Zirconium alloy surface TiNbMoCrx multi-principal-element alloy coating and preparation method and application thereof

Abstract

The invention discloses a TiNbMoCrx multi-principal-element alloy coating on the surface of a zirconium alloy and a preparation method and application of the TiNbMoCrx multi-principal-element alloy coating. The TiNbMoCrx multi-principal-element alloy coating on the surface of the zirconium alloy is prepared from TiNbMoCrx multi-principal-element alloy powder on the surface of the zirconium alloy through a laser cladding technology. Wherein x is 0, 0.2, 0.4 or 0.6. According to the preparation method provided by the invention, the hardness, the wear resistance, the corrosion resistance and the high-temperature oxidation resistance of the obtained zirconium alloy cladding can be effectively improved while the relatively good bonding strength of the coating and a zirconium alloy matrix is ensured, Zr-Cr intermetallic compounds can be prevented from being generated in an interface region, generation of heterogeneous interface cracks is inhibited, and the service life of the zirconium alloy cladding is prolonged. And therefore, the service performance of the component in a water loss accident is enhanced, the service life of the zirconium alloy under complex working conditions is finally prolonged, and the working condition safety is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of multi-principal element alloy coating technology, specifically to a TiNbMoCr coating for zirconium alloy surfaces. x Multi-principal element alloy coatings, their preparation methods and applications. Background Technology

[0002] Zirconium alloys are widely used as cladding materials for fuel assemblies in water-cooled reactors due to their small thermal neutron absorption cross section, excellent high-temperature mechanical properties, and good corrosion resistance. Their core functions are to isolate the coolant from the fuel pellets and provide structural support; their performance directly affects reactor operational safety. However, under extreme conditions such as loss-of-coolant accidents (LOCA), zirconium alloys readily react with water to generate large amounts of hydrogen gas, posing a hydrogen explosion risk and seriously threatening nuclear safety. Therefore, researchers have proposed the development of accident-tolerant materials (ATFs). Preparing protective coatings on the surface of zirconium alloys is a key route to improve their resistance to high-temperature oxidation and corrosion. Among these, metallic coatings, due to their small difference in physical properties with zirconium alloys and ease of achieving good bonding, have become the mainstream research direction. Typical examples include Cr coatings and FeCrAl coatings. These coatings can form a dense oxide film at high temperatures to block oxygen diffusion and improve high-temperature oxidation resistance.

[0003] However, existing metal coatings have significant drawbacks: during long-term high-temperature service, Fe and Cr elements within the coating interdiffusion with Zr elements in the zirconium alloy matrix, forming brittle Fe-Zr and Cr-Zr intermetallic compound layers. This compound layer leads to a sharp decrease in the interfacial bonding strength between the coating and the substrate, making it impossible to maintain interfacial structural stability. Especially in the extreme environment of reactors with both high temperatures and radiation, the coating is prone to detaching from the substrate, completely losing its protective function and failing to meet the requirements for long-term safe service.

[0004] In recent years, multi-principal element alloys (MPEAs) have demonstrated advantages in suppressing brittle intermetallic compounds, improving high-temperature corrosion resistance, and radiation resistance due to their high entropy effect and multi-component solid solution properties. MPEA coatings suitable for zirconium alloys, such as CrCuFeMoNi, AlCrNbTiZr, CrTiZr, and FeCrAl, have been developed. However, current research on MPEA coatings focuses only on optimizing their own performance and has not paid in-depth attention to the interfacial bonding performance with the zirconium alloy substrate. Interfacial bonding strength is a core indicator for the long-term stable operation of coatings, resulting in existing coatings still failing to meet the stringent interfacial bonding performance requirements of nuclear reactors.

[0005] Therefore, developing a multi-principal alloy coating that can suppress the formation of intermetallic compounds at the interface and has both good interfacial bonding performance and excellent overall service performance has become the key to solving the protection problem of zirconium alloy cladding. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a method for surface treatment of TiNbMoCr on zirconium alloys. x Multi-principal element alloy coatings, their preparation methods and applications, including TiNbMoCr x Multi-principal alloys used in zirconium alloy cladding coatings can significantly enhance the safety and economy of zirconium alloy claddings, extend their service life, and improve overall service performance.

