A protective coating against high-temperature water vapor oxidation and a preparation method and application thereof

Abstract

The application provides a high-temperature water vapor oxidation resistant protective coating and a preparation method and application thereof, and belongs to the technical field of alloy coatings. The high-temperature water vapor oxidation resistant protective coating provided by the application comprises the following components in percentage of atoms: 8-35% of Al, 0.5-10% of Nb and / or Ta, 0.5-5% of RE and the balance of Cr. In the application, Cr is used as a matrix, Al is introduced, and a continuous, dense and crack-free Al2O3 oxidation film can be formed at high temperature, the thermodynamic stability of the oxidation film is improved, and the high-temperature oxidation resistance is improved. The introduced Nb element and Y element are enriched at the coating grain boundary and the coating-matrix interface, the Cr / Zr interdiffusion can be blocked, the diffusion of Zr elements into the Cr coating to form an oxygen diffusion channel is avoided, and the high-temperature oxidation resistance of the coating is further improved.

Description

Technical Field

[0001] This invention relates to the field of alloy coating technology, and in particular to a protective coating resistant to high-temperature water vapor oxidation, its preparation method, and its application. Background Technology

[0002] Zirconium alloys are widely used as reactor nuclear fuel cladding materials due to their unique comprehensive properties, such as small thermal neutron absorption cross section, excellent resistance to high-temperature water corrosion, and good mechanical properties.

[0003] However, when a reactor experiences a loss-of-coolant accident, the zirconium alloy cladding oxidizes rapidly, causing a sharp decline in its mechanical properties, leading to cracking, nuclear fuel leakage, and a serious nuclear accident. Preparing an anti-oxidation coating on the zirconium alloy surface can effectively improve the cladding's oxidation resistance and extend accident rescue time, making it an important means of improving the cladding's accident resistance. Currently used pure Cr coatings have the following problems: Due to interdiffusion between the Zr matrix and the Cr coating, after 30–120 minutes under loss-of-coolant accident conditions, Zr diffuses into the Cr coating, forming oxygen diffusion channels. This allows oxygen to penetrate the Cr coating and enter the Zr matrix, causing oxidation of the Zr alloy matrix and reducing the cladding's ability to resist loss-of-coolant accidents. Simultaneously, the diffused Zr reacts with the surface-formed Cr₂O₃ oxide film in a redox reaction, thinning the Cr₂O₃ oxide film and reducing the coating's oxidation resistance.

[0004] Therefore, providing a coating that can both suppress the outward diffusion of Zr elements in the matrix and improve the antioxidant properties has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a protective coating resistant to high-temperature water vapor oxidation, its preparation method and application. The protective coating provided by this invention forms a continuous, dense and crack-free Al2O3 oxide film on the surface after steam oxidation at 1200℃ for 1 hour, while the oxidation weight gain is low and the zirconium alloy substrate is not oxidized.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] The present invention provides a protective coating resistant to high-temperature water vapor oxidation, comprising the following components by atomic percentage: 8-35% Al, 0.5-10% Nb and / or Ta, 0.5-5% RE and the balance Cr.

[0008] Preferably, the protective coating against high-temperature water vapor oxidation comprises, by atomic percentage, 9-25% Al, 4-7% Nb, 1-4% RE and the balance Cr.

[0009] Preferably, the protective coating resistant to high-temperature water vapor oxidation comprises, by atomic percentage, 12-20% Al, 5-6% Nb, 2-3% RE and the balance Cr.

[0010] Preferably, the RE is any one or more of Y, La, and Ce.

[0011] The present invention provides a method for preparing the protective coating against high-temperature water vapor oxidation as described in the above technical solution, comprising: preparing the protective coating against high-temperature water vapor oxidation by physical vapor deposition.

[0012] Preferably, the physical vapor deposition method is magnetron sputtering or arc ion plating.

[0013] Preferably, the magnetron sputtering method includes: installing a Cr target, an Al target, an Nb target, a Y target and a zirconium alloy substrate in a magnetron sputtering device, and then sequentially performing vacuuming, preheating of the zirconium alloy substrate, glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation.

[0014] Preferably, the vacuum degree of the glow discharge cleaning is 3-6 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 5-15 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 50-120 V.

[0015] Preferably, the power of the Cr target during coating is 150-190W; the power of the Al target during coating is 45-100W; the power of the Nb target during coating is 15-80W; the power of the Y target during coating is 5-50W; the bias voltage during coating is 50-120V; the gas pressure during coating is 0.5-2Pa; and the sputtering time during coating is 2-6h.

