High-entropy carbonitride ceramic composite coating and method of making same

Abstract

A high-entropy carbonitride ceramic composite coating, characterized in that the composite coating, from the outside to the inside, consists of a high-entropy alloy carbonitride reaction deposition layer, a carbonitride diffusion layer, a high-entropy alloy layer, and an alloy diffusion layer, wherein the molecular formula of the aforementioned high-entropy alloy carbonitride reaction deposition layer is: (Ti a V b Cr c Si d X e Y f (C) g N h The molecular formula of the aforementioned high-entropy alloy layer is: Ti a V b Cr c Si d X e Y f The present invention also discloses a method for preparing the composite coating. The high-entropy carbonitride ceramic composite coating of the present invention exhibits self-healing and anti-peeling capabilities within different temperature ranges.

Description

Technical Field

[0001] This invention relates to a composite coating applied to a thermal protection material, and also to a method for preparing the composite coating. Background Technology

[0002] During firing, the barrel of an artillery piece is subjected to a complex state of high temperature, high pressure, and transient high-speed impact and wear. Improving its resistance to ablation has become a key challenge limiting the extension of barrel life. Currently used electroplated Cr mainly suffers from easy peeling and cracking. To address this problem, domestic research has primarily focused on electroplated Cr and magnetron sputtering Ta processes. However, due to the fact that metallic coatings are primarily composed of metallic elements and have a single coating structure, there are theoretical limits to their service performance and lifespan, limiting their potential for improvement.

[0003] High-performance aero-engine hot-end components must meet performance requirements such as long lifespan, wide temperature range oxidation resistance, erosion resistance, and fatigue vibration resistance; while the thermal protection systems of hypersonic spacecraft must withstand severe ablation, high-speed airflow erosion, and large-gradient thermal shock during service. Carbon-based composite materials, represented by graphite and carbon / carbon (C / C) composites, have high high-temperature oxidation sensitivity and insufficient ablation resistance, severely limiting their application as thermal structural materials. Coating technology is an effective means to improve the oxidation / ablation resistance of C / C composites.

[0004] To cope with the above extreme environments, it is urgent to develop high-performance thermal protection materials, namely, wide-temperature-range high-temperature protection materials that can be used for a long time under atmospheric conditions of 1200-2500K and above, with resistance to oxidation, ablation, and excellent thermal shock resistance. High entropy ceramics (HECs), also known as multi-principal-component, equiatomic-ratio, or near-equiatomic-ratio multi-component ceramics, are a new type of ceramic material that has been developed recently. Compared with traditional ceramics, high entropy ceramics have the following four characteristics: (1) Multi-principal composition. It contains multiple main constituent elements, each main element is mixed in equiatomic or near-equiatomic ratio, and the atomic percentage content of each main element is between 5-35%. (2) High entropy effect. High entropy ceramics have a much higher configuration entropy than traditional ceramics, so their solidification structure is easy to obtain a single-phase disordered solid solution structure (including face-centered cubic FCC, body-centered cubic BCC, and hexagonal close-packed HCP). (3) Lattice distortion effect. The random distribution of various atoms of different atomic sizes on the same lattice inevitably leads to severe distortion of the crystal lattice. (4) Slow diffusion effect. The complexity of the chemical composition and the severe lattice distortion make the diffusion of atoms inside high-entropy ceramics extremely difficult. The synergistic effect of the above characteristics gives high-entropy ceramics a series of excellent mechanical, physical and chemical properties, showing broad application prospects in terms of high strength, high hardness, high wear resistance, high corrosion resistance, high temperature softening resistance, low thermal conductivity and excellent soft magnetism.

[0005] To date, high-entropy ceramics have not been clearly defined and have been studied extensively in the field of ablation-resistant ceramic coatings. Rost et al. at Duke University first applied this high-entropy alloy concept to the synthesis of high-entropy oxide ceramics (Entropy-stabilized oxides [J]. Nature Communications. 2015, 6: 8485), but only studied the role of entropy in the formation of a single phase, without addressing the performance improvements caused by the four major effects of high entropy. Subsequently, Gild et al. at the University of California applied this high-entropy alloy concept to the synthesis of high-entropy ultra-high temperature ceramics (High-Entropy Metal Diborides: A New Class of High-Entropy Materials and a New Type of Ultrahigh Temperature Ceramics [J]. Scientific Reports. 2016, 6: 37946). This involves adding multiple other elements similar to the matrix elements to an existing binary ultra-high temperature ceramic matrix, resulting in compounds with relatively high thermodynamic mixing entropy, forming a single solid solution structure, which can be called high-entropy ultra-high temperature ceramics.

