A transition metal involved high-entropy carbide ceramic composite material and a preparation method thereof

Abstract

The application discloses a transition group metal participated high-entropy carbide ceramic composite material and a preparation method thereof. Raw materials for preparing the high-entropy carbide ceramic composite material are composed of transition group metal powder and carbide powder; the transition group metal powder comprises Zr, V, Ta, Cr, Mo, W, Ti, Nb and Hf powder; the chemical formula of the carbide is MC, wherein M comprises Ti, V, Nb, Zr, Ta, Hf, Cr, Mo, W and Nb metal; wherein the mass fraction of the transition group metal powder is 11.31-53.23 wt.%, and the rest is the carbide powder. The high-entropy carbide ceramic composite material prepared by the application has a bulk density of 7.35-10.65 g / cm 3 , a compactness of 87-99%, a Vickers hardness of 15.1-22.1 GPa, a fracture toughness of 3-8.4 Mpa·m 1 / 2 , an initial oxidation temperature of 672.4-735.9 DEG C, a final oxidation temperature of 904-1400 DEG C and an oxidation weight gain of 13.93-23.09%. By optimizing the transition group metal addition amount and sintering parameters, the material has excellent hardness, fracture toughness and oxidation resistance.

Description

Technical Field

[0001] This invention relates to the field of ceramic composite materials technology, specifically to a high-entropy carbide ceramic composite material involving transition metals and its preparation method. Background Technology

[0002] High-entropy carbide ceramics exhibit a mixed covalent-metal-ionic bond structure. Their highly symmetrical crystal structure and strong covalent bonds endow the materials with excellent stability, while also possessing high hardness, high strength, excellent thermal shock resistance, and low thermal conductivity. They show great potential in extreme environment applications and are widely used in aerospace thermal protection systems, high-temperature smelting equipment, and high-performance cutting tools. Traditional high-entropy carbide ceramics, due to their strong covalent bonds and low self-diffusion coefficient, suffer from difficulty in eliminating porosity in the later stages of sintering, resulting in lower ceramic density and higher sintering temperatures.

[0003] Therefore, researchers attempted to introduce new phases to construct multi-component carbide ceramic systems, and then use solid solution strengthening and the "cocktail effect" to prepare high-performance composite ceramic materials with low sintering temperature, high density, high hardness, high toughness and excellent oxidation resistance.

[0004] Mo Peicheng et al. mixed transition metals (Ti, Zr), cubic boron nitride, sintering aids, and carbides (SiC, B4C, WC), ball-milled them for 1–5 h at a ball milling speed of 400 r / min, with a material-to-ball mass ratio of 2–8:1, and then subjected them to vacuum treatment at 400–600 °C (vacuum degree of 1×10⁻⁶). -3 ~1×10 -1 The green body was prepared by pressure sintering (Pa) to obtain a carbide ceramic with a hardness of 33.1~33.5 GPa and a density of 99.1~99.4%. By introducing transition metals to react with carbides, new phases were generated, and high-entropy carbide ceramics with good hardness, fracture toughness and density were prepared. Mo Peicheng et al. used a composite sintering of transition metals and carbides to obtain ultra-high hardness and density, but the process route was complicated, the high-temperature oxidation resistance was not systematically verified, and it was difficult to balance toughness and thermal stability [Mo Peicheng et al. A carbide ceramic and its preparation method: CN12129276A. China Nonferrous Metals Guilin Mineral Geology Research Institute Co., Ltd., published on January 9, 2026].

[0005] Zhan Zaiji et al. mixed transition metal elemental Ti with carbides (TiC, Mo2C, TaC, NbC, Cr3C2), wherein the Ti powder had a particle size of 45 μm, the TiC powder had a particle size of 3-5 μm, the Mo2C powder had a particle size of 2-3 μm, the TaC powder had a particle size of 1-3 μm, and the NbC and Cr3C2 powders had a particle size of 5-10 μm. The purity of each raw material was higher than 99.5%. The raw materials were mixed in a molar ratio of 10%-30% Ti, 14-18% TiC, 14-18% Mo2C, 14-18% NbC, 14-18% Cr3C2, with the remainder being TaC. The mixture was mixed using a two-step star ball mill with a ball-to-powder mass ratio of 10:1, a rotation speed of 240 r / min, and a milling time of 10 h. The mixture was then placed in a graphite mold for vacuum hot pressing sintering with a vacuum degree lower than 1.8 × 10⁻⁶. -2 Sintering was initiated at Pa, with a heating rate of 10 ℃ / min, a sintering temperature of 1650 ℃, and a holding time of 2 h. A (TiCrMoNbTa)C-based non-stoichiometric high-entropy ceramic was prepared. This ceramic has a single-phase face-centered cubic structure, high density, uniform microstructure without obvious pores, and a Vickers hardness of 20~22.4 GPa. By adding metallic Ti to introduce carbon vacancies and improve the atomic diffusion rate, complete solid solution and efficient densification at low temperatures were achieved, effectively solving the problems of high sintering temperature and insufficient solid solution in traditional high-entropy carbides. Zhan Zaiji et al. achieved low-temperature densification by introducing metallic Ti to construct carbon vacancies, but the hardness decreased significantly with increasing metal addition, and the fracture toughness and high-temperature performance were not characterized [Zhan Zaiji et al. A (TiCrMoNbTa)C-based high-entropy ceramic and its preparation method: CN119753472A. Yanshan University, published April 4, 2025].

