A transition metal-ceramic composite combined SiC composite material and a preparation method thereof

Abstract

The application discloses a transition metal-ceramic composite combined SiC composite material and a preparation method thereof. The composite material is prepared from at least one of transition metal powder of Ti, V, Zr and Ta, at least one carbide powder of NbC and WC, NbB2 boride powder and SiC powder as raw materials, and the transition metal powder, the carbide powder, the boride powder and the SiC powder are prepared in a proportion of 5-31wt.%, 7-46wt.%, 17-32wt.% and the balance of SiC powder. During preparation, the raw materials are ball-milled and mixed in an air atmosphere, and after cold pressing at 30MPa, the composite material is obtained through discharge plasma sintering, heat preservation for 5-60min and post-processing. The prepared composite material has a bulk density of 5.9-8.3g / cm 3 , a compactness of 90.1-98.9%, a Vickers hardness of 16.1-21.1GPa and a fracture toughness of 6.5-7.6MPa·m 1 / 2 , and has excellent mechanical properties and high-temperature oxidation resistance. The application effectively reduces the sintering temperature of the SiC-based composite material, simplifies the preparation process, realizes the synergistic optimization of the material compactness, mechanical properties and oxidation resistance, and can be applied to the fields of aerospace, high-end cutting, nuclear industry and other extreme service environments.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a transition metal-ceramic composite material with SiC and its preparation method. Background Technology

[0002] SiC composites possess a range of excellent properties, including high hardness, high modulus, corrosion resistance, superior high-temperature strength, and oxidation resistance, making them widely used in harsh environments such as aerospace, nuclear energy, precision optics, and petrochemicals. However, due to the extremely strong covalent bonds (Si-C bonds) in SiC, its self-diffusion coefficient is extremely low, making sintering and densification of the composite material extremely difficult, typically requiring temperatures above 2000 °C. Furthermore, the inherent brittleness and low fracture toughness of SiC composites significantly limit their widespread application as structural materials under complex working conditions.

[0003] In recent years, the introduction of high-entropy ceramics into SiC matrix to form multiphase ceramics, utilizing their unique high-entropy effect, lattice distortion effect and hysteresis diffusion effect, has become an important research direction for improving the sintering performance and mechanical properties of SiC.

[0004] Liu Ling et al. studied a high-density ZrB2-SiC-based ceramic matrix composite material, using ZrB2, SiC and layered MAX / MAB phases as raw materials, where M is a transition metal element such as Ti and Cr, A is a third / fourth group element such as Al and Si, and X is C or N, and the particle size of the raw materials is controlled at 1~3 μm. The materials were mixed by wet ball milling at a volume ratio of (60~68):30:(2~10) and a ball-to-material ratio of (4~5):1 at a speed of 200~500 rpm for 4~6 h to obtain powder. Then, the powder was sintered by discharge plasma at 1700~1900 ℃ and 30~45 MPa for 8~15 min with a heating rate of 50~100 ℃ / min, ultimately obtaining a multiphase ceramic with a density ≥97.0% [Liu Ling et al. A ceramic matrix composite material and its preparation method and application: CN202310036832.8, Beijing Institute of Technology, published April 21, 2023]. This technology involves a complex preparation process for ZrB2-SiC-based ceramic matrix composite materials; while optimizing the raw material ratio and process parameters, it is difficult to achieve a synergistic improvement in material density and comprehensive mechanical properties.

[0005] Jia Yujun et al. studied a transition metal carbonitride-SiC x N yMultiphase ceramics and their preparation method are disclosed. MeSi2 powder (Me being one or more of Hf, Ta, Ni, and Ti) and carbon powder are used as raw materials. The molar ratio of MeSi2 powder to carbon powder is 1:1~5, the ball-to-powder ratio is 2:1, the milling speed is 200~500 rpm, the ball milling time is 4~6 h, the cold pressing pressure is 4~15 MPa, and the holding time is 1~30 min to obtain powder. Transition metal carbonitrides SiC are then synthesized using spark plasma sintering technology at 1500~1800 ℃ for 1~3 h. x N y Compared to single-phase ceramics, multiphase ceramics exhibit significantly improved sintering properties, enhanced strength and toughness, and superior resistance to ablation [Jia Yujun et al. A transition metal carbonitride-SiC]. x N y Multiphase ceramics and their preparation method: CN202411301495.1, Northwestern Polytechnical University, published on September 26, 2025. This technology involves transition metal carbonitrides-SiC. x The preparation of Nᵧ multiphase ceramics often faces the problems of excessively high sintering temperature and excessively long holding time. It is also difficult to achieve synergistic optimization of material density, strength, toughness and ablation resistance while reducing sintering energy consumption and simplifying the preparation process.

