A wide-temperature gradient protective coating with a spider web-like biomimetic structure and its preparation method

Abstract

This invention discloses a wide-temperature-range gradient protective coating with a spiderweb-like biomimetic structure and its preparation method. The spiderweb-like biomimetic structure comprises an oxide phase as the spiderweb structure phase and a borosilicate glass phase as the remaining phase. The preparation method includes: mixing raw materials, densification treatment, polishing, and high-temperature oxidation treatment. The advantages of this invention compared to existing technologies are: based on the concept of a surface spiderweb biomimetic structure, it utilizes a spiderweb-like structure and a transition metal oxide mesh architecture to achieve a "liquid-locking" effect on the liquid glass phase at high temperatures. Furthermore, it leverages the surface tension of the liquid glass phase to fix a high content of liquid glass phase, providing a sealing effect to resist oxygen penetration and providing a protective seal. This enhances the coating's wide-temperature-range protective effect.

Description

Technical Field

[0001] This invention relates to the field of coating structure design, specifically to a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure and its preparation method. Background Technology

[0002] With the development of future scientific technologies such as deep earth, deep sea, and deep space, the requirements for high-temperature strength and oxidation resistance of materials in various fields are becoming increasingly stringent. Carbon materials not only exhibit excellent high-temperature mechanical properties but are also structural materials that can continue to be used in environments exceeding 3000°C. Carbon materials have extremely low density, which can effectively reduce the weight of aircraft. However, without any anti-oxidation treatment, carbon materials begin to oxidize in an aerobic environment at 400°C and undergo rapid oxidation at 500°C, leading to a shortened service life or even failure. Coatings can effectively isolate carbon materials from external oxygen, thereby achieving oxidation protection for longer periods and at higher temperatures.

[0003] Protective coating technology effectively isolates carbon materials from external oxygen, thereby achieving oxidation protection that ensures the material's service life for longer periods and at higher temperatures. Because SiO2 has a low oxygen diffusion coefficient, it is 10–13 g·cm⁻¹ at 1200℃. -2 ·s -1 Therefore, it can effectively protect the carbon matrix during oxidation. The SiO2 generated by silicide oxidation is amorphous at high temperatures and has excellent fluidity, forming a protective film on the material surface, effectively preventing oxygen from contacting and reacting with the internal material. Among these silicides, MoSi2 has consistently demonstrated superior oxidation resistance compared to other silicide coatings in numerous studies. This is because the MoO3 metal oxide generated by MoSi2 is highly volatile at high temperatures, not affecting the flow and spread of SiO2. This allows for more uniform and complete growth and development of the glass film during oxidation, resulting in a denser and more stable internal structure and superior oxidation resistance. Based on this, boride-MoSi2-based high-temperature protective coatings, represented by MoSi2, show great potential for high-temperature oxidation protection.

[0004] Yang Qingqing et al. (Yang Qingqing. Study on Antioxidant Mechanism of MoSi2-HfB2-SiC Coating [D]. China University of Mining and Technology, 2022) used a boride-MoSi2-based gradient protective coating to effectively protect carbon materials by pre-oxidation of the coating, and it showed good antioxidation effect in an ultra-high temperature environment of 1700℃. However, in the early stage of coating pre-oxidation film formation, oxygen can quickly penetrate into the coating structure defects, forming through-channel defects; and the pre-oxidation method is based on the oxidation loss of the system's own components, which is not conducive to the sealing and oxygen barrier of the coating. High-boron glass, as a special high-temperature resistant glass, has great potential applications in the field of antioxidation protection. If a protective layer containing high-boron glass can be pre-laid on the coating surface to form a gradient coating protective structure, it is expected to further broaden the application of boride-silicon-based protective coatings in wide temperature range protection. However, due to the limited fluidity of the glass phase, its content in the coating system should not be too high (usually below 20 vol).

[0005] While lower concentrations of glass phase (%) offer limited optimization effects, higher concentrations exhibit strong flowability during wide-temperature protection, making it difficult to provide stable protection against dynamic temperature environments. Therefore, a feasible solution is urgently needed to address these issues and improve the protective performance of gradient coatings across a wide temperature range. Summary of the Invention

[0006] To address the shortcomings of the existing technology, this invention aims to provide a wide-temperature gradient protective coating with a surface spiderweb biomimetic structure and its preparation method.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] A wide-temperature gradient protective coating with a surface spiderweb biomimetic structure, wherein the spiderweb structure phase is an oxide phase and the remaining phase is a borosilicate glass phase.