[0006] Yi Mingdong et al. used carbides (WC, VC, Mo2C, TaC, TiC) and their corresponding metallic elements (W, V, Mo, Ta, Ti) as raw materials. The particle size of the carbide and W, V, and Ta powders was 1-3 μm, and the particle size of the Mo and Ti powders was 0.8-1.2 μm. Polyethylene glycol-anhydrous ethanol was used as a dispersant, and the materials were prepared at a matrix volume fraction of 80-95% and a binder phase of 5-20%. High-energy ball milling under nitrogen protection was used, with a material-to-ball mass ratio of 1:8-20, a rotation speed of 400 r / min, and a milling time of 45-50 h. After vacuum drying and sieving, spark plasma sintering was performed at a sintering temperature of 1350-1500 ℃, a pressure of 30-40 MPa, and a holding time of 8-12 h. (WVMoTaTi)C-based co-high-entropy carbide cermets were prepared. This material exhibits a coexistence structure of high-entropy carbides and high-entropy alloys, with a hardness of 17.55–18.12 GPa, a flexural strength of 765–822 MPa, and a fracture toughness of 6.93–7.45 MPa·m. 1 / 2By improving interfacial compatibility and solid solution through co-entropy design of the same element, the high-entropy alloy at the grain boundary is significantly toughened and reinforced, effectively solving the problems of insufficient toughness and easy segregation during sintering of traditional high-entropy ceramics. However, the metal binder phase can easily lead to a decrease in hardness, and the sintering process is complex and costly, making it difficult to apply on a large scale [Yi Mingdong et al. A co-entropy carbide cermet material and its preparation method and application: CN121250207B. Qilu University of Technology (Shandong Academy of Sciences), published on February 6, 2026].

[0007] In summary, while current research on the preparation of high-entropy carbide ceramics has made some breakthroughs, solving some traditional technical challenges in areas such as the synergistic effect of high hardness and high density, and low-temperature densification, significant bottlenecks remain in achieving synergistic performance improvement. It is impossible to simultaneously achieve comprehensive synergistic optimization of low sintering temperature, high density, high hardness, high toughness, good thermal insulation, and excellent oxidation resistance. Specifically, existing technologies either suffer from complex process routes and difficulties in large-scale scaling, or fail to balance hardness and toughness, or lack systematic optimization and characterization of key service properties such as high-temperature insulation and oxidation resistance, resulting in a situation where "a single performance is prominent, but overall performance is unbalanced." Therefore, the industry currently lacks a high-entropy carbide ceramic preparation strategy that is simple and efficient, with easily controllable parameters and costs, and can achieve a balanced improvement in all core performance aspects. This has become a core bottleneck restricting the transition of high-entropy carbide ceramics from laboratory research to large-scale industrial application. Summary of the Invention

[0008] The technical problem to be solved: Currently, high-entropy carbide ceramics exhibit low diffusion coefficients due to the hindered atomic diffusion caused by strong covalent bonds. This generally results in problems such as high sintering temperatures, poor fracture toughness, and coarse grains, leading to low ceramic density and significantly reduced mechanical properties. Furthermore, they suffer from complex manufacturing processes and high energy consumption. Existing improvement technologies struggle to simultaneously address sintering costs and overall performance, necessitating the development of high-entropy ceramic manufacturing technologies that are simple to implement, have low sintering temperatures, and can achieve both high hardness and high toughness.

[0009] To address the aforementioned technical problems, this invention provides a high-entropy carbide ceramic composite material involving transition metals and its preparation method.

[0010] 2. Technical Solution: A high-entropy carbide ceramic composite material involving transition metals is prepared from transition metal powder and carbide powder. The transition metal powders include Zr, V, Ta, Cr, Mo, W, Ti, Nb, and Hf powders; The chemical formula of the carbide is MC, where M includes metals such as Ti, V, Nb, Zr, Ta, Hf, Cr, Mo, W, and Nb. The mass fraction of transition metal powder is 11.31~53.23 wt.%, and the balance is carbide powder.

[0011] Furthermore, the transition metal powder is one of Zr, V, and Ta powder.

[0012] Further, the carbide is a mixture of HfC, TiC, NbC, TaC, ZrC and VC powders, wherein the mass fraction of HfC is 7.065~26.63%, the mass fraction of TiC is 2.222~8.37%, the mass fraction of NbC is 6.86~53.89%, the mass fraction of TaC is 7.19~27.11%, the mass fraction of ZrC is 3.825~14.43%, and the mass fraction of VC is 2.335~8.80%.

