High-thermal-conductivity three-dimensional graphene / carbonitride-based metal ceramic composite material as well as preparation method and application thereof

Abstract

The invention discloses a high-thermal-conductivity three-dimensional graphene / carbonitride-based metal ceramic composite material as well as a preparation method and application thereof, and belongs to the technical field of preparation of composite materials for aerospace. The ablation-resistant ultra-high-temperature ceramic-based composite material with the density being larger than or equal to 95% and the proportion of all elements capable of being precisely regulated and controlled is prepared by adopting a three-dimensional graphene and ultra-high-temperature carbonitride-based metal ceramic co-sintering method for the first time. The high-thermal-conductivity three-dimensional graphene / carbonitride-based metal ceramic composite material designed and prepared by the invention is suitable for thermal protection in extremely high-temperature environments of 2500 DEG C and above. Verification shows that after long-time (200s) ablation, the ceramic still keeps a state close to zero ablation rate and a continuous and stable anti-oxidation protection structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials for aerospace, and specifically relates to a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal ceramic composite material and its preparation method and application. Background Art

[0002] Ultra-high temperature ceramics (UHTCs) are considered the most promising candidate materials for ultra-high temperature thermal protection due to their intrinsic properties of ultra-high melting points. However, traditional carbide and boride systems (such as ZrC, HfC; ZrB2, HfB2) still have obvious drawbacks in engineering applications: First, its anti-oxidation-ablation synergistic performance cannot meet the service requirements of the new generation of thermal protection systems; Secondly, the mismatch between the intrinsic brittleness of the material and its thermal shock resistance results in catastrophic structural failure under severe thermal-mechanical coupling loads.

[0003] Therefore, improving the temperature resistance and structural reliability of traditional ultra-high temperature ceramics and developing new thermal protection materials with higher melting points, better oxidation resistance and thermal shock resistance are the keys to realizing their ultra-high temperature ablation-resistant applications, which has very important scientific and practical significance.

[0004] Research has found that adding appropriate lightweight nitrogen elements to the anion sublattice of ultra-high temperature carbide ceramics is a new way to increase their melting point. Its antioxidant and ablation resistance have been significantly improved with the addition of nitrogen, making it a new type of thermal protection material with great application prospects. High-performance metals have excellent ductility and can absorb energy through plastic deformation when the composite material is loaded, effectively inhibiting crack propagation, making them ideal ceramic toughening materials. The preparation of ultra-high melting point metal-ceramic composites can effectively improve the mechanical properties and thermal shock resistance of the material. On this basis, a high thermal conductivity three-dimensional graphene-like network structure is constructed to further enhance the overall performance of the material. Summary of the Invention

[0005] To address the common challenges of existing ultrahigh-temperature ceramic material systems, such as low toughness, insufficient ablation resistance, and poor thermal shock resistance, the present invention provides a high-thermal-conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material, its preparation method, and its application. For the first time, a novel ablation-resistant ultrahigh-temperature composite material with a density ≥95% and precisely controllable elemental content was prepared through rapid hot pressing. Furthermore, for the first time, a high-thermal-conductivity three-dimensional graphene-like and ultrahigh-temperature carbonitride-based metal-ceramic composite material with a density ≥95% and precisely controllable elemental ratios was prepared by co-sintering a high-thermal-conductivity three-dimensional graphene-like and ultrahigh-temperature carbonitride-based metal-ceramic. The designed and prepared high-thermal-conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material is suitable for ultrahigh-temperature ablation protection at temperatures of 2500°C and above. Verification demonstrated that even after prolonged ablation (200 seconds), the ceramic maintained a near-zero ablation rate and a continuous and stable anti-oxidation protective structure.

[0006] The technical solutions of the present invention are as follows: The present invention provides a high thermal conductivity three-dimensional graphene-like / carbon nitride-based metal-ceramic composite material. The high thermal conductivity three-dimensional graphene-like / carbon nitride-based metal-ceramic composite material is suitable for thermal protection in extreme high temperature environments above 2500°C and has a stable anti-oxidation structure.