[0016] This invention provides the application of the protective coating against high-temperature water vapor oxidation described in the above-described technical solution or the protective coating against high-temperature water vapor oxidation prepared by the preparation method described in the above-described technical solution in reactor nuclear fuel cladding materials.

[0017] This invention provides a protective coating resistant to high-temperature steam oxidation, comprising, by atomic percentage: 8-35% Al, 0.5-10% Nb and / or Ta, 0.5-5% RE, and the balance Cr. This invention uses Cr as a matrix and introduces Al, which at high temperatures forms a continuous, dense, and crack-free Al₂O₃ oxide film, improving the thermodynamic stability of the oxide film and thus enhancing its resistance to high-temperature oxidation. Simultaneously, the introduced Nb and Y elements are enriched at the coating grain boundaries and coating-matrix interface, blocking Cr / Zr interdiffusion and preventing Zr from diffusing into the Cr coating to form oxygen diffusion channels, thereby further improving the coating's resistance to high-temperature oxidation. The results of the embodiments show that the protective coating provided by this invention, after steam oxidation at 1200℃ for 1 hour, forms a continuous, dense, and crack-free Al₂O₃ oxide film on the surface, with a minimum oxidation weight gain of 0.15 mg / mm². 2 The zirconium alloy matrix is ​​free of oxidation. Attached Figure Description

[0018] Figure 1 Weight gain curves of the protective coatings provided in Example 1 and Comparative Example 1 under high-temperature water vapor oxidation at 1200°C;

[0019] Figure 2 The surface morphology of the protective coating provided in Example 1 after oxidation with water vapor at 1200°C for 1 hour;

[0020] Figure 3 The surface morphology of the protective coating provided for Comparative Example 1 after high-temperature steam oxidation at 1200℃ for 1 hour;

[0021] Figure 4 The low-magnification cross-sectional morphology of the protective coating provided in Example 1 after oxidation with water vapor at 1200°C for 1 hour;

[0022] Figure 5 The low-magnification cross-sectional morphology of the protective coating provided for Comparative Example 1 after oxidation with water vapor at 1200℃ for 1 hour;

[0023] Figure 6 The high-magnification cross-sectional morphology and surface distribution of O and Al elements of the protective coating provided in Example 1 after oxidation with water vapor at 1200°C for 1 hour. Detailed Implementation

[0024] The present invention provides a protective coating resistant to high-temperature water vapor oxidation, comprising the following components by atomic percentage: 8-35% Al, 0.5-10% Nb and / or Ta, 0.5-5% RE and the balance Cr.

[0025] The protective coating against high-temperature water vapor oxidation provided by this invention comprises 8-35% Al by atomic percentage. As one embodiment of this invention, the atomic percentage of Al can be 9%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, or 34%. By adding a certain amount of Al to the protective coating, this invention can form a continuous, dense, and crack-free Al₂O₃ oxide film at high temperatures, thereby improving its resistance to high-temperature oxidation.

[0026] The protective coating against high-temperature water vapor oxidation provided by this invention, by atomic percentage, comprises 0.5–10% Nb and / or Ta, preferably Nb. In this invention, when the protective coating comprises Nb and Ta, the mass of Ta is preferably 1–90% of the mass of Nb, more preferably 5–50%, and even more preferably 10–20%. As one embodiment of this invention, the atomic percentage of Nb can be 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, or 9.5%. By adding a certain amount of Nb to the protective coating, this invention can enrich it at the coating grain boundaries and coating-matrix interface, blocking Cr / Zr interdiffusion.

[0027] The protective coating against high-temperature water vapor oxidation provided by this invention, by atomic percentage, comprises 0.5% to 5% RE; the RE is preferably any one or more of Y, La, and Ce, more preferably Y. As one embodiment of this invention, the atomic percentage of the RE can be 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, or 4.8%. By adding a certain amount of RE to the protective coating, this invention can enrich it at the coating grain boundaries and coating-matrix interface, blocking Cr / Zr interdiffusion.

[0028] The protective coating against high-temperature water vapor oxidation provided by this invention, by atomic percentage, comprises the balance Cr. In this invention, Cr is the matrix element of the coating.