[0006] Peng Z in the United States used SPS to prepare ultra-high temperature (Ta) materials. 0.2Hf 0.2 Zr 0.2 Ti 0.2 Nb 0.2 C 0.8 N 0.2 And using transition metal carbides as raw materials, (Ta) was prepared using the same method. 0.2 Hf 0.2 Zr 0.2 Ti 0.2 Nb 0.2 The ablation behavior of high-entropy carbonitride ceramics at 2500 K was investigated. The study found that the mass ablation rate and linear ablation rate of high-entropy carbonitride ceramics were reduced by 57% and 72% respectively compared to high-entropy carbonitride ceramics. This indicates that the addition of nitrogen significantly improves the ablation performance of high-entropy ceramics. The dense multi-element oxide film of high-entropy carbonitride ceramics effectively prevents the infiltration of oxygen, thus significantly improving its ablation resistance. However, ablation pores and microcracks were still observed on the surface of the high-entropy carbonitride ceramic samples (Peng Z, Sun W, Xiong X, et al. Novel refractory high entropy ceramics: transition metalcarbonitrides with superior ablation resistance[J]. Corrosion Science, 2021, 184: 109359).

[0007] Pi et al. from Northwestern Polytechnical University added SiC, MoSi2, or ZrSi2 to ceramics, and the ceramics exhibited a certain healing ability. This is because the addition of the Si-containing phase can oxidize to form SiO2 at temperatures below 1500℃. At high temperatures, SiO2, due to its suitable viscosity, can self-heal ablation pores and microcracks in the ceramic phase, thereby improving the oxidation resistance and thermal shock resistance of the matrix (C / SiC-ZrB2-ZrC composites fabricated by reactive melt infiltration with ZrSi2 alloy[J].Ceramics International.2012,38(8):6541-6548.). However, the self-healing ability of SiO2 can only be applied to temperatures of 1600℃ and below, and is difficult to apply to ultra-high temperature environments. Cheng and Xie et al. studied the effects of ultra-high temperature ceramic oxides of nine transition metals (TMxOy, TM = Ti, Cr, Mo, Zr, Nb, Hf, W, V, Ta) on the stability of SiO2 glass at 1973K. The results showed that V2O5, MoO3, WO3, Nb2O5, and Ta2O5 had little effect on the volatilization of SiO2; Cr2O3 could promote the crystallization of SiO2, thereby inhibiting its volatilization; ZrO2, TiO2, and HfO2 were beneficial in alleviating the volatilization of SiO2 glass because Ti, Zr, and Hf diffuse into the SiO2 lattice under high-temperature conditions, increasing the Si-O bond strength and thus reducing the amount of SiO2 volatilized.

[0008] Liu Xiongjun of Beijing University of Science and Technology has invented a self-healing ultra-high temperature high-entropy carbonitride ceramic material. When this material is used in ultra-high temperature environments (≥2500K), it spontaneously forms a medium-entropy oxide (Ti) due to intense oxidation. a V b Cr c O2, with its dense spherical structure and good fluidity, can heal thermal shock microcracks and pores caused by ablation (CN202210590884.5). Furthermore, research by Zhao Fangnan of Jingdezhen Ceramic University found that VC, SiC, and WC all contribute to improving the overall mechanical properties of (TiHfVNbTa)C ceramics, and that SiC whiskers hinder crack propagation. Summary of the Invention

[0009] The first technical problem to be solved by the present invention is to provide a high-entropy carbonitride ceramic composite coating with wide temperature range self-healing properties that improves the ablation resistance of the surface of metal materials and carbon / carbon (C / C) composite materials in view of the above-mentioned technical status.

[0010] The second technical problem to be solved by the present invention is to provide a method for preparing a high-entropy carbonitride ceramic composite coating with wide temperature range self-healing properties.