[0006] Lin Huatai et al. studied a high-entropy boride composite SiC ceramic matrix composite material with controllable microstructure. Zr, Ta, Nb, W, Cr elemental powders, B4C, and SiB6 were used as raw materials, with particle sizes controlled between 1 and 3 μm. The raw materials were mixed by wet ball milling at a mass ratio of 4.87:9.662:4.96:9.81:2.776:2.95:4.962, with anhydrous ethanol at a mass ratio of 14–16:4–6:1–3. The ball milling media were Si3N4 balls or WC balls, and the mixture was sieved through a mesh size of 80–1000 to obtain a mixed powder. After discharge plasma sintering, the material was held at 1850–2050 °C, 20–35 MPa, and a vacuum of 10 Pa for 5–20 min, with a heating rate of 50–150 °C / min, ultimately yielding a material with a density ≥97.0%, a hardness of 27–32 GPa, and a fracture toughness of 4.5–6.5 MPa∙m¹. / ², Multiphase ceramics with flexural strength of 450~600 MPa [Lin Huatai et al. A high-entropy boride composite SiC ceramic with controllable microstructure and its preparation method and application: CN202510611734.1, Guangdong University of Technology, published on September 30, 2025]. In this technology, the preparation of high-entropy boride composite SiC ceramics faces problems such as high sintering temperature and poor matching of process parameters. Furthermore, it is difficult to achieve a synergistic improvement in material density, hardness, fracture toughness, and flexural strength while simplifying the wet ball milling and sintering process and reducing preparation energy consumption. Summary of the Invention

[0007] To address the aforementioned deficiencies in existing technologies, this invention provides a transition metal-ceramic composite SiC composite material and its preparation method. By combining a ternary blend of transition metal elements, carbides, and borides with a one-step ball milling and spark plasma sintering (SPS) process in an air atmosphere, the invention achieves a synergistic improvement in low-temperature sintering, high density, high mechanical properties, and excellent oxidation resistance, while simplifying the preparation process and reducing production energy consumption.

[0008] To achieve the above-mentioned technical objectives, this invention discloses a transition metal-ceramic composite material with SiC, the raw materials for which are prepared include transition metal powder, carbide powder, boride powder, and SiC powder. Transition metal powder: selected from at least one of Ti powder, V powder, Zr powder, and Ta powder; Carbide powder: selected from at least one of NbC powder and WC powder; Boride powder: NbB2 powder; Mass fraction ratio: 5~31 wt.% transition metal powder, 7~46 wt.% carbide powder, 17~32 wt.% boride powder, balance SiC powder; Physicochemical parameters of raw materials: transition metal powder particle size 1~2μm, carbide powder, boride powder, and SiC powder particle size 1~3μm, and purity of all powders ≥99.5%.

[0009] Furthermore, this invention also discloses a method for preparing a transition metal-ceramic composite material with SiC, comprising four steps: composite powder preparation, cold pressing, SPS sintering, and sample post-treatment, as detailed below: S1, Preparation of composite powder The raw material powder is loaded into the air and mixed by ball milling; the mass ratio of ball to material is 2:1 to 20:1, the ball milling speed is 350 to 650 r / min, and the ball milling time is 2 to 30 h to obtain a uniform composite powder.

[0010] S2, Cold pressing The composite powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa and a holding time of 30 s to obtain a cold-pressed blank.

[0011] S3, SPS sintering The cold-pressed billet is subjected to spark plasma sintering with the following core parameters: sintering pressure 40MPa, vacuum degree 60Pa, sintering temperature 1500~1900℃, holding time 5~60min, and then cooled in the furnace to obtain the blank. Segmented heating mechanism: The temperature is increased from room temperature to 600℃ within 5 minutes, and held at 600℃ for 5 minutes; the vacuum is stopped, and argon gas is introduced to -0.05Pa; the temperature is increased at 100℃ / min to a temperature 100℃ lower than the final sintering temperature, and then increased at 25℃ / min to the final sintering temperature; after the holding period, the furnace is cooled.

