1500mpa ultra-high-strength plastic multi-stage heterogeneous titanium-based composite material and preparation method thereof

Abstract

The application discloses a 1500MPa super-high-strength-plastic multi-stage heterogeneous titanium-based composite material and a preparation method thereof, and the method comprises the following steps: firstly, high-defect, high-activity and high-dispersion amorphous pyrolytic carbon nanoparticles are coated on titanium-based powder through multiple steps; secondly, low-temperature short-time large-pulse current spark plasma vacuum hot-pressing sintering is performed; thirdly, a small deformation amount non-constant deformation rate thermal deformation treatment is performed; and fourthly, the non-constant deformation rate thermal deformation treatment is repeatedly performed. The amorphous pyrolytic carbon nanoparticles with high defects, high activity and high dispersion are used as the reinforcing phase precursor, coating and sintering are combined, a non-continuous multi-stage multi-scale heterogeneous phase structure is formed, the strength-plasticity matching of the titanium-based composite material is improved, then the non-constant deformation rate thermal deformation treatment is combined, the dislocation structure is regulated, and the strength of the titanium-based composite material is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composite material preparation technology, specifically relating to a 1500MPa ultra-high strength and plasticity multi-level 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, especially their specific strength. Secondly, they exhibit high corrosion resistance, particularly 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. With the rapid development of application industries, ordinary titanium and titanium alloy materials are no longer sufficient to meet the urgent demands for superior comprehensive performance from civilian and military defense sectors. The design and preparation of super-titanium-based composite materials are considered an important approach to obtaining powder metallurgy titanium-based materials with superior comprehensive performance and represent a significant development trend for titanium and titanium alloy materials.

[0003] Many researchers and technicians employ reinforcing phases such as titanium carbide, titanium boride, diamond, graphene, carbon nanotubes, onion carbon, and MAX ceramics, along with traditional hot deformation processing, in an attempt to obtain ultra-high strength and ductility titanium-based composites. However, the introduction of these traditional reinforcing phases and ordinary hot deformation processing methods not only fail to significantly improve the tensile strength of titanium-based composites but also lead to a sharp decrease in the elongation of the material, making it difficult to obtain ultra-high strength and ductility titanium-based composites. Some technicians have also tried to improve the strength and ductility of titanium-based composites through the design of microstructures such as core-shell and layered structures; however, it remains difficult to achieve a structure and properties with a tensile strength of 1500 MPa and an elongation of 10%. 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 a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material. This method uses highly defective, highly active, and highly dispersed amorphous pyrolytic carbon nanoparticles as a reinforcing phase precursor. Combined with coating and sintering, the highly defective, highly active, and highly dispersed amorphous pyrolytic carbon nanoparticles fully interact with titanium-based powder to construct a multi-level, multi-scale heterogeneous structure. This improves the strength-plasticity matching of the titanium-based composite material, creating favorable conditions for subsequent dislocation structure control. Then, combined with hot deformation treatment at a non-constant deformation rate, the dislocation structure is controlled, significantly improving the strength of the titanium-based composite material.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a method for preparing a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material, characterized in that the method includes the following steps:

[0006] Step 1: Amorphous pyrolytic carbon nanoparticles with high defects, high activity, and high dispersion are uniformly coated onto titanium-based powder using a multi-step coating method to obtain a core-shell structured titanium-based powder coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity; the titanium-based powder is titanium powder or titanium alloy powder.

[0007] Step 2: The titanium-based powder with a core-shell structure and high-defect and high-activity amorphous pyrolytic carbon nanoparticles obtained in Step 1 is subjected to low-temperature short-time large-pulse current spark plasma vacuum hot pressing sintering to obtain a multi-level multi-scale heterostructure titanium-based composite material.

[0008] Step 3: The multi-level, multi-scale heterogeneous titanium matrix composite material obtained in Step 2 is subjected to hot deformation treatment with small deformation amount and non-constant deformation rate to obtain a multi-level, multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material.

[0009] Step 4: Repeat the hot deformation treatment with small deformation amount and non-constant deformation rate in Step 3 on the multi-level and multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material obtained in Step 3 to obtain a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material; the tensile strength of the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material is above 1500MPa and the elongation is above 10%.

