Carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation and preparation method

Abstract

The invention discloses an oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material and a preparation method, and belongs to the technical field of ZrC-SiC ceramic matrix composite material preparation, zirconium-silicon alloy powder is laid layer by layer according to a small (30-50 [mu] m) particle size, a medium (50-75 [mu] m) particle size, a small (75-150 [mu] m) particle size and a large (75-150 [mu] m) particle size in sequence; then a C / C composite material obtained by depositing pyrolytic carbon through a chemical vapor infiltration process is placed on the upper surface of the zirconium-silicon alloy powder composite layer, the thicknesses of powder layers with small, medium and large particle sizes are 20%-40%, 20%-50% and 40%-80% of the C / C composite material in sequence, then a one-way reaction infiltration process is conducted, the C / C composite material forms the carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation, and the carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation is obtained. Not only is oxyacetylene-laser ablation resistance of the surface of the sample realized, but also the mechanical strength is ensured, and the ablation resistance and bearing integrated design is realized.

Description

Technical Field

[0001] This invention belongs to the field of ZrC-SiC ceramic matrix composite material preparation technology, specifically a carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation and its preparation method. Background Technology

[0002] Laser weapons pose a significant threat to aircraft flight safety due to their high mobility, high precision, and resistance to electromagnetic interference. As aircraft speeds continue to increase, their surfaces suffer ablation damage from aerodynamic heat, further weakening their resistance to laser attacks. If a load-bearing structure is damaged by a laser attack during flight, the damage to the aircraft will be devastating. Therefore, developing high-strength ablation-resistant materials that resist both aerodynamic heat and laser ablation is of great significance.

[0003] Ceramic matrix composites have become an advantageous choice for coping with this environment due to their excellent ablation resistance. Among them, carbon fiber reinforced ZrC-SiC composites, especially those prepared by reactive melting process, have shown excellent protective effects under single laser ablation or oxyacetylene ablation environments. A Chinese invention patent application (application number 202211175818.8) entitled "A Gradient Ultra-High Temperature Ceramic Matrix Composite and Its Preparation Method" demonstrates this. However, the ablation resistance of these materials under the combined conditions of aerothermal ablation and laser ablation is insufficient, making it impossible to assess the material failure modes under real service conditions. Furthermore, due to the erosion damage to the carbon fiber bundles by the high-temperature melt during preparation, the flexural strength of 2.5D needle-punched C / C reinforcement ceramic composites is generally low and highly dispersed. This prevents the improvement of the mechanical load-bearing capacity of carbon fiber reinforced ZrC-SiC composites while ensuring their ablation resistance, thus hindering the reduction of the material thickness to achieve lightweight load-bearing structures. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation, and its preparation method, to solve the problems of low mechanical strength and lack of protection against oxyacetylene-laser ablation in reactive infiltration thermal structural components. This invention features a short cycle time, high stability, and employs a unidirectional reactive infiltration process to prepare the carbon fiber reinforced ZrC-SiC ceramic matrix composite material. This not only achieves surface resistance to oxyacetylene-laser ablation but also ensures mechanical strength, realizing an integrated design of ablation resistance and load-bearing capacity.

[0005] This invention is achieved through the following technical solution: A method for preparing a carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation includes the following steps: Step 1: Spread zirconium-silicon alloy powder layer by layer in the order of small particle size, medium particle size, small particle size and large particle size. The small particle size is 30~50μm, the medium particle size is 50~75μm and the large particle size is 75~150μm to obtain a zirconium-silicon alloy powder composite layer. Step 2: The C / C composite material obtained by chemical vapor infiltration deposition of pyrolytic carbon is placed on the upper surface of the zirconium-silicon alloy powder composite layer. The thickness of the powder layers formed by small, medium and large particle sizes is 20%~40%, 20%~50% and 40%~80% of the thickness of the C / C composite material, respectively. Then, a unidirectional reactive melting process is carried out to form a carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation.

[0006] Preferably, the cross-section of the zirconium-silicon alloy powder composite layer in step 1 is circular or quadrilateral.

[0007] Preferably, the molar ratio of Zr to Si atoms in the zirconium-silicon alloy is 1:(3~11).

[0008] Preferably, the thickness of the C / C composite material in step 2 is 2~5mm.

[0009] Preferably, the density of the C / C composite material in step 2 is 1.0~1.55 g / cm³. 3 The 2.5D preform, obtained by needle punching after lamination of non-woven fabric and mesh layer, is obtained by depositing pyrolytic carbon through chemical vapor infiltration process.

