An amorphous enamel tritium-resistant coating resistant to molten lead-lithium corrosion, and a preparation method and application thereof

Abstract

The present application belongs to the technical field of nuclear fusion reaction coating materials, and particularly relates to an amorphous enamel tritium-blocking coating resistant to molten lead-lithium corrosion and a preparation method and application thereof. The coating material is a direct mixture of glaze powder raw materials or a glaze obtained after melting of the glaze powder raw materials. The glaze powder raw materials, with a total mass of 100%, comprise 45-55% of SiO2, 8-12% of Al2O3, 4-6% of TiO2, 13-17% of CaO, 8-12% of Na2O, 4-6% of BaO, 4-6% of B2O3 and inevitable impurities, wherein the total mass of the inevitable impurities is not more than 0.5% of the total mass of the glaze powder raw materials. The amorphous enamel tritium-blocking coating prepared by using the coating material can maintain an amorphous structure at high temperatures, has excellent tritium-blocking permeation capacity and molten lead-lithium corrosion resistance, and has good application prospects and industrial value in the field of nuclear fusion reaction coating and the like.

Description

Technical Field

[0001] This invention belongs to the field of nuclear fusion reaction coating materials technology, specifically relating to an amorphous enamel tritium barrier coating resistant to molten lead-lithium corrosion, its preparation method, and its application. Background Technology

[0002] Nuclear fusion energy is one of the effective ways to solve the energy crisis and environmental problems, and its energy mainly comes from the fusion reaction of the hydrogen isotopes deuterium and tritium. However, hydrogen isotopes have the smallest atomic radius and diffuse in metallic materials as interstitial atoms, exhibiting extremely high permeability. Under high-temperature conditions, the migration and permeation of tritium can cause hydrogen embrittlement in structural materials such as low-activity ferritic martensitic steel and vanadium alloys, thereby reducing the mechanical properties and service life of the materials. Simultaneously, tritium is a radioactive gas, and once leaked into the environment, it will cause serious radiation hazards. Furthermore, tritium permeation also leads to the loss of expensive nuclear fuel. Therefore, fusion reactors must establish effective barriers to prevent tritium permeation.

[0003] To ensure the safe and stable operation of a fusion reactor, the most effective method is to prepare a coating with excellent tritium-blocking properties on the surface of the structural materials. Hydrogen isotopes mainly diffuse atomically in metallic materials, while they mainly diffuse molecularly in ceramic materials, with a much lower permeability. Therefore, ceramic coatings can be prepared on the surface of metallic materials to reduce the diffusion coefficient of hydrogen isotopes, thus protecting the substrate material.

[0004] Current research mainly focuses on oxide and carbide ceramic coatings. However, these tritium-blocking coatings still have many shortcomings. First, existing ceramic coating preparation processes are complex, require sophisticated equipment, have low production efficiency, and high production costs. They are also unsuitable for complex-shaped workpieces, making large-scale production difficult. Second, the interfacial bonding strength between the coating and the substrate is low. The thermal expansion coefficients of the ceramic coating and the substrate are significantly mismatched, leading to substantial thermal stress between them after thermal shock, which can easily cause cracking. Third, oxide coatings are severely corroded in the molten lead-lithium alloys of nuclear fusion reactors, seriously affecting the material's service life and safety. To address these problems, it is necessary to develop novel tritium-blocking and corrosion-resistant coatings.

[0005] Enamel coating is a composite material formed by applying enamel to a metal surface and sintering it at a certain temperature, resulting in a physicochemical reaction between the metal and the enamel. Compared to traditional ceramic tritium-barrier coatings, enamel coatings have excellent wear resistance and corrosion resistance. Furthermore, the preparation process of enamel coatings is simple and inexpensive, suitable for workpieces of various shapes, and has a mature background for large-scale industrial production.

[0006] However, the glass phase of enamel coatings is unstable at high temperatures and is prone to microcrystalline precipitation. Therefore, although existing studies have reported the feasibility of enamel as a hydrogen barrier and its isotope permeation barrier, its application in nuclear fusion reactor scenarios is still in the research stage. Tao Jie et al. (DOI:10.3321 / j.issn:0258-0918.2008.04.011.) prepared an enamel coating of a specific thickness on the surface of a 316L stainless steel substrate using a two-enameling and two-firing method, proving that it can effectively block hydrogen. However, using conventional enamel materials, it is not suitable for nuclear fusion reactor scenarios. Fang Junyi explored the influence of the composition and process of Ti-containing low-carbon enamel steel on hydrogen storage capacity and anti-scaling performance, but his results focused on the anti-scaling performance of specific enamel compositions, lacking direct research on tritium blocking, and could not solve the adaptability problem of nuclear fusion reactor operating conditions.

