A zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x O / SiC multilayer composite coating and preparation method thereof

Abstract

The present invention discloses a zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x O / SiC multilayer composite coating and preparation method thereof, the method comprising: first, pre-oxidizing the zirconium-based fuel cladding to in-situ grow Zr x O oxide film; second, Ar plasma sputtering activation of the pre-oxidized zirconium-based fuel cladding; third, alternating deposition to form a multi-layered SiC composite coating. The present invention combines pre-oxidation with magnetron sputtering deposition, and constructs a Zr in situ growth from the matrix Zr x O and then to the gradient composite structure coating of the surface SiC composite coating, which reduces the thermal mismatch and interface thermal resistance between the base metal and the ceramic coating, enhances the interface adaptability between the base and the SiC composite coating, and with the help of the high corrosion resistance, high thermal conductivity and high hardness of the SiC composite coating, the surface corrosion resistance and wear resistance of the fuel cladding under normal and accident conditions are improved simultaneously, and the fault tolerance of the zirconium-based cladding under accident conditions is optimized.

Description

Technical Field

[0001] The present invention belongs to the technical field of materials and surface engineering, and specifically relates to a zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x O / SiC multilayer composite coating and preparation method thereof. Background Art

[0002] Zirconium-based materials are currently the primary nuclear fuel cladding material used in pressurized water reactor nuclear power plants, primarily due to their favorable "nuclear properties," such as a low neutron absorption cross-section and resistance to neutron irradiation. However, operational applications have shown that corrosion of zirconium-based materials in high-temperature, high-pressure water remains a significant risk hindering their long-term, stable service. Especially under accident conditions, zirconium-based cladding is prone to nodular corrosion, which in turn causes tube wall thinning and fracture. Even more seriously, the exothermic hydrogen evolution reaction of zirconium-water in high-temperature steam can further lead to serious hydrogen explosion accidents. Using functional coatings to protect the surface of zirconium-based materials is currently recognized as an important means of addressing the shortcomings of zirconium-based materials in high-temperature, high-pressure water environments and is also a key area of ​​focus for the development of new accident-tolerant fuel systems.

[0003] SiC materials have excellent high-temperature properties, maintaining high bond strength at high temperatures, exhibiting minimal deformation at high temperatures, a low thermal expansion coefficient, and excellent chemical and thermal stability. Particularly in the nuclear field, SiC materials have a small neutron absorption cross-section, good irradiation dimensional stability, and high thermal conductivity. Furthermore, their high surface hardness provides them with enhanced resistance to grid scratches and fretting wear, making them ideally suited for use as surface protective coatings on existing zirconium-based fuel claddings. However, the current application of SiC as a coating material on zirconium-based alloy surfaces still presents the following problems. First, the commonly used coating preparation method is primarily chemical vapor deposition, a technique with a preparation temperature exceeding 1000°C, which is clearly unsuitable for surface treatment of zirconium-based alloys. Second, SiC materials have higher hardness and brittleness than zirconium-based materials. When deposited as a coating material on the surface of a zirconium-based material, the interfacial thermal mismatch is particularly pronounced, making it very susceptible to induction of interfacial microcracks under external stress. Coupled with their inherent high brittleness, the coating is particularly prone to brittle cracking and failure. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x Preparation method of O / SiC multilayer composite coating. The present invention in situ grows Zr on the surface of zirconium-based fuel cladding by oxidation. xO oxide film is combined with deposition to form a SiC multilayer composite coating to construct a corrosion-resistant, wear-resistant, integrated accident-tolerant composite coating on the surface of nuclear zirconium-based fuel cladding, which enhances the interface adaptability between the substrate and the coating, and simultaneously improves the strength and toughness of the coating while ensuring the surface hardness of the coating, thereby improving the long-term stable service performance of the zirconium-based fuel cladding and solving the problem of easy cracking and failure of the existing SiC coating on the surface of zirconium alloy.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The preparation method of the O / SiC multilayer composite coating is characterized in that the method comprises the following steps:

[0006] Step 1: Zr x Preparation of O oxide film: The surface of the zirconium-based fuel cladding is pickled and rinsed with deionized water to remove surface oxides and attached pollutants. After dehydration and drying, it is pre-oxidized to in-situ grow Zr with a gradient transition structure on the surface of the zirconium-based fuel cladding. x O oxide film;