[0010] This invention utilizes highly defective, highly active, and highly dispersed amorphous pyrolytic carbon nanoparticles as a reinforcing phase precursor. These nanoparticles are coated onto titanium-based powder in multiple steps to obtain a core-shell structured titanium-based powder coated with highly defective and highly active amorphous pyrolytic carbon nanoparticles. This powder is then subjected to low-temperature, short-duration, high-pulse current spark plasma vacuum hot pressing sintering to obtain a multi-level, multi-scale heterostructure reinforced titanium-based composite material. During this sintering process, a β-phase-encapsulated α-phase grain core-shell heterostructure is constructed. Simultaneously, some of the coated highly defective and highly active amorphous pyrolytic carbon nanoparticles fully interact with the titanium-based powder and react in situ with titanium to generate titanium carbide, while others dissolve and solidify into the titanium matrix, precipitating ultrafine and nanoscale titanium carbide at grain boundaries / phase boundaries and within the grains. This constructs a discontinuous, multi-level, multi-scale heterostructure, improving the interfacial bonding between the in-situ and precipitated titanium carbide and the titanium matrix, thereby enhancing the strength-ductility matching of the titanium-based composite material. Furthermore, this heterostructure exhibits excellent deformation resistance. The process exhibits excellent dislocation propagation, pinning, and storage capabilities, creating favorable conditions for subsequent dislocation structure control. Then, a small-deformation, non-constant deformation rate hot deformation treatment is performed and repeated to gradually accumulate and optimize the distribution structure of the dislocation structure and reinforcing phase. During this process, on the one hand, non-constant deformation rate hot deformation treatment is used for dislocation propagation, pinning, and storage; on the other hand, some dislocations are eliminated. Simultaneously, the constructed discontinuous multi-level, multi-scale heterostructure intertwines with dislocation interactions, pinning and storing dislocations, jointly achieving dislocation propagation, storage, and partial decay, thereby realizing the control of the dislocation structure and significantly improving the strength of the titanium-based composite material. Ultimately, synergistic control of strength and plasticity is achieved, improving the strength-plasticity matching of the titanium-based composite material, resulting in a 1500MPa-level ultra-high strength-plasticity matched multi-level, multi-scale heterostructure and dislocation structure synergistically reinforced titanium-based composite material, namely, a 1500MPa ultra-high strength-plasticity multi-level heterogeneous titanium-based composite material.

[0011] The above-mentioned method for preparing a 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium-based composite material is characterized in that the amorphous pyrolytic carbon nanoparticles with high defects, high activity, and high dispersion in step one are generated by the pyrolysis or deposition of carbon-containing gas, liquid, or solid, and have an amorphous or microcrystalline structure with a specific surface area greater than 20m². 2 / g, with an average particle size of less than 100nm at at least one scale. The carbon source in this invention also includes other carbon sources with similar structures, activity, and dispersibility. The ultra-high specific surface area preferred in this invention is beneficial for the coating of the carbon source, improving its reaction / diffusion transport dynamics with the titanium-based powder.

[0012] The preparation method of the above-mentioned 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material is characterized in that, in step one, the titanium-based powder has an average particle size of less than 200μm, the titanium alloy powder is a near-α or biphase (α+β) titanium alloy powder, and is composed of the following components by mass content: Al < 9%, V < 5%, Mo < 4%, Si < 0.3%, Zr < 4%, Sn < 2%, Fe < 0.5%, with the balance being Ti, and all elements are fully dissolved; the mass of the amorphous pyrolysis carbon nanoparticles with high defects, high activity and high dispersion is less than 1.5% of the mass of the titanium-based powder; the multi-step coating method is wet liquid phase pre-coating and low-energy dry ball milling coating, or multi-step low-energy dry ball milling coating. The preferred titanium alloy powder composition of this invention is beneficial for constructing a hard β titanium-coated soft α titanium micro / nano core-shell structure in an α titanium matrix. On the other hand, the solid solution atoms increase the nucleation sites for carbon precipitation and limit its coarsening, creating conditions for dislocation storage and structural control. Under the preferred carbon source ratio of this invention, the distribution of multi-level titanium carbide is more reasonable, ensuring the amount of titanium carbide while avoiding the decrease in elongation caused by the enrichment of titanium carbide at the shell.