[0007] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0008] The first aspect of this invention provides a TiNbMoCr surface treatment for a zirconium alloy. x Multi-principal alloy coating, made of TiNbMoCr x Multi-principal element alloy powder is prepared on the surface of zirconium alloy by laser cladding technology;

[0009] Where x is 0, 0.2, 0.4 or 0.6.

[0010] The zirconium alloy surface TiNbMoCr provided by this invention x In multi-principal element alloy coatings, Ti, Nb, and Mo readily form stable solid solutions with Zr, significantly reducing the tendency for interfacial embrittlement. Furthermore, Ti (melting point 1675 ℃), Nb (melting point 2468 ℃), and Mo (melting point 2617 ℃) are all high-melting-point elements, effectively improving the alloy's thermal stability and high-temperature service performance. Nb and Mo, as refractory metals, not only significantly increase the alloy's melting point and high-temperature stability but also reduce the thermal neutron absorption cross-section and introduce lattice distortion into the alloy, resulting in a solid solution strengthening effect that effectively enhances the coating's hardness and wear resistance. In addition, Nb can form oxide films such as Nb₂O₅ at high temperatures, while Mo can form a protective passivation film based on MoO₂. This passivation film can act as a Cl₂... - The Cr element acts as a barrier to the substrate, hindering the erosion of the matrix by corrosive media and thus improving the corrosion resistance of the alloy. As a key component of high-temperature and corrosion-resistant alloys, Cr promotes the formation of a dense and highly protective Cr₂O₃ oxide film. This oxide film acts as an oxygen diffusion barrier layer, improving oxidation resistance. Simultaneously, Cr also enhances the alloy's corrosion resistance, oxidation resistance, and mechanical properties. However, in this alloy system, Zr and Cr cannot be completely dissolved in solid form, and excessive Cr easily forms intermetallic compounds with Zr. Therefore, precise control of the Cr content is necessary.

[0011] Furthermore, TiNbMoCr x The atomic ratio of each element in the mixture is Ti:Nb:Mo:Cr=1:1:1:x, where x is 0, 0.2, 0.4 or 0.6.

[0012] Furthermore, the TiNbMoCrx The particle size of the multi-principal element alloy powder is 45-150 mesh, preferably 45-105 mesh.

[0013] TiNbMoCr x Multi-principal alloy powder was shaped and processed on the surface of zirconium alloy using laser cladding technology to prepare a thin film of TiNbMoCr. x A multi-principal alloy coating is formed, which in turn creates a composite structure in which the coating is tightly bonded to the zirconium alloy substrate.

[0014] Furthermore, the zirconium alloy can be a Zr-4 plate.

[0015] Furthermore, the zirconium alloy surface TiNbMoCr x The thickness of the multi-principal alloy coating is 0.5-0.6 mm.

[0016] Furthermore, laser cladding was used to prepare TiNbMoCr on the surface of zirconium alloy. x The specific process parameters for the multi-principal element alloy coating are: laser power of 1500-1700 W, scanning speed of 3-5 mm / s, and powder feeding speed of 1.5-2.0 r / min.

[0017] The second aspect of this invention provides a TiNbMoCr surface of the zirconium alloy described in the first aspect. x A method for preparing a multi-principal element alloy coating includes the following steps:

[0018] (1) Titanium powder, niobium powder, molybdenum powder and chromium powder weighed according to their chemical formulas are mixed, and the resulting mixed powder is dried to obtain TiNbMoCr. x Multi-principal element alloy powder;

[0019] (2) The TiNbMoCr x Multi-principal alloy powder is shaped and processed on the surface of zirconium alloy using laser cladding technology to obtain the TiNbMoCr surface of the zirconium alloy. x Multi-principal element alloy coating.

[0020] Furthermore, in step (1), the purity of the titanium powder, niobium powder, molybdenum powder and chromium powder is not less than 99.5%.