[0010] Preferably, in step 1, zirconium-silicon alloy powder is laid layer by layer in a graphite crucible, and then the C / C composite material is placed in the graphite crucible, followed by a unidirectional reaction melting process in a vacuum heat treatment furnace.

[0011] Preferably, the unidirectional reactive melting process described in step 2 is carried out at 1350-1700℃ for 80-120 min.

[0012] Preferably, in step 2, before performing the unidirectional reactive melting process, the temperature is first held at 1150~1250℃ for 30~60 minutes, and then the temperature is raised to 1350-1700℃.

[0013] Preferably, the heating rate is 8-12℃ / min when heating from room temperature to 1150-1250℃, and 4-6℃ / min when heating from 1150-1250℃ to 1350-1700℃.

[0014] An oxyacetylene and laser ablation-resistant carbon fiber reinforced ZrC-SiC composite material obtained by the preparation method of the oxyacetylene and laser ablation-resistant carbon fiber reinforced ZrC-SiC composite material described in any one of the above methods.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: This invention discloses a method for preparing a carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation. Based on the ablation environment of oxyacetylene and laser, the method adjusts the powder particle size, placement order, and thickness parameters. Four layers of powder with different particle sizes and thicknesses are placed layer by layer to optimize the powder filling process and filling degree. Large-diameter particles effectively fill deep pores, while small-diameter particles assist in filling. The middle layer has a coordinated and dense particle size distribution, and the bottom layer has small-diameter particles that optimize the bottom surface. This allows for unidirectional melt infiltration to achieve high density through coating-like melt infiltration. Simultaneously, the smaller-diameter powder with higher silicon content preferentially reacts with pyrolytic carbon to generate SiC. The preferentially generated SiC coats ZrC, controlling the distribution and content of the ceramic phase in the composite material. By controlling the placement of the melt-infiltrated powder, the distribution and content of the ceramic phase in the composite material are controlled, thus densifying the C / C composite material and preparing a uniform and dense ablation-resistant ceramic matrix composite material with a flexural strength exceeding 200 MPa at a heat flux density of 4.18 MW / m³. 2 After ablation under an oxyacetylene flame for 40 seconds, a heat flux density of 70.58 W / mm² was applied. 2 Under laser ablation for 10 s, the linear ablation rate remained low after ablation, exhibiting high flexural strength. This method demonstrates significant advantages in oxyacetylene-laser ablation environments, achieving a combination of oxyacetylene resistance, laser ablation performance, and load-bearing capacity. The optimized ZrC-SiC ceramic phase distribution improved interfacial bonding, maintaining high flexural strength in the composite material. Simultaneously, it improved the viscosity of the Zr-Si-O oxide layer during ablation, effectively mitigating the volatilization of low-melting-point phases and reducing cracking and even spalling. This method is highly scalable, capable of densifying powders with varying zirconium-silicon atomic molar ratios. Under the premise of maintaining the same powder state and melting infiltration process, the composite material prepared by this process maintains a low ablation rate, effectively improving the mechanical strength of the composite material. It can also be applied to the design and preparation of carbon fiber reinforced ceramic matrix composites and ablation-resistant high-strength integrated materials, demonstrating good versatility and promising application prospects. Attached Figure Description

[0016] Figure 1 This is a macroscopic morphology image of the surface of the oxyacetylene-laser ablation sample prepared in Example 1 of the present invention after oxyacetylene-laser ablation.

[0017] Figure 2 This is a macroscopic morphology image of the surface of the oxyacetylene-laser ablation sample prepared in Example 2 of the present invention after oxyacetylene-laser ablation.

[0018] Figure 3 This is a macroscopic morphology image of the surface of the oxyacetylene-laser ablation sample prepared in Example 3 of the present invention after oxyacetylene-laser ablation.

[0019] Figure 4 This is a flowchart illustrating the preparation principle and process of the high-strength carbon fiber reinforced ZrC-SiC ceramic matrix composite material of the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0021] From the perspective of the ablation process, carbon fiber reinforced ZrC-SiC composites form a Zr-Si-O ceramic oxide layer on their surface in an oxyacetylene ablation environment. Under laser irradiation, this oxide layer melts and sublimates, transforming into a melt. The composition of the oxide layer determines the melt viscosity and the degree of material loss. If the viscosity is too low after melting, it increases material loss, enlarges the ablation pit size, and affects the aerodynamic shape of the aircraft. If the viscosity is too high, it significantly reduces the sealing capacity of the ablation pit, leaving pores and cracks that form oxidation channels that oxidize the interior of the material, reducing its mechanical strength. Therefore, an oxide layer that can form a melt with moderate viscosity is crucial for improving the aircraft's resistance to laser attacks. This requires designing the ZrC-SiC composition after melting and infiltration, taking into account the size, shape, and service environment characteristics of the thermal structural components, to achieve an integrated design for ablation resistance and load-bearing capacity.