[0013] The above-mentioned method for preparing a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material is characterized in that, in step two, the low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering temperature is 800℃~1100℃, the pulse current is 1000A~20000A, the sintering pressure is greater than 10MPa, and the sintering time is less than 30min; the low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering is replaced by vacuum hot pressing sintering or isostatic pressing sintering. The preferred temperature of this low-temperature short-time high-pulse current spark plasma sintering ensures the dense sintering of the titanium-based composite material, the preferred current promotes the diffusion and precipitation of carbon elements, the preferred pressure promotes the densification of the titanium-based composite material and generates more deformation dislocations, providing a large number of heterogeneous nucleation sites for the desolvation nucleation and precipitation of carbon inside the titanium-based powder grains, and the preferred sintering time ensures the dense sintering while avoiding the coarsening of the titanium structure and the second phase.

[0014] The above-mentioned method for preparing a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material is characterized in that the multi-level multi-scale heterogeneous titanium matrix composite material in step two has a three-level multi-scale titanium carbide heterogeneous structure with in-situ titanium carbide at the discontinuous core and shell and ultrafine and nano-sized titanium carbide dissolved and precipitated at the grain boundaries and within the grains of the titanium matrix inside the shell. Moreover, the titanium matrix inside the shell also has a β-titanium coated soft α-titanium micro-nano core-shell structure.

[0015] The above-mentioned method for preparing a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material is characterized in that the hot deformation treatment with small deformation amount and non-constant deformation rate in step three is a non-equilibrium dynamic hot deformation treatment, with a temperature of 700℃~1000℃ and a single deformation amount of less than 20%; the number of repetitions in step four is greater than 3 times, and the cumulative deformation amount is greater than 50%. This preferred single deformation amount ensures that the rolling process does not crack, and the preferred rolling temperature gives the titanium-based composite material excellent deformation plasticity, which also helps dislocation proliferation and dynamic recrystallization and recovery; the preferred total deformation amount and number of repetitions are conducive to storing sufficient dislocations and obtaining a lamellar microstructure with excellent performance.

[0016] The preparation method of the above-mentioned 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material is characterized in that the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material in step four has a hybrid composite structure of β titanium and α titanium sheet structure, multi-level multi-scale titanium carbide structure and multi-level multi-scale dislocation cell structure.

[0017] In addition, the present invention also discloses a titanium-based composite material with synergistic reinforcement of multi-level and multi-scale heterostructure and dislocation structure with ultra-high strength and plasticity matching of 1500MPa, characterized in that it is prepared by the above method.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. This invention uses amorphous pyrolytic carbon nanoparticles with high defects, high activity, and high dispersion as a reinforcing phase precursor. Combined with coating and sintering, the amorphous pyrolytic carbon nanoparticles with high defects, high activity, and high dispersion interact fully with titanium-based powder to form a discontinuous multi-level and multi-scale heterostructure, which improves the strength-ductility matching of titanium-based composite materials and creates favorable conditions for subsequent control of dislocation structure. Then, combined with hot deformation treatment with non-constant deformation rate, the control of dislocation structure is realized, which greatly improves the strength of titanium-based composite materials.

[0020] 2. The highly active and highly dispersed amorphous pyrolytic carbon nanoparticles used in this invention are widely available, inexpensive, and have a simple processing technology. Their strong plasticity matching performance and cost as a reinforcing phase are significantly better than traditional reinforcing phases such as titanium carbide, titanium boride, graphene, diamond, carbon nanotubes, and onion carbon.

[0021] 3. This invention uses highly active and highly dispersed amorphous pyrolytic carbon nanoparticles as a reinforcing phase and mixes them with titanium-based powder, which effectively avoids the introduction of impurities such as oxygen, and is significantly superior to other carbon source mixing and introduction methods.

[0022] 4. Compared with traditional carbon-based composite material structures, the discontinuous multi-level multi-scale heterogeneous structure constructed in this invention has an average titanium carbide particle size of less than 5 μm on the first-level shell, an average titanium carbide particle size of less than 500 nm on the second-level grain boundaries, and an average titanium carbide particle size of less than 100 nm on the third-level intragranular structure. This structure has excellent dislocation propagation, pinning, and storage capabilities during deformation, creating favorable conditions for the control of dislocation structures.

[0023] 5. This invention achieves the proliferation, storage and partial decay of dislocations through multiple small-deformation non-equilibrium dynamic thermal deformation processes, thereby realizing the control of dislocation structure. Furthermore, the constructed discontinuous multi-level multi-scale heterogeneous phase structure is intertwined with dislocation interactions, pins and stores dislocations, and achieves a further level of synergistic control and strong plasticity.