[0013] Furthermore, the particle size of the transition metal powder is 20~45 μm, the particle size of the carbide powder is 1~3 μm, and the purity of each powder is not less than 99.5%.

[0014] The preparation method of the above-mentioned high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Powder weighing: Weigh the transition metal powder and carbide powder according to the set mass ratio; S2. Preparation of composite powder: The raw material powder is ball-milled in air for 2-60 h, with a ball-to-powder mass ratio of 2:1-20:1 and a rotation speed of 300-600 r / min. 0.4 mL / 10 g alcohol is added as a dispersant. S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed. The cold pressing pressure is 20 MPa and the holding time is 30 s. S4. Spark plasma sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1600~2000 ℃, and a holding time of 2~60 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic composite material blank. S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0015] Furthermore, the SPS sintering process and parameters are as follows: After placing the graphite mold with graphite felt, it is placed in the SPS sintering system and slowly pressurized to 50 MPa. When the vacuum reaches 60 Pa, the heating is started and the temperature is increased according to the set heating mechanism. The heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, and held at 600 ℃ for 5 min. After the holding period, the vacuum is stopped and argon gas is introduced to -0.05 Pa. Then, the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min. Then, the temperature is sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The temperature is held at the final sintering temperature for 2~60 min. After cooling in the furnace, the blank is taken out.

[0016] 3. Beneficial effects: This invention prepares high-entropy carbide ceramic composite materials using metal powder and carbide powder. The transition metal powder is preferably selected from Zr, V, Ta, Cr, Mo, W, Ti, Nb, and Hf powders. The chemical formula of the carbide in the raw materials is MC, where M is preferably selected from Ti, V, Nb, Zr, Ta, Hf, Cr, Mo, W, and Nb metals. The raw material powders are ball-milled in air to obtain the composite powder. The ball-milling time is 2–60 h, the ball-to-material mass ratio is 10:1–20:1, the rotation speed is 300–600 r / min, and 0.4 mL / 10 g alcohol is added as a dispersant. The mixed powder is uniformly loaded into a graphite mold and cold-pressed at a pressure of 20 MPa for a holding time of 30 s. The cold-pressed sample is then subjected to spark plasma sintering at a pressure of 50 MPa and a sintering temperature of 1600–2000 °C for a holding time of 2–60 min. The bulk density of the prepared high-entropy carbide ceramic composite material is 7.35~10.65 g / cm³. 3 It has a density of 87-99%, a Vickers hardness of 15.1-22.1 GPa, and a fracture toughness of 3-8.4 MPa·m. 1 / 2 The initial oxidation temperature is 672.4~735.9 ℃, the final oxidation temperature is 904~1400 ℃, and the oxidation weight gain is 13.93~23.09%.

[0017] The innovation of this invention lies in using multi-component carbide powder as a matrix and adding transition metal elements to generate carbon vacancies in situ by adding transition metals in high-entropy carbide ceramics. First, the presence of carbon vacancies significantly reduces the diffusion activation energy of atoms or ions in the crystal lattice, accelerating the diffusion process. This allows for rapid densification of materials at lower sintering temperatures, effectively reducing energy consumption and production costs during the preparation process. Furthermore, it enables more efficient diffusion of some atoms to the material surface to form an oxide film, enhancing oxidation resistance. Second, vacancies, as point defects in the crystal lattice, induce crack deflection, branching, or detours during propagation. By extending the crack propagation path and increasing the fracture surface area, they absorb more fracture energy, effectively improving the fracture toughness of the material. Finally, carbon vacancies also have a significant solid solution effect, providing stable solid solution sites for transition metal atoms and other dopants. This effectively broadens the solid solubility range of multi-component transition metals, promotes uniform dispersion of various elements in the multi-component carbide matrix, optimizes the homogeneity of the matrix composition, and thus improves the overall synergistic matching of the material's mechanical and oxidation resistance properties, laying a solid structural foundation for achieving high densification and high performance. Transition metals form metal-vacancy-metal bonds, a novel bond type that increases the metallicity of the system, thereby promoting plastic deformation and weakening and dispersing stress at crack tips. This invention also fully leverages the structural advantages and performance potential of multi-component carbides, which differ from the matrix in elastic modulus and coefficient of thermal expansion. When cracks propagate to the interface region, these differences can induce various toughening mechanisms such as crack deflection, bypassing, or second-phase bridging. Optimizing the amount of transition metals added and sintering parameters results in a material with excellent hardness, fracture toughness, and oxidation resistance. Furthermore, the preparation process eliminates the need for inert atmosphere-protected ball milling, significantly shortening the mixing time and reducing energy consumption and costs, thus facilitating industrial production. Attached Figure Description

[0018] Figure 1 The XRD patterns of C-xZr sintered bodies with different Zr addition amounts (TiVNbZrTaHf) are shown in Examples 1-6.