[0022] Therefore, based on GJB 323A-1996 "Test Methods for Ablation of Ablation Materials", this invention designs a method for preparing a high-strength carbon fiber reinforced ZrC-SiC ceramic matrix (C / C-ZrC-SiC) composite material resistant to oxyacetylene-laser ablation, as follows: Figure 4 As shown, based on the unidirectional reactive melt infiltration process, the specific steps are as follows: Step 1: The zirconium silicon alloy powder is screened by particle size. The molar ratio of Zr:Si atoms is 1:(3~11), and it is divided into three particle size ranges: small particle size (30~50μm), medium particle size (50~75μm), and large particle size (75~150μm). Step 2: Weigh out three different masses of zirconium silicon powder of different particle sizes and spread them layer by layer in a graphite crucible. The layering is divided into four layers from bottom to top, in the following order: small particle size → medium particle size → small particle size → large particle size, to obtain a zirconium silicon alloy powder composite layer. In addition to graphite crucibles, the process can also be carried out on other containers, which allows the cross-section of the zirconium-silicon alloy powder composite layer to be circular or quadrilateral, and further, the zirconium-silicon alloy powder composite layer to be cylindrical or quadrangular prism. Step 3: Place the cleaned low-density C / C composite material with dimensions of Ф30 mm×3 mm and 30 mm×5 mm×2 mm on the upper surface of the zirconium-silicon alloy powder composite layer; The mass of the four-layer powder is related to its natural stacking volume, and each layer of powder should be laid out to the corresponding thickness (d). n The relationship between the particle size distribution and the thickness of the C / C composite sample (D=3 mm or 2 mm) satisfies the following: the first layer has a small particle size (d1=0.2~0.4D), the second layer has a medium particle size (d2=0.2~0.5D), the third layer has a small particle size (d3=0.2~0.4D), and the fourth layer has a large particle size (d4=0.4~0.8D). Low-density C / C composite material refers to a 2.5D preform obtained by needle punching a laminate of non-woven fabric and a mesh layer (combining the high strength of non-woven fabric and the uniformity of the mesh layer, improving the overall integrity and interlaminar shear strength of the material) (density ≈ 0.45-0.55 g / cm³). 3 Pyrolytic carbon was deposited using the CVI process to a density of 1.0~1.55 g / cm³. 3 The obtained C / C composite material.

[0023] Step 4: In a vacuum heat treatment furnace, the bottom-up melting and infiltration process is carried out at 1350-1700℃ for 80-120 min. The control of the holding time enables the control of the reaction degree of SiC and ZrC and optimizes the distribution morphology of the ceramic phase, so that C / C composite material can be obtained as C / C-ZrC-SiC composite material.

[0024] The heat treatment process involves first heating from room temperature to 1150-1250℃ and holding at that temperature for 30-60 minutes for melt absorption, followed by heating to 1350-1700℃ and holding at that temperature for 80-120 minutes for the melting and infiltration reaction. During the heating process, the heating rate is 8-12℃ / min before reaching 1200℃; after the first holding, the heating rate is 4-6℃ / min between 1350-1700℃.

[0025] By controlling the arrangement of the melt-infiltrating powder, the melting and heating rate, and the holding time, the ablation rate of the composite material prepared by conventional processes is reduced, and the flexural strength can exceed 200 MPa.

[0026] Example 1: Step 1: The zirconium-silicon alloy powder with an atomic molar ratio of 1:3 is screened by particle size and divided into three particle size ranges: small particle size (30~50μm), medium particle size (50~75μm), and large particle size (75~150μm). Step 2: Weigh out 15g of small-particle-size, 25g of medium-particle-size, 10g of small-particle-size, and 35g of large-particle-size alloy powder in sequence and place them in a graphite crucible with an inner diameter of 160 mm. After each layer is placed, use a brush to flatten the surface of the powder before placing the next layer, until a flat powder layer is formed. Step 3: Use tweezers to pick up the cleaned samples with dimensions of Ф30 mm × 3 mm and 30 mm × 5 mm × 2 mm, and a density of 1.2 g / cm³. 3 The C / C composite material is placed on the surface of the powder layer; Step 4: Place the above sample in a vacuum heat treatment furnace. First, heat to 1200℃ at 10℃ / min and hold for 30 min. Then, heat to 1700℃ at 5℃ / min and hold for 120 min. Finally, cool to room temperature with the furnace. This yields an oxyacetylene-laser ablation resistant C / C-ZrC-SiC material.