[0024] 6. The multi-level, multi-scale heterogeneous structure and dislocation structure synergistically reinforced titanium matrix composite material constructed by this invention, namely the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material, has a tensile strength of over 1500MPa and an elongation of over 10%, which is significantly better than the ordinary structure titanium matrix composite material prepared by traditional powder metallurgy.

[0025] 7. The synergistic control method of strength and plasticity in the preparation method of 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material of the present invention can be extended to the preparation of different high strength and plasticity titanium-based materials. The method is simple and low cost.

[0026] 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

[0027] Figure 1 This is an electron microscope image of the titanium alloy powder used in Example 1 of the present invention.

[0028] Figure 2 This is an electron microscope image of the core-shell structured titanium alloy powder coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity, prepared in Example 1 of the present invention.

[0029] Figure 3a The energy spectrum of titanium element distribution in the core-shell structure titanium alloy powder coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity prepared in Example 1 of this invention.

[0030] Figure 3b The energy spectrum of carbon element distribution in the core-shell structure titanium alloy powder coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity prepared in Example 1 of this invention is shown.

[0031] Figure 4 The image shows a metallographic SEM image of a multi-level, multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material prepared in Example 1 of this invention.

[0032] Figure 5 This is a phase distribution diagram of the multi-level, multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium-based composite material prepared in Example 1 of the present invention.

[0033] Figure 6 Tensile property curves of the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium alloy composite material prepared in Example 3 of the present invention and the titanium alloy material prepared in Comparative Example 1.

[0034] Figure 7 Tensile property curves of the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium alloy composite material prepared in Example 5 of the present invention and the titanium alloy material prepared in Comparative Example 2. Detailed Implementation

[0035] Example 1

[0036] This embodiment includes the following steps:

[0037] Step 1: Amorphous pyrolytic carbon nanoparticles with high defects, high activity and high dispersion are uniformly coated onto titanium alloy powder by wet liquid phase pre-coating and low-energy dry ball milling coating to obtain a core-shell structured titanium alloy powder coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity.

[0038] The highly defective, highly active, and highly dispersed amorphous pyrolysis carbon nanoparticles are generated by the pyrolysis of carbon-containing gases, with a carbon mass content of 99%, exhibiting amorphous and microcrystalline structures and a specific surface area greater than 100 m². 2 / g; the titanium alloy powder has an average particle size of less than 100μm, is a duplex (α+β) titanium alloy powder, and is composed of the following components by mass content: Al 6.45%, Mo 3.46%, Si 0.26%, Zr 1.7%, Fe 0.02%, O 0.11%, with the balance being Ti, and all elements are fully dissolved in solid solution, such as Figure 1 As shown; the mass of the highly defective, highly active, and highly dispersed amorphous pyrolytic carbon nanoparticles is 0.5% of the mass of the titanium-based powder;

[0039] Step 2: The titanium-based powder with a core-shell structure and high-defect and high-activity amorphous pyrolytic carbon nanoparticles obtained in Step 1 is subjected to low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering to obtain a multi-level, multi-scale heterostructure titanium-based composite material; the temperature of the low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering is 800℃~1000℃, the pulse current is 1000A~20000A, the sintering pressure is 40MPa, and the sintering time is 10min;

[0040] Step 3: The multi-level, multi-scale heterostructure titanium matrix composite material obtained in Step 2 is subjected to hot deformation treatment at 700℃~1000℃ with small deformation amount and non-constant deformation rate, and the single deformation amount is less than 20%, to obtain a multi-level, multi-scale heterostructure titanium carbide storage and interwoven special dislocation structure titanium matrix composite material.

[0041] Step 4: Repeat the hot deformation treatment with small deformation amount and non-constant deformation rate in Step 3 12 times on the multi-level and multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material obtained in Step 3. The cumulative deformation amount of the hot deformation treatment with non-constant deformation rate is 75%, and a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material is obtained.

[0042] Testing revealed that the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material prepared in this embodiment has a hybrid composite structure consisting of β-titanium and α-titanium sheet structures, multi-level multi-scale titanium carbide structures, and multi-level multi-scale dislocation cell structures.

[0043] Testing showed that the 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium alloy composite material prepared in this embodiment has a tensile strength of 1513MPa and an elongation of 11%.