[0007] Providing novel enamel protective coatings that can be matched to nuclear fusion reactor scenarios and exhibit excellent tritium-blocking performance in high-temperature and molten lead-lithium corrosive environments is a technical problem that needs to be solved. Summary of the Invention

[0008] To address the aforementioned technical problems, one objective of this invention is to provide an amorphous enamel tritium-resistant coating material resistant to molten lead-lithium corrosion.

[0009] The technical solution adopted in this invention is as follows:

[0010] A tritium-barrier amorphous enamel coating material resistant to molten lead-lithium corrosion is disclosed. The coating material is a direct mixture of glaze powder raw materials or a glaze obtained by melting the glaze powder raw materials. The glaze powder raw materials, based on 100% of their total mass, include 45%~55% SiO2, 8%~12% Al2O3, 4%~6% TiO2, 13%~17% CaO, 8%~12% Na2O, 4%~6% BaO, 4%~6% B2O3, and unavoidable impurities. The total mass of the unavoidable impurities does not exceed 0.5% of the total mass of the glaze powder raw materials.

[0011] The aforementioned unavoidable impurities may include K. + Li + Mg 2+ Sr 2+ Cations derived from alkali metals or alkaline earth metals, or Cl - SO4 2- Anions.

[0012] The second objective of this invention is to provide an amorphous enamel tritium barrier coating resistant to molten lead-lithium corrosion, wherein the amorphous enamel tritium barrier coating is prepared using the coating material described above.

[0013] Preferably, the thickness of the coating is 50~300 μm.

[0014] The third objective of this invention is to provide a method for preparing the amorphous enamel tritium-resistant coating resistant to molten lead-lithium corrosion as described above, comprising the following steps:

[0015] S1. The set amount of the glaze powder raw material is ball-milled and mixed, then heated and melted, and quenched with water to obtain enamel glaze. The heating and melting method is to melt at a temperature of 1450~1550 ℃ for 2~3 h.

[0016] S2. Prepare the enamel glaze into enamel micro powder with a particle size of less than 20 μm;

[0017] S3. Mix the enamel micro powder and dispersant at a ratio of 1 g : (10~20) mL to prepare an enamel slurry;

[0018] S4. The enamel slurry is sprayed onto the desired substrate using a spraying method, dried, and then kept at a high temperature of 800~1000 ℃ for 2~5 min, followed by natural air cooling to obtain an enamel coating.

[0019] Preferably, the ball milling speed is 250~350 rpm, and the ball milling ensures that the maximum particle size of the enamel powder after milling is no greater than 20 μm. Generally, the ball milling time is 12~24 h.

[0020] Preferably, the heating and melting process involves heating from room temperature to 1450-1550 °C at a heating rate of 10-20 °C / min.

[0021] Preferably, the dispersant is anhydrous ethanol or acetone.

[0022] Preferably, in step S4, the drying method is to dry at a temperature of 200~300 ℃. The drying process must ensure that the dispersant on the surface and inside the coating evaporates completely. The drying is considered complete when the coating mass loss within 5 minutes does not exceed 0.1% of its initial mass.

[0023] The fourth objective of this invention is to provide the application of the amorphous enamel tritium barrier coating as described above as a protective coating for nuclear fusion reactors.

[0024] Preferably, the protective coating is disposed on the surface of the plasma-facing component in the nuclear fusion reactor, and / or disposed on the inner surface of the liquid lead-lithium cladding of the nuclear fusion reactor.

[0025] The fifth objective of this invention is to provide a metal material with high tritium barrier capability, wherein the surface of the metal material is coated with an amorphous enamel tritium barrier coating as described above.

[0026] The beneficial effects of this invention are as follows:

[0027] (1) The amorphous enamel tritium barrier coating provided in this application achieves excellent high-temperature tritium barrier performance through the synergistic effect of specific component design and preparation process. Its underlying mechanism mainly stems from the following three aspects: First, the coating effectively suppresses crystal nucleation and crystal growth through the significant differences in composition and lattice structure of the multi-element oxides, combined with the melt-rapid cooling process, enabling the coating to maintain an amorphous structure for a long time during high-temperature service, thereby blocking the rapid diffusion channels of tritium along grain boundaries. Second, the electron-rich elements such as transition metals (e.g., Ti) and alkaline earth metals (Ca, Na, Ba) in the coating can form stable bonds with hydrogen atoms through charge transfer effects, confining them to local energy low points; while the high formation energy of hydrogen and main group elements (Si, Al, B) together construct a high diffusion barrier, further delaying the migration of tritium. Finally, the coating adopts a fully oxidized system, with a highly dense structure and extremely low oxygen vacancy concentration, fundamentally suppressing the structural defect channels required for hydrogen permeation. Experiments show that the coating provided in this application has a tritium barrier factor of ≥1300 at 500 ℃ and a tritium barrier factor of ≥800 at 600 ℃, demonstrating excellent tritium barrier performance.