[0021] Further, in step (1), the particle size of the titanium powder, niobium powder, molybdenum powder and chromium powder is 45-105 μm.

[0022] Further, in step (1), the titanium powder, niobium powder, molybdenum powder and chromium powder weighed according to the chemical formula and the ceramic grinding ball are placed in a ball mill jar, and then the ball mill jar is placed in a ball mill for mechanical mixing.

[0023] Further, in step (1), the mixing speed is 100-150 r / min.

[0024] Furthermore, the ball-to-material ratio in the ball mill jar is 1:8.

[0025] Specifically, after placing the grinding jar into the ball mill, rotate it for 5-7 hours at a speed of 100-150 r / min in a unidirectional rotation pattern of 30 minutes of rotation followed by a 10-minute rest.

[0026] Furthermore, in step (1), the drying process also includes a sieving step.

[0027] Furthermore, in step (1), the temperature for drying the mixed powder is 180-220 ℃.

[0028] Furthermore, in step (1), the drying time of the mixed powder is 80-100 min.

[0029] The third aspect of this invention provides a TiNbMoCr surface of the zirconium alloy described in the first aspect. x Application of multi-principal element alloy coating in the preparation of zirconium alloy cladding.

[0030] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0031] This invention uses TiNbMoCr x Using multi-principal alloy powder as raw material, a dense TiNbMoCr layer was prepared on the surface of zirconium alloy by laser cladding technology. x The multi-principal alloy coating method can effectively improve the hardness, wear resistance, corrosion resistance and high-temperature oxidation resistance of the obtained zirconium alloy shell while ensuring good bonding strength between the coating and the zirconium alloy substrate. It can also avoid the formation of Zr-Cr intermetallic compounds in the interface region, inhibit the generation of heterogeneous interface cracks, thereby enhancing the service performance of the component in the event of water loss, and ultimately extending the service life of the zirconium alloy under complex working conditions, significantly improving the safety of the working conditions. Attached Figure Description

[0032] Figure 1 The image shows a scanning electron microscope (SEM) image of the TiNbMo multi-principal element alloy coating on the zirconium alloy surface of Example 1 (scale bar is 50 μm).

[0033] Figure 2 The zirconium alloy surface TiNbMoCr of Example 2 0.2 SEM image of multi-principal element alloy coating (scale bar is 50 μm).

[0034] Figure 3The zirconium alloy surface TiNbMoCr of Example 3 0.4 SEM image of multi-principal element alloy coating (scale bar is 50 μm).

[0035] Figure 4 The zirconium alloy surface TiNbMoCr of Example 4 0.6 SEM image of multi-principal element alloy coating (scale bar is 50 μm).

[0036] Figure 5 The zirconium alloy surfaces of Examples 1-4 contain TiNbMo and TiNbMoCr. 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 Cross-sectional SEM images and corresponding elemental distribution diagrams (scale bar is 50 μm) of the interface between the multi-principal alloy coating and the Zr-4 heterostructure; where (a) is Example 1, (b) is Example 2, (c) is Example 3, and (d) is Example 4.

[0037] Figure 6 TiNbMo and TiNbMoCr were deposited on the surfaces prepared in Examples 1-4, respectively. 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 Hardness distribution diagram of Zr-4 plate with multi-principal element alloy coating.

[0038] Figure 7 The zirconium alloy surfaces of Examples 1-4 are TiNbMo and TiNbMoCr. 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 A schematic diagram and a shear performance curve of the interface between the multi-principal element alloy coating and the Zr-4 plate; wherein, (a) and (b) are schematic diagrams of the shear test, and (c) is a shear performance curve.

[0039] Figure 8 For Zr-4 plates and the zirconium alloy surfaces of Examples 1-4, TiNbMo and TiNbMoCr are used. 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 Wear resistance curves of multi-principal element alloy coatings; where (a) is the wear resistance curve and (b) is the wear rate data at 30 min.