[0011] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a high-entropy carbonitride compound ceramic composite coating, characterized in that the composite coating is composed of, from the outside to the inside, a high-entropy alloy carbonitride reaction deposition layer, a carbonitride diffusion layer, a high-entropy alloy layer, and an alloy diffusion layer.

[0012] The molecular formula of the aforementioned high-entropy alloy carbonitride reactive deposition layer is: (Ti a V b Cr c Si d X e Y f (C) g N h The molecular formula of the aforementioned high-entropy alloy layer is: Ti a V b Cr c Si d X e Y f ,

[0013] Among them, 0.1≤a≤0.25at.%, 0.01≤b≤0.25at.%, 0.01≤c≤0.25at.%, 0.01≤d≤0.15at.%, 0.01≤e≤0.25at.%, 0.01≤f≤0.25at.% and satisfying a+b+c+d+e+f=1, X and Y are one of Zr, Nb, Hf, Ta and W respectively, C is carbon element, N is nitrogen element, 0.1≤g≤1at.%, 0.1≤h≤1at.%, and satisfying g+h=1;

[0014] Preferably, the high-entropy alloy carbonitride reaction deposition layer involves a single face-centered cubic phase structure.

[0015] The thickness of the high-entropy alloy carbonitride reaction deposit layer is 10–40 μm. The 10–40 μm high-entropy alloy carbonitride reaction deposit layer has low internal stress and is not easy to peel off.

[0016] The carbon-nitrogen diffusion layer has a thickness of 2–5 μm. This 2–5 μm thickness ensures good adhesion between the high-entropy ceramic deposition layer and the high-entropy alloy layer, and guarantees that there are no abrupt changes in the composition of the interface between the high-entropy ceramic coating and the high-entropy alloy, resulting in a good match.

[0017] The high-entropy alloy layer is 5-20 μm thick. Using a 5-20 μm high-entropy alloy as the base layer can reduce the stress between the substrate and the ceramic coating, and improve the adhesion strength between the substrate and the outer coating, making the coating bond tighter.

[0018] The thickness of the alloy diffusion layer is 2–5 μm.

[0019] The carbon and nitrogen content in the high-entropy alloy carbonitride reaction deposit layer exhibits a gradient distribution, gradually decreasing from the outside to the inside. This gradient carbonitride and metal infiltration layer improves the strain tolerance of the composite coating, and the gradient change in composition helps reduce stress, significantly enhancing the bonding strength between the coating and the substrate.

[0020] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a method for preparing a high-entropy carbonitride ceramic composite coating, characterized by comprising the following steps in sequence:

[0021] (1) The surface of the substrate material is pre-ground, polished, and cleaned, and then pre-treated by sputtering.

[0022] (2) The TiVCrSiXY system high-entropy alloy target and graphite target are placed in an arc glow plasma metal infiltration device, with the matrix material as the workpiece electrode and the high-entropy alloy target and graphite target as the source electrode.

[0023] (3) Evacuate the vacuum, supply argon gas, start the glow discharge, and adjust the process parameters such as the power supply and current of the workpiece and the high-entropy alloy target to complete the preparation of the high-entropy alloy coating.

[0024] (4) Introduce ammonia gas, adjust the power supply and current process parameters of the workpiece and graphite target, and complete the preparation of the carbon-nitrogen diffusion layer;

[0025] (5) Introduce ammonia gas, adjust the power supply and current process parameters of the workpiece, high-entropy alloy target and graphite target, and complete the preparation of the high-entropy alloy carbonitride reaction deposition layer.

[0026] The glow discharge was stopped, the power was turned off, and the vacuum was adjusted to atmospheric pressure to complete the preparation of the high-entropy carbonitride ceramic composite coating, resulting in an ablation-resistant composite coating with wide temperature range self-healing properties.

[0027] By first preparing a TiVCrSiXY system high-entropy alloy thin film coating on the material surface using arc glow plasma metal infiltration technology, and then preparing a metallurgically bonded high-entropy alloy carbonitride coating using arc glow plasma reactive sputtering technology, the bonding strength between the coating and the substrate and the ablation resistance are significantly improved through metallurgical bonding and self-healing phase structure design, thus extending the service life of metal materials and carbon / carbon (C / C) composite materials at high temperatures.