[0044] Figure 2 This is an electron microscope image of the core-shell structured titanium alloy powder coated with highly defective and highly active amorphous pyrolytic carbon nanoparticles prepared in this embodiment. Figure 3a The image shows the energy spectrum of titanium element distribution in the core-shell structure titanium alloy powder coated with highly defective and highly active amorphous pyrolytic carbon nanoparticles prepared in this embodiment. Figure 3b The energy spectrum of carbon element distribution in the core-shell structured titanium alloy powder coated with highly defective and highly active amorphous pyrolytic carbon nanoparticles prepared in this embodiment is shown below. Figure 2 and Figures 3a-3b It can be seen that in the core-shell structure titanium alloy powder with high defect and high activity amorphous pyrolysis carbon nanoparticles prepared in this embodiment, the carbon nanoparticles are uniformly coated on the surface of the titanium alloy powder.

[0045] Figure 4 The images shown are metallographic SEM images of the multi-level, multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite materials prepared in this embodiment. Figure 5 This is a phase distribution diagram of the multi-level, multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium-based composite material prepared in this embodiment, combined with... Figure 4 and Figure 5It is known that the multi-level multi-scale heterostructure reinforced titanium matrix composite material has a three-level multi-scale titanium carbide heterostructure with in-situ titanium carbide at the discontinuous core and shell, and ultrafine and nano-sized titanium carbide dissolved from the grain boundaries and intragranular titanium matrix inside the shell. Among them, the average particle size of titanium carbide on the first-level shell is less than 5 μm, the average particle size of titanium carbide on the second-level grain boundary is less than 500 nm, and the average particle size of the third-level titanium carbide in the grain is less than 200 nm.

[0046] The highly defective, highly active, and highly dispersed amorphous pyrolytic carbon nanoparticles in this embodiment can also be formed by the pyrolysis or deposition of carbon-containing liquids or solids.

[0047] Example 2

[0048] This embodiment includes the following steps:

[0049] Step 1: Amorphous pyrolysis carbon nanoparticles with high defects, high activity and high dispersion are uniformly dispersed in the liquid phase, and then coated onto titanium alloy powder by low-energy ball milling in 5 times to obtain a core-shell structured titanium alloy powder coated with amorphous pyrolysis carbon nanoparticles with high defects and high activity.

[0050] The highly defective, highly active, and highly dispersed amorphous pyrolytic carbon nanoparticles are generated from the pyrolysis of carbon-containing solids, with a carbon mass content greater than 99% and a specific surface area greater than 200 m². 2 / g, and the average particle size in terms of thickness is less than 10nm; the titanium alloy powder has an average particle size of less than 100μm, is a biphase (α+β) titanium alloy powder, and is composed of the following components by mass content: Al 6.45%, Mo 3.46%, Si 0.26%, Zr 1.7%, Fe 0.02%, O 0.11%, with the balance being Ti, and all elements are fully dissolved; the mass of the highly defective, highly active, and highly dispersed amorphous pyrolysis carbon nanoparticles is 0.5% of the mass of the titanium alloy powder;

[0051] Step 2: The titanium-based powder with a core-shell structure coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity obtained in Step 1 is subjected to low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering to obtain a multi-level, multi-scale heterostructure titanium-based composite material; the temperature of the low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering is 900℃~1100℃, the pulse current is 1000A~20000A, the sintering pressure is 40MPa, and the sintering time is 5min;

[0052] Step 3: The multi-level, multi-scale heterostructure titanium matrix composite material obtained in Step 2 is subjected to hot deformation treatment at 700℃~1000℃ with small deformation amount and non-constant deformation rate, and the single deformation amount is less than 20%, to obtain a multi-level, multi-scale heterostructure titanium carbide storage and interwoven special dislocation structure titanium matrix composite material.

[0053] Step 4: Repeat the hot deformation treatment with small deformation amount and non-constant deformation rate in Step 3 12 times on the multi-level and multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material obtained in Step 3. The cumulative deformation amount of the hot deformation treatment with non-constant deformation rate is 75%, and a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material is obtained.

[0054] Testing revealed that the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material prepared in this embodiment has a hybrid composite structure consisting of β-titanium and α-titanium sheet structures, multi-level multi-scale titanium carbide structures, and multi-level multi-scale dislocation cell structures.

[0055] Testing showed that the 1500MPa ultra-high strength plastic multi-level heterogeneous titanium-based composite material prepared in this embodiment has a tensile strength of 1550MPa and an elongation of 10%.