[0019] Figure 2 The XRD patterns of (TiVNbZrTaHf)C-4Zr sintered bodies at different sintering temperatures corresponding to Examples 7-11 are shown.

[0020] Figure 3 The XRD patterns of (TiVNbZrTaHf)C-xV sintered bodies with different V addition amounts corresponding to Examples 12-15 are shown.

[0021] Figure 4 The XRD patterns of (TiVNbZrTaHf)C-xTa sintered bodies with different Ta addition amounts corresponding to Examples 16-19 are shown.

[0022] Figure 5 The bulk density and compaction density of (TiVNbZrTaHf)C-xZr sintered bodies with different Zr addition amounts are shown in Examples 1-6.

[0023] Figure 6 The bulk density and compaction density of (TiVNbZrTaHf)C-4Zr sintered bodies at different sintering temperatures corresponding to Examples 7-11 are shown.

[0024] Figure 7 The bulk density and compaction density of (TiVNbZrTaHf)C-xV sintered bodies with different V addition amounts corresponding to Examples 12-15 are shown.

[0025] Figure 8 The bulk density and compaction density of (TiVNbZrTaHf)C-xTa sintered bodies with different Ta addition amounts corresponding to Examples 16-19 are shown.

[0026] Figure 9 Mechanical properties of (TiVNbZrTaHf)C-xZr sintered bodies with different Zr addition amounts corresponding to Examples 1-6.

[0027] Figure 10 The mechanical properties of (TiVNbZrTaHf)C-4Zr sintered bodies at different sintering temperatures corresponding to Examples 7-11 are shown.

[0028] Figure 11 Mechanical properties of (TiVNbZrTaHf)C-xV sintered bodies with different V addition amounts corresponding to Examples 12-15.

[0029] Figure 12 Mechanical properties of (TiVNbZrTaHf)C-xTa sintered bodies with different Ta addition amounts corresponding to Examples 16-19.

[0030] Figure 13 The DSC-TG curves are for the sintered bodies corresponding to Examples 3, 4, 14, and 18.

[0031] Figure 14 The sintered body morphology corresponds to Examples 3, 4, 5, 7, 9, 11, 13, 14, 17, and 18. Detailed Implementation

[0032] The testing equipment described in this invention are all instruments used in conventional testing methods, such as X-ray diffractometer, Vickers hardness tester, apparent porosity and bulk density tester, scanning electron microscope, universal testing machine, assembled material surface and interface performance tester, and synchronous thermal analyzer, etc.

[0033] The present invention will now be described in detail with reference to the accompanying drawings.

[0034] As attached Figure 1 To be continued Figure 14 . Example 1

[0035] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 2.663 g of HfC powder, 0.837 g of TiC powder, 1.466 g of NbC powder, 2.711 g of TaC powder, 1.443 g of ZrC powder, and 0.880 g of VC powder and put them into the ball mill jar.

[0036] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0037] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0038] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0039] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold with graphite felt, it is placed in the SPS sintering system. The pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process. The heating is carried out according to the set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, and held at 600 ℃ for 5 min. After the holding period, the vacuum is stopped, and argon gas is introduced to -0.05 Pa. Then, the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min. Then, the temperature is sintered at a rate of 15 ℃ / min for 2 min and then at a rate of 10 ℃ / min for 2 min to the final sintering temperature. The temperature is held at the final sintering temperature for 2~60 min, and the blank is removed after cooling in the furnace.

[0040] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0041] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 1 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; density results are shown in […]. Figure 5Its bulk density is 7.69 g / cm³. 3 The density is 87%; mechanical property results are shown in [link to results]. Figure 9 Its Vickers hardness is 22.1 GPa and its fracture toughness is 4.1 MPa·m. 1 / 2 . Example 2

[0042] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 2.362 g of HfC powder, 0.742 g of TiC powder, 1.301 g of NbC powder, 2.404 g of TaC powder, 1.280 g of ZrC powder, 0.780 g of VC powder, and 1.131 g of Zr powder and put them into the ball mill jar.

[0043] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0044] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0045] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0046] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0047] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0048] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 1 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; density results are shown in […]. Figure 5 Its bulk density is 7.84 g / cm³. 3 The density is 92%; mechanical property results are shown in [link to relevant documentation]. Figure 9 Its Vickers hardness is 18.4 GPa and its fracture toughness is 6.3 MPa·m. 1 / 2 . Example 3

[0049] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 2.019 g of HfC powder, 0.635 g of TiC powder, 1.112 g of NbC powder, 2.056 g of TaC powder, 1.094 g of ZrC powder, 0.667 g of VC powder, and 2.417 g of Zr powder and put them into the ball mill jar.