[0028] In step (1), during the sputtering pretreatment, the substrate material is used as the workpiece electrode, the source electrode voltage and current are set to zero, the workpiece voltage is set to 500-700V, and the workpiece current is set to 0.1A-0.3A; simultaneously, high-purity argon gas is introduced, with an argon gas pressure of 20-60Pa, and the pre-sputtering time is 0.5-2h. High-energy argon ion excitation is used to begin pre-sputtering on the material surface, resulting in a clean sample surface and the appearance of microscopic defects such as vacancies on the substrate surface, thereby increasing the penetration rate of alloying elements.

[0029] In step (2), 0.01% to 0.02 at.% of the rare earth element iridium is added to the T high-entropy alloy target. The rare earth element iridium can promote the diffusion of alloying elements on the substrate surface during the arc glow discharge process, forming a thicker diffusion layer. If the amount added is too small, the diffusion effect will not be obvious, and if the amount added is too large, it will easily lead to the segregation of iridium, resulting in uneven diffusion effect.

[0030] As a preferred embodiment, in step (3), the voltage of the high-entropy alloy target is 700-950V, the voltage of the workpiece is 400-650V, the argon gas pressure is 25-45Pa, the distance between the target and the workpiece is 10-25mm, the heat preservation time is 4-8h, and the processing temperature is 600℃-1100℃.

[0031] Preferably, in step (4), ammonia and argon are introduced with a flow ratio of 4:1, the gas pressure is stabilized at 40-50 Pa, and the process parameters are adjusted as follows: graphite target voltage: 700-950 V, workpiece voltage: 400-650 V, target-workpiece electrode distance: 15-20 mm, heat preservation time: 4-5 h, and processing temperature: 800℃-1000℃.

[0032] Preferably, in step (5), ammonia and argon are introduced at a flow rate ratio of 2:1, and the gas pressure is stabilized at 30-45 Pa. The process parameters are as follows: graphite target voltage: 700-950V, high-entropy alloy target voltage: 700-1000V, workpiece voltage: 400-650V, target-workpiece electrode distance: 15-20mm, heat preservation time: 5-8h, and processing temperature: 700℃-1000℃.

[0033] Compared with existing technologies, the advantages of this invention are as follows: The TiVCrSiXY system high-entropy alloy coating prepared by arc glow discharge plasma diffusion technology can form an interdiffusion layer with a gradient elemental distribution between the coating and the substrate. The elemental content decreases from the surface to the interior, thereby achieving metallurgical bonding between the coating and the substrate, greatly improving the bonding strength between the substrate and the alloy. Through the combined action of ammonia gas and graphite target, carbonitriding is performed on the subsurface layer of the TiVCrSiXY system high-entropy alloy coating, serving as a transition layer between the high-entropy alloy coating and the high-entropy alloy ceramic coating, ensuring the compositional continuity of the two coatings. A TiVCrSiXY system high-entropy alloy carbonitride ceramic coating is prepared through a co-sputtering reaction of ammonia gas, graphite target, and TiVCrSiXY system high-entropy alloy target. The composite coating structure of high-entropy alloy ceramic coating + carbonitriding layer + high-entropy alloy coating + metal diffusion layer can maintain the excellent properties of the high-entropy alloy while also possessing the excellent tribological and wear resistance and corrosion resistance of ceramics. The high-entropy alloy layer (underlayer) of the TiVCrSiXY system acts as a soft bonding layer between the substrate and the ceramicized TiVCrSiXY system high-entropy alloy carbonitride ceramic coating. By gradually changing the flow rate of ammonia gas and the input power of the graphite target power supply, a high-entropy alloy ceramic coating with a compositional gradient is obtained.

[0034] High-entropy alloys, used as the underlayer for carbonitride ceramic coatings, can reduce stress between the substrate and the ceramic coating, and improve the adhesion strength between the substrate and the outer coating, resulting in a tighter bond. A high-entropy alloy transition layer is formed on the substrate surface to prevent damage under pressure due to the high surface hardness of the high-entropy alloy ceramic coating and insufficient support. High-entropy alloy transition layers and carbonitride transition layers containing interdiffusion layers are prepared using arc glow discharge plasma diffusion technology. Interdiffusion between the diffusion layer and the substrate elements achieves metallurgical bonding between the coating and the substrate, as well as between the metal and ceramic layers within the coating, greatly improving the bonding strength between the coating and the substrate, and between coating layers.

