Long-time ablation-resistant zirconium carbonitride ultra-high-temperature ceramic matrix composite material, preparation method and application thereof

Abstract

The application discloses a long-time ablation-resistant zirconium carbonitride ultra-high-temperature ceramic matrix composite material and a preparation method and application thereof, and relates to the technical field of composite material preparation for aerospace. The application first proposes a process of wet ball milling+ultrasonic heating stirring+spark plasma sintering for preparing short carbon fiber toughened ZrC x N y ceramic matrix composite material with a density of 92% or more. The nitrogen-containing carbide ultra-high-temperature ceramic matrix composite material designed and prepared in the application is suitable for ablation-resistant protection at a temperature of 2500 DEG C or above. It is found through verification that the ceramic can keep a state of near-zero ablation rate and a continuous and stable oxidation-resistant protection structure after long-time (200s) ablation.

Description

Technical Field

[0001] This invention belongs to the field of aerospace composite materials technology, specifically relating to a long-term ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material, its preparation method, and its application. It is a short-cut carbon fiber toughened zirconium carbonitride ultra-high temperature ceramic composite material, its preparation method, and its application. Background Technology

[0002] Ultra-high temperature ceramics (UHTCs) possess excellent hardness, high-temperature ablation resistance, and thermal shock resistance. They typically include high-melting-point transition metal compounds such as borides, carbides, and nitrides, and have become the most promising space structure materials. As the Mach numbers of next-generation hypersonic vehicles continue to increase, more stringent requirements are placed on thermal protection materials. These materials need to withstand higher temperatures (≥2500℃), have longer service lives, higher thermal protection efficiency, and be lightweight and reliable. Therefore, despite the numerous advantages of existing UHTCs, several problems remain to be solved before they can be applied to key hot-end components of hypersonic vehicles.

[0003] Carbon fiber possesses physical properties such as high strength, high modulus, high temperature resistance, corrosion resistance, and low coefficient of thermal expansion, making it an ideal material for toughening ceramics. Short-cut carbon fiber-reinforced ceramic matrix composites improve the inherent brittleness of pure ceramic materials while retaining the advantages of ceramic materials such as high temperature resistance, corrosion resistance, ablation resistance, and high strength.

[0004] Studies have shown that nitrogen (N) enhances the oxidation and ablation resistance of carbide ceramics, making them a promising new type of thermal protection material. Zirconium carbonitride ceramics, in particular, offer advantages such as low cost, high melting point, and excellent ablation resistance. However, the brittleness, poor reliability, and difficulty in processing of ceramic materials severely limit their widespread application in harsh environments. These drawbacks are determined by the type of bonding between the atoms in ceramic materials. Ceramic materials are typically composed of strong covalent and ionic bonds with few slip systems, making them extremely difficult to plastically deform and prone to brittle fracture failure under excessive external loads.

[0005] Currently, the toughening methods for structural ceramic materials have shifted from increasing the sintering density and reducing defects to adding a second phase that is insensitive to defects and can improve the material's damage tolerance. Summary of the Invention

[0006] To address the problems of low fracture toughness and insufficient ablation resistance in existing ultra-high temperature ceramics, this invention provides a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material, its preparation method, and its application. This invention is a short-cut carbon fiber-reinforced zirconium carbonitride ultra-high temperature ceramic composite material, and its preparation method and application. For the first time, this invention utilizes metallic zirconium powder, carbon powder, zirconium nitride, carbon nitride powder, and short-cut carbon fibers to prepare a short-cut carbon fiber-reinforced zirconium carbonitride ultra-high temperature ceramic composite material with a density ≥92% and a uniform C / N content distribution through wet ball milling, ultrasonic stirring, and spark plasma sintering.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material includes the following steps:

[0009] 1) Prepare zirconium powder, carbon powder, and zirconium nitride powder according to the molar ratio: Zr:C:ZrN:g-C3N4=(1-6):(3-10):(1-3):(0.2-2). The powder is nano-sized or micron-sized. Mix the prepared powders uniformly by wet ball milling to obtain mixed powder. Dry the mixed powder at 50-150℃ for 8-12 hours under vacuum atmosphere and pass it through a 200-mesh sieve. Take the sieve material as the reserve material for plasma sintering.

[0010] The wet ball milling process uses organic media, controls the ball milling speed at 200-400 r / min, the ball milling time at 12-24 h, and the ball-to-material ratio at (3-10):1.