[0040] Figure 9 TiNbMo and TiNbMoCr were deposited on the Zr-4 plate and the surfaces prepared in Examples 1-4, respectively. 0.2 TiNbMoCr 0.4TiNbMoCr 0.6 Corrosion resistance curves of Zr-4 plates with multi-principal element alloy coatings; the left graph shows the test solution used was 0.01 mol / L LiOH solution, and the right graph shows the test solution used was 3.5% NaCl solution.

[0041] Figure 10 TiNbMo and TiNbMoCr were deposited on the Zr-4 plate and the surfaces prepared in Examples 1-4, respectively. 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 High-temperature oxidation resistance curve of Zr-4 plate with multi-principal element alloy coating. Detailed Implementation

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0044] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available.

[0045] In the following examples, the thickness of the Zr-4 plate is 10 mm.

[0046] Example 1

[0047] A TiNbMo multi-principal-element alloy coating for zirconium alloy surface is prepared by the following steps:

[0048] (1) 20.2 g of titanium powder, 39.3 g of niobium powder, 40.5 g of molybdenum powder and ceramic grinding balls were weighed according to the chemical formula TiNbMo and placed in a ball mill jar (the ball-to-material ratio was 1:8). Then the ball mill jar was placed in a ball mill and mechanically mixed for 6 hours at a speed of 120 r / min with a unidirectional rotation mode of 30 minutes of rotation followed by a 10-minute pause. The resulting mixed powder was dried at 200 °C for 90 min using a far-infrared dryer. After drying, the powder was sieved to a particle size of 45-105 mesh to obtain TiNbMo multi-principal element alloy powder.

[0049] (2) The TiNbMo multi-principal alloy powder is formed on the surface of Zr-4 plate by laser cladding technology. The laser power is 1600 W, the scanning speed is 4 mm / s, and the powder feeding speed is 1.8 r / min to obtain the TiNbMo multi-principal alloy coating on the zirconium alloy surface. The coating thickness is 0.5 mm.

[0050] Example 2

[0051] A zirconium alloy surface TiNbMoCr 0.2 The preparation method of multi-principal element alloy coating includes the following steps:

[0052] (1) According to the chemical formula TiNbMoCr 0.2 19.4 g of titanium powder, 37.6 g of niobium powder, 38.8 g of molybdenum powder, and 4.2 g of chromium powder, along with ceramic grinding balls, were weighed and placed in a ball mill jar (ball-to-powder ratio of 1:8). The jar was then placed in a ball mill and mechanically mixed for 6 hours at 120 r / min with a unidirectional rotation pattern of 30 minutes of rotation followed by a 10-minute pause. The resulting mixed powder was dried in a far-infrared dryer at 200 °C for 90 min. After drying, the powder was sieved to a particle size of 45-105 mesh to obtain TiNbMoCr. 0.2 Multi-principal element alloy powder.

[0053] (2) The TiNbMoCr 0.2 Multi-principal element alloy powder was shaped and processed on the surface of a Zr-4 plate using laser cladding technology. The laser power was 1600 W, the scanning speed was 4 mm / s, and the powder feeding speed was 1.8 r / min, resulting in the TiNbMoCr alloy surface. 0.2 Multi-principal alloy coating with a thickness of 0.5 mm.

[0054] Example 3

[0055] A zirconium alloy surface TiNbMoCr 0.4 The preparation method of multi-principal element alloy coating includes the following steps:

[0056] (1) According to the chemical formula TiNbMoCr 0.418.6 g of titanium powder, 36.1 g of niobium powder, 37.2 g of molybdenum powder, 8.1 g of chromium powder, and ceramic grinding balls were weighed and placed in a ball mill jar. The jar was then placed in a ball mill (ball-to-powder ratio of 1:8). Mechanical mixing was performed for 6 hours at 120 r / min, rotating in one direction for 30 minutes followed by a 10-minute pause. The resulting mixed powder was dried in a far-infrared dryer at 200 °C for 90 min. After drying, the powder was sieved to a particle size of 45-105 mesh to obtain TiNbMoCr. 0.4 Multi-principal element alloy powder.