[0007] The purpose of the present invention is achieved through the following technical solutions: A high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material, wherein the chemical formula of the ceramic material is: MC x N 1-x , where 0<X<1, M is Hf, Zr, Ta, Nb, Ti; the metal material is transition metal Fe, Co, Ni, Cu, Cr; the density of the composite material is ≥95%, and the mass ablation rate after plasma ablation at 2500℃ for 200s is 1×10 -3 g / s - 5×10 -3 g / s, the linear ablation rate is 3×10 -3 mm / s - 2×10 -2 mm / s.

[0008] The method for preparing the above-mentioned high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material comprises the following steps: S1. Preparing carbonitride ceramic powder: uniformly mixing a metal raw material and carbon powder in a molar ratio of (1-8):(3-10) by nitrogen ball milling, and then passing the material through a 300-mesh sieve under a vacuum atmosphere to obtain a carbonitride ceramic raw material powder; The metal raw materials are Hf, Zr, Ta, Nb, and Ti metal powders; S2. Weigh commercial spherical metal powder and add it to the mixed solution. Stir it with ultrasonic stirring until the solvent is completely evaporated. Place the resulting mixture in a vacuum oven and dry it to obtain a metal / glucose precursor powder. The commercial spherical metal powder is powder of Fe, Co, Ni, Cu, or Cr; The mixed solution is prepared by dissolving glucose in a mixed solution of water and ethanol, stirring until the glucose is fully dissolved to obtain a uniform and transparent solution, wherein the concentration of glucose is 0.029 mol / L-0.05 mol / L, the molar ratio of deionized water to anhydrous ethanol in the mixed solution is (0.8-1):(1.8-2.3), and the mass ratio of glucose to commercial spherical metal powder is (1-6):(50-93); S3, transferring the obtained metal / glucose precursor powder to a tube furnace, heating it in a heating zone of 800° C. to 1000° C. under an atmosphere of argon and hydrogen for 10 min to 15 min, cooling the powder to room temperature, and sieving to obtain a metal / graphene-like composite powder; S4. Weigh the metal / graphene-like composite powder and the carbonitride ceramic raw material powder in a mass ratio of (20-43): (50-87), mix them evenly to obtain a metal ceramic preform powder, and then place it into a graphite mold; S5, the metal ceramic preform powder obtained in the above step is subjected to rapid hot pressing and sintering to obtain a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal ceramic composite material, wherein the chemical formula of the ceramic material is: MC x N 1-x , where 0<X<1, M is Hf, Zr, Ta, Nb, Ti; the metal material is transition metal Fe, Co, Ni, Cu, Cr; the density of the composite material is ≥95%, and the mass ablation rate after plasma ablation at 2500℃ for 200s is 1×10 -3 g / s - 5×10 -3 g / s, the linear ablation rate is 3×10 - 3 mm / s - 2×10 -2 mm / s.

[0009] Furthermore, the metal raw materials and carbon powder described in S1 are nano-scale powders or micron-scale powders, the particle size of the powders are all <10μm, the purity is all ≥99.9%, and when used, they are sealed and stored under air-tight conditions; the nitrogen ball mill uses silicon nitride as the ball milling medium, the ball milling speed is controlled to 300-600r / min, the ball milling time is 12-24h, and the ball-to-material ratio is (2-13):1.

[0010] Furthermore, the particle size of the powder described in S2 is less than 10 μm, and the purity is ≥99.9%. When used, it is sealed and stored under air-tight conditions; the ultrasonic stirring is performed at a temperature of 60°C-80°C and a time of 60 min-120 min; the drying is performed at a temperature of 60°C-90°C and a time of 3 h-8 h; and the stirring is performed at a stirring rate of 200 r / min-500 r / min.