[0029] This invention uses Cr as a matrix and introduces Al elements to form a continuous, dense, and crack-free Al2O3 oxide film at high temperatures, thereby improving the thermodynamic stability of the oxide film and thus enhancing its resistance to high-temperature oxidation. At the same time, the introduced Nb and Y elements are enriched at the coating grain boundaries and coating-substrate interface, which can block Cr / Zr interdiffusion and prevent Zr elements from diffusing into the Cr coating to form oxygen diffusion channels, thereby further improving the coating's resistance to high-temperature oxidation.

[0030] The present invention provides a method for preparing the protective coating against high-temperature water vapor oxidation as described in the above technical solution, comprising: preparing the protective coating against high-temperature water vapor oxidation by physical vapor deposition.

[0031] In this invention, the physical vapor deposition method is preferably magnetron sputtering or arc ion plating.

[0032] The present invention does not impose any special limitations on the specific operation of the arc ion plating. The parameters can be determined based on the technical common sense of those skilled in the art, as long as the parameters of the protective coating meet the requirements.

[0033] In this invention, the magnetron sputtering method preferably includes: installing a Cr target, an Al target, an Nb target, a Y target and a zirconium alloy substrate in a magnetron sputtering device, and then sequentially performing vacuuming, preheating of the zirconium alloy substrate, glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation.

[0034] The present invention does not have any special limitation on the specific source of the Cr target, Al target, Nb target, Y target and zirconium alloy matrix. Commercially available Cr targets, Al targets, Nb targets, Y targets and zirconium alloy matrices known to those skilled in the art can be used as long as they meet the technical requirements.

[0035] The present invention does not impose any special limitations on the specific model and source of the magnetron sputtering equipment; commercially available magnetron sputtering equipment known to those skilled in the art can be used.

[0036] In this invention, the diameters of the Cr, Al, Nb, and Y targets are preferably 40–80 mm; the thicknesses of the Cr, Al, Nb, and Y targets are preferably 3–10 mm. As one embodiment of this invention, the diameters of the Cr, Al, Nb, and Y targets can be 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, or 75 mm; the thicknesses of the Cr, Al, Nb, and Y targets can be 5 mm, 6 mm, 7 mm, 8 mm, or 9 mm. This invention, by controlling the dimensions of the Cr, Al, Nb, and Y targets, facilitates their installation in magnetron sputtering equipment and subsequent coating processes.

[0037] The present invention does not impose any specific limitation on the dimensions of the zirconium alloy substrate; the dimensions can be determined according to the requirements of those skilled in the art. As one embodiment of the present invention, the length of the zirconium alloy substrate can be 5–50 mm, or 10 mm, 15 mm, 25 mm, 30 mm, 35 mm, 40 mm, or 45 mm; the width of the zirconium alloy substrate can be 5–50 mm, or 10 mm, 15 mm, 25 mm, 30 mm, 35 mm, 40 mm, or 45 mm; the thickness of the zirconium alloy substrate can be 0.8–1.5 mm, or 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, or 1.4 mm.

[0038] In this invention, the zirconium alloy substrate is preferably pretreated before installation; the pretreatment is preferably performed sequentially by grinding, cleaning, and drying. In this invention, the grinding method is preferably sandpaper grinding; the sandpaper grinding is preferably performed using #200 to #2000 sandpaper, more preferably by sequentially using #200, #600, #800, #1000, #1500, and #2000 sandpaper; the cleaning method is preferably ultrasonic cleaning in acetone and ethanol sequentially; the ultrasonic cleaning time is preferably 10 to 20 minutes. As one embodiment of this invention, the ultrasonic cleaning time can be 12 minutes, 15 minutes, or 18 minutes. This invention does not have specific limitations on the grinding time, ultrasonic power, or drying method; based on the technical knowledge of those skilled in the art, it is sufficient to remove impurities from the surface of the zirconium alloy substrate. This invention removes impurities from the surface of the zirconium alloy substrate by pretreatment.

[0039] In this invention, the zirconium alloy substrate is preferably mounted on the fixture of a magnetron sputtering apparatus; the Cr target, Al target, Nb target, and Y target are respectively placed on four target positions of the magnetron sputtering apparatus; the tilt angle of the four target positions is preferably independently 30-45°. As one embodiment of this invention, the tilt angle of the four target positions can be independently 32°, 35°, 38°, 40°, or 42°.