[0012] S4. Sample Post-processing The blank is subjected to surface grinding and deburring to obtain the final composite material.

[0013] The performance parameters of the composite material obtained by this invention are as follows: Bulk density: 5.9~8.3 g / cm³ 3 ; Density: 90.1%~98.9%; Vickers hardness: 16.1~21.1 GPa; Fracture toughness: 6.5~7.6 MPa·m 1 / 2 ; Compressive strength: 1436~2242MPa; Flexural strength: 415.6 MPa; Initial oxidation temperature: 653.6~921℃; Oxidative weight gain: 0.09~23.56%.

[0014] Compared with the prior art, the present invention can achieve the following technical effects: Transition metals promote the diffusion of high-entropy ceramic elements, reducing the sintering temperature from over 2000℃ to 1500~1900℃, significantly reducing sintering energy consumption; one-step ball milling in air atmosphere generates vacancies in situ, eliminating the need for additional vacancy preparation / introduction, simplifying the process and improving production efficiency; carbides and borides provide high hardness, high-temperature stability, and corrosion resistance, forming a stable interface with SiC and inhibiting grain growth; transition metals enhance the material's toughness, achieving a synergistic effect of high density, high hardness, high toughness, and high oxidation resistance; the material combines the high-temperature resistance and corrosion resistance of SiC with the toughness of transition metal ceramics, making it suitable for high-temperature structural components, wear-resistant cutting tools, and corrosion-resistant components in aerospace, high-end cutting, and nuclear industries.

[0015] Of course, any product implementing this invention does not necessarily need to achieve all of the technical effects described above at the same time. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 The XRD patterns of the SiC composite materials corresponding to Examples 1, 2, and 5 are shown.

[0017] Figure 2 The XRD patterns of the sintered SiC composite materials corresponding to Examples 1, 2, and 5 are shown.

[0018] Figure 3 The XRD patterns of the SiC composite materials corresponding to Examples 3, 4, 5, and 6 are shown.

[0019] Figure 4 The DSC-TG curves are for the SiC composite material corresponding to Example 3.

[0020] Figure 5 The DSC-TG curves are for the SiC composite material corresponding to Example 4.

[0021] Figure 6 The DSC-TG curves are for the SiC composite material corresponding to Example 5.

[0022] Figure 7 The DSC-TG curves are for the SiC composite material corresponding to Example 6.

[0023] Figure 8 The hardness and toughness of the SiC composite materials corresponding to Examples 3, 4, 5, and 6 are shown.

[0024] Figure 9 The density and compaction density of the SiC composite materials corresponding to Examples 3, 4, 5, and 6 are given.

[0025] Figure 10 The powder XRD patterns of the SiC composite materials corresponding to Examples 7, 8, and 12 are shown.

[0026] Figure 11 The XRD patterns of the sintered SiC composite materials corresponding to Examples 7, 8, and 12 are shown.

[0027] Figure 12 The hardness and toughness of the SiC composite materials corresponding to Examples 9, 10, 11, and 12 are shown.

[0028] Figure 13 The density and compaction density of the SiC composite materials corresponding to Examples 9, 10, 11, and 12 are given.

[0029] Figure 14 The powder XRD patterns of the SiC composite materials corresponding to Examples 13, 14, and 16 are shown.

[0030] Figure 15 The XRD patterns of the sintered SiC composite materials corresponding to Examples 13, 14, and 16 are shown.

[0031] Figure 16 The DSC-TG curves are for the SiC composite material corresponding to Example 15.

[0032] Figure 17 The hardness and toughness of the SiC composite materials corresponding to Examples 13, 14, and 16 are shown.

[0033] Figure 18 The density and compaction density of the SiC composite materials corresponding to Examples 13, 14, and 16 are given. Detailed Implementation

[0034] The following will describe in detail the implementation of the present invention with reference to the accompanying drawings and embodiments, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0035] The raw materials and equipment used in this invention are all commercially available conventional products, and the performance testing uses conventional instruments such as XRD, Vickers hardness tester, universal testing machine, and synchronous thermal analyzer. Example 1

[0036] S1. Preparation of composite powder: Weigh 0.5 g of Ti powder, 0.6 g of V powder, 1 g of Zr powder, 2 g of Ta powder, 4.6 g of NbC powder and 1.3 g of SiC powder in air.