[0011] Furthermore, the flow rate of the argon gas described in S3 is 200 ml / min-290 ml / min, and the flow rate of the hydrogen gas is 90 ml / min-150 ml / min.

[0012] Furthermore, the mixing described in S4 is uniform, and the mixing stirring rate is 300r / min-600r / min.

[0013] Furthermore, the rapid hot pressing sintering described in S5 has the following conditions: the temperature in the sintering furnace is 1600°C-2500°C, the insulation time is 15min-120min, the heating rate is 25°C / min-130°C / min, the pressure is 20MPa-80MPa, and the sintering atmosphere is nitrogen; furthermore, 60MPa-80MPa is preferred.

[0014] The present invention also relates to the application of the above-mentioned high thermal conductivity three-dimensional graphene / carbonitride-based metal ceramic composite material, which is used to prepare ultra-high temperature ablation-resistant protective materials of 2500°C and above.

[0015] Compared with the prior art, the present invention has the following advantages: 1. The method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material described in the present invention has a simple and easy preparation process and a short preparation cycle.

[0016] 2. The high thermal conductivity three-dimensional graphene / carbon nitride-based metal-ceramic composite material described in the present invention is a new type of ultra-high temperature metal-ceramic composite material that solves the problem of poor comprehensive mechanical properties of traditional ceramic materials and improves the thermal shock resistance of the material under extreme high temperatures.

[0017] 3. The high thermal conductivity three-dimensional graphene / carbonitride-based metal ceramic composite material described in the present invention has excellent ablation resistance. The sample maintains a low ablation rate after 200s of plasma ablation at 2500°C and has an intact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0019] Figure 1This is a macroscopic morphology of the surface of a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material sample prepared in Example 1 of the present invention; Figure 2 This is a surface micromorphology of a sample of a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material prepared in Example 1 of the present invention; Figure 3 This is a microscopic morphology of the ablated surface of a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material sample prepared in Example 1 of the present invention after plasma ablation at 2500°C for 200s; Figure 4 This is a macroscopic morphology of the ablated surface of the high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material sample prepared in Example 1 of the present invention after plasma ablation at 2500°C for 200s. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below by way of examples, but these examples should not be considered as limiting the present invention.

[0021] Example 1: A method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material comprises the following steps: S1. Weigh a raw material powder with a particle size of 2 μm and a purity greater than 99.9% according to a molar ratio of Zr:Hf:C=1:1:2.8; place the raw material powder in a ball mill at a speed of 400 r / min and ball mill for 12 h under a nitrogen atmosphere with a ball-to-material ratio of 3:1, then place the raw material powder in a vacuum glove box and sieve it through 300 mesh to obtain a carbonitride ceramic raw material powder; S2. Add 0.5 g of glucose to a mixed solution of 32 ml of deionized water and 60 ml of anhydrous ethanol, stirring at a rate of 200 r / min, until the glucose is fully dissolved to obtain a uniform and transparent solution; then, weigh 15 g of spherical Fe metal powder and add it to the mixed solution, and ultrasonically stir at 70° C. for 80 min until the solvent is completely evaporated; place the obtained mixture in a vacuum oven and dry it at 70° C. for 6 h to obtain Fe / glucose precursor powder; S3, transferring the prepared Fe metal / glucose precursor powder to a tube furnace; then, placing the Fe / glucose precursor powder in a heating zone at 950° C. and heating for 15 minutes in an atmosphere of Ar and H2, wherein the argon flow rate is 180 ml / min and the hydrogen flow rate is 120 ml / min; finally, cooling the heat-treated powder to room temperature, and then grinding and sieving to obtain Fe / graphene-like composite powder; S4. Weigh 10 g of the Fe / graphene-like composite powder and 19.3 g of the carbonitride ceramic raw material powder, mix them at a speed of 400 r / min to obtain an Fe metal ceramic preform powder, and then put it into a graphite mold; S5, the Fe metal ceramic preform powder prepared in the above steps is subjected to rapid hot pressing sintering, the sintering conditions are: the temperature in the sintering furnace is 1600 ° C, the heat preservation is 10 min, the heating rate is 100 ° C / min, the pressure is 70 MPa, and the sintering atmosphere is nitrogen, to obtain Fe-graphene / Hf 0.5 Zr 0.5 C 0.24 N 0.76 Metal-ceramic composite material with a density of ≥95% and a mass ablation rate of 1×10 after plasma ablation at 2500℃ for 200s -3 g / s, and the linear ablation rate is 2.3×10 -3 mm / s.