[0050] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0051] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0052] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0053] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0054] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0055] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 1 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; SEM microstructure test results are shown in […]. Figure 14 The fracture modes were found to include both transgranular and intergranular fracture; density results are shown in [reference needed]. Figure 5 Its bulk density is 7.81 g / cm³. 3 The density is 96%; the mechanical properties are shown in the figure. Figure 9 Its Vickers hardness is 19.6 GPa and its fracture toughness is 6.6 MPa·m. 1 / 2 DSC / TG results are shown below. Figure 13 Its initial oxidation temperature was 712.7 ℃, its final oxidation temperature was 1057.9 ℃, and its oxidation weight gain was 14.49%. Example 4

[0056] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.841 g of HfC powder, 0.579 g of TiC powder, 1.014 g of NbC powder, 1.875 g of TaC powder, 0.998 g of ZrC powder, 0.608 g of VC powder, and 3.085 g of Zr powder and put them into the ball mill jar.

[0057] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0058] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0059] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0060] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0061] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0062] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 1 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; the results of scanning electron microscopy (SEM) microstructure analysis are shown in […]. Figure 14 It was found that large particles fractured through both transgranular and intergranular processes, while small particles fractured only intergranular processes; density results are shown in [reference needed]. Figure 5 Its bulk density is 7.73 g / cm³. 3 The density is 97%; mechanical property results are shown in [link to relevant documentation]. Figure 9 Its Vickers hardness is 20.2 GPa and its fracture toughness is 7.5 MPa·m. 1 / 2 DSC / TG results are shown below. Figure 13 Its initial oxidation temperature was 711.5 ℃, its final oxidation temperature was 994.8 ℃, and its oxidation weight gain was 16.14%. Example 5

[0063] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.764 g of HfC powder, 0.554 g of TiC powder, 0.971 g of NbC powder, 1.795 g of TaC powder, 0.956 g of ZrC powder, 0.583 g of VC powder, and 3.377 g of Zr powder and put them into the ball mill jar.

[0064] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0065] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0066] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0067] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0068] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0069] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 1 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; SEM microstructure test results are shown in […]. Figure 14 Numerous transgranular fractures were found; density results are shown in [reference needed]. Figure 5 Its bulk density is 7.7 g / cm³. 3 The density is 98%; mechanical property results are shown in [link to relevant documentation]. Figure 9 Its Vickers hardness is 19.1 GPa and its fracture toughness is 8.4 MPa·m. 1 / 2 . Example 6

[0070] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.692 g of HfC powder, 0.532 g of TiC powder, 0.932 g of NbC powder, 1.723 g of TaC powder, 0.917 g of ZrC powder, 0.559 g of VC powder, and 3.646 g of Zr powder and put them into the ball mill jar.

[0071] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0072] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0073] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0074] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0075] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0076] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 1 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; density results are shown in […]. Figure 5 Its bulk density is 7.68 g / cm³. 3 The density is 99%; mechanical property results are shown in [link to relevant documentation]. Figure 9 Its Vickers hardness is 18.5 GPa and its fracture toughness is 7.3 MPa·m. 1 / 2 . Example 7

[0077] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.841 g of HfC powder, 0.579 g of TiC powder, 1.014 g of NbC powder, 1.875 g of TaC powder, 0.998 g of ZrC powder, 0.608 g of VC powder, and 3.085 g of Zr powder and put them into the ball mill jar.

[0078] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0079] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0080] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1600 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0081] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0082] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0083] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 2 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; SEM microstructure test results are shown in […]. Figure 14 Numerous fine grains were found to be dispersed throughout the area, and both transgranular and intergranular fractures were observed; density results are shown in [reference needed]. Figure 6 Its bulk density is 7.81 g / cm³. 3 The density is 99%; mechanical property results are shown in [link to relevant documentation]. Figure 10Its Vickers hardness is 18.2 GPa and its fracture toughness is 6.1 MPa·m. 1 / 2 . Example 8

[0084] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.841 g of HfC powder, 0.579 g of TiC powder, 1.014 g of NbC powder, 1.875 g of TaC powder, 0.998 g of ZrC powder, 0.608 g of VC powder, and 3.085 g of Zr powder and put them into the ball mill jar.

[0085] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0086] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0087] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0088] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0089] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0090] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 2 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; density results are shown in […]. Figure 6 Its bulk density is 7.7 g / cm³. 3 The density is 98%; mechanical property results are shown in [link to relevant documentation]. Figure 10 Its Vickers hardness is 19.1 GPa and its fracture toughness is 8.4 MPa·m. 1 / 2 . Example 9

[0091] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.841 g of HfC powder, 0.579 g of TiC powder, 1.014 g of NbC powder, 1.875 g of TaC powder, 0.998 g of ZrC powder, 0.608 g of VC powder, and 3.085 g of Zr powder and put them into the ball mill jar.