[0040] This invention does not impose specific limitations on the vacuuming operation, as long as the vacuum level of the magnetron sputtering equipment chamber meets the requirements. In one embodiment of this invention, the vacuum level of the magnetron sputtering equipment chamber can be <10. -3 Pa. This invention removes air and avoids the influence of impurities by drawing a vacuum.

[0041] The present invention does not impose any specific limitations on the preheating operation of the zirconium alloy substrate, as long as the temperature of the zirconium alloy substrate meets the requirements. As one embodiment of the present invention, the preheating temperature of the zirconium alloy substrate can be 250–350°C, or even 280°C, 300°C, or 320°C; the preheating holding time of the zirconium alloy substrate can be 20–60 minutes, or even 30 minutes, 40 minutes, or 50 minutes. By preheating the zirconium alloy substrate, the present invention can improve the adhesion of the coating during subsequent magnetron sputtering.

[0042] In this invention, the vacuum degree of the glow discharge cleaning is preferably 3-6 Pa; the atmosphere of the glow discharge cleaning is preferably argon; the glow discharge cleaning time is preferably 5-15 min; and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is preferably 50-120 V. As one embodiment of this invention, the vacuum degree of the glow discharge cleaning can be 4-5 Pa; the glow discharge cleaning time can be 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, or 14 min; and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning can be 60 V, 70 V, 80 V, 90 V, 100 V, or 110 V. This invention, through glow discharge cleaning, can obtain an atomically clean surface, thereby greatly improving the adhesion of the coating.

[0043] In this invention, the power of the Cr target during coating is preferably 150-190W; the power of the Al target during coating is preferably 45-100W; the power of the Nb target during coating is preferably 15-80W; the power of the Y target during coating is preferably 5-50W; the bias voltage during coating is preferably 50-120V; the gas pressure during coating is preferably 0.5-2Pa; the sputtering time during coating is preferably 2-6h; the Cr and Al targets preferably use DC power supplies; and the Nb and Y targets preferably use radio frequency power supplies. In one embodiment of the present invention, the power of the Cr target during coating can be 160W, 170W, or 180W; the power of the Al target during coating can be 50W, 60W, 70W, 80W, or 90W; the power of the Nb target during coating can be 20W, 30W, 40W, 50W, 60W, or 70W; the power of the Y target during coating can be 10W, 15W, 20W, 25W, 30W, 35W, 40W, or 45W; the bias voltage during coating can be 60V, 70V, 80V, 90V, 100V, or 110V; the gas pressure during coating can be 0.8Pa, 1Pa, 1.2Pa, 1.5Pa, or 1.8Pa; and the sputtering time during coating can be 3h, 4h, or 5h. This invention, by controlling the coating process parameters, can produce a dense coating free of defects such as cracks and pores, with uniform element distribution. After isothermal oxidation at 1200℃ / 1h, a continuously dense Al2O3 oxide film is formed on the coating surface. The Al2O3 film has a lower growth rate and higher thermal stability. Furthermore, by enriching Nb and Y elements at the coating grain boundaries and coating-substrate interface, the outward diffusion of Zr elements is suppressed, significantly improving the oxidation resistance of the coating and protecting the Zr alloy matrix.

[0044] In this invention, the thickness of the protective coating resistant to high-temperature water vapor oxidation is preferably 13–16 μm, more preferably 14–15 μm. By controlling the thickness of the protective coating, this invention can further improve its antioxidant properties.

[0045] This invention uses physical vapor deposition to prepare a protective coating, which can make the coating dense, free of defects such as cracks and pores, and with uniform distribution of elements, thereby improving the coating's resistance to high-temperature oxidation.

[0046] The present invention also provides the application of the protective coating against high-temperature water vapor oxidation described in the above technical solution or the protective coating against high-temperature water vapor oxidation prepared by the preparation method described in the above technical solution in reactor nuclear fuel cladding materials.

[0047] The present invention does not impose any special limitations on the specific operation of the application, and any application method known to those skilled in the art can be used.

[0048] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0049] Example 1

[0050] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage: 20% Al, 5% Nb, 2% Y and balance Cr;

[0051] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0052] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0053] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3 Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 180 W, the power of the Al target is 100 W, the power of the Nb target is 40 W, and the power of the Y target is 25 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0054] The protective coating against high-temperature water vapor oxidation provided in Example 1 has a thickness of 15 μm.