[0007] Step 2: Ar plasma sputtering activation: Place the pre-oxidized zirconium-based fuel cladding in step 1 into a vacuum vapor deposition device, and control the background vacuum to be better than 5×10 -3 Pa, the temperature does not exceed 400 ° C, and then Ar gas is introduced, and Ar plasma generated by Ar gas glow discharge is used for sputtering cleaning to clean and eliminate dust and other debris adsorbed by static electricity on the surface and activate the surface;

[0008] Step 3, SiC ion sputtering cleaning: Turn on the SiC sputtering target source, and under the action of high pulse bias, use the SiC ions generated by the SiC target source to perform SiC ion sputtering cleaning on the surface of the zirconium-based fuel cladding after the Ar plasma sputtering cleaning in step 2;

[0009] Step 4, SiC composite coating deposition: Under the action of low pulse bias, the surface of the zirconium-based fuel cladding cleaned by SiC ion sputtering in step 3 is alternately deposited to form a multi-layered SiC composite coating, thereby obtaining a surface with a gradient transition structure Zr x Zirconium-based fuel cladding with O / SiC multilayer composite coating.

[0010] The present invention first pre-oxidizes the zirconium-based fuel cladding, and in-situ grows Zr on the surface of the zirconium-based fuel cladding. x O oxide film, and then alternately deposited to form a multilayer SiC composite coating. x O oxide film serves as a gradient buffer layer between the zirconium-based fuel cladding substrate and the surface SiC composite coating, achieving a non-interface transition from the substrate to the surface ceramic coating. xThe interface thermal mismatch difference between the O oxide film and the surface SiC composite coating is small, which is beneficial to improving the interface bonding strength between the surface SiC composite coating and the substrate, and improving the application performance of the SiC coating on the surface of the zirconium alloy. At the same time, the present invention uses SiC ion sputtering cleaning, utilizes the bombardment of high-energy SiC to strengthen the interface to construct a low-stress, densified interface, combines multiple alternating depositions, and utilizes multi-cycle cyclic deposition to intermittently enhance the SiC ion energy to interrupt the continuous growth trend of SiC grains, enhance the structural density of the SiC composite coating, and construct a SiC composite coating system with a multi-layer structure. While ensuring the surface hardness of the coating, the coating toughness is enhanced, the probability of brittle cracking is reduced, and the defect of large SiC brittleness is effectively alleviated, thereby achieving a simultaneous improvement in the strength and toughness of the surface SiC coating.

[0011] The above-mentioned zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The preparation method of O / SiC multilayer composite coating is characterized in that the pre-oxidation in step 1 is carried out in an oxygen-containing atmosphere or in high-temperature and high-pressure steam. The pre-oxidation conditions in high-temperature and high-pressure steam are: pre-oxidation for 72 hours under high-temperature steam conditions of 400℃±3℃ and 10.3MPa±0.7MPa in an autoclave. This pre-oxidation process can directly grow Zr in situ on the surface of the zirconium-based fuel cladding. x O oxide film, forming a gradient transition without interface and building an integrated interface structure.

[0012] The above-mentioned zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The preparation method of the O / SiC multilayer composite coating is characterized in that during the Ar plasma sputtering cleaning in step 2, Ar gas is used to adjust the vacuum value in the vacuum vapor deposition equipment to 3Pa~50Pa, and the pulse bias is 500V~1500V, the duty cycle is 30%~80%, and the time is 7min~15min.

[0013] The above-mentioned zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The preparation method of the O / SiC multilayer composite coating is characterized in that, during the SiC ion sputtering cleaning in step three, the pulse bias voltage is 500V to 1000V and the time is 2min to 5min.

[0014] The above-mentioned zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The method for preparing an O / SiC multilayer composite coating is characterized in that the deposition of the SiC composite coating in step 4 comprises the following steps:

[0015] Step 401, preparation of SiC pre-deposition layer: maintaining the SiC sputtering target source in an on state, reducing the pulse bias voltage, and preparing a SiC pre-deposition layer on the surface of the zirconium-based fuel cladding cleaned by SiC ion sputtering in step 3;

[0016] Step 402 , preparation of SiC thickening layer: reducing the pulse bias voltage, and depositing a SiC thickening layer on the surface of the SiC pre-deposition layer of the zirconium-based fuel cladding in step 401 .