[0011] 2) Weigh out carbon fibers with a volume fraction of (1-50) vol.% equivalent to the spare material obtained in step 1), the length of the carbon fibers is 0.5-5 mm, and prepare an ethanol solution in which the carbon fibers are dispersed according to the mass ratio: carbon fibers: anhydrous ethanol = (0.5-2): 200.

[0012] 3) Add the prepared material obtained in step 1) to the carbon fiber-ethanol solution prepared in step 2) and stir to mix evenly; place the resulting mixed solution in an oven and dry at 50-100℃ for 24-30 hours to obtain mixed powder.

[0013] 4) The mixed powder obtained in step 3) is subjected to spark plasma sintering. The spark plasma sintering conditions are: furnace temperature of 1600-2500℃, holding time of 5-40 min, heating rate of 25-150℃ / min, cooling rate of 25-150℃ / min, pressure of 10-80 MPa, and vacuum degree of <5 Pa. This yields a long-lasting, ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material. The composite material has a density ≥92%, and after ablation in an oxyacetylene flame at 3000℃ for 200 s, the mass ablation rate is 1×10⁻⁶. -3 g / s-3×10 -3 g / s, linear ablation rate 5×10 -3 mm / s-1×10 -2 mm / s.

[0014] In this invention:

[0015] Furthermore, in step 1), the particle size of the powder is all <10μm, and even more specifically, the particle size of the powder is all <3μm; the purity of the powder is all ≥99.9%.

[0016] Furthermore, in step 1), the ball milling media is an organic material, preferably ethanol; the material taken from the sieve is used as a reserve material for plasma sintering, and in industrial applications, the reserve material is sealed and stored under air-isolated conditions.

[0017] Furthermore, in step 2), carbon fibers with a volume fraction (5-40) vol.% equivalent to the spare material obtained in step 1) are weighed out; the purity of the carbon fibers is ≥99.9%.

[0018] Furthermore, in step 4), the conditions for spark plasma sintering are as follows: the temperature inside the sintering furnace is 1700-2200℃, the holding time is 10-30 min, the heating rate is 100-150℃ / min, the cooling rate is 100-150℃ / min, the pressure is 20-60 MPa, and the vacuum degree is <5 Pa.

[0019] This invention also relates to a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material, which is also a short-cut carbon fiber-reinforced zirconium carbonitride ultra-high temperature ceramic composite material. This composite material has a density ≥92%, and after ablation in an oxyacetylene flame at 3000℃ for 200 s, its mass ablation rate is 1×10⁻⁶. -3 g / s-3×10 -3 g / s, linear ablation rate 5×10 -3 mm / s-1×10 -2 mm / s.

[0020] This invention also relates to the application of the aforementioned long-term ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material, which is used for ultra-high temperature ablation protection at 2500℃ and above.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. In the preparation process of the long-term ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material described in this invention, for the first time, zirconium metal powder, carbon powder, zirconium nitride, carbon nitride powder, and short-cut carbon fibers are used to prepare a short-cut carbon fiber toughened zirconium carbonitride ultra-high temperature ceramic composite material with a density ≥92% and a uniform C / N content distribution through wet ball milling + ultrasonic stirring + spark plasma sintering. The preparation process is simple and easy to implement, and the preparation cycle is short; the raw materials have the advantage of low cost.

[0023] 2. The present invention provides a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material. The novel ultra-high melting point ceramic matrix composite material designed and prepared overcomes the defects of poor oxidation resistance and weak comprehensive mechanical properties of existing ceramic matrix composite materials. By improving and optimizing the preparation method of ultra-high temperature ceramic matrix composite material, an ultra-high temperature ceramic matrix composite material with good oxidation and ablation resistance and strong comprehensive mechanical properties is prepared.