[0055] Example 2

[0056] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage: 20% Al, 1.5% Nb, 0.5% Y and balance Cr;

[0057] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0058] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0059] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3 Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 170 W, the power of the Al target is 100 W, the power of the Nb target is 15 W, and the power of the Y target is 5 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0060] The protective coating against high-temperature water vapor oxidation provided in Example 2 has a thickness of 15 μm.

[0061] Example 3

[0062] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage: 8% Al, 10% Nb, 3% Y and balance Cr;

[0063] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0064] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0065] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3 Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 160 W, the power of the Al target is 50 W, the power of the Nb target is 80 W, and the power of the Y target is 30 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0066] The protective coating against high-temperature water vapor oxidation provided in Example 3 has a thickness of 15 μm.

[0067] Example 4

[0068] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage, 12% Al, 5% Nb, 5% Y and the balance Cr;

[0069] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0070] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0071] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3 Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 175 W, the power of the Al target is 70 W, the power of the Nb target is 35 W, and the power of the Y target is 50 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0072] The protective coating against high-temperature water vapor oxidation provided in Example 4 has a thickness of 15 μm.

[0073] Example 5

[0074] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage: 8% Al, 7% Nb, 0.5% Y and balance Cr;

[0075] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0076] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0077] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 190 W, the power of the Al target is 45 W, the power of the Nb target is 50 W, and the power of the Y target is 5 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0078] The protective coating against high-temperature water vapor oxidation provided in Example 5 has a thickness of 15 μm.

[0079] Example 6

[0080] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage: 25% Al, 4% Nb, 4% Y and balance Cr;

[0081] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0082] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0083] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 150 W, the power of the Al target is 120 W, the power of the Nb target is 30 W, and the power of the Y target is 40 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0084] The protective coating against high-temperature water vapor oxidation provided in Example 6 has a thickness of 15 μm.

[0085] Example 7

[0086] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage: 12% Al, 5% Nb, 3% Y and balance Cr;

[0087] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0088] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0089] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3Pa, then the zirconium alloy substrate is preheated to 250℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angle of the four target positions is 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 50 V; the power of the Cr target is 180 W, the power of the Al target is 70 W, the power of the Nb target is 40 W, and the power of the Y target is 30 W during coating; the bias voltage during coating is 50 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0090] The protective coating against high-temperature water vapor oxidation provided in Example 7 has a thickness of 15 μm.

[0091] Example 8

[0092] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage: 9% Al, 10% Nb, 0.5% Y and balance Cr;

[0093] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0094] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0095] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 100 V; during the coating process, the power of the Cr target is 185 W, the power of the Al target is 55 W, the power of the Nb target is 80 W, and the power of the Y target is 5 W; the bias voltage during the coating process is 100 V, the gas pressure is 0.5 Pa, and the sputtering time during the coating process is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0096] The protective coating against high-temperature water vapor oxidation provided in Example 8 has a thickness of 15 μm.

[0097] Example 9

[0098] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage: 18% Al, 1.5% Nb, 4% Y and balance Cr;

[0099] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0100] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0101] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3Pa, then the zirconium alloy substrate is preheated to 250℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 120 V; the power of the Cr target is 165 W, the power of the Al target is 95 W, the power of the Nb target is 15 W, and the power of the Y target is 40 W during coating; the bias voltage during coating is 120 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0102] The protective coating against high-temperature water vapor oxidation provided in Example 9 has a thickness of 15 μm.

[0103] Example 10

[0104] A protective coating resistant to high-temperature water vapor oxidation, comprising, by atomic percentage, 12% Al, 10% Nb, 4% Y and balance Cr;

[0105] The preparation method of the protective coating resistant to high-temperature water vapor oxidation includes the following steps:

[0106] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0107] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3Pa, then the zirconium alloy substrate is preheated to 250℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angles of the four target positions are all 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 120 V; the power of the Cr target is 170 W, the power of the Al target is 75 W, the power of the Nb target is 80 W, and the power of the Y target is 40 W during coating; the bias voltage during coating is 120 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0108] The protective coating against high-temperature water vapor oxidation provided in Example 10 has a thickness of 15 μm.

[0109] Comparative Example 1

[0110] A protective coating, by atomic percentage, consists of 20% Al and the balance Cr;

[0111] The protective coating is prepared by the following steps:

[0112] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0113] (2) Mount the zirconium alloy substrate obtained in step (1) onto the fixture of the magnetron sputtering equipment. Place the Cr target and Al target on the two target positions of the magnetron sputtering equipment, respectively. Evacuate the equipment until the vacuum level in the magnetron sputtering chamber is <10. -3 Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating; the diameter of the Cr target and the Al target are both 60 mm and the thickness is both 5 mm; the tilt angle of the two target positions is 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 170 W and the power of the Al target is 75 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr target and the Al target are powered by DC power supply.