[0035] The resulting composite coating exhibits self-healing and anti-peeling capabilities across different temperature ranges. Below 1500℃, it forms SiO2 with suitable viscosity, capable of self-healing ablated pores and microcracks; above 1500℃, it forms (Ti) with a dense, spherical structure. a V b Cr c The O2 medium-entropy oxide self-healing phase repairs ablation pores and thermal cracks, thereby improving the substrate's resistance to ablation and thermal shock. Surface microhardness is 1450–1950 HV. Attached Figure Description

[0036] Figure 1 This is a schematic cross-sectional view of the high-entropy carbonitride ceramic composite coating in the embodiment. Detailed Implementation

[0037] The dual-glow plasma alloying experiments used in the following examples were conducted using a self-developed arc-assisted glow discharge plasma surface diffusion coating equipment manufactured by Anhui Jiashuo Vacuum Technology Co., Ltd. The substrate material was steel, and the purity of both argon and ammonia used was 99.99%.

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0039] like Figure 1 As shown, the coating structure on the steel surface in this embodiment consists of a surface (TiVCrSiXY)CN system high-entropy alloy carbonitriding ceramic deposition layer 11, a carbonitriding diffusion layer 12, a TiVCrSiXY system high-entropy alloy layer 13, and an alloy diffusion layer 14. These layers are arranged sequentially from top to bottom. The thickness of the surface high-entropy ceramic deposition layer 11 is 10–40 μm, the thickness of the carbonitriding diffusion layer 12 is 2–5 μm, the thickness of the high-entropy alloy layer 13 is 5–20 μm, and the thickness of the alloy diffusion layer 14 is 2–5 μm. The carbon and nitrogen content in the carbonitriding diffusion layer 12 exhibits a gradient distribution, and the carbon and nitrogen content gradually decreases from top to bottom.

[0040] The above-mentioned method for preparing the coating structure includes the following steps in sequence:

[0041] (1) Before the matrix material enters the vacuum chamber, it is first cleaned with an ultrasonic cleaning device for 15 to 20 minutes, and then its surface is wiped with alcohol. After the alcohol evaporates, the sample is fixed on the worktable.

[0042] (2) The TiVCrSiXY system high-entropy alloy target and graphite target are placed in an arc-assisted glow discharge plasma metal infiltration device, with the matrix material as the workpiece electrode and the TiVCrSiXY system high-entropy alloy target and graphite target as the source electrode; the molecular formula of the TiVCrSiXY system high-entropy alloy target is: Ti a V b Cr c Si d X e Y f Among them, 0.1≤a≤0.25at.%, 0.01≤b≤0.25at.%, 0.01≤c≤0.25at.%, 0.01≤d≤0.15at.%, 0.01≤e≤0.25at.%, 0.01≤f≤0.25at.% and satisfying a+b+c+d+e+f=1, X and Y are one of Zr, Nb, Hf, Ta and W respectively.

[0043] (3) Evacuate the vacuum, introduce argon gas, start the glow discharge, and begin the pre-sputtering treatment of the substrate material. During the sputtering pretreatment, the substrate material is used as the workpiece electrode, the source electrode voltage and current are set to zero, the workpiece voltage is set to 500-700V, and the workpiece current is set to 0.1A-0.3A; at the same time, high-purity argon gas is introduced, the argon gas pressure is 20-60Pa, the pre-sputtering time is 0.5-2h, and high-energy argon ion excitation is used to start the pre-sputtering of the material surface, so that the material surface forms a clean sample surface, and at the same time, micro-defects such as vacancies appear on the substrate surface, thereby improving the alloy element penetration rate.

[0044] (4) Adjust the process parameters such as power supply and current of the workpiece and the TiVCrSiXY system high-entropy alloy target. Specifically, the voltage of the TiVCrSiXY system high-entropy alloy target is 700–950V, the workpiece voltage is 400–650V, the argon gas pressure is 25–45Pa, the distance between the target and the workpiece is 10–25mm, the holding time is 4–8h, and the processing temperature is 600℃–1100℃. Complete the preparation of the TiVCrSiXY system high-entropy alloy coating (undercoat).