[0009] A method for preparing a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure specifically includes the following steps:

[0010] 1) Mixing raw materials: ZrB2, MoSi2 and high borosilicate glass powder are mixed according to volume ratio to prepare ZrB2-MoSi2-high borosilicate glass precursor powder;

[0011] 2) Densification treatment: ZrB2-MoSi2-high borosilicate glass precursor powder is loaded into a graphite mold, filled with carbon matrix, and placed in a low-temperature hot pressing sintering device to carry out carbon matrix surface coating densification treatment.

[0012] 3) Polishing: After the processing is completed, the sample is taken out and polished to obtain a ZrB2-MoSi2-high borosilicate glass wide temperature range protective coating.

[0013] 4) High-temperature oxidation treatment: The ZrB2-MoSi2-high borosilicate glass wide-temperature range protective coating is placed in a high-temperature oxidation furnace for rapid oxidation treatment to obtain a wide-temperature range gradient protective coating with a surface spider web biomimetic structure.

[0014] As a preferred embodiment, the volume ratio of ZrB2, MoSi2, and high borosilicate glass powder raw materials in step 1) is 30–32.5:30–32.5:35–40.

[0015] As a preferred embodiment, the coating densification treatment temperature in step 2) is 1200–1250°C.

[0016] As a preferred embodiment, the rapid oxidation treatment time in step 4) is 80–100 min.

[0017] The advantages of this invention compared with the prior art are as follows: Based on the concept of surface spider web biomimetic structure, it uses a spider web-like structure to achieve the "liquid-locking and fixing" effect of transition metal oxide grid architecture on the liquid glass phase at high temperature. Then, it uses the surface tension of the liquid glass phase to fix the high content of liquid glass phase, which plays a sealing role to resist oxygen penetration and provide a sealing and protection effect. It has the advantage of improving the protective effect of the coating over a wide temperature range. Attached Figure Description

[0018] Figure 1 The surface morphology of the wide-temperature gradient protective coating with a surface spider web biomimetic structure obtained in Example 1 of the present invention is shown.

[0019] Figure 2 The surface morphology of the wide-temperature gradient protective coating with a surface spider web biomimetic structure obtained in Example 2 of the present invention is shown.

[0020] Figure 3 The surface morphology of the wide-temperature gradient protective coating with a surface spider web biomimetic structure obtained in Example 3 of the present invention is shown.

[0021] Figure 4 The surface morphology of the conventional wide-temperature gradient protective coating obtained in Comparative Example 1 of the present invention is shown.

[0022] Figure 5 The surface morphology of the conventional wide-temperature-range protective coating obtained in Comparative Example 2 of the present invention is shown.

[0023] Figure 6 The images show the oxidation weight gain of the wide-temperature gradient protective coatings obtained in Examples 1-3 and Comparative Example 1 of this invention after wide-temperature protection. Detailed Implementation

[0024] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0025] Example 1:

[0026] This embodiment relates to a preferred scheme for a wide-temperature gradient protective coating with a surface spiderweb biomimetic structure, wherein the spiderweb structure phase in the surface spiderweb biomimetic structure is an oxide phase, and the remaining phase is a borosilicate glass phase.

[0027] A method for preparing a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure as described above, comprising the following steps:

[0028] (1) ZrB2, MoSi2 and high borosilicate glass powder were mixed in a volume ratio of 32.5:32.5:35 to prepare ZrB2-MoSi2-high borosilicate glass precursor powder with a volume ratio of 32.5:32.5:35.

[0029] (2) The ZrB2-MoSi2-high borosilicate glass precursor powder was loaded into a graphite mold, filled with carbon matrix, and placed in a low-temperature hot pressing sintering device for carbon matrix surface coating densification treatment at 1200℃.

[0030] (3) After the processing is completed, the sample is taken out and polished to obtain a ZrB2-MoSi2-high borosilicate glass wide temperature range protective coating.

[0031] (4) The ZrB2-MoSi2-high borosilicate glass wide temperature range protective coating was placed in a high temperature oxidation furnace for rapid oxidation treatment for 80 min to obtain a wide temperature range gradient protective coating with a surface spider web biomimetic structure.

