A high-toughness antioxidant coating and its manufacturing method

Abstract

A high-toughness, oxidation-resistant coating and its manufacturing method are disclosed, belonging to the field of heat-resistant coatings. This high-toughness, oxidation-resistant coating contains 0.01%-1% Si, 0.01%-0.7% O, and the balance Cr by weight. The coating matrix is ​​crystalline Cr, with at least a portion of the Si and O dispersed in the matrix as amorphous SiO2. This high-toughness, oxidation-resistant coating exhibits excellent oxidation resistance. Under high-temperature conditions above 1100℃, the amorphous SiO2 can achieve self-healing of defects and cracks within the coating, effectively improving the lifespan and reliability of zirconium alloy parts using this coating.

Description

Technical Field

[0001] This invention belongs to the field of heat-resistant coatings, specifically relating to a high-toughness, oxidation-resistant coating and its manufacturing method. Background Technology

[0002] With the development of nuclear power technology, accident-resistant fuel cladding that can maintain structural integrity for extended periods while exhibiting good oxidation resistance under accident conditions is receiving increasing attention from the industry. Due to its excellent neutron permeability and radiation resistance, zirconium alloy is still considered the most mature and reliable fuel rod cladding material. Applying an accident-resistant protective coating to the surface of zirconium alloy can, to some extent, delay the oxidation and corrosion of zirconium alloy under accident conditions, improving the reliability of the zirconium alloy cladding tube. O has an extremely low diffusion rate in SiO2, and SiO2 crystals have a high melting point of 1723℃; therefore, SiO2 coatings are considered a promising accident-resistant protective coating material. However, SiO2 is a brittle material with insufficient toughness; once damaged under alternating thermal and vibrational environments, its oxidation resistance will suffer irreversible loss. Therefore, providing a highly tough oxidation-resistant coating is of positive significance for improving the safety of zirconium alloy fuel rod cladding. Summary of the Invention

[0003] The purpose of this invention is to provide a high-toughness, oxidation-resistant coating to improve the service life of zirconium alloys under accident conditions. This invention also provides a method for manufacturing the high-toughness, oxidation-resistant coating.

[0004] According to one aspect of the present invention, a high-toughness anti-oxidation coating is provided, the coating being disposed on the surface of a zirconium alloy substrate, the high-toughness anti-oxidation coating containing, by weight: 0.01%-1% Si, 0.01%-0.7% O, and the balance being Cr; the substrate of the high-toughness anti-oxidation coating is crystalline Cr, and at least a portion of Si and O are dispersed in the substrate in the form of amorphous SiO2.

[0005] Amorphous SiO2 is dispersed in the Cr matrix. While maintaining the good oxidation resistance of the SiO2 coating, the Cr matrix can coordinate the stress and strain between the coating and the zirconium alloy matrix, preventing cracks from initiating at the interface between the coating and the zirconium alloy matrix or within the coating. At the same time, amorphous SiO2 softens significantly and becomes fluid at temperatures far below the melting point of crystalline SiO2, enabling it to self-repair cracks within the coating. This significantly improves the coating's lifespan under accident conditions, thereby enhancing the reliability of zirconium alloy parts using this coating under accident conditions.

[0006] Further, in some embodiments, the high-toughness antioxidant coating contains, by weight ratio: 0.2% - 1% of Si, 0.2% - 0.7% of O, and the balance is Cr, where 0.875 < Si:O ≤ 1.75. Strict control of the Si and O contents is beneficial to the formation of amorphous SiO₂.

[0007] Further, in some embodiments, the amorphous SiO₂ dispersed in the Cr matrix transforms from a solid phase to a viscous flow phase at temperatures above 1100°C. The amorphous SiO₂ transforms from a solid phase to a viscous flow phase at temperatures above 1100°C in a closed and low-oxygen environment, and can flow along grain boundaries or pores to fill cracks in the coating.

[0008] Further, in some embodiments, the thickness of the high-toughness antioxidant coating is 15 μm - 20 μm.

[0009] Further, in some embodiments, in a steam environment at 1200°C, the time for O to diffuse through the high-toughness antioxidant coating to the surface of the zirconium alloy substrate is not less than 48 h.

[0010] Further, in some embodiments, the cracks in the high-toughness antioxidant coating reduce in size by at least 20% within 1 h in a steam environment at 1200°C.