[0017] The present invention adopts high pulse bias voltage to increase the energy of deposited ions to obtain a denser SiC pre-deposition layer structure, and then reduces the pulse bias voltage to promote the deposition of a large number of ions, thereby achieving thickening of the SiC composite coating and improving deposition efficiency. At the same time, by successively reducing the energy of deposited ions, it helps to eliminate deposition stress and further improve the quality of the SiC composite coating.

[0018] The above-mentioned zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The preparation method of the O / SiC multilayer composite coating is characterized in that the pulse bias voltage used in the preparation of the SiC pre-deposition layer in step 401 is 300V~500V, the time is 5min~10min, and the vacuum degree is 0.1Pa~1Pa; the pulse bias voltage used in the preparation of the SiC thickening layer in step 402 is 50V~100V, and the vacuum degree is 0.1Pa~1Pa.

[0019] The above-mentioned zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The method for preparing an O / SiC multilayer composite coating is characterized in that the SiC pre-deposition layer preparation process in step 401 and the SiC thickening layer preparation process in step 402 are repeated alternately multiple times to form a multilayer SiC composite coating.

[0020] The above-mentioned zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The method for preparing an O / SiC multilayer composite coating is characterized by adding an auxiliary plasma source to the vacuum vapor deposition equipment described in step 2. By adding the auxiliary plasma source to the vacuum vapor deposition equipment to complete the subsequent sputtering and deposition processes, the sputtering rate of the SiC target source and the coating deposition efficiency are increased, thereby improving the interface bonding between the body and the coating and enhancing the overall performance of the coating.

[0021] At the same time, the present invention also discloses a zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr -x The O / SiC multilayer composite coating is characterized in that it is prepared by the above method.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention in situ grows Zr by pre-oxidation on the surface of zirconium-based fuel cladding x O oxide film, constructing a gradient channel from the substrate to the surface SiC coating, realizing the interface-free transition from the substrate to the surface SiC coating, enhancing the interface adaptability between the substrate and the coating, and improving the degree of bonding between the two; at the same time, the present invention constructs a SiC composite coating system with a multi-layer structure through SiC ion bombardment strengthening and multi-layer alternating deposition, while ensuring the surface hardness of the coating. The coating toughness is improved year-on-year, and the surface interface integration Zr-based fuel cladding with excellent corrosion resistance, wear resistance and accident fault tolerance is obtained. x O / SiC multilayer composite coating improves the long-term stable service performance of zirconium-based fuel cladding.

[0024] 2. In the structural design and preparation of the surface SiC coating, the present invention introduces an interface ion pre-strengthening process to artificially construct a low-stress, densified and strengthened interface. At the same time, alternating deposition is used to periodically interrupt the continuous growth of SiC grains, thereby improving the density of the composite coating and ensuring that a multi-layered SiC composite coating is obtained through multi-cycle cycles, thereby achieving a simultaneous improvement in the strength and toughness of the SiC composite coating.

[0025] 3. The interface integrated Zr constructed on the surface of the zirconium-based fuel cladding of the present invention x O / SiC multilayer composite coating contains in-situ grown dense Zr x O oxide film and SiC multilayer composite coating, using the substrate Zr in situ growth Zr x O and then to the gradient composite structure of the SiC composite coating on the surface, which reduces the thermal mismatch and interface thermal resistance between the base metal and the ceramic coating, avoids the "thin ice effect" in which the soft metal (Zr) / hard coating (SiC) system is prone to brittle fracture, and at the same time, with the help of the high corrosion resistance, high thermal conductivity and high hardness of the SiC composite coating, the surface corrosion resistance and wear resistance of the zirconium-based fuel cladding under normal and accident conditions are improved, thereby optimizing the fault tolerance of the zirconium-based fuel cladding under accident conditions.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The Zr formed on the surface of the Zr-4 zirconium alloy cladding in Example 1 of the present invention x Surface morphology of O / SiC multilayer composite coating.

[0028] Figure 2 The Zr formed on the surface of the Zr-4 zirconium alloy cladding in Example 1 of the present invention x Cross-sectional morphology of O / SiC multilayer composite coating.

[0029] Figure 3The Zr formed on the surface of the Zr-4 zirconium alloy cladding in Example 1 of the present invention x Surface wear scar morphology of the O / SiC multilayer composite coating after 3N load and 30min of wear.