[0022] Figure 1 This is a macroscopic morphology of the surface of the high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material sample prepared in Example 1; Figure 1 As shown, it can be observed that the prepared high thermal conductivity three-dimensional graphene-like / carbon nitride-based metal-ceramic composite material is uniform and dense, and no phase separation occurs; Figure 2 This is a microscopic morphology of the surface of the high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material sample prepared in Example 1; Figure 2 As shown, it can be observed that the various phases of the prepared high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material have strong physical and chemical compatibility, and no cracks or pores appear; Figure 3 This is a microscopic morphology of the ablated surface of the high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material sample prepared in Example 1 after plasma ablation at 2500°C for 200s; Figure 3 As shown in the figure, after plasma ablation at 2500°C for 200s, the high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material prepared in Example 1 still has an extremely high density. At the same time, the inherent thermal conductivity of the high thermal conductivity graphene-like material can conduct heat, thereby reducing the heat on the sample surface and reducing the impact of thermal stress concentration caused by heat flow erosion. Figure 4 This is a macroscopic morphology of the ablated surface of the high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material sample prepared in Example 1 after plasma ablation at 2500°C for 200s; Figure 4As shown, no brittle fracture occurs after long-term ultra-high temperature ablation, which proves that the high thermal conductivity three-dimensional graphene-like / carbon nitride-based metal ceramic composite material prepared in Example 1 has very excellent thermal shock resistance and ablation resistance.

[0023] Example 2: A method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material comprises the following steps: S1. Weigh a raw material powder with a particle size of 3 μm and a purity greater than 99.9% according to a molar ratio of Zr:C = 1:2.4; place the raw material powder in a ball mill at a speed of 400 r / min and ball mill for 8 h under a nitrogen atmosphere with a ball-to-material ratio of 3:1, then place the raw material powder in a vacuum glove box and sieve it through 300 mesh to obtain a carbonitride ceramic raw material powder; S2. Add 0.36 g of glucose to a mixed solution of 22 ml of deionized water and 45 ml of anhydrous ethanol, stirring at a rate of 300 r / min, until the glucose is fully dissolved to obtain a uniform and transparent solution; then, weigh 24 g of spherical Ni metal powder and add it to the mixed solution, and ultrasonically stir at 75° C. for 60 min until the solvent is completely evaporated; place the obtained mixture in a vacuum oven and dry it at 60° C. for 5 h to obtain a Ni / glucose precursor powder; S3, transferring the prepared Ni metal / glucose precursor powder to a tube furnace; then, placing the metal / glucose precursor powder in a heating zone at 900°C and heating for 10 minutes in an atmosphere of Ar and H2, wherein the argon flow rate is 200 ml / min and the hydrogen flow rate is 100 ml / min; finally, cooling the heat-treated powder to room temperature, and then grinding and sieving to obtain Ni / graphene-like composite powder; S4. Weigh 13 g of the Ni / graphene-like composite powder and 32.5 g of the carbonitride ceramic raw material powder, mix them at a speed of 300 r / min to obtain a metal ceramic preform powder, and then put it into a graphite mold; S5, the Ni metal ceramic preform powder prepared in the above steps is subjected to rapid hot pressing sintering, the sintering conditions are: the temperature in the sintering furnace is 1800 ° C, the heat preservation is 20 min, the heating rate is 80 ° C / min, the pressure is 20 MPa, and the sintering atmosphere is nitrogen to obtain Ni-graphene / ZrC 0.65 N 0.35 Metal-ceramic composite material with a density of ≥95% and a mass ablation rate of 1.8×10 -3 g / s, and the linear ablation rate is 2.6×10 -3 mm / s.