[0057] (2) The TiNbMoCr 0.4 Multi-principal element alloy powder was shaped and processed on the surface of a Zr-4 plate using laser cladding technology. The laser power was 1600 W, the scanning speed was 4 mm / s, and the powder feeding speed was 1.8 r / min, resulting in the TiNbMoCr alloy surface. 0.4 Multi-principal alloy coating with a thickness of 0.5 mm.

[0058] Example 4

[0059] A zirconium alloy surface TiNbMoCr 0.6 The preparation method of multi-principal element alloy coating includes the following steps:

[0060] (1) According to the chemical formula TiNbMoCr 0.6 17.9 g of titanium powder, 34.7 g of niobium powder, 35.8 g of molybdenum powder, 11.6 g of chromium powder, and ceramic grinding balls were weighed and placed in a ball mill jar. The jar was then placed in a ball mill (ball-to-powder ratio of 1:8). Mechanical mixing was performed for 6 hours at 120 r / min, rotating in one direction for 30 minutes followed by a 10-minute pause. The resulting mixed powder was dried in a far-infrared dryer at 200 °C for 90 min. After drying, the powder was sieved to a particle size of 45-105 mesh to obtain TiNbMoCr. 0.6 Multi-principal element alloy powder.

[0061] (2) The TiNbMoCr 0.6 Multi-principal element alloy powder was shaped and processed on the surface of a Zr-4 plate using laser cladding technology. The laser power was 1600 W, the scanning speed was 4 mm / s, and the powder feeding speed was 1.8 r / min, resulting in the TiNbMoCr alloy surface. 0.6 Multi-principal alloy coating with a thickness of 0.5 mm.

[0062] Test Example 1

[0063] The surface of the zirconium alloy with TiNbMo and TiNbMoCr in Examples 1-4 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 Morphological characterization and elemental distribution analysis of multi-principal element alloy coatings were performed, and SEM images are shown below. Figures 1-4 As shown, TiNbMoCr x The coating exhibits a predominantly dendritic morphology; with increasing Cr content, the dendrites initially become lighter, then gradually become clearer and their number increases. This may be due to the TiNbMoCr... 0.2 The Cr content is relatively low, and its distribution effect in the melt is weak, resulting in no obvious compositional undercooling and solute segregation, thus the dendrite morphology is not obvious. When the Cr content continues to increase, the difference in the distribution coefficient of Cr between dendrites increases, which leads to a decrease in solute undercooling and an increase in dendrite spacing. This manifests as dendrites gradually widening and having clearer boundaries. At the same time, the segregation effect of Cr also makes the dendrites gradually clearer and more numerous.

[0064] Combination Figure 5 Further observation of cross-sectional SEM images and corresponding elemental distribution maps of the zirconium alloy surface multi-principal element alloy coating and Zr-4 heterostructure interface in Examples 1-4 revealed significant Cr segregation within the dendrites of the Cr-containing coating. This indicates that the widening of dendrite growth with increasing Cr content is due to Cr segregation. Furthermore, for Zr / TiNbMoCr... x The morphological observation results of the interface area show that there are no obvious defects such as cracks and pores in the interface area, and the coating and Zr-4 plate have achieved good metallurgical bonding.

[0065] Test Example 2

[0066] The Zr-4 plates prepared in Examples 1-4 and the TiNbMo and TiNbMoCr deposited on their surfaces were respectively tested. 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 The Zr-4 plate with multi-principal element alloy coating was subjected to a Vickers hardness test according to GB / T 4340.1-2024. The load for the Vickers hardness test was 1 kg, and the holding time was 10 s. The test results are as follows: Figure 6 As shown in Table 1:

[0067] Table 1

[0068]

