Figure 2d The energy spectrum of Zr in the single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolytic carbon nanoparticles with high active sites prepared in Example 1 of this invention is shown.

[0030] Figure 2e The energy spectrum of carbon in the single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolytic carbon nanoparticles with high active sites prepared in Example 1 of this invention is shown.

[0031] Figure 3 This is a scanning electron microscope image of the carbon and boron-coated multi-level core-shell structure titanium alloy powder prepared in Example 1 of the present invention.

[0032] Figure 4a The energy spectrum of carbon in the multi-level core-shell structure titanium alloy powder coated with carbon and boron prepared in Example 1 of this invention is shown.

[0033] Figure 4b The energy spectrum of element B in the multi-level core-shell structure titanium alloy powder coated with carbon and boron prepared in Example 1 of this invention is shown.

[0034] Figure 5a This is a scanning electron microscope image of the shell of the three-dimensional multi-level multi-scale heterogeneous phase structure billet prepared in Example 1 of the present invention.

[0035] Figure 5b This is a scanning electron microscope image of the shell inside the three-dimensional multi-level multi-scale heterogeneous phase structure billet prepared in Example 1 of the present invention.

[0036] Figure 6 Tensile property curves of the three-dimensional multi-level hybrid heterogeneous titanium-based composite material prepared in Example 1 and the titanium-based material prepared in Comparative Example 1. Detailed Implementation

[0037] Example 1

[0038] This embodiment includes the following steps:

[0039] Step 1: Titanium alloy powder is subjected to flow friction treatment with modified amorphous pyrolysis carbon containing highly active sites at a rotation speed of 150 r / min to 300 r / min to obtain a single-level core-shell structure titanium alloy powder pre-coated with amorphous pyrolysis carbon nanoparticles containing highly active sites. The titanium alloy powder is a near-α titanium alloy with an average particle size of less than 100 μm, and is composed of the following mass percentages: Al 6.5%, V 2%, Mo 1.3%, Zr 2%, with the balance being Ti. The modified amorphous pyrolysis carbon containing highly active sites is a near-spherical amorphous and microcrystalline structure with a purity of 99% and a specific surface area of ​​10⁴ m². 2 / g, with an average particle size of 20nm, and the amount added is 0.15% of the mass of titanium alloy powder;

[0040] Step 2: The single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolysis carbon nanoparticles with high active sites obtained in Step 1 is subjected to flow friction treatment with a modified high-activity and highly dispersed boron source at a rotation speed of 150 r / min to 300 r / min to obtain a multi-level core-shell structure titanium alloy powder coated with carbon and boron. The modified high-activity and highly dispersed boron source is boron carbide with a mass purity greater than 99%, an average particle size of less than 50 nm, and an addition amount of 0.15% of the mass of the titanium alloy powder.

[0041] Step 3: The multi-level core-shell structured titanium alloy powder coated with carbon and boron obtained in Step 2 is subjected to low-temperature short-time high-pulse current assisted vacuum hot pressing sintering to obtain a three-dimensional multi-level multi-scale heterogeneous phase structure billet. The three-dimensional multi-level multi-scale heterogeneous phase structure billet has an ultra-fine titanium boride fiber structure at the shell, a β-titanium-encapsulated α-phase grain core-shell structure inside the shell, and a nano-titanium carbide structure dispersed within the α-phase. The temperature of the low-temperature short-time high-pulse current assisted vacuum hot pressing sintering is 800℃~1000℃, the sintering time is 5min, and the sintering pressure is 30MPa~50MPa.

[0042] Step 4: The three-dimensional multi-level multi-scale heterogeneous phase structure blank obtained in Step 3 is subjected to 10 non-constant rate hot deformation treatments and micro-cold deformation treatments at 700℃~1000℃. The deformation amount of each pass of the non-constant rate hot deformation treatment is less than 15%, and the total deformation amount is 67%. The total deformation amount of the micro-cold deformation treatment is 1.3%, resulting in a three-dimensional multi-level hybrid heterogeneous titanium-based composite material. The three-dimensional multi-level hybrid heterogeneous titanium-based composite material has a four-dimensional multi-level multi-scale multi-heterogeneous phase structure, including an ultrafine boride titanium fiber structure in the shell, a β titanium-encapsulated α phase grain lamellar structure in the shell, a three-dimensional multi-level multi-scale multi-heterogeneous phase structure with dispersed nano-titanium carbide structure in the α phase, and an interweaving of multi-level dislocation and dislocation cell structures.