[0092] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0093] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0094] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1800 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0095] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0096] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0097] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 2 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; SEM microstructure test results are shown in […]. Figure 14 Both transgranular and intergranular fractures were found, with transgranular fracture occurring more readily than intergranular fracture; density results are shown in [reference needed]. Figure 6 Its bulk density is 7.67 g / cm³. 3 The density is 97%; mechanical property results are shown in [link to relevant documentation]. Figure 10 Its Vickers hardness is 18.5 GPa and its fracture toughness is 5.5 MPa·m. 1 / 2 . Example 10

[0098] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.841 g of HfC powder, 0.579 g of TiC powder, 1.014 g of NbC powder, 1.875 g of TaC powder, 0.998 g of ZrC powder, 0.608 g of VC powder, and 3.085 g of Zr powder and put them into the ball mill jar.

[0099] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0100] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0101] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1900 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0102] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0103] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0104] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 2 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; density results are shown in […]. Figure 6 Its bulk density is 7.7 g / cm³. 3 The density is 98%; mechanical property results are shown in [link to relevant documentation]. Figure 10 Its Vickers hardness is 20.2 GPa and its fracture toughness is 3.1 MPa·m. 1 / 2 . Example 11

[0105] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.841 g of HfC powder, 0.579 g of TiC powder, 1.014 g of NbC powder, 1.875 g of TaC powder, 0.998 g of ZrC powder, 0.608 g of VC powder, and 3.085 g of Zr powder and put them into the ball mill jar.

[0106] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0107] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0108] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 2000 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0109] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0110] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0111] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 2 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; SEM microstructure test results are shown in […]. Figure 11 Both transgranular and intergranular fractures were present, with transgranular fracture occurring more frequently than intergranular fracture; density results are shown in [reference needed]. Figure 6 Its bulk density is 7.69 g / cm³. 3 The density is 98%; mechanical property results are shown in [link to relevant documentation]. Figure 10 Its Vickers hardness is 19.8 GPa and its fracture toughness is 3.0 MPa·m. 1 / 2 . Example 12

[0112] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 2.663 g of HfC powder, 0.837 g of TiC powder, 1.466 g of NbC powder, 2.711 g of TaC powder, 1.443 g of ZrC powder, and 0.88 g of VC powder and put them into the ball mill jar.

[0113] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0114] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0115] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0116] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0117] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0118] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 3 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; density results are shown in […]. Figure 7 Its bulk density is 7.69 g / cm³. 3 The density is 87%; mechanical property results are shown in [link to results]. Figure 11 Its Vickers hardness is 22.1 GPa and its fracture toughness is 4.1 MPa·m. 1 / 2 . Example 13

[0119] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 2.132 g of HfC powder, 0.67 g of TiC powder, 1.174 g of NbC powder, 2.17 g of TaC powder, 1.155 g of ZrC powder, 0.704 g of VC powder, and 1.995 g of V powder and put them into the ball mill jar.

[0120] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0121] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0122] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0123] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0124] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0125] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 3 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; SEM microstructure test results are shown in […]. Figure 14 Two fracture modes were observed: transgranular fracture and intergranular fracture. Density results are shown in [link to density data]. Figure 7 Its bulk density is 7.55 g / cm³. 3 The density is 93%; mechanical property results are shown in [link to results]. Figure 11 Its Vickers hardness is 17 GPa and its fracture toughness is 6.6 MPa·m.1 / 2 . Example 14

[0126] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 2.073 g of HfC powder, 0.652 g of TiC powder, 1.141 g of NbC powder, 2.11 g of TaC powder, 1.123 g of ZrC powder, 0.685 g of VC powder, and 2.217 g of V powder and put them into the ball mill jar.

[0127] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0128] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0129] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0130] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0131] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0132] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 3 The system mainly consists of face-centered cubic carbide phases, ZrO2, and HfO2 phases. SEM microstructure results are shown below. Figure 14Two fracture modes were observed: transgranular fracture and intergranular fracture. Furthermore, small oxide particles were observed, along with dimples left after the oxide particles were pulled out. Density results are shown in […]. Figure 7 Its bulk density is 7.39 g / cm³. 3 The density is 92%; mechanical property results are shown in [link to relevant documentation]. Figure 11 Its Vickers hardness is 18.2 GPa and its fracture toughness is 6.6 MPa·m. 1 / 2 DSC / TG results are shown below. Figure 13 Its initial oxidation temperature was 672.4 ℃, its final oxidation temperature was 1187.8 ℃, and its oxidation weight gain was 23.09%. Example 15

[0133] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 2.017 g of HfC powder, 0.634 g of TiC powder, 1.111 g of NbC powder, 2.053 g of TaC powder, 1.093 g of ZrC powder, 0.666 g of VC powder, and 2.426 g of V powder and put them into the ball mill jar.

[0134] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0135] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0136] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0137] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0138] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0139] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 3 The density results are shown in Figure 7 Its bulk density is 7.35 g / cm³. 3 The density is 92%; mechanical property results are shown in [link to relevant documentation]. Figure 11 Its Vickers hardness is 16.5 GPa and its fracture toughness is 5.8 MPa·m. 1 / 2 . Example 16

[0140] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 2.663 g of HfC powder, 0.837 g of TiC powder, 1.466 g of NbC powder, 2.711 g of TaC powder, 1.443 g of ZrC powder, and 0.88 g of VC powder and put them into the ball mill jar.