[0032] This embodiment provides a preferred formulation and preparation method for a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure, wherein the surface morphology is as follows: Figure 1 As shown, the oxidative weight gain results after wide-temperature protection are as follows: Figure 6 As shown in the figure, the high-temperature resistant protective coating provided in this embodiment exhibits a significant spiderweb-like structure. Thanks to the surface spiderweb biomimetic structure, the gradient protective coating in this embodiment demonstrates good protection over a wide temperature range.

[0033] Example 2:

[0034] This embodiment relates to a preferred scheme for a wide-temperature gradient protective coating with a surface spiderweb biomimetic structure, wherein the spiderweb structure phase in the surface spiderweb biomimetic structure is an oxide phase, and the remaining phase is a borosilicate glass phase.

[0035] A method for preparing a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure as described above, comprising the following steps:

[0036] (1) ZrB2, MoSi2 and high borosilicate glass powder were mixed in a volume ratio of 31.25:31.25:37.5 to prepare ZrB2-MoSi2-high borosilicate glass precursor powder with a volume ratio of 31.25:31.25:37.5.

[0037] (2) The ZrB2-MoSi2-high borosilicate glass precursor powder was loaded into a graphite mold, filled with carbon matrix, and placed in a low-temperature hot pressing sintering device for carbon matrix surface coating densification treatment at 1225℃.

[0038] (3) After the processing is completed, the sample is taken out and polished to obtain a ZrB2-MoSi2-high borosilicate glass wide temperature range protective coating.

[0039] (4) The ZrB2-MoSi2-high borosilicate glass wide temperature range protective coating was placed in a high temperature oxidation furnace for rapid oxidation treatment for 90 min to obtain a wide temperature range gradient protective coating with a surface spider web biomimetic structure.

[0040] This embodiment provides a preferred formulation and preparation method for a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure, wherein the surface morphology is as follows: Figure 2 As shown, the oxidative weight gain results after wide-temperature protection are as follows: Figure 6 As shown in the figure, the high-temperature resistant protective coating provided in this embodiment exhibits a significant spiderweb-like structure. Thanks to the surface spiderweb biomimetic structure, the gradient protective coating in this embodiment demonstrates good protection over a wide temperature range.

[0041] Example 3:

[0042] This embodiment relates to a preferred scheme for a wide-temperature gradient protective coating with a surface spiderweb biomimetic structure, wherein the spiderweb structure phase in the surface spiderweb biomimetic structure is an oxide phase, and the remaining phase is a borosilicate glass phase.

[0043] A method for preparing a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure as described above, comprising the following steps:

[0044] (1) ZrB2, MoSi2 and high borosilicate glass powder were mixed in a volume ratio of 30:30:40 to prepare ZrB2-MoSi2-high borosilicate glass precursor powder with a volume ratio of 30:30:40.

[0045] (2) The ZrB2-MoSi2-high borosilicate glass precursor powder was loaded into a graphite mold, filled with carbon matrix, and placed in a low-temperature hot pressing sintering device to perform carbon matrix surface coating densification treatment at 1250℃.

[0046] (3) After the processing is completed, the sample is taken out and polished to obtain a ZrB2-MoSi2-high borosilicate glass wide temperature range protective coating.

[0047] (4) The ZrB2-MoSi2-high borosilicate glass wide temperature range protective coating was placed in a high temperature oxidation furnace for rapid oxidation treatment for 100 min to obtain a wide temperature range gradient protective coating with a surface spider web biomimetic structure.

[0048] This embodiment provides a preferred formulation and preparation method for a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure, wherein the surface morphology is as follows: Figure 3 As shown, the oxidative weight gain results after wide-temperature protection are as follows: Figure 6 As shown in the figure, the high-temperature resistant protective coating provided in this embodiment exhibits a significant spiderweb-like structure. Thanks to the surface spiderweb biomimetic structure, the gradient protective coating in this embodiment demonstrates good protection over a wide temperature range.

[0049] Comparative Example 1:

[0050] This comparative example relates to a conventional wide-temperature gradient protective coating, wherein the coating system does not contain a high borosilicate glass phase, but is entirely composed of ZrB2-MoSi2 ceramic phase, and its surface does not have a surface spider web biomimetic structure.