[0069] The Vickers hardness test results above show that: TiNbMoCr deposited on the surface respectively xThe hardness values ​​of the four multi-principal element alloy coatings on Zr-4 plates (x=0, 0.2, 0.4, 0.6) are concentrated around 500 HV, and the overall hardness is significantly better than that of the uncoated Zr-4 plate (approximately 180 HV). Combined with... Figure 6 Zr / TiNbMoCr x The hardness distribution at the interface shows that the coating area has high and stable hardness. As the test location transitions towards the interface, the hardness gradually decreases, reaching approximately 300 HV at the interface before smoothly transitioning to the hardness level of the Zr-4 plate. This continuous hardness gradient without significant abrupt changes indicates that all coatings achieve good metallurgical bonding with the Zr-4 plate, and no intermetallic compound layer is formed. Furthermore, the hardness distribution of coatings with different Cr contents does not differ significantly, suggesting that variations in Cr content have a relatively small impact on the overall hardness gradient after bonding between the coating and the Zr-4 plate.

[0070] Test Example 3

[0071] The surface of the zirconium alloy with TiNbMo and TiNbMoCr in Examples 1-4 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 Shear tests were conducted on the interface between the multi-principal element alloy coating and the Zr-4 plate, according to the test standard GB / T 6396-2008. A schematic diagram of the test is shown below. Figure 7 As shown, the test results are as follows: Figure 7 As shown in Table 2:

[0072] Table 2

[0073]

[0074] The above Zr-4 plate and TiNbMoCr x Shear test results at the interface of multi-principal alloy coatings show that: Zr / TiNbMoCr x The shear strength of the heterogeneous interface ranges from 176 to 263 MPa, and the converted tensile strength ranges from 305 to 456 MPa. (Combined) Figure 7 Analysis of the shear properties of coatings with different Cr contents revealed that the Zr / TiNbMo heterostructure exhibited the highest shear strength, indicating the strongest interfacial bonding. While the overall shear strength of the heterostructure decreased with increasing Cr content, the Zr / TiNbMoCr... 0.2 With Zr / TiNbMoCr 0.4 The decrease in shear strength was relatively small, indicating that the introduction of an appropriate amount of Cr element would not have a significant negative impact on the service performance of the coating. Meanwhile, Zr / TiNbMoCr 0.4 The shear strength is slightly higher than that of Zr / TiNbMoCr 0.2 With Zr / TiNbMoCr0.6 The results show that the introduction of an appropriate amount of Cr can balance the interfacial metallurgical bonding and the structural stability of the coating, maintaining good mechanical properties while ensuring reliable coating adhesion.

[0075] Test Example 4

[0076] The TiNbMo and TiNbMoCr surfaces of the Zr-4 plate and the zirconium alloys in Examples 1-4 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 Tribological performance tests were conducted on multi-principal alloy coatings using an MS-T3000 ball-and-disc tribological testing machine. GGr15 stainless steel balls were used as the friction pair. The test parameters were set as follows: rotational speed 150 r / min, load 500g, friction circumference radius 3 mm, and friction time 30 min. The wear mass change of the samples was obtained by weighing using an electronic balance. The test results are as follows: Figure 8 As shown in Table 3:

[0077] Table 3

[0078]

[0079] Combination Figure 8 Compared with the above Zr-4 plate and TiNbMoCr x The tribological and wear performance test results of multi-principal element alloy coatings show that, compared with Zr-4 plates, TiNbMoCr... x (x=0.2, 0.4, 0.6) The wear rate of the multi-principal element alloy coating decreased significantly, indicating a significant improvement in its wear resistance; with the increase of Cr content, the wear rate of TiNbMoCr... x The wear rate of multi-principal element alloy coatings gradually decreases while the average friction coefficient increases, especially for TiNbMoCr. 0.4 With TiNbMoCr 0.6 The multi-principal element alloy coating exhibited the lowest wear rate and best wear resistance. This result indicates that the appropriate introduction of Cr can effectively improve the coating's resistance to plastic deformation and wear stability during friction and wear processes, thereby enhancing the coating's service reliability.