[0056] Example 3

[0057] This embodiment includes the following steps:

[0058] Step 1: Amorphous pyrolytic carbon nanoparticles with high defects, high activity and high dispersion are uniformly coated onto titanium alloy powder through a two-step low-energy dry ball milling coating method to obtain a core-shell structured titanium alloy powder coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity.

[0059] The highly defective, highly active, and highly dispersed amorphous pyrolysis carbon nanoparticles are generated by the pyrolysis of carbon-containing gases, with a carbon mass content of 99%, exhibiting amorphous and microcrystalline structures, and a specific surface area greater than 100 m². 2 / g; the titanium alloy powder has an average particle size of less than 100μm, is a dual-phase (α+β) titanium alloy powder, and is composed of the following components by mass: Al 6.31%, V 4.15%, Fe 0.15%, with the balance being Ti, and all elements are fully dissolved; the mass of the highly defective, highly active, and highly dispersed amorphous pyrolysis carbon nanoparticles is 0.5% of the mass of the titanium alloy powder;

[0060] Step 2: The titanium-based powder with a core-shell structure and coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity obtained in Step 1 is subjected to low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering to obtain a multi-level, multi-scale heterostructure titanium-based composite material. The temperature of the low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering is 800℃~1000℃, the pulse current is 1000A~20000A, the sintering pressure is 30MPa~50MPa, and the sintering time is 5min. In the multi-level, multi-scale heterostructure reinforced titanium alloy composite material, the average particle size of titanium carbide on the first-level shell is less than 5μm, the average particle size of titanium carbide on the second-level grain boundaries is less than 500nm, and the average particle size of titanium carbide in the third-level grain is less than 100nm.

[0061] Step 3: The multi-level, multi-scale heterostructure titanium matrix composite material obtained in Step 2 is subjected to hot deformation treatment at 700℃~1000℃ with small deformation amount and non-constant deformation rate, and the single deformation amount is less than 20%, to obtain a multi-level, multi-scale heterostructure titanium carbide storage and interwoven special dislocation structure titanium matrix composite material.

[0062] Step 4: Repeat the hot deformation treatment with small deformation amount and non-constant deformation rate in Step 3 12 times on the multi-level and multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material obtained in Step 3. The cumulative deformation amount of the hot deformation treatment with non-constant deformation rate is 75%, and a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material is obtained.

[0063] Testing revealed that the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material prepared in this embodiment has a hybrid composite structure consisting of β-titanium and α-titanium sheet structures, multi-level multi-scale titanium carbide structures, and multi-level multi-scale dislocation cell structures.

[0064] Testing showed that the 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium alloy composite material prepared in this embodiment has a tensile strength of 1505MPa and an elongation of 10%.

[0065] Comparative Example 1

[0066] The specific process of this comparative example is as follows: the titanium alloy powder selected in Example 3 is subjected to low-temperature short-time large pulse current spark plasma vacuum hot pressing sintering under vacuum atmosphere to obtain titanium alloy material; the temperature of the low-temperature short-time large pulse current spark plasma vacuum hot pressing sintering is 800℃~1000℃, the pulse current is 1000A~20000A, the sintering pressure is 40MPa, and the sintering time is 5min.

[0067] Testing showed that the titanium alloy material prepared in this comparative example had a tensile strength of 900 MPa and an elongation of 11.5%.

[0068] Figure 6 The tensile property curves are shown for the 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium alloy composite material prepared in Example 3 of this invention and the titanium alloy material prepared in Comparative Example 1. Figure 6 It can be seen that, compared with Comparative Example 1, the multi-level heterogeneous titanium alloy composite material prepared in Example 3 of the present invention has ultra-high strength and plasticity.

[0069] Example 4

[0070] The difference between this embodiment and Embodiment 3 is that the mass of the amorphous pyrolysis carbon nanoparticles with high defects, high activity, and high dispersion mentioned in step one is 0.75% of the mass of the titanium alloy powder.

[0071] Testing revealed that the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material prepared in this embodiment has a hybrid composite structure consisting of β-titanium and α-titanium sheet structures, multi-level multi-scale titanium carbide structures, and multi-level multi-scale dislocation cell structures.

[0072] Testing showed that the 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium alloy composite material prepared in this embodiment has a tensile strength of 1540MPa and an elongation of 7%.

[0073] Example 5

[0074] This embodiment includes the following steps:

[0075] Step 1: High-defect, high-activity, and high-dispersion amorphous pyrolytic carbon nanoparticles are uniformly coated onto titanium alloy powder through a two-step low-energy dry ball milling process to obtain a core-shell structured titanium alloy powder coated with high-defect and high-activity amorphous pyrolytic carbon nanoparticles.