[0011] According to an embodiment of another aspect of the present invention, a method for manufacturing a high-toughness antioxidant coating is provided, which is used to manufacture the high-toughness antioxidant coating provided in any of the foregoing embodiments, and includes the following steps:

[0012] Step a): Provide a Cr - Si - O target, which contains, by weight ratio: 0.01% - 1% of Si, 0.01% - 0.7% of O, and the balance is Cr; where Cr is added in the form of pure Cr powder, and Si and O are added in the form of a pre-oxidized Si - SiO₂ composite powder;

[0013] The Si - SiO₂ composite powder is prepared by the following method: Pre-oxidize pure Si powder in a dry oxygen environment, where the pre-oxidation temperature T °C, the holding time t h, and the particle size D nm of the pure Si powder satisfy: T = 5D ± 50°C, t = 0.02D ± 0.5 h;

[0014] Step b): Provide a zirconium alloy workpiece, and use the Cr - Si - O target to coat a Cr - Si - O composite coating on the surface of the zirconium alloy workpiece by a magnetron pulsed sputtering process;

[0015] Step c): Keep the zirconium alloy workpiece at 80°C for at least 1 h.

[0016] Furthermore, in some embodiments, in step a), the particle size of the pure Si powder is 50nm-150nm.

[0017] Further, in some embodiments, in step a), the Cr-Si-O target material contains, by weight: 0.2%-1% Si, 0.2%-0.7% O, and the balance being Cr, of which 0.875 <Si:O≤1.75。

[0018] Furthermore, in some embodiments, in step a), the Si-SiO2 composite powder includes a Si core and a SiO2 shell, wherein the SiO2 shell uniformly covers the Si core.

[0019] Furthermore, in some embodiments, in step b), the magnetron pulse sputtering process involves a heating temperature of 300℃-400℃ and a vacuum degree not exceeding 4×10⁻⁶. -4 Pa, power of 300W-400W, sputtering time of 20min-25min. Attached Figure Description

[0020] Figure 1 This is a transmission electron microscope image of a portion of the high-toughness, antioxidant coating in one embodiment;

[0021] Figure 2 for Figure 1 Electron diffraction image of the region shown;

[0022] Figure 3 This is a transmission electron microscope image of a pre-fabricated crack in one embodiment;

[0023] Figure 4 This is a transmission electron microscope image of a pre-fabricated crack after being placed in a 1200°C water vapor environment for 1 hour in one embodiment.

[0024] Figure 5 This is a transmission electron microscope image of a pair of pre-existing cracks placed in a 1200℃ water vapor environment for 1 hour.

[0025] The purpose of the above figures is to provide a detailed description of the invention so that those skilled in the art can understand the technical concept of the invention, and not to limit the invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0027] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment herein. The phrase appearing in various places in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive, independent, or alternative embodiments. Those skilled in the art will understand that the embodiments herein can be combined with other embodiments without causing structural conflicts.

[0028] In this description, terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating relative importance or limiting the number, specific order, or primary / secondary relationship of the described technical features. In this description, "multiple" means at least two.

[0029] With the development and promotion of nuclear power technology, the public and industry have placed increasingly higher demands on the reliability of nuclear power facilities under accident conditions. Among these demands, the fuel rod cladding of the reactor core has a crucial impact on the safety of nuclear power facilities. In commercial pressurized water reactors, zirconium alloy is commonly used as the structural material for fuel rod cladding. Under normal operating conditions, the dense oxide layer formed on the surface of the zirconium alloy can prevent further oxidation of the zirconium alloy substrate, giving the zirconium alloy cladding tubes good oxidation resistance. However, in severe accident conditions such as coolant loss-of-coolant accidents, the core temperature may rise rapidly. When the temperature reaches 800℃-1000℃, the zirconium oxide layer may undergo a phase transformation, changing from a monoclinic crystal system to a tetragonal crystal system, leading to a significant increase in the oxidation rate of the zirconium alloy substrate and causing the zirconium alloy cladding to fail. To improve the reliability of zirconium alloy fuel rod cladding under accident conditions, applying a protective coating with good high-temperature oxidation resistance to its surface is considered one of the effective technical means. O in SiO2 has an extremely low diffusion rate, and SiO2 is stable at high temperatures; therefore, SiO2 is considered a good material for preparing anti-oxidation coatings. However, crystalline SiO2 is significantly brittle, and its coefficient of thermal expansion differs greatly from that of the zirconium alloy matrix. Under alternating thermal conditions and long-term vibration, the SiO2 coating lacks sufficient toughness, and once the SiO2 coating cracks, its protective effect on the zirconium alloy matrix will irreversibly deteriorate. This limits the application of SiO2 as an antioxidant coating material.