[0141] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0142] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0143] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0144] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0145] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0146] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 4 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; density results are shown in […]. Figure 8 The mechanical properties results are shown in Figure 12 The results showed that the system mainly consisted of face-centered cubic carbide phases, ZrO2, and HfO2 phases. Its bulk density was 7.69 g / cm³. 3 It has a density of 87%, a Vickers hardness of 22.1 GPa, and a fracture toughness of 4.1 MPa·m. 1 / 2 . Example 17

[0147] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.413 g of HfC powder, 0.444 g of TiC powder, 10.778 g of NbC powder, 1.438 g of TaC powder, 0.765 g of ZrC powder, 0.467 g of VC powder, and 4.695 g of Ta powder and put them into the ball mill jar.

[0148] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0149] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0150] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0151] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0152] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0153] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 4 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; SEM microstructure test results are shown in […]. Figure 14 The grains are irregularly shaped and loosely bonded, with gaps between almost every grain, resulting in low density; density results are shown in [see figure]. Figure 8 Its bulk density is 10.23 g / cm³. 3 The density is 89%; mechanical property results are shown in [link to relevant documentation]. Figure 12 Its Vickers hardness is 16.1 GPa and its fracture toughness is 6 MPa·m. 1 / 2 . Example 18

[0154] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.324 g of HfC powder, 0.416 g of TiC powder, 0.729 g of NbC powder, 1.348 g of TaC powder, 0.717 g of ZrC powder, 0.437 g of VC powder, and 5.029 g of Ta powder and put them into the ball mill jar.

[0155] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0156] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0157] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0158] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0159] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0160] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 4 The system mainly consists of face-centered cubic carbide phases, ZrO2 and HfO2 phases; SEM microstructure test results are shown in […]. Figure 14 The grains are better bonded together; although there are still gaps, they are all very small. See the density results below. Figure 8 Its bulk density is 10.35 g / cm³. 3 The density is 92%; mechanical property results are shown in [link to relevant documentation]. Figure 12 Its Vickers hardness is 15.7 GPa and its fracture toughness is 5.2 MPa·m. 1 / 2 DSC / TG results are shown below. Figure 13 Its initial oxidation temperature was 735.9 ℃, its final oxidation temperature was 904.4 ℃, and its oxidation weight gain was 13.93%. Example 19

[0161] A method for preparing a high-entropy carbide ceramic composite material involving transition metals includes the following steps: S1. Weighing of powders: Weigh 1.245 g of HfC powder, 0.391 g of TiC powder, 0.686 g of NbC powder, 1.268 g of TaC powder, 0.675 g of ZrC powder, 0.412 g of VC powder, and 5.323 g of Ta powder and put them into the ball mill jar.

[0162] S2. Preparation of composite powder: The raw material powder is ball-milled in air for 30 h, with a ball-to-powder mass ratio of 20:1 and a rotation speed of 450 r / min. 0.4 mL / 10 g alcohol is added as a dispersant.

[0163] S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed at a pressure of 20 MPa for 30 s.

[0164] S4. Spark Plasma Sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1700 ℃, and a holding time of 10 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic blank.

[0165] The specific sintering process and parameters of SPS are as follows: After placing the graphite mold in the SPS sintering system with graphite felt, the pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating process, which follows the pre-set heating mechanism. The specific heating mechanism is as follows: the temperature is increased from room temperature to 600 ℃ in 5 min, held at 600 ℃ for 5 min, the vacuum is stopped after the holding period, and argon gas is introduced to -0.05 Pa; then the temperature is increased to 50 ℃ below the final sintering temperature at a heating rate of 100 ℃ / min, and then sintered at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 10 min, and the blank is removed after cooling in the furnace.

[0166] S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

[0167] The obtained composite material was subjected to microstructure and property testing. The XRD test results are shown in the figure. Figure 4 The system mainly consists of face-centered cubic carbide phases, ZrO2, HfO2, and Ta2O5 phases; density results are shown in [reference needed]. Figure 8 Its bulk density is 10.65 g / cm³. 3 The density is 93%; mechanical property results are shown in [link to results]. Figure 12Its Vickers hardness is 15.1 GPa and its fracture toughness is 5.2 MPa·m. 1 / 2 .