[0030] Figure 4 The Zr formed on the surface of the Zr-4 zirconium alloy cladding in Example 1 of the present invention x Cross-sectional morphology of the O / SiC multilayer composite coating after high-temperature steam corrosion at 1200℃ for 2h. DETAILED DESCRIPTION

[0031] Example 1

[0032] This embodiment includes the following steps:

[0033] Step 1: Zr x Preparation of O oxide film: The Zr-4 zirconium alloy cladding is pickled and rinsed with deionized water to remove surface oxides and attached pollutants, and then pre-oxidized after dehydration and drying. Zr with a gradient transition structure is in situ grown on the surface of the Zr-4 zirconium alloy cladding. x O oxide film; the pre-oxidation is pre-oxidation for 72 hours under high temperature steam conditions of 400°C ± 3°C and 10.3MPa ± 0.7MPa in an autoclave;

[0034] Step 2: Ar plasma sputtering activation: After cleaning and drying the pre-oxidized Zr-4 zirconium alloy cladding in step 1, place it in a vacuum vapor deposition device with an auxiliary plasma source, vertically hang it on the workpiece rack, and make it rotate and revolve synchronously at the same time. The background vacuum is controlled to be 5×10 -3 Pa, the temperature is 220 ° C, and then Ar gas is introduced. The vacuum value in the vacuum vapor deposition equipment is adjusted to 10Pa, and the pulse bias voltage is 1000V, the duty cycle is 80%, and Ar plasma generated by Ar gas glow discharge is used for sputter cleaning for 10 minutes to clean and eliminate dust and other debris adsorbed by static electricity on the surface and activate the surface;

[0035] Step 3, SiC ion sputtering cleaning: reduce the Ar gas flow rate to adjust the vacuum value in the vacuum vapor deposition equipment to 0.3 Pa, turn on the SiC sputtering target source, control the power of the SiC sputtering target source to 5 kW, and use the SiC ions generated by the SiC target source sputtering to perform SiC ion sputtering cleaning on the surface of the Zr-4 zirconium alloy cladding after Ar plasma sputtering cleaning in step 2 for 5 minutes under the conditions of a pulse bias of 500 V and a duty cycle of 80%;

[0036] Step 4, SiC composite coating deposition: Under the action of low pulse bias, the surface of the Zr-4 zirconium alloy shell that has been cleaned by SiC ion sputtering in step 3 is alternately deposited to form a multi-layer SiC composite coating, thereby obtaining a surface with a gradient transition structure Zr x O / SiC multilayer composite coating Zr-4 zirconium alloy cladding; the SiC composite coating deposition comprises the following steps:

[0037] Step 401, preparing a SiC pre-deposition layer: maintaining the SiC sputtering target source in an on state and with the power of the SiC sputtering target source at 5 kW, reducing the pulse bias voltage to 400 V, controlling the duty cycle to 80%, and the vacuum degree to 0.3 Pa, and pre-depositing a SiC pre-deposition layer for 7 minutes on the surface of the Zr-4 zirconium alloy cladding cleaned by SiC ion sputtering in step 3;

[0038] Step 402, preparation of SiC thickening layer: reducing the pulse bias voltage to 80V, controlling the duty cycle to 80%, and the vacuum degree to 0.3Pa, depositing the SiC pre-deposition layer on the surface of the Zr-4 zirconium alloy cladding in step 401 for 60 minutes to prepare a SiC thickening layer with a thickness of 2 μm;

[0039] The SiC pre-deposition layer preparation process in step 401 and the SiC thickening layer preparation process in step 402 were alternately repeated 5 times each to form a SiC composite coating having a 6-layer periodic structure and a total thickness of 12 μm.

[0040] Figure 1 and Figure 2 They are the Zr formed on the surface of the Zr-4 zirconium alloy cladding in this embodiment. x Surface morphology and cross-sectional morphology of O / SiC multilayer composite coatings. Figure 1 and Figure 2 It can be seen that the Zr formed on the surface of the Zr-4 zirconium alloy cladding in this embodiment x The surface of the O / SiC multilayer composite coating is uniform and compact, and its cross-sectional structure shows that due to the presence of the SiC pre-deposition layer, the overall structural consistency of the SiC composite coating is very significant, and there is no obvious multilayer composite structure. x The thickness of the O / SiC multilayer composite coating is about 15 μm.

[0041] The Zr formed on the surface of the Zr-4 zirconium alloy cladding in this embodiment x The sliding wear test of O / SiC multilayer composite coating was carried out. Under the test conditions of 3N external load, φ6mm stainless steel ball of friction pair and wear linear speed of 1m / s, the surface morphology after 30min of wear time was as follows: Figure 3 As shown. Figure 3It can be seen that the surface of the composite coating presents a uniform wear state, without obvious abrasive wear, coating peeling and other phenomena.