[0080] Test Example 5

[0081] TiNbMo and TiNbMoCr were deposited on the Zr-4 plate and the surfaces prepared in Examples 1-4, respectively. 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6Electrochemical corrosion resistance tests were conducted on Zr-4 plates with multi-principal element alloy coatings using a conventional three-electrode measurement system. A platinum electrode served as the counter electrode, a saturated calomel electrode as the reference electrode, and the test sample as the working electrode. The test solutions used were either 0.01 mol / L LiOH solution to simulate the cooling water environment during normal reactor operation, or 3.5% NaCl solution to simulate the seawater cooling environment during a nuclear accident. The test results are as follows: Figure 9 As shown in Table 4:

[0082] Table 4

[0083]

[0084] Combined with Table 4 Figure 9 The electrochemical corrosion resistance curves show that TiNbMoCr deposited on the surface is obtained in 3.5% NaCl solution and 0.01 mol / L LiOH solution. x The corrosion voltage of Zr-4 plates with multi-principal element alloy coatings was higher than that of uncoated Zr-4 plates. A positive shift in corrosion voltage indicates that the material is less susceptible to electrochemical corrosion and exhibits superior corrosion resistance. This suggests that in 3.5% NaCl solution and 0.01 mol / L LiOH solution, the surface deposition of TiNbMoCr... x The corrosion resistance of Zr-4 plates with multi-principal element alloy coatings was superior to that of uncoated Zr-4 plates. Furthermore, with increasing Cr content, the corrosion potential of the coated Zr-4 plates shifted positively overall, indicating a gradual improvement in corrosion resistance. In a 0.01 mol / L LiOH solution, TiNbMoCr was deposited on the surface... 0.4 E of Zr-4 plates with multi-principal alloy coating corr At -1.45 V, it is less prone to electrochemical corrosion compared to other samples, indicating relatively superior corrosion resistance in a simulated reactor coolant environment. In a 3.5% NaCl solution, TiNbMoCr was deposited on its surface. x The corrosion voltage of Zr-4 plates with multi-principal alloy coatings also shifts positively overall, especially for those with TiNbMoCr deposited on the surface. 0.2 The Zr-4 plate with a multi-principal element alloy coating exhibits the highest Ecorr value (-1.31 V), indicating that it is more resistant to chloride-induced corrosion in simulated seawater environments and demonstrates the best corrosion resistance. In summary, TiNbMoCr... x Multi-principal alloy coatings exhibit good corrosion resistance under various corrosive environments, among which TiNbMoCr... 0.4 Multi-principal element alloy coatings performed best in a simulated cooling water environment (0.01 mol / L LiOH) solution. TiNbMoCr 0.2The multi-principal element alloy coating exhibits superior corrosion resistance in a simulated seawater environment (3.5% NaCl solution), demonstrating that the appropriate introduction of Cr can effectively improve corrosion resistance in different environments.

[0085] Test Example 6

[0086] TiNbMo and TiNbMoCr were deposited on the surfaces of Zr-4 plates and in Examples 1-4, respectively. 0.2 TiNbMoCr 0.4 TiNbMoCr 0.6 The high-temperature oxidation resistance of Zr-4 plates with multi-principal element alloy coatings was tested. The test samples were held at 900℃, 1000℃, 1100℃, and 1200℃ for 1 hour each, and then cooled to room temperature in the furnace. The oxidation weight gain per unit area of ​​the test samples was measured to evaluate their oxidation resistance under actual high-temperature conditions. The test results are as follows: Figure 10 As shown in Table 5:

[0087] Table 5

[0088]