[0024] 3. The present invention provides a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material. Addressing the poor dispersibility of short-cut carbon fibers, the process is optimized to improve their dispersibility. Furthermore, the preparation process for the short-cut carbon fiber-toughened zirconium carbonitride samples is simple, quick, and cost-effective; it exhibits excellent oxidation and ablation resistance, making it highly valuable for applications in aerospace materials. The C... The present invention prepares... sf / ZrC x N y The carbon fibers in the ultra-high temperature ceramic composite material are uniformly distributed without obvious agglomeration or breakage. The prepared material has excellent ablation resistance. By selecting an appropriate ratio of powder and carbon fibers and combining them with spark plasma sintering, the resulting sample maintains a low ablation rate after being tested at 3000℃ for 200s. The prepared material has good mechanical properties. Combining an appropriate amount of carbon fibers with the mixed powder improves the intrinsic defect of low fracture toughness of the single ceramic and greatly enhances the bending strength and fracture toughness of the ceramic. Attached Figure Description

[0025] Figure 1 C prepared in Example 1 sf / ZrC 0.75 N 0.25 Macroscopic morphology of the sample surface;

[0026] Figure 2 C prepared in Example 1 sf / ZrC 0.75 N 0.25 Microscopic morphology of the sample surface;

[0027] Figure 3 C prepared in Example 1 sf / ZrC 0.75 N 0.25 Microscopic morphology of the ablation surface of the sample after 200s of oxyacetylene flame ablation at 3000℃ Detailed Implementation

[0028] The present invention will be further described in detail below through embodiments, but these embodiments should not be considered as limiting the present invention.

[0029] Example 1:

[0030] A method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material includes the following steps:

[0031] The raw materials were prepared according to a molar ratio of Zr:C:ZrN:g-C3N4 = 4:5:2:0.5, and then ball-milled in a planetary ball mill for 10 hours. The powder particle size was 1-5 μm, and the purity was greater than 99.9%. The ball milling medium was an ethanol solution, the rotation speed was 300 r / min, and the ball-to-material ratio was 4:1. The powder was then dried in a 70℃ oven for 24 hours and sieved to obtain a mixed powder.

[0032] Weigh 30 vol.% carbon fibers with a length of 0.5 mm and prepare a carbon fiber-ethanol solution according to the mass ratio of carbon fiber: anhydrous ethanol = 1:200; add the mixed powder to the carbon fiber-ethanol solution and stir at the same time to obtain a mixed powder solution; then place it in an oven at 70℃ for 24 h to dry, and sieve to obtain the mixed powder.

[0033] The mixed powder was placed in a graphite mold for spark plasma sintering. The vacuum degree inside the furnace was less than 5 Pa. The temperature was increased to 1700℃ at a heating rate of 80℃ / min, held for 15 min, and the pressure was 45 MPa. Then, it was cooled to room temperature at a cooling rate of 100℃ / min to obtain C. f / ZrC 0.75 N 0.25 Ceramic composite material (density of 95.2%).

[0034] Ablation tests were conducted using the ablation experimental equipment described in national standard GJB323A-96. After ablation for 200 seconds in an oxyacetylene flame at 3000℃, the mass ablation rate was 1×10⁻⁶. -3 g / s, linear ablation rate 2×10 -3 mm / s.

[0035] Example 2:

[0036] A method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material includes the following steps:

[0037] The raw materials were prepared according to a molar ratio of Zr:C:ZrN:g-C3N4 = 5:3:1:0.6, and then ball-milled in a planetary ball mill for 10 hours. The powder particle size was 1-5 μm, and the purity was greater than 99.9%. The ball milling medium was an ethanol solution, the rotation speed was 300 r / min, and the ball-to-material ratio was 4:1. The powder was then dried in a 60℃ oven for 24 hours and sieved to obtain a mixed powder.

[0038] Weigh 20 vol.% carbon fibers with a length of 0.5 mm and prepare a carbon fiber-ethanol solution according to the mass ratio of carbon fiber: anhydrous ethanol = 0.5: 200; add the mixed powder to the carbon fiber-ethanol solution and stir at the same time to obtain a mixed powder solution; then place it in an oven at 60℃ for 24 h to dry, and sieve to obtain the mixed powder.

[0039] The mixed powder was placed in a graphite mold for spark plasma sintering. The vacuum degree inside the furnace was less than 5 Pa. The temperature was increased to 1800℃ at a heating rate of 150℃ / min, held for 30 min, and the pressure was 50 MPa. Then, it was cooled to room temperature at a cooling rate of 150℃ / min to obtain C. f / ZrC 0.80 N 0.20 Ceramic composite material (density of 92.5%).

[0040] Ablation tests were conducted using the ablation experimental equipment described in national standard GJB323A-96. After ablation for 200 seconds in an oxyacetylene flame at 3000℃, the mass ablation rate was 2×10⁻⁶. -3 g / s, linear ablation rate 2×10 -2 mm / s.