[0037] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0038] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 10 min. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0039] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to 1800 ℃; after 10 min at the final sintering temperature, the blank is removed after cooling in the furnace.

[0040] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0041] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. Figure 1 The image shows the powder XRD pattern of the SiC composite material corresponding to Example 1. Metallic elements (Ti, V, Zr, Ta) complete solid solution treatment to form TiC. x VC x ZrC x TaC x Simultaneously, due to the C atoms being taken away by the metallic element atoms, NbC is also transformed into carbon-deficient NbC. x Its bulk density, compactness, Vickers hardness, and fracture toughness are 6.90 g / cm³. 3 97.7%, 17.8 GPa and 6.4 MPa·m 1 / 2 . Example 2

[0042] S1. Preparation of composite powder: Weigh 0.6 g of Ti powder, 0.7 g of V powder, 1.2 g of Zr powder, 2.3 g of Ta powder, 3.6 g of NbC powder and 1.6 g of SiC powder in air.

[0043] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0044] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0045] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0046] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0047] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. Figure 2 The image shows the XRD pattern of the sintered SiC composite material corresponding to Example 2. As can be seen from the image, after sintering, the main phase is the face-centered cubic (FCC) phase, with small amounts of oxides and SiC also present. No oxides were detected in the XRD of the powder, indicating that the oxides in the sintered body were formed during the sintering process. Its bulk density, compactness, Vickers hardness, and fracture toughness are 6.5 g / cm³. 3 98.6%, 17.0 GPa and 5.7 MPa·m 1 / 2 . Example 3

[0048] S1. Preparation of composite powder: Weigh 0.7 g of Ti powder, 0.8 g of V powder, 1.4 g of Zr powder, 2.7 g of Ta powder, 2.6 g of NbC powder and 1.8 g of SiC powder in air.

[0049] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0050] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1600 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0051] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0052] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0053] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. Figure 3 The image shows the powder XRD pattern of the SiC composite material corresponding to Example 3. The XRD pattern reveals that the material exhibits a face-centered cubic (FCC) phase structure. The metallic elements (Ti, V, Zr, Ta) in the powder are dissolved into the NbC-dominated lattice, forming (TiVZrTaNb)C. x Solid solution. No metallic elements or oxides were detected in the XRD of the powder, but two different crystalline forms of zirconium oxide were detected in the XRD of the sintered body at 28°-30°, as shown in Figure 4. The sample exhibited significant exothermic oxidation and weight gain behavior, indicating that ZrC... x Zirconia is formed during the sintering process by reacting with oxygen in the air. Its bulk density, compactness, Vickers hardness, fracture toughness, initial oxidation temperature, final oxidation temperature, and oxidation weight gain are all 6.7 g / cm³. 3 ,96.3%, 20.0 GPa, 5.8 MPa·m 1 / 2 621.1 ℃, 1184.0 ℃ and 23.43%. Example 4

[0054] S1. Preparation of composite powder: Weigh 0.7 g of Ti powder, 0.8 g of V powder, 1.4 g of Zr powder, 2.7 g of Ta powder, 2.6 g of NbC powder and 1.8 g of SiC powder in air.

[0055] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0056] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1700 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0057] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0058] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0059] As shown in Figure 5, the oxidation characteristics of the sample are similar to those of Example 3, with a slight increase in the peak oxidation temperature.

[0060] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that its bulk density, compactness, Vickers hardness, fracture toughness, initial oxidation temperature, final oxidation temperature, and oxidation weight gain were all 7.0 g / cm³. 3 ,97.6%, 17.6 GPa, 5.6 MPa·m 1 / 2 641.4 ℃, 1033.4 ℃ and 23.19%. Example 5

[0061] S1. Preparation of composite powder: Weigh 0.7 g of Ti powder, 0.8 g of V powder, 1.4 g of Zr powder, 2.7 g of Ta powder, 2.6 g of NbC powder and 1.8 g of SiC powder in air.

[0062] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0063] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0064] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0065] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0066] As shown in Figure 6, the oxidative weight gain of the sample was significantly reduced, and its high-temperature antioxidant properties were improved.