[0114] The protective coating provided in Comparative Example 1 has a thickness of 15 μm.

[0115] Comparative Example 2

[0116] A protective coating, by atomic percentage, consists of the following components: 10% Al, 5% Nb, and the balance Cr;

[0117] The protective coating is prepared by the following steps:

[0118] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0119] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, and Nb target are placed at the three target positions of the magnetron sputtering equipment, respectively. The vacuum level in the magnetron sputtering equipment chamber is evacuated to <10. -3 Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating; the diameter of the Cr target, Al target and Nb target are all 60 mm, and the thickness is 5 mm; the tilt angle of the three target positions is 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 180 W, the power of the Al target is 60 W, and the power of the Nb target is 40 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr target and Al target use DC power supply, and the Nb target uses radio frequency power supply.

[0120] The protective coating provided in Comparative Example 2 has a thickness of 15 μm.

[0121] Comparative Example 3

[0122] A protective coating, by atomic percentage, consists of the following components: 5% Al, 5% Nb, 2% Y and the balance Cr;

[0123] The protective coating is prepared by the following steps:

[0124] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0125] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3 Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angle of the four target positions is 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 150 W, the power of the Al target is 30 W, the power of the Nb target is 40 W, and the power of the Y target is 25 W during coating; the bias voltage during coating is 70 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0126] The protective coating provided in Comparative Example 3 has a thickness of 15 μm.

[0127] Comparative Example 4

[0128] A protective coating, by atomic percentage, consists of the following components: 10% Al, 5% Nb, 2% Y and the balance Cr;

[0129] The protective coating is prepared by the following steps:

[0130] (1) The untreated zirconium alloy substrate was polished sequentially with #200, #600, #800, #1000, #1500 and #2000 sandpaper, then ultrasonically cleaned with acetone and ethanol for 15 minutes respectively, and finally dried to obtain the zirconium alloy substrate; the zirconium alloy substrate has a length of 40 mm, a width of 40 mm and a thickness of 1.2 mm;

[0131] (2) The zirconium alloy substrate obtained in step (1) is mounted on the fixture of the magnetron sputtering equipment. The Cr target, Al target, Nb target and Y target are placed at the four target positions of the magnetron sputtering equipment, respectively. The vacuum level of the magnetron sputtering equipment chamber is evacuated to <10. -3Pa, then the zirconium alloy substrate is preheated to 350℃ and held for 30 min, followed by glow discharge cleaning and coating to obtain a protective coating; the diameters of the Cr, Al, Nb, and Y targets are all 60 mm, and the thickness is 5 mm; the tilt angle of the four target positions is 45°; the vacuum degree of the glow discharge cleaning is 5 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 10 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 70 V; the power of the Cr target is 180 W, the power of the Al target is 60 W, the power of the Nb target is 40 W, and the power of the Y target is 25 W during coating; the bias voltage during coating is 0 V, the gas pressure is 0.5 Pa, and the sputtering time during coating is 4 h; the Cr and Al targets use DC power supplies, and the Nb and Y targets use RF power supplies.

[0132] The protective coating provided in Comparative Example 4 has a thickness of 15 μm.

[0133] The coating parameters for the protective coatings prepared in Examples 1-10 and Comparative Examples 1-4 are shown in Table 1:

[0134] Table 1. Parameters of the protective coatings prepared in Examples 1-10 and Comparative Examples 1-4.

[0135]

[0136]

[0137] The performance of the protective coatings provided in Examples 1-10 and Comparative Examples 1-4 was tested using the following methods:

[0138] 1) The protective coating is cut with diamond wire to a target size of 10mm×10mm×1.2mm, and then the cut sample is processed.

[0139] 2) The cut sample obtained in step 1) was subjected to a steam oxidation experiment at 1200℃ using a synchronous thermal analyzer to obtain the sample after high-temperature steam oxidation and to obtain the weight gain curve of the sample.

[0140] 3) The sample obtained in step 2) after high-temperature water vapor oxidation is sequentially subjected to diamond wire cutting, epoxy resin encapsulation, sandpaper grinding and polishing to obtain metallographic specimens. The cross-sectional morphology of the metallographic specimens and the surface morphology of the oxidized coating are observed using a scanning electron microscope (SEM) to analyze the oxidation resistance of the protective coating.