[0041] Example 3:

[0042] A method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material includes the following steps:

[0043] The raw materials were prepared according to a molar ratio of Zr:C:ZrN:g-C3N4 = 2:3:1:0.5, and ball-milled in a planetary ball mill for 10 hours. The powder particle size was 1-5 μm, and the purity was greater than 99.9%. The ball milling medium was ethanol solution, the rotation speed was 300 r / min, and the ball-to-material ratio was 4:1. Then, the powder was dried in a 70℃ oven for 24 hours and sieved to obtain a mixed powder.

[0044] Weigh out 10 vol.% carbon fibers with a length of 1 mm and prepare a carbon fiber-ethanol solution according to the mass ratio of carbon fiber: anhydrous ethanol = 2:200; add the mixed powder to the carbon fiber-ethanol solution and stir at the same time to obtain a mixed powder solution; then place it in an oven at 70℃ for 24 h to dry, and sieve to obtain the mixed powder.

[0045] The mixed powder was placed in a graphite mold for spark plasma sintering. The vacuum degree inside the furnace was less than 5 Pa. The temperature was increased to 2200℃ at a heating rate of 80℃ / min, held for 20 min, and the pressure was 60 MPa. Then, it was cooled to room temperature at a cooling rate of 100℃ / min to obtain C. f / ZrC 0.65 N 0.35 Ceramic composite material (density 94.9%).

[0046] Ablation tests were conducted using the ablation experimental equipment described in national standard GJB323A-96. After ablation for 200 seconds in an oxyacetylene flame at 3000℃, the mass ablation rate was 3×10⁻⁶. -3 g / s, linear ablation rate 3×10 -2 mm / s.

[0047] Example 4:

[0048] A method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material includes the following steps:

[0049] The raw materials were prepared according to the molar ratio of Zr:C:ZrN:g-C3N4 = 2:5:3:0.6, and ball-milled in a planetary ball mill for 10 hours. The powder particle size was 1-5 μm and the purity was greater than 99.9%. The ball milling medium was ethanol solution, the rotation speed was 300 r / min, and the ball-to-material ratio was 4:1. Then, the powder was dried in an oven at 60℃ for 24 hours and sieved to obtain a mixed powder.

[0050] Weigh out 30 vol.% carbon fibers with a length of 3 mm and prepare a carbon fiber-ethanol solution according to the mass ratio of carbon fiber: anhydrous ethanol = 1.5:200; slowly add the mixed powder into the carbon fiber-ethanol solution while stirring to obtain a mixed powder solution; then place it in a 60℃ oven to dry for 24 h, and sieve to obtain the mixed powder.

[0051] The mixed powder was placed in a graphite mold for spark plasma sintering. The vacuum degree inside the furnace was less than 5 Pa. The temperature was increased to 2100℃ at a heating rate of 150℃ / min, held for 30 min, and the pressure was 50 MPa. Then, it was cooled to room temperature at a cooling rate of 100℃ / min to obtain C. f / ZrC 0.82 N 0.18 Ceramic composite material (density of 92.3%).

[0052] Ablation tests were conducted using the ablation experimental equipment described in national standard GJB323A-96. After ablation for 200 seconds in an oxyacetylene flame at 3000℃, the mass ablation rate was 4×10⁻⁶. -3 g / s, linear ablation rate 1×10 -2 mm / s.

[0053] Comparative example:

[0054] The main difference between the comparative example and the embodiment is that no reinforcing and toughening carbon fiber component was added;

[0055] The raw materials were prepared according to a molar ratio of Zr:C:ZrN:g-C3N4 = 4:5:1:0.5, and ball-milled in a planetary ball mill for 10 hours. The powder particle size was 1-3 μm, and the purity was greater than 99.9%. The ball milling medium was an ethanol solution, the rotation speed was 300 r / min, and the ball-to-material ratio was 5:1. The powder was then dried in a 70℃ oven for 24 hours and sieved to obtain the final powder.

[0056] The powder was placed in a graphite mold for spark plasma sintering. The vacuum degree in the furnace was less than 5 Pa. The temperature was raised to 2100℃ at a heating rate of 80℃ / min, held for 10 min, and the pressure was 30 MPa. Then it was cooled to room temperature at a cooling rate of 100℃ / min to obtain a high-purity single-phase face-centered cubic ceramic (density of 96.8%).