[0067] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that their bulk density, compactness, Vickers hardness, fracture toughness, initial oxidation temperature, final oxidation temperature, and oxidation weight gain were all 6.8 g / cm³. 3 ,98.9%, 17.5 GPa, 6.0 MPa·m 1 / 2 660.3 ℃, 1058.2 ℃ and 19.19%. Example 6

[0068] S1. Preparation of composite powder: Weigh 0.7 g of Ti powder, 0.8 g of V powder, 1.4 g of Zr powder, 2.7 g of Ta powder, 2.6 g of NbC powder and 1.8 g of SiC powder in air.

[0069] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0070] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1900 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0071] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0072] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0073] Figure 7 The DSC-TG curves for the SiC composite material in Example 6 are shown. Two exothermic peaks appear in the DSC curves, at 921 °C and 1279.8 °C, respectively. The weight change of the composite material can be divided into two stages: the initial stage and the later stage. In the initial stage, the weight of the composite material increases sharply, with a weight gain rate of 19.19%, and the maximum weight gain occurs around 921 °C.

[0074] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that their bulk density, compactness, Vickers hardness, fracture toughness, initial oxidation temperature, final oxidation temperature, and oxidation weight gain were all 6.8 g / cm³. 3 ,98.9%, 17.9 GPa, 6.9 MPa·m 1 / 2 713.3 ℃, 1184.0 ℃ and 19.02%. Example 7

[0075] S1. Preparation of composite powder: Weigh 0.8 g of Ti powder, 0.8 g of V powder, 1.5 g of Zr powder, 2.9 g of Ta powder, 0.7 g of NbC powder, 1.4 g of WC powder and 1.9 g of SiC powder in air.

[0076] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0077] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0078] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0079] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0080] Figure 10 The image shows the powder XRD pattern of the SiC composite material corresponding to Example 7. The XRD pattern reveals that the main phase in the powder is WC, with small amounts of oxides and Nb6C5. There are no diffraction peaks for elemental metals (Ti, V, Zr, Ta), indicating that elemental metals are dissolved in the tungsten carbide-dominated lattice, forming the corresponding carbon-deficient phase (TiC). x VC x ZrC x TaC x ).

[0081] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that their bulk density, compactness, Vickers hardness, and fracture toughness were 7.4 g / cm³. 3 98.4%, 18.2 GPa and 6.7 MPa·m 1 / 2 . Example 8

[0082] S1. Preparation of composite powder: Weigh 0.7 g of Ti powder, 0.9 g of V powder, 1.3 g of Zr powder, 2.6 g of Ta powder, 1.0 g of NbC powder, 1.8 g of WC powder and 2.7 g of SiC powder in air.

[0083] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0084] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0085] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0086] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0087] Figure 11 The image shows the XRD pattern of the sintered SiC composite material corresponding to Example 8. The XRD pattern reveals that the material exhibits a face-centered cubic (FCC) phase, where elemental metals (Ti, V, Zr, Ta) are dissolved into a lattice dominated by NbC and WC, forming FCC(TiVZrTaNbW)C. x High-entropy ceramic phase.

[0088] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that their bulk density, compactness, Vickers hardness, and fracture toughness were 7.0 g / cm³. 3 99.7%, 20.5 GPa and 7.1 MPa·m 1 / 2 . Example 9

[0089] S1. Preparation of composite powder: Weigh 0.8 g of Ti powder, 0.8 g of V powder, 1.5 g of Zr powder, 2.9 g of Ta powder, 0.7 g of NbC powder, 1.4 g of WC powder and 1.9 g of SiC powder in air.

[0090] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0091] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1500 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0092] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0093] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0094] Figure 12 The hardness and toughness of the SiC composite material corresponding to Example 9 are shown. Figure 13 The density and compactness of the SiC composite material corresponding to Example 9 are shown. With increasing temperature, the hardness of the ceramic exhibits a trend of first increasing and then decreasing, reaching a maximum value of 20 ± 0.23 GPa at 1600 ℃; the fracture toughness shows an increasing trend with temperature change, reaching a maximum value of 6.9 ± 0.3 MPa∙m at 1700~1800 ℃. 1 / 2 The bulk density and compaction density of the composite material both showed a trend of first decreasing and then increasing, with the compaction density reaching a maximum of 96.1% at 1700 ℃.