[0141] The weight gain curves of the protective coatings provided in Example 1 and Comparative Example 1 under high-temperature water vapor oxidation at 1200°C are shown below. Figure 1 As shown. By Figure 1 It can be seen that the protective coating provided in Embodiment 1 of the present invention, when oxidized by steam at a high temperature of 1200℃ for 1 hour (i.e., Figure 1 After a period of 20–80 minutes, the oxidative weight gain was only 0.15 mg / mm². 2 The protective coating provided in Comparative Example 1, after steam oxidation at 1200℃ for 1 hour, showed an oxidation weight gain of 0.5 mg / mm². 2 The oxidation weight gain of the zirconium alloy matrix is ​​0.9 mg / mm². 2 This indicates that although the protective coating provided in Comparative Example 1 can reduce the oxidation rate of the zirconium alloy substrate to a certain extent, its oxidation resistance is far lower than that of Example 1 of the present invention because the coating does not contain Nb and Y elements. This shows that the present invention can significantly improve the high-temperature oxidation resistance of the coating by introducing Nb and Y elements into the protective coating and enriching Nb and Y elements.

[0142] The surface morphology of the protective coating provided in Example 1 after oxidation with water vapor at 1200℃ for 1 hour is as follows. Figure 2 As shown; the surface morphology of the protective coating provided in Comparative Example 1 after oxidation with water vapor at 1200℃ for 1 hour is as follows. Figure 3 As shown. By Figure 2 and Figure 3 As can be seen, the protective coating of the present invention, after component optimization, forms a continuous, dense and crack-free protective oxide film on its surface, and enhances the adhesion of the oxide film, with the oxide film remaining intact and crack-free; while in Comparative Example 1, the oxide film cracked because Nb and Y elements were not added.

[0143] The low-magnification cross-sectional morphology of the protective coating provided in Example 1 after oxidation with water vapor at 1200℃ for 1 hour is as follows: Figure 4 As shown; the low-magnification cross-sectional morphology of the protective coating provided in Comparative Example 1 after oxidation with water vapor at 1200℃ for 1 hour is as follows. Figure 5 As shown. By Figure 4 and Figure 5 It can be seen that the zirconium alloy matrix in Example 1 was not oxidized; while in Comparative Example 1, the zirconium alloy matrix was severely oxidized, and ZrO2 was generated in the matrix. This shows that the present invention introduces Nb and Y elements into the protective coating. Nb and Y elements are enriched at the coating grain boundaries and coating-substrate interface, blocking Cr / Zr interdiffusion, thereby avoiding the oxidation of the zirconium alloy matrix.

[0144] The high-magnification cross-sectional morphology and surface distribution of O and Al elements of the protective coating provided in Example 1 after oxidation with water vapor at 1200℃ for 1 hour are shown below. Figure 6 As shown. By Figure 6 As can be seen, Example 1 generates a continuous and dense Al2O3 oxide film on the surface after oxidation, which effectively inhibits the further diffusion of corrosive media such as oxygen into the coating and substrate, giving the coating excellent anti-oxidation properties and protective effects.

[0145] Table 2 shows the oxidation weight gain and morphological structure characteristics of the protective coatings provided in Examples 1-10 after oxidation with water vapor at 1200℃ for 1 hour:

[0146] Table 2 shows the oxidation weight gain and morphological characteristics of the protective coatings provided in Examples 1-10 after oxidation with high-temperature water vapor at 1200℃ for 1 hour.

[0147] Example Coating composition / at.% <![CDATA[Oxidation weight gain / mg / mm 2 > Is the matrix oxidized? Example 1 Al20-Nb5-Y2-Cr 0.15 no Example 2 Al20-Nb1.5-Y0.5-Cr 0.22 no Example 3 Al8-Nb10-Y3-Cr 0.31 no Example 4 Al12-Nb5-Y5-Cr 0.30 no Example 5 Al8-Nb7-Y0.5-Cr 0.35 no Example 6 Al25-Nb4-Y4-Cr 0.37 no Example 7 Al12-Nb5-Y3-Cr 0.32 no Example 8 Al9-Nb10-Y0.5-Cr 0.31 no Example 9 Al18-Nb1.5-Y4-Cr 0.25 no Example 10 Al12-Nb10-Y4-Cr 0.29 no

[0148] As shown in Table 2, the protective coating provided by this invention exhibits an oxidation weight gain of ≤0.37 mg / mm² after 1 hour of oxidation with water vapor at 1200℃. 2 Meanwhile, the substrate was not oxidized, indicating that the protective coating provided by the present invention has excellent high-temperature resistance and oxidation resistance. At the same time, the comparison of Examples 1 to 10 shows that the protective coating has the best performance when the composition of the protective coating is Al20-Nb5-Y2-Cr.