[0042] The Zr formed on the surface of the Zr-4 zirconium alloy cladding in this embodiment x The O / SiC multilayer composite coating was subjected to a steam corrosion test in 1200℃ high temperature steam for 2h. The cross-sectional morphology of the coating after corrosion is shown in Figure 2. Figure 4 As shown. Figure 4 It can be seen that the composite coating has a complete surface, the Zr-4 zirconium alloy cladding substrate has no oxidation corrosion, and the composite coating has a significant protective effect.

[0043] Example 2

[0044] This embodiment includes the following steps:

[0045] Step 1: Zr x Preparation of O oxide film: The Zr-4 zirconium alloy cladding is pickled and rinsed with deionized water to remove surface oxides and attached pollutants, and then pre-oxidized after dehydration and drying. Zr with a gradient transition structure is in situ grown on the surface of the Zr-4 zirconium alloy cladding. x O oxide film; the pre-oxidation is carried out in O2, and the pre-oxidation vacuum is controlled to 5Pa by adjusting the O2 flow rate, and the pre-oxidation time is 30min;

[0046] Step 2: Ar plasma sputtering activation: After cleaning and drying the pre-oxidized Zr-4 zirconium alloy cladding in step 1, place it in a vacuum vapor deposition device with an auxiliary plasma source, vertically hang it on the workpiece rack, and make it rotate and revolve synchronously at the same time. The background vacuum is controlled to be 5×10 -3 Pa, the temperature is 300 ° C, and then Ar gas is introduced. The vacuum value in the vacuum vapor deposition equipment is adjusted to 50 Pa, the pulse bias voltage is 500 V, and the duty cycle is 30%. Ar plasma generated by Ar gas glow discharge is used for sputter cleaning for 15 minutes to clean and eliminate dust and other debris adsorbed by static electricity on the surface and activate the surface;

[0047] Step 3, SiC ion sputtering cleaning: reduce the Ar gas flow rate to adjust the vacuum value in the vacuum vapor deposition equipment to 1 Pa, turn on the SiC sputtering target source, control the power of the SiC sputtering target source to 8 kW, and use the SiC ions generated by the SiC target source sputtering to perform SiC ion sputtering cleaning on the surface of the Zr-4 zirconium alloy cladding after Ar plasma sputtering cleaning in step 2 for 3 minutes under the conditions of a pulse bias of 1000 V and a duty cycle of 30%;

[0048] Step 4, SiC composite coating deposition: Under the action of low pulse bias, the surface of the Zr-4 zirconium alloy shell that has been cleaned by SiC ion sputtering in step 3 is alternately deposited to form a multi-layer SiC composite coating, thereby obtaining a surface with a gradient transition structure Zr x O / SiC multilayer composite coating Zr-4 zirconium alloy cladding; the SiC composite coating deposition comprises the following steps:

[0049] Step 401, preparing a SiC pre-deposition layer: maintaining the SiC sputtering target source in an on state and with the power of the SiC sputtering target source at 8 kW, reducing the pulse bias voltage to 300 V, controlling the duty cycle to 40%, and the vacuum degree to 1 Pa, and pre-depositing a SiC pre-deposition layer on the surface of the Zr-4 zirconium alloy cladding cleaned by SiC ion sputtering in step 3 for 5 minutes;

[0050] Step 402, preparation of SiC thickening layer: reducing the pulse bias voltage to 50V, controlling the duty cycle to 40%, and the vacuum degree to 1Pa, depositing the SiC pre-deposition layer on the surface of the Zr-4 zirconium alloy cladding in step 401 for 60 minutes to prepare a SiC thickening layer with a thickness of 3 μm;

[0051] The SiC pre-deposition layer preparation process in step 401 and the SiC thickening layer preparation process in step 402 were alternately repeated 4 times each to form a SiC composite coating having a 6-layer periodic structure and a total thickness of 15 μm.

[0052] The Zr formed on the surface of the Zr-4 zirconium alloy cladding in this embodiment x The O / SiC multilayer composite coating was placed in a high-temperature furnace at 1210°C for 5 minutes and then quickly placed in cold water at 10°C. After being taken out, it was found that the surface of the composite coating was intact without defects such as falling off and bulging. The surface SiC composite coating had no cracks, bulging, or falling off.