[0024] Example 3: A method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material comprises the following steps: S1. Weigh a raw material powder with a particle size of 1 μm and a purity greater than 99.9% according to a molar ratio of Zr:Hf:Ta:C=0.2:0.5:0.3:2, place the raw material powder in a ball mill at a speed of 600 r / min, and ball mill for 20 h under a nitrogen atmosphere with a ball-to-material ratio of 3:1. Then, place the raw material powder in a vacuum glove box and sieve it through 300 mesh to obtain a carbonitride ceramic raw material powder; S2. Add 1 g of glucose to a mixed solution of 60 ml of deionized water and 78 ml of anhydrous ethanol, stirring at a rate of 300 r / min, until the glucose is fully dissolved to obtain a uniform and transparent solution; then, weigh 26.8 g of spherical Cr metal powder and add it to the mixed solution, and ultrasonically stir at 75°C for 70 min until the solvent is completely evaporated; the obtained mixture is placed in a vacuum oven and dried at 65°C for 8 h to obtain a Cr / glucose precursor powder; S3, transferring the prepared Cr / glucose precursor powder to a tube furnace; then, placing the metal / glucose precursor powder in a heating zone at 800°C and heating for 13 minutes in an atmosphere of Ar and H2, wherein the argon flow rate is 230 ml / min and the hydrogen flow rate is 150 ml / min; finally, cooling the heat-treated powder to room temperature, and then grinding and sieving to obtain a Cr / graphene-like composite powder; S4. Weigh 10 g of the Cr / graphene-like composite powder and 25.2 g of the carbonitride ceramic powder, mix them at a speed of 550 r / min to obtain a Cr metal ceramic preform powder, and then place it into a graphite mold; S5, the Cr metal ceramic preform powder prepared in the above steps is subjected to rapid hot pressing sintering, the sintering conditions are: the temperature in the sintering furnace is 1900℃, the heat preservation is 30min, the heating rate is 50℃ / min, the pressure is 40MPa, and the sintering atmosphere is nitrogen, to obtain Cr-graphene / Hf 0.3 Zr 0.2 Ta 0.3 C 0.55 N 0.45 Metal-ceramic composite material with a density of ≥95% and a mass ablation rate of 2×10 -3 g / s, and the linear ablation rate is 2.8×10 -3 mm / s.

[0025] Example 4: A method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material comprises the following steps: S1. Weigh a raw material powder with a particle size of 3 μm and a purity greater than 99.9% according to a molar ratio of Zr:Hf:Ta:Nb:Ti:C=0.2:0.2:0.2:0.2:0.2:1.7; place the raw material powder in a ball mill at a speed of 400 r / min and ball mill for 24 h under a nitrogen atmosphere with a ball-to-material ratio of 3:1, and then place the raw material powder in a vacuum glove box and sieve 300 mesh to obtain a carbonitride ceramic raw material powder; S2. Add 0.7 g of glucose to a mixed solution of 26 ml of deionized water and 40 ml of anhydrous ethanol, stirring at a rate of 300 r / min, until the glucose is fully dissolved to obtain a uniform and transparent solution; then, weigh 29.4 g of spherical Cu metal powder and add it to the mixed solution, and ultrasonically stir at 90° C. for 75 min until the solvent is completely evaporated; place the obtained mixture in a vacuum oven and dry it at 90° C. for 3 h to obtain a Cu / glucose precursor powder; S3, transferring the prepared Cu / glucose precursor powder to a tube furnace; then, placing the Cu / glucose precursor powder in a heating zone at 1000° C. and heating for 12 minutes in an atmosphere of Ar and H2, wherein the argon flow rate is 210 ml / min and the hydrogen flow rate is 90 ml / min; finally, cooling the heat-treated powder to room temperature, and then grinding and sieving to obtain a Cu / graphene-like composite powder; S4. Weigh 6 g of the Cu / graphene-like composite powder and 14.3 g of the carbonitride ceramic powder, mix them at a speed of 600 r / min to obtain a Cu metal ceramic preform powder, and then put it into a graphite mold; S5, the Cu metal ceramic preform powder prepared in the above steps is subjected to rapid hot pressing sintering, the sintering conditions are: the temperature in the sintering furnace is 1600℃, the heat preservation is 20min, the heating rate is 100℃ / min, the pressure is 30MPa, and the sintering atmosphere is nitrogen, to obtain Cu-graphene / Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Ti 0.2 C 0.5 N 0.5 Metal-ceramic composite material with a density of ≥95% and a mass ablation rate of 1.8×10 -3 g / s, the linear ablation rate is 1.5×10 -3 mm / s.