[0028] (2) Compared with oxide coatings, this coating has an extremely low corrosion weight loss rate (≤0.02% in lead-lithium at 550 °C for 5000 h), which mainly depends on the synergistic effect of multiple components: the network formation mainly composed of SiO2, together with Al2O3, B2O3 and TiO2, constructs a kinetically sluggish "quasi-high entropy" amorphous network, which significantly inhibits ion interdiffusion; the network modifiers (CaO, Na2O, BaO) achieve dynamic interface stability by optimizing the structural density and inducing a passivation transition layer at the corrosion interface; at the same time, the controlled content of TiO2 strengthens the network skeleton in the form of [TiO4] and maintains the interface oxidation state, forming a static-dynamic composite protective barrier, thereby achieving corrosion resistance and structural safety superior to traditional oxide coatings in extreme environments.

[0029] (3) During the sintering process, the coating and the metal substrate of this application undergo chemical reaction and interdiffusion of components. This chemical bonding is significantly stronger than that of general van der Waals forces and mechanical bonding, and the bonding cross section is serrated, which increases the interface roughness between the substrate and the coating and further enhances the bonding force between the coating and the substrate. At the same time, the coating and the substrate have good matching thermal expansion coefficients, outstanding anti-stripping ability under thermal cycling conditions, good interfacial bonding force, and can extend the service life of the coating.

[0030] (4) The raw materials for the coating of this application are inexpensive and easy to obtain. At the same time, the preparation method is simple, the preparation process is mature, the quality of the prepared coating is controllable, and the prepared coating has excellent tritium penetration resistance and resistance to molten lead and lithium corrosion. It breaks through the limitations of traditional ceramic tritium barrier coatings with low bonding strength and poor thermal shock resistance. It has good application prospects and industrial value in fields such as nuclear fusion reaction coatings. Attached Figure Description

[0031] Figure 1 The microstructure of the enamel coating prepared in Example 1 is shown in Figure a, and the cross-sectional microstructure is shown in Figure b.

[0032] Figure 2 The cross-sectional morphology (Figure a) and energy dispersive spectral line scan (Figure b) of the enamel coating and substrate interface prepared in Example 1.

[0033] Figure 3 The image shows the energy dispersive spectroscopy (EDS) pattern of the enamel coating prepared in Example 1. In the image, a represents the microstructure of the coating surface, and bi represents the signals of elements Si, Al, Ti, Ca, Na, Ba, B, and O, respectively.

[0034] Figure 4 The XPS spectrum of the enamel coating prepared in Example 1 is shown, where a-h are the fine spectra of elements Si, Al, Ti, Ca, Na, Ba, B and O, respectively.

[0035] Figure 5 The XRD patterns of the enamel coating prepared in Example 1 after being heat-treated at different temperatures are shown.

[0036] Figure 6 The results of hydrogen isotope permeation tests on different groups of coating samples are shown.

[0037] Figure 7 The image shows the energy dispersive spectroscopy (EDS) spectrum of the enamel coating of Example 1 after a hydrogen permeation test. In the image, a represents the microstructure of the coating surface, and bi represents the signals of Si, Al, Ti, Ca, Na, Ba, B, and O elements, respectively.

[0038] Figure 8 The image shows the XRD pattern of the enamel coating of Example 1 after a hydrogen permeation test.

[0039] Figure 9 The graph shows the weight changes of different groups of coated samples after 5000 h of corrosion in liquid lead-lithium alloy at 550 °C.

[0040] Figure 10 The XRD pattern of the coating sample prepared in Comparative Example 4.

[0041] Figure 11 The image shows the cross-sectional microstructure of the enamel coating prepared in Example 2.

[0042] Figure 12 The image shows the cross-sectional microstructure of the enamel coating prepared in Example 3.

[0043] Figure 13 The image shows the cross-sectional microstructure of the enamel coating prepared in Example 4.

[0044] Figure 14 The image shows the cross-sectional microstructure of the enamel coating prepared in Example 5.

[0045] Figure 15 The image shows the morphology of the enamel tritium-barrier coating prepared on the surface of the irregular part in Example 6. In the image, a is the overall morphology of the irregular part, and b is the microscopic morphology of the coating at the corner of the irregular part. Detailed Implementation

[0046] Unless otherwise stated, the terms used herein have the meanings commonly understood by those skilled in the art.