[0095] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that their bulk density, compactness, Vickers hardness, and fracture toughness were 6.8 g / cm³. 3 93.4%, 11.5 GPa and 4.2 MPa·m 1 / 2 . Example 10

[0096] S1. Preparation of composite powder: Weigh 0.8 g of Ti powder, 0.8 g of V powder, 1.5 g of Zr powder, 2.9 g of Ta powder, 0.7 g of NbC powder, 1.4 g of WC powder and 1.9 g of SiC powder in air.

[0097] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0098] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1600 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0099] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0100] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0101] As shown in Figures 12 and 13, the hardness has increased but the density remains low.

[0102] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that their bulk density, compactness, Vickers hardness, and fracture toughness were 6.1 g / cm³. 3 83.9%, 20.0 GPa and 5.4 MPa·m 1 / 2 . Example 11

[0103] S1. Preparation of composite powder: Weigh 0.8 g of Ti powder, 0.8 g of V powder, 1.5 g of Zr powder, 2.9 g of Ta powder, 0.7 g of NbC powder, 1.4 g of WC powder and 1.9 g of SiC powder in air.

[0104] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0105] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1700 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0106] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0107] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0108] As shown in Figures 12 and 13, the density and toughness are significantly improved.

[0109] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that its bulk density, compactness, Vickers hardness, fracture toughness, initial oxidation temperature, final oxidation temperature, and oxidation weight gain were all 7.0 g / cm³. 3 ,96.1%, 16.5 GPa, 6.9 MPa·m 1 / 2 650 ℃, 960 ℃ and 23.56%. Example 12

[0110] S1. Preparation of composite powder: Weigh 0.8 g of Ti powder, 0.8 g of V powder, 1.5 g of Zr powder, 2.9 g of Ta powder, 0.7 g of NbC powder, 1.4 g of WC powder and 1.9 g of SiC powder in air.

[0111] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0112] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0113] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0114] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0115] As shown in Figures 12 and 13, the overall performance reaches the peak value of the system.

[0116] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. The results showed that their bulk density, compactness, Vickers hardness, fracture toughness, initial oxidation temperature, final oxidation temperature, and oxidation weight gain were all 6.8 g / cm³. 3 ,98.7%, 18.0 GPa, 6.9 MPa·m 1 / 2 640 ℃, 1384.1 ℃ and 22.42%. Example 13

[0117] S1. Preparation of composite powder: Weigh 0.7 g of Ti powder, 0.8 g of V powder, 1.3 g of Zr powder, 2.5 g of Ta powder, 3.1 g of NbB2 powder and 1.6 g of SiC powder in air.

[0118] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0119] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0120] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0121] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0122] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. Figure 14 The image shows the powder XRD pattern of the SiC composite material corresponding to Example 13. Figure 15 The XRD pattern of the sintered SiC composite material corresponding to Example 13 is shown. The XRD pattern of the powder shows that the main phase is WC, with small amounts of oxides and Nb6C5. There are no diffraction peaks for elemental metals (Ti, V, Zr, Ta), indicating that elemental metals are dissolved in the tungsten carbide-dominated lattice, forming the corresponding carbon-deficient phase (TiC). x VC x ZrC x TaC x The XRD patterns of the sintered bodies show that all materials exhibit a face-centered cubic (FCC) phase. The metallic elements (Ti, V, Zr, Ta) in the powder are dissolved into a lattice dominated by NbC and WC, forming FCC(TiVZrTaNbW)C. x High-entropy ceramic phase. As shown in Figures 17 and 18, it exhibits excellent matching between fracture toughness and density, with a bulk density, density, Vickers hardness, and fracture toughness of 6.1 g / cm³. 3 95.8%, 16.6 GPa and 7.2 MPa·m 1 / 2 . Example 14

[0123] S1. Preparation of composite powder: Weigh 0.7 g of Ti powder, 0.8 g of V powder, 1.4 g of Zr powder, 2.8 g of Ta powder, 2.4 g of NbB2 powder and 1.9 g of SiC powder in air.

[0124] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0125] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0126] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0127] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0128] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. As shown in Figures 17 and 18, the decrease in NbB2 content led to a slight decrease in toughness. The results showed that its bulk density, compactness, Vickers hardness, and fracture toughness were 6.5 g / cm³. 3 92.4%, 16.4 GPa and 6.4 MPa·m 1 / 2 . Example 15

[0129] S1. Preparation of composite powder: Weigh 0.8 g of Ti powder, 0.9 g of V powder, 1.5 g of Zr powder, 3.1 g of Ta powder, 1.7 g of NbB2 powder and 2.0 g of SiC powder in air.