[0168] Through a comparative analysis of Examples 1-6, 12-15, and 16-19, the fracture toughness of the ceramics showed a trend of first increasing and then decreasing with increasing metal addition. Transition metal doping can integrate into the carbide matrix lattice, effectively improving matrix toughness through solid solution strengthening. Furthermore, it can induce the in-situ generation of carbon vacancies. Low to medium concentrations of carbon vacancies, acting as lattice point defects, can directly induce crack deflection, branching, and bypassing during propagation, extending the propagation path and absorbing more fracture energy. Simultaneously, carbon vacancies promote the formation of metal-vacancy-metal bonds, enhancing the metallicity of the ceramic, promoting plastic deformation, and dispersing stress concentration at the crack tip, thus continuously improving fracture toughness. However, when the carbon vacancy concentration is too high, the proportion of lattice defects increases dramatically, the crack propagation resistance decreases significantly, and the toughness decreases accordingly. Through a comparative analysis of Examples 1-6 and 16-19, the doping of Zr and Ta metals generates ZrO2 and Ta2O5 phases. When cracks propagate to the interface between the oxide phase and the matrix, they are deflected, bypassed, or even bifurcated due to interfacial stress. Some cracks also form a second-phase bridging effect, extending the crack propagation path, increasing the energy required for fracture, and further enhancing the toughening effect. Through a comparative analysis of Examples 12-15, fracture toughness generally shows an initial increase followed by a decrease with increasing V addition. As V addition increases, lattice defects increase, promoting the formation of Zr-rich phases. This requires more energy to penetrate or bypass the Zr-rich phases during crack fracture, making solid solution strengthening dominant, thus improving hardness and fracture toughness. Through a comparative analysis of Examples 7-11, as sintering temperature increases, bulk density and compactness generally show an initial decrease followed by an increase. This is because the increased sintering temperature leads to abnormal growth of some grains, resulting in the formation of trace amounts of porosity, which slightly reduces the compactness. However, as the sintering temperature continues to increase, the abnormal grains will continue to grow and fill the pores, thus improving the density.

[0169] Although the present invention has been disclosed above with reference to preferred embodiments, these are not intended to limit the invention. Any person skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be defined by the scope of the claims of this application.

Claims

1. A high-entropy carbide ceramic composite material involving transition metals, characterized in that, The raw materials for its preparation consist of transition metal powder and carbide powder; The transition metal powders include Zr, V, Ta, Cr, Mo, W, Ti, Nb, and Hf powders; The chemical formula of the carbide is MC, where M includes metals such as Ti, V, Nb, Zr, Ta, Hf, Cr, Mo, W, and Nb. The mass fraction of transition metal powder is 11.31~53.23 wt.%, and the balance is carbide powder.

2. The high-entropy carbide ceramic composite material involving transition metals according to claim 1, characterized in that, The transition metal powder is one of Zr, V, and Ta powder.

3. A high-entropy carbide ceramic composite material involving transition metals according to claim 1 or 2, characterized in that, The carbide is a mixture of HfC, TiC, NbC, TaC, ZrC and VC powders.

4. The high-entropy carbide ceramic composite material involving transition metals according to claim 3, characterized in that, The mass fractions of HfC ranged from 7.065% to 26.63%, TiC from 2.222% to 8.37%, NbC from 6.86% to 53.89%, TaC from 7.19% to 27.11%, ZrC from 3.825% to 14.43%, and VC from 2.335% to 8.80%.

5. The high-entropy carbide ceramic composite material involving transition metals according to claim 1, characterized in that, The transition metal powder has a particle size of 20-45 μm, the carbide powder has a particle size of 1-3 μm, and the purity of each powder is not less than 99.5%.

6. The method for preparing high-entropy carbide ceramic composite materials involving transition metals as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Powder weighing: Weigh the transition metal powder and carbide powder according to the set mass ratio; S2. Preparation of composite powder: The raw material powder is ball-milled in air for 2-60 h, with a ball-to-powder mass ratio of 2:1-20:1 and a rotation speed of 300-600 r / min. 0.4 mL / 10 g alcohol is added as a dispersant. S3. Cold pressing: The prepared composite powder is loaded into a graphite mold and cold pressed. The cold pressing pressure is 20 MPa and the holding time is 30 s. S4. Spark plasma sintering (SPS): The cold-pressed sample is subjected to SPS sintering at a pressure of 50 MPa, a vacuum of 60 Pa, a sintering temperature of 1600~2000 ℃, and a holding time of 2~60 min. Then, the sample is cooled and depressed to obtain a high-entropy carbide ceramic composite material blank. S5. Post-processing: The prepared blank is subjected to surface grinding and deburring to obtain a high-entropy carbide ceramic composite material involving transition metals.

7. The method for preparing high-entropy carbide ceramic composite materials involving transition metals according to claim 6, characterized in that, The SPS sintering process and parameters are as follows: After placing the graphite mold with graphite felt, it is placed in the SPS sintering system. The pressure is slowly increased to 50 MPa, and the vacuum is evacuated to 60 Pa before starting the heating. The heating is carried out according to the set heating mechanism, which is: heating from room temperature to 600 ℃ in 5 min, holding at 600 ℃ for 5 min, stopping the vacuum after the holding period, and filling with argon gas to -0.05 Pa; then heating at a rate of 100 ℃ / min to a temperature 50 ℃ lower than the final sintering temperature, and then sintering at a rate of 15 ℃ / min for 2 min and 10 ℃ / min for 2 min to the final sintering temperature. The final sintering temperature is held for 2~60 min, and the blank is removed after cooling in the furnace.

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