[0030] To overcome the above problems, one embodiment of the present invention provides a high-toughness, oxidation-resistant coating. This coating is applied to the surface of a zirconium alloy substrate and, by weight, contains 0.01%-1% Si, 0.01%-0.7% O, and the balance Cr. The coating substrate is crystalline Cr, with at least a portion of the Si and O dispersed in the Cr matrix as amorphous SiO2. In a preferred embodiment, the Si content is 0.2%-1%, the O content is 0.2%-0.7%, and 0.875 < Si:O ≤ 1.75.

[0031] In this coating, Cr can form a dense Cr2O3 layer under oxidizing conditions, exhibiting excellent high-temperature oxidation resistance. Due to the low O content in the coating, and the fact that amorphous SiO2 transforms from a solid phase to a viscous flow phase at temperatures above 1100℃ in a closed, low-oxygen environment, the viscous flow phase of SiO2 can self-repair coating defects by flowing along grain boundaries or pores once pores or cracks appear in the coating. This effectively extends the coating's lifespan under high-temperature conditions, improves its oxidation resistance, and enhances the reliability of the zirconium alloy substrate under high-temperature conditions. In a water vapor environment at 1200℃, oxygen diffuses through the coating to the surface of the zirconium alloy substrate for no less than 48 hours.

[0032] The above-mentioned coating can be manufactured by a method for manufacturing a high-toughness, antioxidant coating provided in another aspect of the present invention, the method specifically including the following steps:

[0033] Step a): Provide a Cr-Si-O target material, which contains 0.01%-1% Si and 0.01%-0.7% O by weight, with the balance being Cr; wherein Cr is added in the form of pure Cr powder, and Si and O are added in the form of pre-oxidized Si-SiO2 composite powder. In a preferred embodiment, the Si content in the target material is 0.2%-1%, the O content is 0.2%-0.7%, and 0.875 < Si:O ≤ 1.75, that is, in terms of atomic number, 1 ≤ Si:O < 2.

[0034] The Si-SiO2 composite powder is prepared through the following process: First, pure Si powder is pre-oxidized in a dry oxygen environment. In a preferred embodiment, the Si powder is nanoscale pure Si powder with a particle size of 50nm-150nm. The pre-oxidation temperature T ℃ and the holding time th satisfy T=5D±50℃ and t=0.02D±0.5h respectively, depending on the particle size D nm of the pure Si powder. After the pre-oxidation treatment, the pure Si powder is transformed into Si@SiO2 powder with a spherical shell structure. The uniform and dense SiO2 shell coats the surface of the Si core, giving Si and O good uniformity.

[0035] Si-SiO2 composite powder and pure Cr powder are processed into bulk target material using powder metallurgy.

[0036] Step b): Provide a zirconium alloy component. In different embodiments, the zirconium alloy component can be a zirconium alloy fuel rod cladding, a zirconium alloy wire guide tube, or other zirconium alloy structural components within the reactor core. Using the Cr-Si-O target material from step a), a uniform Cr-Si-O composite coating is applied to the surface of the zirconium alloy component via magnetron pulse sputtering. Specifically, in the magnetron pulse sputtering process, the heating temperature is 300℃-400℃, and the vacuum degree does not exceed 4×10⁻⁶. -4 Pa, power of 300W-400W, sputtering time of 20min-25min.

[0037] Step c): Transfer the zirconium alloy part to a muffle furnace and hold it at 80°C in air for at least 1 hour to obtain a stable, high-toughness, oxidation-resistant coating. The coating thickness is 15μm-20μm.

[0038] In the above method, Si@SiO2 powder is obtained by pre-oxidizing Si powder, and the content of Si and O in it is accurately controlled. In the subsequent magnetron sputtering process, it can ensure that Si and O are distributed in the coating matrix in an amorphous form, inhibiting the formation of crystalline SiO2 or Cr2O3. Amorphous SiO2 can be converted into a viscous flow state below the melting point of crystalline SiO2. Its fluidity can effectively fill and repair cracks in the coating, thereby effectively improving the service life of the coating.

[0039] In the first preferred embodiment, the high-toughness antioxidant coating is prepared by the following process:

[0040] First, a Cr-Si-O target material is prepared. In the Cr-Si-O target material, by weight ratio, Si accounts for 0.23%, O accounts for 0.2%, and the balance is Cr, with a Si:O ratio of 1.15. Cr is added in the form of micron-sized pure Cr powder, while Si and O are added in the form of Si-SiO2 composite powder. The Cr powder and Si-SiO2 composite powder are then processed into a bulk target material using powder metallurgy.