[0051] A method for preparing a conventional wide-temperature-range gradient protective coating as described above is carried out according to the following steps:

[0052] (1) Mix ZrB2 and MoSi2 powders in a volume ratio of 50:50 to prepare ZrB2-MoSi2 precursor powder with a volume ratio of 50:50.

[0053] (2) The ZrB2-MoSi2 precursor powder was loaded into a graphite mold, filled with carbon matrix, and placed in a low-temperature hot pressing sintering device to perform carbon matrix surface coating densification treatment at 1200℃.

[0054] (3) After the processing is completed, the sample is taken out and polished to obtain the ZrB2-MoSi2 protective coating.

[0055] (4) The ZrB2-MoSi2 wide temperature range protective coating was placed in a high temperature oxidation furnace for rapid oxidation treatment for 80 minutes to obtain a conventional wide temperature range gradient protective coating.

[0056] This comparative example provides a conventional wide-temperature-range gradient protective coating and its preparation method, wherein the surface morphology is as follows: Figure 4 As shown, the oxidative weight gain results after wide-temperature protection are as follows: Figure 6As shown in the figure, this comparative system does not contain borosilicate glass and does not have a surface spiderweb biomimetic structure. Compared with Example 1, its wide-temperature protection effect is worse.

[0057] Comparative Example 2:

[0058] This comparative example relates to a conventional wide-temperature-range protective coating, wherein the coating system has not undergone rapid oxidation treatment, and therefore its surface does not have a surface spider web biomimetic structure.

[0059] A method for preparing a conventional wide-temperature-range protective coating as described above is carried out according to the following steps:

[0060] (1) ZrB2, MoSi2 and high borosilicate glass powder were mixed in a volume ratio of 30:30:40 to prepare ZrB2-MoSi2-high borosilicate glass precursor powder with a volume ratio of 30:30:40.

[0061] (2) The ZrB2-MoSi2-high borosilicate glass precursor powder was loaded into a graphite mold, filled with carbon matrix, and placed in a low-temperature hot pressing sintering device to perform carbon matrix surface coating densification treatment at 1250℃.

[0062] (3) After the processing is completed, the sample is taken out and polished to obtain a conventional wide temperature range protective coating of ZrB2-MoSi2-high borosilicate glass.

[0063] This comparative example provides a conventional wide-temperature-range protective coating and its preparation method, wherein the surface morphology is as follows: Figure 5 As shown, the oxidative weight gain results after wide-temperature protection are as follows: Figure 6 As shown. Compared to Example 3, the rapid oxidation treatment in step (4) was not performed, therefore the sample did not form a protective coating with a gradient structure, and thus did not possess a surface spiderweb biomimetic structure. Compared to Example 3, its wide-temperature-range protective effect is poor.

[0064] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for preparing a wide-temperature-range gradient protective coating with a surface spiderweb biomimetic structure, characterized in that: In the aforementioned surface spiderweb biomimetic structure, the spiderweb structure phase is an oxide phase, and the remaining phase is a borosilicate glass phase. The preparation method specifically includes the following steps: 1) Mixing raw materials: ZrB2, MoSi2 and high borosilicate glass powder are mixed according to volume ratio to prepare ZrB2-MoSi2-high borosilicate glass precursor powder; 2) Densification treatment: ZrB2-MoSi2-high borosilicate glass precursor powder is loaded into a graphite mold, filled with carbon matrix, and placed in a low-temperature hot pressing sintering device to carry out carbon matrix surface coating densification treatment. 3) Polishing: After the processing is completed, the sample is taken out and polished to obtain a ZrB2-MoSi2-high borosilicate glass wide temperature range protective coating. 4) High-temperature oxidation treatment: The ZrB2-MoSi2-high borosilicate glass wide-temperature range protective coating is placed in a high-temperature oxidation furnace for rapid oxidation treatment to obtain a wide-temperature range gradient protective coating with a surface spider web biomimetic structure. In step 1), the volume ratio of ZrB2, MoSi2, and high borosilicate glass powder raw materials is 30–32.5:30–32.5:35–40. The coating densification treatment temperature in step 2) is 1200–1250℃; The rapid oxidation treatment time in step 4) is 80-100 min.

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