[0043] Testing revealed that the three-dimensional multi-level hybrid heterogeneous titanium-based composite material obtained in this embodiment has a tensile strength of 1605 MPa, a tensile yield strength exceeding 1550 MPa, and an elongation of 8.7%, which is significantly better than that of titanium-based composite materials with traditional structures.

[0044] Figure 1 This is a scanning electron microscope (SEM) image of the single-level core-shell structure titanium alloy powder pre-coated with amorphous pyrolysis carbon nanoparticles with pre-coated high-activity sites prepared in this embodiment. Figures 2a-2e The energy spectrum of Ti, V, Al, Zr, and C elements in the single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolysis carbon nanoparticles with pre-coated high-activity sites prepared in Example 1 of this invention is shown in the figure. Figure 1 and Figures 2a-2e It can be seen that in the single-level core-shell structure titanium alloy powder with pre-coated amorphous pyrolysis carbon nanoparticles with high active sites, carbon is uniformly coated onto the surface of the titanium alloy powder.

[0045] Figure 3 This is a scanning electron microscope image of the carbon and boron-coated multi-level core-shell structured titanium alloy powder prepared in this embodiment. Figures 4a-4b The energy spectrum of C and B elements in the carbon and boron-coated multi-level core-shell structure titanium alloy powder prepared in Example 1 of this invention is shown in the figure. Figure 3 and Figures 4a-4b It can be seen that in this multi-level core-shell structure titanium alloy powder coated with carbon and boron, both boron and carbon are uniformly coated on the surface of the titanium alloy powder.

[0046] Figure 5a This is a scanning electron microscope (SEM) image of the shell of the three-dimensional multi-level, multi-scale heterogeneous phase structure preform prepared in this embodiment. Figure 5a It can be seen that the shell is formed by a large number of ultrafine titanium boride fibers.

[0047] Figure 5b This is a scanning electron microscope (SEM) image of the shell inside the three-dimensional multi-level, multi-scale heterogeneous phase structure billet prepared in this embodiment. Figure 5b It can be seen that the shell contains a core-shell structure of α-phase grains encapsulated by β-titanium and a large number of titanium carbide nanoparticles inside the grains.

[0048] The highly active amorphous pyrolysis carbon obtained after modification in step one of this embodiment and the highly active and highly dispersed boron source obtained after modification in step two are modified by ultrasonic irradiation, plasma irradiation or mechanical friction treatment, wherein the rotation speed of mechanical friction treatment is less than 300 r / min; the highly active and highly dispersed boron source obtained after modification in this embodiment can also be replaced by elemental boron.

[0049] Comparative Example 1

[0050] The difference between this comparative example and Example 1 is that the coating process of step one and step two, which involves flow friction treatment, and the non-constant rate hot deformation treatment and micro-cold deformation treatment in step four are omitted. Instead, the titanium alloy powder is directly subjected to low-temperature short-time large pulse current assisted vacuum hot pressing sintering to obtain titanium-based materials.

[0051] The tensile strength of the titanium-based material obtained in this comparative example was 807 MPa, and the elongation was 7%.

[0052] Figure 6 The tensile property curves are shown for the three-dimensional multi-level hybrid heterogeneous titanium-based composite material prepared in Example 1 and the titanium-based material prepared in Comparative Example 1. Figure 6 It is evident that, compared to titanium-based materials with ordinary structures, the three-dimensional multi-level hybrid heterogeneous titanium-based composite material prepared by the method of this invention exhibits extremely high strength and plasticity.

[0053] Example 2

[0054] The difference between this embodiment and Embodiment 1 is that the total deformation amount of the micro-cold deformation treatment in step four is 1.6%.

[0055] Testing revealed that the three-dimensional multi-level hybrid heterogeneous titanium-based composite material obtained in this embodiment has a tensile strength of 1600 MPa and an elongation of 7.5%, which is significantly better than that of titanium-based composite materials with traditional structures.

[0056] Example 3

[0057] The difference between this embodiment and Embodiment 1 is as follows: the amount of highly active amorphous pyrolysis carbon obtained after modification treatment in step one is 0.07% of the mass of titanium alloy powder; the amount of highly active and highly dispersed boron source obtained after modification treatment in step two is 0.23% of the mass of titanium alloy powder; and no micro-cold deformation treatment is performed in step four.

[0058] Testing revealed that the three-dimensional multi-level hybrid heterogeneous titanium-based composite material obtained in this embodiment has a tensile strength of 1542 MPa and an elongation of 8.8%, which is significantly better than that of titanium-based composite materials with traditional structures.