[0041] Specifically, the Si-SiO2 composite powder is Si@SiO2 powder obtained by holding 100nm pure Si powder at 500℃ for 2h, with the SiO2 shell uniformly coating the surface of the Si core. The particle size D (100nm) of the pure Si powder satisfies the limiting conditions T=5D±50℃ and t=0.02D±0.5h with respect to the pre-oxidation treatment temperature T℃ and the holding time th.

[0042] Next, using the prepared Cr-Si-O target, a Cr-Si-O composite layer was fabricated on the surface of the zirconium alloy fuel rod cladding tube via magnetron pulse sputtering. The heating temperature within the magnetron pulse sputtering chamber was set to 300℃, and the vacuum degree was 4×10⁻⁶. -4 Pa, power of 400W, sputtering time of 20min.

[0043] Finally, the zirconium alloy fuel rod cladding tube was placed in a muffle furnace and kept at 80°C in air for 1 hour to obtain a high-toughness, oxidation-resistant coating with a stable structure on the surface of the zirconium alloy fuel rod cladding tube.

[0044] Multiple coated samples were placed in a water vapor environment at 1200℃ for oxidation tests. Samples were taken out at intervals to characterize the oxidation of the zirconium alloy surface. After 48 hours of testing, no oxidation occurred on the zirconium alloy surface, indicating that O had not yet diffused through the coating to the zirconium alloy substrate. Oxidation corrosion began to appear on the zirconium alloy surface after 52 hours of testing.

[0045] TEM (transmission electron microscopy) samples were cut from the prepared coating and characterized, and their morphology was as follows: Figure 1 As shown, for Figure 1 The results of electron diffraction analysis of the area are as follows: Figure 2 As shown, the diffraction pattern includes diffraction spots formed by crystalline Cr and diffraction rings formed by amorphous SiO2, indicating that... Figure 1 The region shown includes a crystalline Cr matrix and amorphous SiO2. A coating is prepared as follows: Figure 3 The pre-crack 1 shown is formed when the coated sample is placed in a water vapor environment at 1200℃ for 1 hour. The morphology of the pre-crack is as follows. Figure 4 As shown, the cracks were locally repaired, and the crack size (pore area in the coating) was reduced by 40%. This is because, in a closed, low-oxygen environment, amorphous SiO2 changed from a solid phase to a viscous flow phase, flowing along grain boundaries and pores, filling the pre-cracked area, and achieving self-healing of the coating.

[0046] In the second preferred embodiment, the high-toughness antioxidant coating is prepared by the following process:

[0047] First, a Cr-Si-O target material is prepared. In the Cr-Si-O target material, by weight ratio, Si accounts for 0.55%, O accounts for 0.42%, and the balance is Cr, with a Si:O ratio of 1.31. Cr is added in the form of micron-sized pure Cr powder, while Si and O are added in the form of Si-SiO2 composite powder. The Cr powder and Si-SiO2 composite powder are then processed into a bulk target material using powder metallurgy.

[0048] Specifically, the Si-SiO2 composite powder is Si@SiO2 powder obtained by holding pure 100nm Si powder at 550℃ for 2h, with the SiO2 shell uniformly coating the surface of the Si core. The particle size D (100nm) of the pure Si powder satisfies the limiting conditions T=5D±50℃ and t=0.02D±0.5h with respect to the pre-oxidation treatment temperature T℃ and the holding time th.

[0049] Next, using the prepared Cr-Si-O target, a Cr-Si-O composite layer was fabricated on the surface of the zirconium alloy fuel rod cladding tube via magnetron pulse sputtering. The heating temperature within the magnetron pulse sputtering chamber was set to 300℃, and the vacuum degree was 4×10⁻⁶. -4 Pa, power of 400W, sputtering time of 20min.

[0050] Finally, the zirconium alloy fuel rod cladding tube was placed in a muffle furnace and kept at 80°C in air for 1 hour to obtain a high-toughness, oxidation-resistant coating with a stable structure on the surface of the zirconium alloy fuel rod cladding tube.

[0051] Multiple coated samples were placed in a water vapor environment at 1200℃ for oxidation tests. Samples were taken out at intervals to characterize the oxidation of the zirconium alloy surface. After 48 hours of testing, no oxidation occurred on the zirconium alloy surface, indicating that O had not yet diffused through the coating to the zirconium alloy substrate. Oxidation corrosion began to appear on the zirconium alloy surface after 58 hours of testing.