[0053] The Zr formed on the surface of the Zr-4 zirconium alloy cladding in this embodiment x The O / SiC multilayer composite coating was subjected to a steam corrosion test in high-temperature steam at 1200°C for 2 hours. The results showed that the composite coating had an intact surface, and the Zr-4 zirconium alloy cladding substrate did not show any oxidation corrosion, indicating that the composite coating had a significant protective effect.

[0054] Example 3

[0055] This embodiment includes the following steps:

[0056] Step 1: Zr x Preparation of O oxide film: The Zr-4 zirconium alloy cladding is pickled and rinsed with deionized water to remove surface oxides and attached pollutants, and then pre-oxidized after dehydration and drying. Zr with a gradient transition structure is in situ grown on the surface of the Zr-4 zirconium alloy cladding.x O oxide film; the pre-oxidation is carried out in O2, and the pre-oxidation vacuum is controlled to 5Pa by adjusting the O2 flow rate, and the pre-oxidation time is 30min;

[0057] Step 2: Ar plasma sputtering activation: After cleaning and drying the pre-oxidized Zr-4 zirconium alloy cladding in step 1, place it in a vacuum vapor deposition device with an auxiliary plasma source, vertically hang it on the workpiece rack, and make it rotate and revolve synchronously at the same time. The background vacuum is controlled to be 5×10 -3 Pa, the temperature is 200 ° C, and then Ar gas is introduced. The vacuum value in the vacuum vapor deposition equipment is adjusted to 3Pa, and the pulse bias voltage is 1500V, the duty cycle is 50%, and Ar plasma generated by Ar gas glow discharge is used for sputter cleaning for 7 minutes to clean and eliminate dust and other debris adsorbed by static electricity on the surface and activate the surface;

[0058] Step 3, SiC ion sputtering cleaning: reduce the Ar gas flow rate to adjust the vacuum value in the vacuum vapor deposition equipment to 0.1 Pa, turn on the SiC sputtering target source, control the power of the SiC sputtering target source to 10 kW, and use the SiC ions generated by the SiC target source sputtering to perform SiC ion sputtering cleaning on the surface of the Zr-4 zirconium alloy cladding after Ar plasma sputtering cleaning in step 2 for 2 minutes under the conditions of a pulse bias of 1500 V and a duty cycle of 50%;

[0059] Step 4, SiC composite coating deposition: Under the action of low pulse bias, the surface of the Zr-4 zirconium alloy shell that has been cleaned by SiC ion sputtering in step 3 is alternately deposited to form a multi-layer SiC composite coating, thereby obtaining a surface with a gradient transition structure Zr x O / SiC multilayer composite coating Zr-4 zirconium alloy cladding; the SiC composite coating deposition comprises the following steps:

[0060] Step 401, preparing a SiC pre-deposition layer: maintaining the SiC sputtering target source in an on state and with the power of the SiC sputtering target source at 10 kW, reducing the pulse bias voltage to 500 V, controlling the duty cycle to 50%, and the vacuum degree to 0.1 Pa, and pre-depositing a SiC pre-deposition layer for 10 minutes on the surface of the Zr-4 zirconium alloy cladding cleaned by SiC ion sputtering in step 3;

[0061] Step 402, preparation of SiC thickening layer: reducing the pulse bias voltage to 100 V, controlling the duty cycle to 50%, and the vacuum degree to 0.1 Pa, depositing the SiC pre-deposition layer on the surface of the Zr-4 zirconium alloy cladding in step 401 for 30 minutes to prepare a SiC thickening layer with a thickness of 1 μm;

[0062] The SiC pre-deposition layer preparation process in step 401 and the SiC thickening layer preparation process in step 402 were alternately repeated 9 times each to form a SiC composite coating having a 10-layer periodic structure and a total thickness of 10 μm.

[0063] The Zr formed on the surface of the Zr-4 zirconium alloy cladding in this embodiment x The O / SiC multilayer composite coating was placed in a high-temperature furnace at 1210°C for 5 minutes and then quickly placed in cold water at 10°C. After being taken out, it was found that the surface of the composite coating was intact without defects such as falling off and bulging. The surface SiC composite coating had no cracks, bulging, or falling off.