[0130] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0131] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1700 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0132] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0133] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0134] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. Figure 16 The DSC-TG curves for the SiC composite material corresponding to Example 15 are shown. Two strong thermal peaks appear in the DSC curves at 825.5 ℃ and 1316.6 ℃, respectively. The weight gain of the composite material is 2.95%. Its bulk density, compactness, Vickers hardness, fracture toughness, initial oxidation temperature, final oxidation temperature, and oxidation weight gain are 5.9 g / cm³. 3 ,95.4%, 16.2 GPa, 5.6 MPa·m 1 / 2 700 ℃, 960 ℃ and 2.95%. Example 16

[0135] S1. Preparation of composite powder: Weigh 0.8 g of Ti powder, 0.9 g of V powder, 1.5 g of Zr powder, 3.1 g of Ta powder, 1.7 g of NbB2 powder and 2.0 g of SiC powder in air.

[0136] S2. Cold pressing: The powder is loaded into a graphite mold for pre-pressing at a pressure of 30 MPa for a holding time of 30 s.

[0137] S3, SPS sintering: The cold-pressed sample is subjected to spark plasma sintering (SPS). The sintering pressure is 40 MPa, the vacuum degree is 60 Pa, the sintering temperature is 1800 ℃, and the holding time is 5~10 h. Then, the sample is cooled and depressurized to obtain a transition metal-ceramic composite SiC composite material.

[0138] The specific sintering process and parameters for SPS are as follows: After placing the graphite mold in a graphite felt, it is placed in the SPS sintering furnace and the pressure is slowly increased to 40 MPa. After the vacuum in the sintering furnace reaches 60 Pa, sintering 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, held at 600 ℃ for 5 min, after which the vacuum is stopped and argon gas is introduced to -0.05 Pa; then the temperature is increased at a rate of 100 ℃ / min to a temperature 100 ℃ lower than the final sintering temperature, and then sintered at a rate of 25 ℃ / min to the final sintering temperature; the final sintering temperature is held for 5 h, and the blank is removed after cooling in the furnace.

[0139] S4. Sample processing: The prepared blank is subjected to surface grinding and deburring to obtain a transition metal-ceramic composite SiC composite material.

[0140] The prepared cemented carbide samples were ground and polished before their microstructure and properties were tested. As shown in Figures 17 and 18, the toughness increased with increasing temperature. The results showed that the bulk density, compactness, Vickers hardness, fracture toughness, initial oxidation temperature, final oxidation temperature, and oxidation weight gain were all 6.3 g / cm³. 3 ,90.1%, 16.5 GPa, 6.7 MPa·m 1 / 2 700 ℃, 1030.2 ℃ and 5.44%.

[0141] A comparison of Examples 1, 2, and 3 shows that in the pure carbide system, with increasing metal powder mass fraction, hardness first increases and then decreases, while fracture toughness shows a decreasing trend, reaching its highest point at approximately 46% metal powder mass fraction (Example 3). This is because increasing metal powder content generates more vacancies in situ, promoting solid solution formation and increasing hardness. However, excessive metal powder leads to a decrease in the NbC ratio, weakening the strengthening effect of carbides and increasing the difficulty of densification, resulting in fluctuations in fracture toughness. The initial oxidation temperature gradually increases, while the termination oxidation temperature remains high, and the oxidation weight gain remains at a high level. This is because metal powder has a strong affinity for oxygen, making the initial oxidation reaction easier, while the carbide solid solution still provides a certain degree of high-temperature oxidation resistance. A comparison of Examples 3, 4, 5, and 6 shows that, under the same raw material ratio, with increasing sintering temperature, density continuously increases, and fracture toughness gradually increases. Increasing the sintering temperature reduces the sintering difficulty of the material, promotes atomic diffusion, increases density, and optimizes the interfacial bonding state, thereby improving fracture toughness. As the initial oxidation temperature gradually increases, the oxidation weight gain gradually decreases. This is because the dense oxide film formed by high-temperature sintering effectively hinders oxygen diffusion, significantly improving the material's high-temperature oxidation resistance. Comparisons of implementation cases 7, 8, 9, 10, 11, and 12 show that in WC-containing carbide systems, excessively low sintering temperatures lead to incomplete powder dissolution, resulting in significantly lower density and fracture toughness. Appropriately increasing the sintering temperature to 1800℃ achieves peak density, hardness, and fracture toughness. Prolonged holding at high temperatures did not show clear negative effects, but low-temperature sintering leads to performance degradation due to insufficient dissolution, while at 1800℃, WC forms a synergistically strengthening solid solution with other carbides. Comparisons of implementation cases 13, 14, 15, and 16 show that in boride systems, as the NbB2 mass fraction decreases, hardness decreases, fracture toughness initially decreases then increases, and density decreases. NbB2 is key to improving toughness; its lower content reduces the toughening effect of the boride solid solution, but this deficiency can be partially compensated for by increasing the sintering temperature, promoting interfacial bonding. The initial oxidation temperature remains high, and the oxidation weight gain is significantly lower than that of the carbide system. This is because the oxidation products of the boride can form a dense protective film, hindering further oxidation. Therefore, Example 8 represents the optimal preparation process for this transition metal-high-entropy carbon / boride-SiC composite material: it possesses the highest hardness, highest density, and high fracture toughness, achieving a balance between hardness, fracture toughness, and density, making it suitable for applications with high mechanical performance requirements. Example 13, on the other hand, exhibits the best performance in terms of fracture toughness and oxidation resistance, making it suitable for service requirements in high-temperature oxidizing environments.