[0052] In the third preferred embodiment, the high-toughness antioxidant coating is prepared by the following process:

[0053] First, Cr-Si-O target materials are prepared. In the Cr-Si-O target material, by weight ratio, Si accounts for 0.77%, O accounts for 0.69%, and the balance is Cr, with a Si:O ratio of 1.12. Cr is added in the form of micron-sized pure Cr powder, while Si and O are added in the form of Si-SiO2 composite powder. The Cr powder and Si-SiO2 composite powder are then processed into bulk target materials using powder metallurgy.

[0054] Specifically, the Si-SiO2 composite powder is Si@SiO2 powder obtained by holding 100nm pure Si powder at 550℃ for 1.5h, with the SiO2 shell uniformly coating the surface of the Si core. The particle size D (100nm) of the pure Si powder satisfies the limiting conditions T=5D±50℃ and t=0.02D±0.5h with respect to the pre-oxidation treatment temperature T℃ and the holding time th.

[0055] Next, using the prepared Cr-Si-O target, a Cr-Si-O composite layer was fabricated on the surface of the zirconium alloy fuel rod cladding tube via magnetron pulse sputtering. The heating temperature within the magnetron pulse sputtering chamber was set to 300℃, and the vacuum degree was 4×10⁻⁶. -4 Pa, power of 400W, sputtering time of 20min.

[0056] Finally, the zirconium alloy fuel rod cladding tube was placed in a muffle furnace and kept at 80°C in air for 1 hour to obtain a high-toughness, oxidation-resistant coating with a stable structure on the surface of the zirconium alloy fuel rod cladding tube.

[0057] Multiple coated samples were placed in a water vapor environment at 1200℃ for oxidation tests. Samples were taken out at intervals to characterize the oxidation of the zirconium alloy surface. After 48 hours of testing, no oxidation occurred on the zirconium alloy surface, indicating that O had not yet diffused through the coating to the zirconium alloy substrate. Oxidation corrosion began to appear on the zirconium alloy surface after 88 hours of testing.

[0058] In one comparative example, an antioxidant coating was prepared via the following process:

[0059] Cr-Si-O targets were prepared by powder metallurgy, wherein Si accounted for 1.55% and O for 1.28% by weight, with the balance being Cr. Cr was added as pure Cr powder; Si and O were added as a mixed powder that had undergone natural oxidation. Specifically, the mixed powder was prepared by naturally oxidizing pure Si powder with a particle size of 100 nm in dry air. The pure Cr powder was then mixed with the naturally oxidized mixed powder, pressed, and sintered to obtain the Cr-Si-O target.

[0060] Using this Cr-Si-O target, a coating was prepared on the surface of a zirconium alloy tube by magnetron pulse sputtering. Specifically, the magnetron pulse sputtering chamber was heated to 300°C and the vacuum degree was 4×10⁻⁶. -4 Pa, sputtered at 400W power for 20 minutes.

[0061] An oxidation test was conducted on the anti-oxidation coating at 1200℃. Oxidation corrosion began to appear on the surface of the zirconium alloy substrate after 10 hours of the test.

[0062] Pre-cracks were introduced into the antioxidant coating. After being placed in a water vapor environment at 1200℃ for 1 hour, the pre-cracked area was characterized by TEM, and its morphology is as follows. Figure 5 As shown, the threshold crack exhibits a clear through-structure and does not self-heal. The difference in antioxidant and self-healing properties between the comparative example and the embodiment is due to the fact that in the comparative example, O is introduced into the Si powder through natural oxidation, resulting in a thinner and incomplete SiO2 layer that does not form a complete shell structure covering the Si core. Therefore, amorphous SiO2 structure cannot be formed during magnetron sputtering. Simultaneously, due to the relatively high Si content and relatively insufficient O, Si reacts with the Cr matrix to form a Cr-Si grain boundary phase, which creates a rapid diffusion path for O within the coating, weakening the coating's ability to resist O. Furthermore, under high-temperature oxidation conditions, Cr2O3 easily vaporizes, leading to coating loss. The antioxidant coating provided in the comparative example cannot repair coating defects through the flow of amorphous SiO2, further contributing to the rapid failure of the coating.