[0064] The Zr formed on the surface of the Zr-4 zirconium alloy cladding in this embodiment x The O / SiC multilayer composite coating was subjected to a steam corrosion test in high-temperature steam at 1200°C for 2 hours. The results showed that the composite coating had an intact surface, and the Zr-4 zirconium alloy cladding substrate did not show any oxidation corrosion, indicating that the composite coating had a significant protective effect.

[0065] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent variation made to the above embodiment based on the essence of the invention technology shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x The preparation method of O / SiC multilayer composite coating is characterized in that: The method comprises the following steps: Step 1: Zr x Preparation of O oxide film: The surface of the zirconium-based fuel cladding is pickled and rinsed with deionized water to remove surface oxides and attached pollutants. After dehydration and drying, it is pre-oxidized to in-situ grow Zr with a gradient transition structure on the surface of the zirconium-based fuel cladding. x O oxide film; Step 2: Ar plasma sputtering activation: Place the pre-oxidized zirconium-based fuel cladding in step 1 into a vacuum vapor deposition device, and control the background vacuum to be better than 5×10 -3 Pa, the temperature does not exceed 400 ° C, and then Ar gas is introduced, and Ar plasma generated by Ar gas glow discharge is used for sputtering cleaning to clean and eliminate dust and debris adsorbed by static electricity on the surface and activate the surface; Step 3, SiC ion sputtering cleaning: Turn on the SiC sputtering target source, and under the action of high pulse bias, use the SiC ions generated by the SiC target source to perform SiC ion sputtering cleaning on the surface of the zirconium-based fuel cladding after the Ar plasma sputtering cleaning in step 2; Step 4, SiC composite coating deposition: Under the action of low pulse bias, the surface of the zirconium-based fuel cladding cleaned by SiC ion sputtering in step 3 is alternately deposited to form a multi-layered SiC composite coating, thereby obtaining a surface with a gradient transition structure Zr x Zirconium-based fuel cladding with an O / SiC multilayer composite coating; the SiC composite coating deposition comprises the following steps: Step 401, preparation of SiC pre-deposition layer: maintaining the SiC sputtering target source in an on state, reducing the pulse bias voltage, and preparing a SiC pre-deposition layer on the surface of the zirconium-based fuel cladding cleaned by SiC ion sputtering in step 3; Step 402, SiC thickening layer preparation: reducing the pulse bias voltage, and depositing a SiC thickening layer on the surface of the SiC pre-deposition layer of the zirconium-based fuel cladding in step 401; The SiC pre-deposition layer preparation process in step 401 and the SiC thickening layer preparation process in step 402 are repeated alternately multiple times to form a multi-layer SiC composite coating.

2. A zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr according to claim 1 x The preparation method of O / SiC multilayer composite coating is characterized in that: The pre-oxidation in step 1 is carried out in an oxygen-containing atmosphere, or in high-temperature, high-pressure steam. The conditions for pre-oxidation in high-temperature, high-pressure steam are: pre-oxidation for 72 hours under high-temperature steam conditions of 400°C ± 3°C and 10.3MPa ± 0.7MPa in an autoclave.

3. The zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr according to claim 1 x The preparation method of O / SiC multilayer composite coating is characterized in that: During the Ar plasma sputtering cleaning in step 2, Ar gas is used to adjust the vacuum value in the vacuum vapor deposition equipment to 3Pa~50Pa, and the pulse bias is 500V~1500V, the duty cycle is 30%~80%, and the time is 7min~15min.

4. The zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr according to claim 1 x The preparation method of O / SiC multilayer composite coating is characterized in that: The pulse bias voltage of the SiC ion sputtering cleaning in step 3 is 500V~1000V, and the time is 2min~5min.

5. The zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr according to claim 1 x The preparation method of O / SiC multilayer composite coating is characterized in that: The pulse bias voltage used in preparing the SiC pre-deposition layer in step 401 is 300V~500V, the time is 5min~10min, and the vacuum degree is 0.1Pa~1Pa; the pulse bias voltage used in preparing the SiC thickening layer in step 402 is 50V~100V, and the vacuum degree is 0.1Pa~1Pa.

6. The zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr according to claim 1 x The preparation method of O / SiC multilayer composite coating is characterized in that: An auxiliary plasma source is added to the vacuum vapor deposition equipment described in step 2.

7. A zirconium-based fuel cladding surface corrosion-resistant interface integrated Zr x O / SiC multilayer composite coating, characterized in that: The method is prepared by any one of claims 1 to 6.

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