[0142] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A transition metal-ceramic composite material with SiC, characterized in that, The raw materials used in the preparation include transition metal powder, carbide powder, boride powder, and SiC powder; The transition metal powder is selected from at least one of Ti powder, V powder, Zr powder, and Ta powder; The carbide powder is selected from at least one of NbC powder and WC powder; The boride powder is NbB2 powder; The content of transition metal powder is 5~31 wt.% by mass fraction, the content of carbide powder is 7~46 wt.% by mass fraction, the content of boride powder is 17~32 wt.% by mass fraction, and the balance is SiC powder.

2. The transition metal-ceramic composite SiC composite material according to claim 1, characterized in that, The transition metal powder has a particle size of 1~2μm, and the carbide powder, boride powder, and SiC powder all have a particle size of 1~3μm; the purity of each raw material powder is not less than 99.5%.

3. A method for preparing a transition metal-ceramic composite material with SiC, characterized in that, Includes the following steps: S1. Preparation of composite powder: The raw material powder described in claim 1 or 2 is mixed in air by ball milling, with a ball-to-material mass ratio of 2:1 to 20:1, a ball milling speed of 350 to 650 r / min, and a ball milling time of 2 to 30 h, to obtain composite powder; S2. Cold pressing: The composite powder is loaded into a graphite mold for pre-pressing. The pre-pressing pressure is 30MPa and the holding time is 30s to obtain a cold-pressed blank. S3, SPS sintering: The cold-pressed blank is subjected to spark plasma sintering at a sintering pressure of 40MPa, a sintering vacuum of 60Pa, a sintering temperature of 1500~1900℃, and a holding time of 5~60min. After cooling in the furnace, the blank is obtained. S4. Sample processing: The blank is subjected to surface grinding and deburring to obtain the transition metal-ceramic composite SiC composite material.

4. The preparation method according to claim 3, characterized in that, The specific heating mechanism for SPS sintering in step S3 is as follows: the temperature is raised from room temperature to 600℃ within 5 minutes, and held at 600℃ for 5 minutes; after the holding period, the vacuum is stopped, and argon gas is introduced to -0.05Pa; the temperature is raised at a rate of 100℃ / min to a temperature 100℃ lower than the final sintering temperature, and then raised at a rate of 25℃ / min to the final sintering temperature.

5. The preparation method according to claim 3, characterized in that, In step S3, the sintering temperature is 1800℃ and the holding time is 5~10min.

6. A transition metal-ceramic composite material with SiC, characterized in that, Prepared by the preparation method according to any one of claims 3 to 5; The bulk density of the composite material is 5.9~8.3g / cm 3 , the density is 90.1~98.9%, the Vickers hardness is 16.1~21.1GPa, the fracture toughness is 6.5~7.6MPa·m 1 / 2 , the compressive strength is 1436~2242MPa, the bending strength is 415.6MPa, the initial oxidation temperature is 653.6~921℃, and the oxidation weight gain is 0.09~23.56%.

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