[0063] The manufacturing method of the high-toughness anti-oxidation coating provided in the above embodiments, by strictly controlling the Si and O content in the coating and performing magnetron pulse sputtering in an environment with a Si to O mass ratio close to 1:1 and a relative O deficiency, can effectively induce the formation of amorphous SiO2 while inhibiting the reactions of Cr with O and Cr with Si. The resulting high-toughness anti-oxidation coating exhibits excellent anti-oxidation performance under high-temperature oxidation conditions. Furthermore, by utilizing the fluidity of amorphous SiO2 as it transforms into a viscous phase at high temperatures, it achieves self-healing of coating cracks and defects, effectively improving the service life of the coating itself. This enhances the reliability of zirconium alloy structural components using this high-toughness anti-oxidation coating under high-temperature accident conditions, delays structural failure, and improves accident resistance.

[0064] The purpose of the above embodiments is to provide a further detailed description of the present invention in conjunction with the accompanying drawings, so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the present invention, optimization or equivalent substitution of the technical features involved, as well as combination of implementation methods in different embodiments without causing structural and principle conflicts, all fall within the protection scope of the present invention.

Claims

1. A high-toughness, oxidation-resistant coating, applied to the surface of a zirconium alloy substrate, characterized in that, The high-toughness antioxidant coating contains, by weight: 0.01%-1% Si, 0.01%-0.7% O, and the balance is Cr; the matrix of the high-toughness antioxidant coating is crystalline Cr, and at least some of the Si and O exist in the matrix in the form of amorphous SiO2.

2. The high-toughness antioxidant coating according to claim 1, characterized in that, The high-toughness antioxidant coating contains, by weight: 0.2%-1% Si, 0.2%-0.7% O, and the balance being Cr, of which 0.875 <Si:O≤1.75。 3. The high-toughness antioxidant coating according to claim 1 or 2, characterized in that, The amorphous SiO2 dispersed in the Cr matrix transforms from a solid phase to a viscous flow phase at temperatures above 1100°C.

4. The high-toughness antioxidant coating according to claim 1 or 2, characterized in that, The thickness of the high-toughness antioxidant coating is 15μm-20μm.

5. The high-toughness antioxidant coating according to claim 4, characterized in that, In a water vapor environment at 1200℃, the time for O to diffuse through the high-toughness anti-oxidation coating to the surface of the zirconium alloy substrate is no less than 48 hours.

6. The high-toughness antioxidant coating according to claim 1 or 2, characterized in that, The cracks in the high-toughness anti-oxidation coating are reduced by at least 20% within 1 hour in a water vapor environment at 1200°C.

7. A method for manufacturing a high-toughness, antioxidant coating, characterized in that, For manufacturing a high-toughness, antioxidant coating as described in any one of claims 1 to 6, the method comprises the following steps: Step a): Provide a Cr-Si-O target material, wherein the Cr-Si-O target material contains 0.01%-1% Si and 0.01%-0.7% O by weight, with the balance being Cr; wherein Cr is added in the form of pure Cr powder, and Si and O are added in the form of Si-SiO2 composite powder that has undergone pre-oxidation treatment. The Si-SiO2 composite powder is prepared by the following method: pure Si powder is pre-oxidized in a dry oxygen environment, wherein the pre-oxidation temperature T ℃, the holding time th, and the particle size D nm of the pure Si powder satisfy the following conditions: T=5D±50℃, t=0.02D±0.5h. Step b): Provide a zirconium alloy part, and use the Cr-Si-O target to coat the surface of the zirconium alloy part with a Cr-Si-O composite coating by magnetron pulse sputtering process; Step c): Hold the zirconium alloy part at 80°C for at least 1 hour.

8. The method for manufacturing the high-toughness antioxidant coating according to claim 7, characterized in that, In step a), the particle size of the pure Si powder is 50nm-150nm.

9. The method for manufacturing a high-toughness, antioxidant coating according to claim 7 or 8, characterized in that, In step a), the Cr-Si-O target material contains, by weight: 0.2%-1% Si, 0.2%-0.7% O, and the balance is Cr, of which 0.875 <Si:O≤1.75。 10. The method for manufacturing the high-toughness antioxidant coating according to claim 7 or 8, characterized in that, In step a), the Si-SiO2 composite powder includes a Si core and a SiO2 shell, wherein the SiO2 shell uniformly coats the Si core.

11. The method for manufacturing a high-toughness, antioxidant coating according to claim 7 or 8, characterized in that, In step b), the magnetron pulse sputtering process involves a heating temperature of 300℃-400℃ and a vacuum degree not exceeding 4×10⁻⁶. -4 Pa, power of 300W-400W, sputtering time of 20min-25min.

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