[0089] Figure 10 And the Zr-4 plates and surface deposited TiNbMoCr in Table 5 x High-temperature oxidation resistance test results of Zr-4 plates with multi-principal element alloy coatings show that under high-temperature conditions (>1000 ℃), the surface deposited with TiNbMoCr... x The oxidation weight gain per unit area of ​​the Zr-4 plate with multi-principal element alloy coating was significantly lower than that of the uncoated Zr-4 plate, demonstrating that its high-temperature oxidation resistance was significantly superior to that of the uncoated Zr-4 plate. At a relatively low temperature of 900 ℃, TiNbMo and TiNbMoCr were deposited on the surface. 0.2 With TiNbMoCr 0.4 The oxidation weight gain of the Zr-4 plate with multi-principal element alloy coating is basically the same as that of the uncoated Zr-4 plate, indicating that the high-temperature oxidation resistance of these three coatings is comparable to that of Zr-4; while the surface-deposited TiNbMoCr 0.6 The oxidation weight gain of the Zr-4 plate with multi-principal element alloy coating was significantly higher than that of the uncoated Zr-4 plate, indicating its poor high-temperature oxidation resistance at this temperature. This is because the higher Cr content leads to more significant solute segregation during solidification, resulting in Cr-rich heterogeneous structures in local areas. These areas are more prone to forming coarse oxides or oxide film rupture during high-temperature oxidation, leading to an overall increase in oxidation weight gain. Furthermore, excessively high Cr content may also reduce the stability of the Ti-Nb-Mo principal element solid solution, decreasing the continuity of the oxide film. As the experimental temperature gradually increases, the surface deposited TiNbMoCr... 0.4The oxidation weight gain rate of the Zr-4 plate with multi-principal element alloy coating was significantly slower and less than that of other coatings, indicating that TiNbMoCr... 0.4 Multi-principal element alloy coatings exhibit superior high-temperature oxidation resistance. This also demonstrates that the appropriate addition of Cr can significantly improve the coating's oxidation resistance in high-temperature environments, enhancing the performance of TiNbMoCr coatings. 0.4 Multi-principal alloy coatings exhibit optimal high-temperature oxidation resistance performance.

[0090] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art should understand that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A zirconium alloy surface TiNbMoCr x Multi-principal element alloy coating, characterized in that, TiNbMoCr x Multi-principal element alloy powder is prepared on the surface of zirconium alloy by laser cladding technology; Where x is 0, 0.2, 0.4 or 0.

6.

2. The zirconium alloy surface TiNbMoCr according to claim 1 x Multi-principal element alloy coating, characterized in that, The TiNbMoCr x The particle size of the multi-principal element alloy powder is 45-150 mesh.

3. The zirconium alloy surface TiNbMoCr according to claim 1 x Multi-principal element alloy coating, characterized in that, The zirconium alloy surface TiNbMoCr x The thickness of the multi-principal alloy coating is 0.5-0.6 mm.

4. The zirconium alloy surface TiNbMoCr according to claim 1 x Multi-principal element alloy coating, characterized in that, Laser cladding for preparing TiNbMoCr on zirconium alloy surfaces x The specific process parameters for the multi-principal element alloy coating are: laser power of 1500-1700 W, scanning speed of 3-5 mm / s, and powder feeding speed of 1.5-2.0 r / min.

5. The zirconium alloy surface TiNbMoCr according to any one of claims 1-4 x A method for preparing multi-principal element alloy coatings, characterized in that, Includes the following steps: (1) Titanium powder, niobium powder, molybdenum powder and chromium powder weighed according to their chemical formulas are mixed, and the resulting mixed powder is dried to obtain TiNbMoCr. x Multi-principal element alloy powder; (2) The TiNbMoCr x Multi-principal alloy powder is shaped and processed on the surface of zirconium alloy using laser cladding technology to obtain the TiNbMoCr surface of the zirconium alloy. x Multi-principal element alloy coating.

6. The preparation method according to claim 5, characterized in that, In step (1), the titanium powder, niobium powder, molybdenum powder and chromium powder weighed according to their chemical formulas and ceramic grinding balls are placed in a ball mill jar, and then the ball mill jar is placed in a ball mill for mechanical mixing.

7. The preparation method according to claim 5, characterized in that, In step (1), the mixing speed is 100-150 r / min.

8. The preparation method according to claim 5, characterized in that, In step (1), the drying process also includes a sieving step.

9. The preparation method according to claim 5, characterized in that, In step (1), the temperature for drying the mixed powder is 180-220 ℃.

10. The zirconium alloy surface TiNbMoCr according to any one of claims 1-4 x Application of multi-principal element alloy coating in the preparation of zirconium alloy cladding.

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