[0027] The composite material obtained in this embodiment was subjected to a heat flux density of 4.18 MW / m. 2 The sample was ablated for 40 seconds under an oxyacetylene flame (surface temperature > 2500℃) and then subjected to a heat flux of 70.58 W / mm². 2 The material was ablated under a laser for 10 seconds (reaching the material's melting point), resulting in no macroscopic defects on the coating surface and a thickness reduction of 28 μm. The flexural strength of the material obtained in this embodiment was 202.35 MPa.

[0028] Example 2: Step 1: The zirconium-silicon alloy powder with an atomic molar ratio of 1:11 is screened by particle size and divided into three particle size ranges: small particle size (30~50μm), medium particle size (50~75μm), and large particle size (75~150μm). Step 2: Weigh 12g of small-particle-size, 22g of medium-particle-size, 8g of small-particle-size, and 28g of large-particle-size alloy powder in sequence and place them in a graphite crucible with an inner diameter of 160 mm in the order of weighing. After each layer is placed, use a brush to flatten the surface of the powder before placing the next layer, and finally form a flat powder layer. Step 3: Use tweezers to pick up the cleaned samples with dimensions of Ф30 mm × 3 mm and 30 mm × 5 mm × 2 mm, and a density of 1.55 g / cm³. 3 The C / C composite material is placed on the surface of the powder layer; Step 4: Place the above sample in a vacuum heat treatment furnace. First, heat to 1200℃ at 10℃ / min and hold for 60 min. Then, heat to 1350℃ at 5℃ / min and hold for 80 min. Finally, cool to room temperature with the furnace. This yields an oxyacetylene-laser ablation resistant C / C-ZrC-SiC material.

[0029] The composite material obtained in this embodiment was subjected to a heat flux density of 4.18 MW / m. 2The sample was ablated for 40 seconds under an oxyacetylene flame (surface temperature > 2500℃) and then subjected to a heat flux of 70.58 W / mm². 2 The material was ablated under a laser for 10 seconds (reaching the material's melting point), resulting in no macroscopic defects on the coating surface and an increase in thickness of 48 μm. The flexural strength of the material obtained in this embodiment was 229.14 MPa.

[0030] Example 3: Step 1: The zirconium-silicon alloy powder with an atomic molar ratio of 1:11 is screened by particle size and divided into three particle size ranges: small particle size (30~50μm), medium particle size (50~75μm), and large particle size (75~150μm). Step 2: Weigh 12g of small-particle-size, 22g of medium-particle-size, 8g of small-particle-size, and 28g of large-particle-size alloy powder in sequence and place them in a graphite crucible with an inner diameter of 160 mm in the order of weighing. After each layer is placed, use a brush to flatten the surface of the powder before placing the next layer, and finally form a flat powder layer. Step 3: Use tweezers to pick up the cleaned samples with dimensions of Ф30 mm × 3 mm and 30 mm × 5 mm × 2 mm, and a density of 1.0 g / cm³. 3 The C / C composite material is placed on the surface of the powder layer; Step 4: Place the above sample in a vacuum heat treatment furnace. First, heat to 1200℃ at 10℃ / min and hold for 60 min. Then, heat to 1350℃ at 5℃ / min and hold for 80 min. Finally, cool to room temperature with the furnace. This yields an oxyacetylene-laser ablation resistant C / C-ZrC-SiC material.

[0031] The composite material obtained in this embodiment was subjected to a heat flux density of 4.18 MW / m. 2 The sample was ablated for 40 seconds under an oxyacetylene flame (surface temperature > 2500℃) and then subjected to a heat flux of 70.58 W / mm². 2 Under laser ablation for 10 s (reaching the material's melting point), the coating surface showed no macroscopic defects, and the thickness increased by 32 μm. ZrC and SiC react with oxygen in an oxyacetylene ablation environment to form ZrO2 and SiO2; subsequently, under laser ablation, ZrO2 melts, and SiO2 and C / C vaporize, leaving ablation pits and causing degradation. If the viscosity of the molten ZrO2 and vaporized SiO2 is suitable, they will backfill the ablation pits when the laser stops. The increased thickness indicates that the backfilling capacity is greater than the laser volatilization, indicating good performance. The flexural strength of the material obtained in this embodiment is 203.52 MPa.

[0032] The present invention provides composite materials prepared using the same process with different zirconium-silicon ratio powders, all of which achieve resistance to oxyacetylene laser ablation and maintain high mechanical strength.