[0076] The highly defective, highly active, and highly dispersed amorphous pyrolysis carbon nanoparticles are generated by the pyrolysis of carbon-containing gases, with a carbon mass content of 99% and a specific surface area greater than 100 m². 2 / g; the titanium alloy powder has an average particle size of less than 150μm, is a near-α titanium alloy powder, and is composed of the following components by mass: Al 6.4%, V 2%, Mo 1.3%, Zr 2%, O 0.13%, with the balance being Ti, and all elements are fully dissolved; the mass of the highly defective, highly active, and highly dispersed amorphous pyrolytic carbon nanoparticles is 0.3% of the mass of the titanium-based powder;

[0077] Step 2: The titanium-based powder with a core-shell structure and coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity obtained in Step 1 is subjected to low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering to obtain a multi-level, multi-scale heterostructure titanium-based composite material. The temperature of the low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering is 900℃~1100℃, the pulse current is 1000A~20000A, the sintering pressure is 40MPa, and the sintering time is 5min. In the multi-level, multi-scale heterostructure reinforced titanium alloy composite material, the average particle size of titanium carbide on the first-level shell is less than 5μm, the average particle size of titanium carbide on the second-level grain boundaries is less than 500nm, and the average particle size of titanium carbide in the third-level grains is less than 100nm.

[0078] Step 3: The multi-level, multi-scale heterogeneous titanium matrix composite material obtained in Step 2 is subjected to hot deformation treatment at 900℃~1000℃ with small deformation amount and non-constant deformation rate, and the single deformation amount is less than 20%, to obtain a multi-level, multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material.

[0079] Step 4: Repeat the hot deformation treatment with small deformation amount and non-constant deformation rate in Step 3 8 times on the multi-level and multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material obtained in Step 3. The cumulative deformation amount of the hot deformation treatment with non-constant deformation rate is 67%, and a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material is obtained.

[0080] Testing revealed that the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material prepared in this embodiment has a hybrid composite structure consisting of β-titanium and α-titanium sheet structures, multi-level multi-scale titanium carbide structures, and multi-level multi-scale dislocation cell structures.

[0081] Testing showed that the 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium alloy composite material prepared in this embodiment has a tensile strength of 1560MPa and an elongation of 11%.

[0082] Comparative Example 2

[0083] The specific process of this comparative example is as follows: the titanium alloy powder selected in Example 5 is subjected to low-temperature short-time large pulse current spark plasma vacuum hot pressing sintering under vacuum atmosphere to obtain titanium alloy material; the temperature of the low-temperature short-time large pulse current spark plasma vacuum hot pressing sintering is 900℃~1100℃, the pulse current is 1000A~20000A, the sintering pressure is 40MPa, and the sintering time is 5min.

[0084] Tests showed that the titanium alloy material prepared in this comparative example had a tensile strength of 810 MPa and an elongation of 7%.

[0085] Figure 7 The tensile property curves are shown for the 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium alloy composite material prepared in Example 5 and the titanium alloy material prepared in Comparative Example 2. Figure 7 It can be seen that, compared with Comparative Example 2, the multi-level heterogeneous titanium alloy composite material prepared in Example 5 of the present invention has extremely high strength and plasticity.

[0086] Example 6

[0087] The difference between this embodiment and embodiment 5 is that the titanium alloy powder used in step one is composed of the following components by mass: Al 6.4%, Mo 1.93%, Zr 3.57%, Sn 1.86%, Si 0.082%, with the balance being Ti.

[0088] Testing showed that the 1500MPa ultra-high strength plastic multi-level heterogeneous titanium-based composite material prepared in this embodiment has a tensile strength of 1550MPa and an elongation of 10%.

[0089] Example 7

[0090] The difference between this embodiment and Embodiment 6 is that the sintering method in step two is vacuum hot pressing sintering, with a sintering temperature of 1000℃, a pressure of 30MPa, a time of 60min, and a vacuum degree of less than 10. -2 Pa.

[0091] Testing showed that the 1500MPa ultra-high strength plastic multi-level heterogeneous titanium-based composite material prepared in this embodiment has a tensile strength of 1501MPa and an elongation of 11.6%.

[0092] Testing revealed that the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material prepared in this embodiment has a hybrid composite structure consisting of β-titanium and α-titanium sheet structures, multi-level multi-scale titanium carbide structures, and multi-level multi-scale dislocation cell structures.