[0057] Ablation tests were conducted using the ablation experimental equipment described in national standard GJB323A-96. After ablation for 200 seconds in an oxyacetylene flame at 3000℃, obvious ablation pits appeared, and the material fractured. Its ablation resistance was not as excellent as that of the short-cut carbon fiber-reinforced zirconium carbonitride ultra-high temperature ceramic composite material in Example 3.

[0058] The results show that:

[0059] As can be seen from Examples 1-4, the obtained long-term ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material exhibits excellent ablation resistance after testing in an oxyacetylene flame at 3000℃, and its ablation resistance is significantly improved compared to zirconium carbonitride ultra-high temperature ceramic.

[0060] The comparison between Examples 1-4 and the comparative examples shows that adding appropriate short-cut carbon fibers can significantly improve the thermal shock resistance and ablation resistance of ceramic materials.

[0061] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Various process solutions that are not substantially different from the concept of the present invention are all within the scope of protection of the present invention.

Claims

1. A method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material, characterized in that: Includes the following steps: 1) Zirconium metal powder, carbon powder, zirconium nitride powder, and carbon nitride powder are prepared according to the molar ratio: Zr:C:ZrN:g-C3N4 = (1-6):(3-10):(1-3):(0.2-2). The powders are micron-sized. The prepared powders are mixed uniformly by wet ball milling to obtain a mixed powder. The mixed powder is dried at 50-150℃ for 8-12 hours under vacuum and then passed through a 200-mesh sieve. The undersize material is used as a reserve material for plasma sintering. The particle size of the powders is <10μm and the purity of the powders is ≥99.9%. The wet ball milling process uses organic media, controls the ball milling speed at 200-400 r / min, the ball milling time at 12-24 h, and the ball-to-material ratio at (3-10):

1. 2) Weigh out carbon fibers with a volume fraction of (1-50) vol.% equivalent to the spare material obtained in step 1), the length of the carbon fibers is 0.5-5 mm, and prepare an ethanol solution in which the carbon fibers are dispersed according to the mass ratio: carbon fibers: anhydrous ethanol = (0.5-2):

200. 3) Add the spare material obtained in step 1) to the carbon fiber-ethanol solution prepared in step 2) and stir to mix evenly; place the resulting mixed solution in an oven and dry at 50-100℃ for 24-30 hours to obtain mixed powder; 4) The mixed powder obtained in step 3) is subjected to spark plasma sintering. The spark plasma sintering conditions are as follows: furnace temperature 1600-2500℃, holding time 5-40 min, heating rate 25-150℃ / min, cooling rate 25-150℃ / min, pressure 10-80 MPa, vacuum degree < 5 Pa. This yields a long-lasting, ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material. The composite material has a density ≥92%, and after ablation in an oxyacetylene flame at 3000℃ for 200 s, the mass ablation rate is 1×10⁻⁶. -3 g / s - 3×10 -3 g / s, linear ablation rate 5×10 -3 mm / s - 1×10 -2 mm / s.

2. The method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material according to claim 1, characterized in that: In step 1), the particle size of the powder is all <3μm.

3. The method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material according to claim 1, characterized in that: In step 1), the ball milling medium is ethanol.

4. The method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material according to claim 1, characterized in that: In step 2), carbon fibers with a volume fraction (5-40) vol.% equivalent to the spare material obtained in step 1) are weighed out; the purity of the carbon fibers is ≥99.9%.

5. The method for preparing a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material according to claim 1, characterized in that: In step 4), the conditions for spark plasma sintering are as follows: the temperature inside the sintering furnace is 1700-2200℃, the holding time is 10-30 min, the heating rate is 100-150℃ / min, the cooling rate is 100-150℃ / min, the pressure is 20-60 MPa, and the vacuum degree is < 5Pa.

6. A long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material, characterized in that: The composite material, prepared by the method described in any one of claims 1-5, exhibits a long-lasting ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material with a density ≥92% and a mass ablation rate of 1×10⁻⁶ after ablation in an oxyacetylene flame at 3000℃ for 200 s. -3 g / s - 3×10 -3 g / s, linear ablation rate 5×10 -3 mm / s - 1×10 -2 mm / s.

7. The application of the long-term ablation-resistant zirconium carbonitride ultra-high temperature ceramic matrix composite material according to claim 6, characterized in that: The composite material is used for ultra-high temperature ablation protection above 2500℃.

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