[0045] (5) Introduce ammonia and argon gas at a flow ratio of 4:1 and stabilize the gas pressure at 40-50 Pa. Adjust the process parameters such as the power supply and current of the workpiece and graphite target. The graphite target voltage is 700-950V, the workpiece voltage is 400-650V, the distance between the target and the workpiece is 15-20mm, the heat preservation time is 4-5h, and the processing temperature is 800℃-1000℃ to complete the preparation of the carbon-nitrogen diffusion layer.

[0046] (6) Introduce ammonia and argon gas at a flow ratio of 2:1 and stabilize the gas pressure at 30-45 Pa. Adjust the process parameters such as the power supply and current of the workpiece, TiVCrSiXY system high-entropy alloy target and graphite target. Among them, the graphite target voltage is 700-950V, the TiVCrSiXY system high-entropy alloy target voltage is 700-1000V, the workpiece voltage is 400-650V, the target-workpiece electrode distance is 15-20mm, the heat preservation time is 5-8h, and the processing temperature is 700℃-1000℃. Complete the preparation of the (TiVCrSiXY)CN system high-entropy alloy carbonitride reaction deposition layer.

[0047] (4) Stop the glow discharge, turn off the power, adjust the vacuum to atmospheric pressure, open the device, take out the sample, and complete the preparation of the high-entropy alloy ceramic composite coating to obtain a wide-temperature-range self-healing ablation-resistant coating.

[0048] The TiVCrSiXY system high-entropy alloy target material incorporates 0.01% to 0.02 at.% of the rare earth element iridium, as detailed in the 11 examples listed in the table below. The composition of the TiVCrSiXY system high-entropy alloy target material in the 11 examples is shown in Table 1. The process parameters for the 11 examples are shown in Tables 2 and 3. The coating thickness, adhesion, and ablation parameters for the 11 examples are shown in Table 4.

[0049] Table 1. Composition (at.%) of the TiVCrSiXY system high-entropy alloy sputtering targets in each embodiment.

[0050]

[0051] Table 2 Process parameters for each embodiment 1

[0052]

[0053]

[0054] Table 3 Process parameters for each embodiment 2

[0055]

[0056] Table 4. Coating thickness, ablation performance, and adhesion parameters for each embodiment.

[0057]

[0058]

[0059] As shown in Table 4, the surface microhardness of the coating is 1450-1950 HV after adding rare earth elements to the target material.

[0060] After a single firing test, the 11 embodiments described above showed no cracks or peeling on the chromium-plated coating surface, only scouring grooves caused by the gunpowder gas. The chromium-plated layer on this surface has good adhesion to the substrate and will not peel off, thus protecting the substrate from the direct action of high-temperature and high-pressure gunpowder gas and significantly improving the ablation resistance of the substrate material.

[0061] In the above embodiments, the hardness testing method was as follows: a 401MVA Vickers hardness tester was used to measure the surface microhardness of the steel in each embodiment, and a standard Knoop indenter was used. To reduce the experimental error in reading the indentation length L, a load of 10g and a loading time of 15s were selected; the test results were selected as the arithmetic mean of 5 measurement points.

[0062] The bonding strength test method was as follows: critical load data was obtained through observation using an acoustic emission sensor and a built-in microscope to analyze the bonding performance between the coating and substrate materials. The bonding strength was measured using a WS-2005 automatic scratch tester with a Rockwell diamond standard 120° cone indenter (R = 0.2 mm). The linear loading speed was 20 N / min, the horizontal sliding speed was 2 mm / min, the maximum load was 100 N, the scratch length was 5 mm, and the test temperature was 25℃.

[0063] The ablation resistance test method is mainly based on the ablation resistance evaluation method in Fan Xinmin's "Evaluation of the Ablation Resistance of Three Coating Materials" published in the Journal of Ballistics. It will not be described in detail in this embodiment.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A high-entropy carbonitride ceramic composite coating, characterized in that... The composite coating consists of, from the outside in, a high-entropy alloy carbonitride reactive deposition layer, a carbonitride diffusion layer, a high-entropy alloy layer, and an alloy diffusion layer. The molecular formula of the aforementioned high-entropy alloy carbonitride reactive deposition layer is: (Ti a V b Cr c Si d X e Y f ) (C g N h The molecular formula of the aforementioned high-entropy alloy layer is: Ti a V b Cr c Si d X e Y f , Among them, 0.1≤a≤0.25at.%, 0.01≤b≤0.25at.%, 0.01≤c≤0.25at.%, 0.01≤d≤0.15at.%, 0.01≤e≤0.25at.%, 0.01≤f≤0.25at.% and satisfying a+b+c+d+e+f=1, X and Y are one of Zr, Nb, Hf, Ta and W respectively, C is carbon element, N is nitrogen element, 0.1≤g≤1at.%, 0.1≤h≤1at.%, and satisfying g+h=1.