[0093] The sintering method in this embodiment can also be replaced by hot isostatic pressing.

[0094] 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 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium-based composite material, characterized in that, The method includes the following steps: Step 1: High-defect, high-activity, and highly dispersed amorphous pyrolytic carbon nanoparticles are uniformly coated onto titanium-based powder using a multi-step coating method to obtain a core-shell structured titanium-based powder coated with high-defect, high-activity amorphous pyrolytic carbon nanoparticles; the titanium-based powder is titanium powder or titanium alloy powder; the high-defect, high-activity, and highly dispersed amorphous pyrolytic carbon nanoparticles are generated by the pyrolysis or deposition of carbon-containing gases, liquids, or solids, and have an amorphous or microcrystalline structure with a specific surface area greater than 20 m². 2 / g, with an average particle size of less than 100nm at at least one scale; the titanium-based powder has an average particle size of less than 200μm, and the titanium alloy powder is a near-α or α+β dual-phase titanium alloy powder, composed of the following components by mass: Al < 9%, V < 5%, Mo < 4%, Si < 0.3%, Zr < 4%, Sn < 2%, Fe < 0.5%, with the balance being Ti, and all elements are fully dissolved; the mass of the highly defective, highly active, and highly dispersed amorphous pyrolysis carbon nanoparticles does not exceed 0.5% of the mass of the titanium-based powder; Step 2: The titanium-based powder with a core-shell structure and coated with amorphous pyrolytic carbon nanoparticles with high defects and high activity obtained in Step 1 is subjected to low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering to obtain a multi-level, multi-scale heterostructure titanium-based composite material; the temperature of the low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering is 800℃~1100℃, the pulse current is 1000A~20000A, the sintering pressure is greater than 10MPa, and the sintering time is less than 30min; Step 3: The multi-level, multi-scale heterogeneous titanium matrix composite material obtained in Step 2 is subjected to hot deformation treatment with small deformation amount and non-constant deformation rate to obtain a multi-level, multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material. Step 4: Repeat the hot deformation treatment with small deformation amount and non-constant deformation rate in Step 3 on the multi-level and multi-scale heterogeneous titanium carbide storage and interwoven special dislocation structure titanium matrix composite material obtained in Step 3 to obtain a 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material; the tensile strength of the 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium matrix composite material is above 1500MPa and the elongation is above 10%.

2. The method for preparing a 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium-based composite material according to claim 1, characterized in that, The multi-step coating method mentioned in step one is wet liquid phase pre-coating and low-energy dry ball milling coating, or multi-step low-energy dry ball milling coating.

3. The method for preparing a 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium-based composite material according to claim 1, characterized in that, In step two, the low-temperature short-time high-pulse current spark plasma vacuum hot pressing sintering is replaced by vacuum hot pressing sintering, with a sintering temperature of 1000℃, a pressure of 30MPa, a time of 60min, and a vacuum degree of less than 10. -2 Pa.

4. The method for preparing a 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium-based composite material according to claim 1, characterized in that, The multi-level, multi-scale heterostructure titanium-based composite material described in step two has a three-level, multi-scale titanium carbide heterostructure with in-situ titanium carbide at the discontinuous core and shell and ultrafine and nano-sized titanium carbide dissolved from the grain boundaries and intragranular areas of the titanium matrix inside the shell. Moreover, the titanium matrix inside the shell also has a β-titanium-coated soft α-titanium micro-nano core-shell structure.

5. The method for preparing a 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium-based composite material according to claim 1, characterized in that, The small deformation amount and non-constant deformation rate thermal deformation treatment in step three is a non-equilibrium dynamic thermal deformation treatment with a temperature of 700℃~1000℃ and a single deformation amount of less than 20%; the number of repetitions in step four is more than 3 times and the cumulative deformation amount is more than 50%.

6. The method for preparing a 1500MPa ultra-high strength and ductility multi-level heterogeneous titanium-based composite material according to claim 1, characterized in that, The 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material described in step four has a hybrid composite structure of β titanium and α titanium sheet structure, multi-level multi-scale titanium carbide structure and multi-level multi-scale dislocation cell structure.

7. A 1500MPa ultra-high strength and plasticity multi-level heterogeneous titanium-based composite material, characterized in that, Prepared by the method described in any one of claims 1 to 6.

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