[0149] Table 3 shows the oxidation weight gain, morphological structure characteristics, and failure analysis of the protective coatings provided in Comparative Examples 1-4 after oxidation with water vapor at 1200℃ for 60 min.

[0150] Table 3 shows the oxidation weight gain, morphological characteristics, and failure analysis of the protective coatings provided in Comparative Examples 1-4 after oxidation with high-temperature water vapor at 1200℃ for 60 min.

[0151]

[0152]

[0153] As shown in Table 3, when neither Y nor Nb is added to the coating, Cr / Zr interdiffusion is severe and the oxide film cracks. Without Y, the coating's oxidation resistance decreases and the resulting oxide film has poor density and is prone to cracking. When the Al content is too low, although aluminum oxide can be formed at high temperatures, a dense oxide film cannot be formed, resulting in a significant decrease in its protective effect. When the bias voltage during coating is 0V, although the composition of the coating meets the requirements, the coating has poor density, leading to an increase in oxygen diffusion channels at high temperatures, and it still does not have excellent high-temperature oxidation resistance.

[0154] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A protective coating against high-temperature water vapor oxidation, characterized in that, On an atomic percentage basis, it comprises the following components: 8-35% Al, 0.5-10% Nb, 0.5-5% RE and the balance Cr, wherein the RE is Y; The method for preparing the protective coating resistant to high-temperature water vapor oxidation includes: preparing the protective coating resistant to high-temperature water vapor oxidation using a magnetron sputtering method; The magnetron sputtering method includes: installing a Cr target, an Al target, an Nb target, a Y target and a zirconium alloy substrate in a magnetron sputtering device, and then sequentially performing vacuuming, preheating of the zirconium alloy substrate, glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation. The power of the Cr target during coating is 150~190W; the power of the Al target during coating is 45~100W; the power of the Nb target during coating is 15~80W; the power of the Y target during coating is 5~50W; the bias voltage during coating is 50~120V; the gas pressure during coating is 0.5~2Pa; and the sputtering time during coating is 2~6h.

2. The protective coating against high-temperature water vapor oxidation according to claim 1, characterized in that, On an atomic percentage basis, it comprises the following components: 9-25% Al, 4-7% Nb, 1-4% RE and the balance Cr, wherein the RE is Y.

3. The protective coating against high temperature water vapor oxidation according to claim 1, characterized in that, On an atomic percentage basis, it comprises the following components: 12-20% Al, 5-6% Nb, 2-3% RE and the balance Cr, wherein the RE is Y.

4. A method for producing the protective coating against high-temperature water vapor oxidation according to any one of claims 1 to 3, characterized by, include: A protective coating resistant to high-temperature water vapor oxidation was prepared by magnetron sputtering. The magnetron sputtering method includes: installing a Cr target, an Al target, an Nb target, a Y target and a zirconium alloy substrate in a magnetron sputtering device, and then sequentially performing vacuuming, preheating of the zirconium alloy substrate, glow discharge cleaning and coating to obtain a protective coating resistant to high-temperature water vapor oxidation. The power of the Cr target during coating is 150~190W; the power of the Al target during coating is 45~100W; the power of the Nb target during coating is 15~80W; the power of the Y target during coating is 5~50W; the bias voltage during coating is 50~120V; the gas pressure during coating is 0.5~2Pa; and the sputtering time during coating is 2~6h.

5. The preparation method according to claim 4, characterized in that, The vacuum degree of the glow discharge cleaning is 3~6 Pa, the atmosphere of the glow discharge cleaning is argon, the glow discharge cleaning time is 5~15 min, and the bias voltage applied to the zirconium alloy substrate during glow discharge cleaning is 50~120V.

6. The application of the protective coating against high-temperature water vapor oxidation as described in any one of claims 1 to 3 or the protective coating against high-temperature water vapor oxidation prepared by the preparation method described in any one of claims 4 to 5 in reactor nuclear fuel cladding materials.

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