2. The high-entropy carbonitride ceramic composite coating according to claim 1, characterized in that... The high-entropy alloy carbonitride reaction deposit layer has a single face-centered cubic phase structure.

3. The high-entropy carbonitride ceramic composite coating according to claim 1, characterized in that... The thickness of the high-entropy alloy carbonitride reaction deposition layer is 10~40μm, the thickness of the carbonitride diffusion layer is 2~5μm, the thickness of the high-entropy alloy layer is 5~20μm, and the thickness of the alloy diffusion layer is 2~5μm.

4. The high-entropy carbonitride ceramic composite coating according to claim 1, characterized in that... The carbon and nitrogen content in the high-entropy alloy carbonitride reaction deposition layer exhibits a gradient distribution, gradually decreasing from the outside to the inside.

5. A method for preparing a high-entropy carbonitride ceramic composite coating as described in any one of claims 1 to 4, characterized in that... The steps are as follows: (1) The surface of the substrate material is pre-ground, polished, and cleaned, and then pre-treated for sputtering; (2) Place the TiVCrSiXY system high-entropy alloy target and graphite target into an arc glow plasma metal infiltration device, with the matrix material as the workpiece electrode and the high-entropy alloy target and graphite target as the source electrode. (3) Evacuate, supply argon gas, start glow discharge, and adjust the power supply and current process parameters of the workpiece and high-entropy alloy target to complete the preparation of the high-entropy alloy coating; (4) Introduce ammonia gas, adjust the power supply and current process parameters of the workpiece and graphite target, and complete the preparation of the carbon-nitrogen diffusion layer; (5) Introduce ammonia gas, adjust the power supply and current process parameters of the workpiece, high-entropy alloy target and graphite target, and complete the preparation of the high-entropy alloy carbonitride reaction deposition layer; The glow discharge was stopped, the power was turned off, and the vacuum was adjusted to atmospheric pressure to complete the preparation of the high-entropy carbonitride ceramic composite coating, resulting in an ablation-resistant composite coating with wide temperature range self-healing properties.

6. The preparation method according to claim 5, characterized in that... In step (1), during the sputtering pretreatment, the substrate material is used as the workpiece electrode, the source electrode voltage and current are set to zero, the workpiece voltage is set to 500~700V, and the workpiece current is set to 0.1A~0.3A; at the same time, high-purity argon gas is introduced, with an argon gas pressure of 20~60Pa and a pre-sputtering time of 0.5~2h.

7. The preparation method according to claim 5, characterized in that: In step (2), 0.01~0.02 at.% of iridium was added to the high-entropy alloy target of the TiVCrSiXY system.

8. The preparation method according to claim 5, characterized in that... In step (3), the voltage of the high-entropy alloy target is 700~950V, the voltage of the workpiece is 400~650V, the argon gas pressure is 25~45Pa, the distance between the target and the workpiece is 10~25mm, the heat preservation time is 4~8h, and the processing temperature is 600℃~1100℃.

9. The preparation method according to claim 5, characterized in that... In step (4), ammonia and argon are introduced to a flow ratio of 4:1, and the gas pressure is stabilized at 40-50 Pa. The process parameters are as follows: graphite target voltage: 700-950 V, workpiece voltage: 400-650 V, target-workpiece electrode distance: 15-20 mm, heat preservation time: 4-5 h, and processing temperature: 800℃-1000℃.

10. The preparation method according to claim 5, characterized in that: In step (5), ammonia and argon are introduced to a flow ratio of 2:1, and the gas pressure is stabilized at 30-45 Pa. The process parameters are as follows: graphite target voltage: 700-950V, high-entropy alloy target voltage: 700-1000V, workpiece voltage: 400-650V, target-workpiece distance: 15-20mm, heat preservation time: 5-8h, and processing temperature: 700℃-1000℃.

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