[0026] Comparative Example: The main difference between the comparative example and the embodiment is the presence or absence of high thermal conductivity three-dimensional graphene-like and metal components: Comparative Example 1: S1. Weigh a raw material powder with a particle size of 3 μm and a purity greater than 99.9% according to a molar ratio of Zr:C=1:2.4; place the raw material powder in a ball mill at a speed of 400 r / min and ball mill for 8 h under a nitrogen atmosphere with a ball-to-material ratio of 3:1, then place the raw material powder in a vacuum glove box and sieve it through 300 mesh to obtain a carbonitride raw material powder; S2, the carbonitride raw material powder prepared in the above steps is subjected to rapid hot pressing sintering, the sintering conditions are: the temperature in the sintering furnace is 1800℃, the heat preservation is 20min, the heating rate is 80℃ / min, the pressure is 20MPa, and the sintering atmosphere is nitrogen, to obtain ZrC 0.65 N 0.35 Ceramics, the density of the ceramic material is ≥85%; the mass ablation rate after plasma ablation at 2500℃ for 200s is 3.8×10 -3 g / s, the linear ablation rate is 5×10 -3 mm / s.

[0027] Compared with Example 2, the ZrC prepared in Comparative Example 1 0.65 N 0.35 Due to its poor thermal shock resistance, ceramics suffer brittle fracture after plasma ablation at 2500℃ for 200s.

[0028] Comparative Example 2: S1. Weigh a raw material powder with a particle size of 2 μm and a purity greater than 99.9% according to a molar ratio of Zr:Hf:C=1:1:2.8; place the raw material powder in a ball mill at a speed of 400 r / min and ball mill for 12 h under a nitrogen atmosphere with a ball-to-material ratio of 3:1, and then place the raw material powder in a vacuum glove box and sieve it through 300 mesh to obtain a carbonitride raw material powder; S2. Weigh 10 g of the Cr metal powder and 32.3 g of the carbonitride ceramic powder, mix them at a speed of 500 r / min to obtain a Cr metal ceramic preform powder, and then place it into a graphite mold; S3, the carbonitride raw material powder prepared in the above steps is subjected to rapid hot pressing sintering, the sintering conditions are: the temperature in the sintering furnace is 1600℃, the heat preservation is 10min, the heating rate is 100℃ / min, the pressure is 70MPa, and the sintering atmosphere is nitrogen, to obtain Cr / Hf 0.5 Zr 0.5 C 0.24 N 0.76 Ceramic, the density of the ceramic material is ≥90%; the mass ablation rate after 200s of plasma ablation at 2500℃ is 4.6×10 -3 g / s, and the linear ablation rate is 1.5×10 -2 mm / s.