[0033] Table 1. Mechanical strength of the samples prepared in the embodiments of the present invention.

[0034] from Figure 1 It can be seen that the central area of ​​laser ablation is bright white, indicating that the molten pool can self-fill after laser ablation.

[0035] from Figure 2 It can be seen that the laser ablation center is bright white and the ablation edge is clear, indicating that the molten pool can self-fill after laser ablation and the viscosity design is better.

[0036] from Figure 3 It can be seen that the laser ablation center is bright white and the ablation edge is clear, indicating that the molten pool can self-fill after laser ablation, and combined with the density, it shows that the lightweight effect is better.

[0037] Example 4: Step 1: The zirconium-silicon alloy powder with an atomic molar ratio of 1:5 is screened by particle size and divided into three particle size ranges: small particle size (30~50μm), medium particle size (50~75μm), and large particle size (75~150μm). Step 2: Weigh 10g of small-particle-size, 20g of medium-particle-size, 10g of small-particle-size, and 20g of large-particle-size alloy powder in sequence and place them in a graphite crucible with an inner diameter of 160 mm in the order of weighing. After each layer is placed, use a brush to flatten the surface of the powder before placing the next layer, and finally form a flat powder layer. Step 3: Use tweezers to pick up the cleaned sample, which measures Ф30 mm × 3 mm and has a density of 1.55 g / cm³. 3 The C / C composite material is placed on the surface of the powder layer; Step 4: Place the above sample into a vacuum heat treatment furnace. First, heat the sample to 1200℃ at 10℃ / min and hold for 45 min. Then, heat the sample to 1550℃ at 5℃ / min and hold for 120 min. Finally, cool the sample to room temperature with the furnace to obtain an oxyacetylene-laser ablation resistant C / C-ZrC-SiC material.

Claims

1. A method for preparing a carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation, characterized in that, Includes the following steps: S1, zirconium-silicon alloy powder is laid out layer by layer in the order of small particle size, medium particle size, small particle size and large particle size, with small particle size of 30~50μm, medium particle size of 50~75μm and large particle size of 75~150μm, to obtain a zirconium-silicon alloy powder composite layer. S2, the C / C composite material obtained by chemical vapor infiltration deposition of pyrolytic carbon is placed on the upper surface of the zirconium-silicon alloy powder composite layer, wherein the thickness of the powder layer formed by small particle size, medium particle size and large particle size is 20%~40%, 20%~50% and 40%~80% of the thickness of the C / C composite material, respectively. Then, a unidirectional reactive melt infiltration process is carried out, and the C / C composite material forms a carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation.

2. The method for preparing the oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material according to claim 1, characterized in that, The cross-section of the zirconium-silicon alloy powder composite layer described in S1 is circular or quadrilateral.

3. The method for preparing the oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material according to claim 1, characterized in that, The molar ratio of Zr to Si atoms in the zirconium-silicon alloy is 1:(3~11).

4. The method for preparing the oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material according to claim 1, characterized in that, The thickness of the C / C composite material described in S2 is 2~5mm.

5. The method for preparing the oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material according to claim 1, characterized in that, The density of the C / C composite material described in S2 is 1.0~1.55 g / cm³. 3 The 2.5D preform, obtained by needle punching after lamination of non-woven fabric and mesh layer, is obtained by depositing pyrolytic carbon through chemical vapor infiltration process.

6. The method for preparing the oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material according to claim 1, characterized in that, S1 involves layering zirconium-silicon alloy powder into a graphite crucible, then placing the C / C composite material into the graphite crucible, and finally performing a unidirectional reactive melting process in a vacuum heat treatment furnace.

7. The method for preparing the oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material according to claim 1, characterized in that, The unidirectional reactive melting process described in S2 is carried out at 1350-1700℃ for 80-120 min.

8. The method for preparing the oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material according to claim 7, characterized in that, Before performing the unidirectional reactive melting process, S2 is first kept at 1150~1250℃ for 30~60 min, and then the temperature is raised to 1350-1700℃.

9. The method for preparing the oxyacetylene and laser ablation resistant carbon fiber reinforced ZrC-SiC composite material according to claim 8, characterized in that, When the temperature rises from room temperature to 1150-1250℃, the heating rate is 8-12℃ / min. When the temperature rises from 1150-1250℃ to 1350-1700℃, the heating rate is 4-6℃ / min.

10. A carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation, obtained by the preparation method of the carbon fiber reinforced ZrC-SiC composite material resistant to oxyacetylene and laser ablation as described in any one of claims 1 to 9.

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