[0059] Example 4

[0060] The differences between this embodiment and Embodiment 1 are as follows: In Step 1, the amount of highly active amorphous pyrolysis carbon obtained after modification is 0.05% of the mass of the titanium alloy powder. The titanium alloy powder is composed of the following components by mass: Al 6.45%, Mo 3.46%, Si 0.26%, Zr 1.7%, O 0.11%, with the balance being Ti; In Step 2, the amount of highly active and highly dispersed boron source obtained after modification is 0.15% of the mass of the titanium alloy powder; In Step 3, the temperature of the low-temperature short-time large pulse current assisted vacuum hot pressing sintering is 900℃~1100℃, and the sintering time is 10min; In Step 4, the number of non-constant rate hot deformation treatments is 13, the total deformation is 75%, and no micro-cold deformation treatment is performed.

[0061] Testing revealed that the three-dimensional multi-level hybrid heterogeneous titanium-based composite material obtained in this embodiment has a tensile strength of 1430 MPa and an elongation of 9%, which is significantly better than that of titanium-based composite materials with traditional structures.

[0062] 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 ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous titanium-based composite materials, characterized in that, The method includes the following steps: Step 1: Titanium alloy powder is subjected to a flow friction coating treatment with modified amorphous pyrolysis carbon containing highly active sites to obtain a single-level core-shell structure titanium alloy powder pre-coated with amorphous pyrolysis carbon nanoparticles containing highly active sites. The modified amorphous pyrolysis carbon containing highly active sites is a near-spherical amorphous and microcrystalline structure with an average particle size of less than 100 nm, and its addition amount is less than 1% of the mass of the titanium alloy powder. Step 2: The monolevel core-shell structure titanium alloy powder with pre-coated amorphous pyrolysis carbon nanoparticles with high-activity sites obtained in Step 1 is subjected to flow friction coating treatment with a modified high-activity and highly dispersed boron source to obtain a multilevel core-shell structure titanium alloy powder coated with carbon and boron; the modified high-activity and highly dispersed boron source is elemental boron or a boron-containing compound, and the amount added is less than 0.5% of the mass of the titanium alloy powder; The high-activity site amorphous pyrolysis carbon obtained after modification in step one and the high-activity, highly dispersed boron source obtained after modification in step two are modified by ultrasonic irradiation, plasma irradiation or mechanical friction treatment, wherein the rotation speed of mechanical friction treatment is less than 300 r / min. Step 3: The multi-level core-shell structure titanium alloy powder coated with carbon and boron obtained in Step 2 is subjected to low-temperature short-time high-pulse current assisted vacuum hot pressing sintering to obtain a three-dimensional multi-level multi-scale heterogeneous phase structure billet; the temperature of the low-temperature short-time high-pulse current assisted vacuum hot pressing sintering is 800℃~1100℃, and the sintering pressure is greater than 10MPa; the three-dimensional multi-level multi-scale heterogeneous phase structure billet has an ultra-fine titanium boride fiber structure at the shell, a β titanium encapsulating α phase grain core-shell structure inside the shell, and a nano-dispersed titanium carbide structure within the α phase; Step 4: The three-dimensional multi-level, multi-scale heterogeneous phase structure blank obtained in Step 3 is subjected to multiple non-constant rate hot deformation treatments to obtain a three-dimensional multi-level hybrid heterogeneous titanium-based composite material. The temperature of the multiple non-constant rate hot deformation treatments is 700℃~1000℃, the number of treatments is greater than 3, the deformation amount of each treatment is less than 15%, and the total deformation amount is greater than 50%. After the multiple non-constant rate hot deformation treatments, a micro-cold deformation treatment is performed, and the deformation amount of the micro-cold deformation treatment is less than 5%. The three-dimensional multi-level, multi-scale, and heterogeneous phase structure has four dimensions, including an ultra-fine titanium boride fiber structure in the shell, a β-titanium-encapsulated α-phase grain lamellar structure in the shell, a three-dimensional multi-level, multi-scale, and heterogeneous phase structure with dispersed nano-titanium carbide structure in the α-phase, and an interweaving of multi-level dislocation and dislocation cell structures. The tensile strength of the three-dimensional multi-level, multi-scale, and heterogeneous titanium-based composite material reaches 1430MPa~1605MPa, and the elongation reaches 7.5%~9%.

2. The method for preparing the ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous titanium-based composite material according to claim 1, characterized in that, The titanium alloy powder mentioned in step one is a near-α titanium alloy or (α+β) titanium alloy, and the titanium alloy powder is composed of the following components by mass content: Al < 9%, V < 5%, Mo < 4%, Si < 0.3%, Zr < 4%, with the balance being Ti.

3. An ultra-high strength and plasticity three-dimensional multi-level hybrid heterogeneous titanium-based composite material, characterized in that, Prepared by the method according to claim 1 or 2.

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