[0029] Compared with Example 1, the Cr / Hf0.5 Zr 0.5 C 0.24 N 0.76 After the ceramic was plasma ablated at 2500℃ for 200s, the thermal stress concentration generated by the ceramic at high temperature could not quickly dissipate the heat, causing the sample to fracture brittlely when it cooled to room temperature.

[0030] Comparative Example 3: S1. Weigh a raw material powder with a particle size of 3 μm and a purity greater than 99.9% according to a molar ratio of Zr:Hf:Ta:Nb:Ti:C=0.2:0.2:0.2:0.2:0.2:1.7; place the raw material powder in a ball mill at a speed of 400 r / min and ball mill for 24 h under a nitrogen atmosphere with a ball-to-material ratio of 3:1, and then place the raw material powder in a vacuum glove box and sieve 300 mesh to obtain a carbonitride raw material powder; S2. Add 0.7 g of glucose to a mixed solution of 26 ml of deionized water and 40 ml of anhydrous ethanol, stirring at a rate of 300 r / min, until the glucose is fully dissolved to obtain a uniform and transparent solution; then, weigh 29.4 g of carbonitride ceramic powder and add it to the mixed solution, and ultrasonically stir at 90° C. for 75 min until the solvent is completely evaporated; place the obtained mixture in a vacuum oven and dry it at 90° C. for 3 h to obtain a carbonitride ceramic / glucose precursor powder; S3, transferring the prepared carbonitride ceramic / glucose precursor powder to a tube furnace; then, placing the carbonitride ceramic / glucose precursor powder in a heating zone at 1000° C. and heating for 12 minutes in an atmosphere of Ar and H2, wherein the argon flow rate is 210 ml / min and the hydrogen flow rate is 90 ml / min; finally, cooling the heat-treated powder to room temperature, and then grinding and sieving to obtain a carbonitride ceramic / graphene-like composite powder; S4, weighing 20.3g of the carbonitride ceramic / graphene-like composite powder, placing it into a graphite mold for rapid hot pressing sintering, the sintering conditions are: the temperature in the sintering furnace is 1600℃, holding for 20min, the heating rate is 100℃ / min, the pressure is 30MPa, and the sintering atmosphere is nitrogen, to obtain rGO-Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Ti 0.2 C 0.5 N 0.5 The density of the composite material is ≥90%; the mass ablation rate is 3.7×10 -3 g / s, the linear ablation rate is 6×10 -3 mm / s.

[0031] Compared with Example 4, the graphene-like Hf prepared in Comparative Example 3 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Ti 0. 2C 0.5 N 0.5 After plasma ablation at 2500℃ for 200s, ceramics not only produced many macro cracks, but also many pores in the surface oxide layer.

[0032] The results show that: The high-thermal-conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material of the comparative example exhibited significant ablation pitting and fracture after plasma ablation at 2500°C for 200 seconds. The ablation resistance of the comparative example was not as good as that of the high-thermal-conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite materials of Examples 1-4.

[0033] By comparing Examples 1 to 4 with the comparative example, it can be seen that the comprehensive mechanical properties and ablation resistance of the high thermal conductivity three-dimensional graphene-like / carbon nitride-based metal ceramic composite material of the present application are significantly improved compared with the comparative example.

[0034] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. Various process solutions that have no substantial difference from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material, characterized by: The following steps are involved: S1. Preparing carbonitride ceramic powder: uniformly mixing a metal raw material and carbon powder in a molar ratio of (1-8):(3-10) by nitrogen ball milling, and then passing the material through a 300-mesh sieve under a vacuum atmosphere to obtain a carbonitride ceramic raw material powder; The metal raw materials are Hf, Zr, Ta, Nb, and Ti metal powders; S2. Weigh commercial spherical metal powder and add it to the mixed solution. Stir it with ultrasonic stirring until the solvent is completely evaporated. Place the resulting mixture in a vacuum oven and dry it to obtain a metal / glucose precursor powder. The commercial spherical metal powder is powder of Fe, Co, Ni, Cu, or Cr; The mixed solution is prepared by dissolving glucose in a mixed solution of water and ethanol, stirring until the glucose is fully dissolved to obtain a uniform and transparent solution, wherein the concentration of glucose is 0.029 mol / L-0.05 mol / L, the molar ratio of deionized water to anhydrous ethanol in the mixed solution is (0.8-1):(1.8-2.3), and the mass ratio of glucose to commercial spherical metal powder is (1-6):(50-93); S3, transferring the obtained metal / glucose precursor powder to a tube furnace, heating it in a heating zone of 800° C. to 1000° C. under an atmosphere of argon and hydrogen for 10 min to 15 min, cooling the powder to room temperature, and sieving to obtain a metal / graphene-like composite powder; S4. Weigh the metal / graphene-like composite powder and the carbonitride ceramic raw material powder in a mass ratio of (20-43): (50-87), mix them evenly to obtain a metal ceramic preform powder, and then place it into a graphite mold; S5, the metal ceramic preform powder obtained in the above step is subjected to rapid hot pressing and sintering to obtain a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal ceramic composite material, wherein the chemical formula of the ceramic material is: MC x N 1-x , where 0<X<1, M is Hf, Zr, Ta, Nb, Ti; the metal material is transition metal Fe, Co, Ni, Cu, Cr; the density of the composite material is ≥95%, and the mass ablation rate after plasma ablation at 2500℃ for 200s is 1×10 -3 g / s - 5×10 -3 g / s, the linear ablation rate is 3×10 - 3 mm / s - 2×10 -2 mm / s.

2. The method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material according to claim 1, characterized in that: The metal raw materials and carbon powder described in S1 are nano-scale powders or micron-scale powders, the particle size of the powders are all less than 10μm, the purity is all ≥99.9%, and when used, they are sealed and stored under air-tight conditions; the nitrogen ball mill uses silicon nitride as the ball milling medium, the ball milling speed is controlled to 300-600r / min, the ball milling time is 12-24h, and the ball-to-material ratio is (2-13):

1.

3. The method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material according to claim 1, characterized in that: The particle size of the powder described in S2 is less than 10μm, and the purity is ≥99.9%. When used, it is sealed and stored under air-tight conditions; the ultrasonic stirring is performed at a temperature of 60℃-80℃ and a time of 60min-120min; the drying is performed at a temperature of 60℃-90℃ and a time of 3h-8h; the stirring is performed at a stirring rate of 200r / min-500r / min.

4. The method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material according to claim 1, characterized in that: S3 The flow rate of argon gas is 200ml / min-290ml / min, and the flow rate of hydrogen gas is 90ml / min-150ml / min.

5. The method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material according to claim 1, characterized in that: The mixing described in S4 is uniform, and the mixing stirring rate is 300r / min-600r / min.

6. The method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material according to claim 1, characterized in that: The rapid hot pressing sintering described in S5 has the following conditions: the temperature in the sintering furnace is 1600°C-2500°C, the insulation time is 15min-120min, the heating rate is 25°C / min-130°C / min, the pressure is 20MPa-80MPa, and the sintering atmosphere is nitrogen.

7. A high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material, characterized by: The method for preparing a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material according to any one of claims 1 to 6 is obtained, wherein the chemical formula of the ceramic material is: MC x N 1-x , where 0<X<1, M is Hf, Zr, Ta, Nb, Ti; the metal material is transition metal Fe, Co, Ni, Cu, Cr; the density of the composite material is ≥95%, and the mass ablation rate after plasma ablation at 2500℃ for 200s is 1×10 -3 g / s - 5×10 -3 g / s, the linear ablation rate is 3×10 -3 mm / s - 2×10 -2 mm / s.

8. The use of a high thermal conductivity three-dimensional graphene-like / carbonitride-based metal-ceramic composite material according to claim 7, characterized in that: It is used to prepare ultra-high temperature plasma ablation resistant thermal protection materials of 2500℃ and above.

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