[0047] The main preparation process of the low-activation martensitic steel used in the experiment was as follows: ton-scale smelting was carried out using vacuum induction melting technology. The specific chemical composition (mass fraction) was 0.094% C, 8.88% Cr, 1.48% W, 0.16% V, 0.13% Ta, 0.50% Mn, and 0.04% Si. After multi-directional forging of the ingot into a 470×470×1300 mm³ billet, the 90 mm thick cubic billet was precision hot rolled to a thickness of 22 mm. Subsequently, a 50×30×22 mm steel was produced by wire EDM along the rolling direction. 3 Standard specimens. Finally, the specimens were subjected to normalizing heat treatment (980 ℃ / 30 min / air cooling) and high-temperature tempering (760 ℃ / 90 min / air cooling) to obtain experimental materials with the target microstructure.

[0048] The technical solution of the present invention will be described in more detail below with reference to the embodiments.

[0049] Example 1

[0050] An amorphous enamel tritium-barrier coating material, based on a total mass of 100%, includes 50% SiO2, 10% Al2O3, 5% TiO2, 15% CaO, 10% Na2O, 5% BaO, 5% B2O3, and unavoidable impurities, wherein the total mass of unavoidable impurities does not exceed 0.5% of the total mass of the enamel powder raw material.

[0051] The specific method for preparing an amorphous enamel tritium-barrier coating using this amorphous enamel tritium-barrier coating material is as follows:

[0052] 1. Enamel glaze melting:

[0053] Weigh the above raw materials according to the above proportions, and use a planetary ball mill to ball mill and mix them at 300 rpm for 18 h. Then, heat and melt the uniformly mixed raw materials from room temperature to 1500 ℃ at a rate of 10 ℃ / min, and keep them at 1500 ℃ for 2 h. Then, quench them with water to obtain glass glaze blocks.

[0054] 2. Preparation of enamel micro powder:

[0055] Using a planetary ball mill, the glass enamel block was ball-milled at 300 rpm for 20 hours. The ball-milled glass enamel powder was then passed through a 200-mesh sieve to obtain enamel micro powder with a particle size of less than 20 μm.

[0056] 3. Preparation of enamel slurry:

[0057] Enamel powder and anhydrous ethanol were mixed at a ratio of 1g:10mL, and the mixture was magnetically stirred and ultrasonically vibrated for 15 minutes to obtain a uniformly dispersed enamel slurry.

[0058] 4. Enamel coating:

[0059] Enamel slurry was sprayed onto the substrate surface using an air compressor at an atmospheric pressure of 0.4 MPa. The substrate was Chinese low-activation martensitic steel, which was sanded with 400-grit sandpaper and then sandblasted. The spraying distance was 20 cm. After spraying, the substrate was dried in an oven at 250 ℃ for 10 min to obtain the original enamel coating blank.

[0060] 5. Enamel coating sintering:

[0061] The dried original enamel coating blank was sintered in a muffle furnace at 900 °C for 2 min and then cooled in the atmosphere to obtain the enamel coating.

[0062] Observation and testing

[0063] Figure 1 The microstructure of the prepared enamel coating is shown in Figure a. The surface microstructure is shown in Figure b. It can be seen that the enamel coating has a smooth and flat surface, a dense interior, and no obvious grain features. The coating thickness is uniform, approximately 250 μm.

[0064] Figure 2 Figure a shows the cross-sectional morphology (Figure a) and energy dispersive spectroscopy (EDS) scan of the interface between the enamel coating and the substrate. It can be seen that the coating and the low-activation martensitic steel substrate exhibit good matching of thermal expansion coefficients, resulting in a tight bond and a serrated interface. Due to chemical reactions and interdiffusion of components between the coating and the substrate, this is a chemical bond, significantly stronger than typical van der Waals forces or mechanical bonds. Simultaneously, the serrated interface structure increases the interfacial roughness between the substrate and the coating, further enhancing the bond between them.

[0065] Figure 3 This is an energy dispersive spectroscopy (EDS) scan of the enamel coating. Signals from Si, Al, Ti, Ca, Na, Ba, B, and O elements can be detected in the coating, and all elements are uniformly distributed without significant segregation.

[0066] Figure 4 The image shows the XPS spectra of the enamel coating, indicating that all elements are in an oxidized state.

[0067] Finally, the enamel coating samples were kept at different temperatures for 10 hours and then removed. XRD (X-ray diffraction) patterns were then analyzed on the samples after the high-temperature heat treatment. The results are shown in [reference needed]. Figure 5 As can be seen, within the temperature range of 550~700 ℃, the diffraction patterns of the sample in the range of 15°~40° all show diffuse peak characteristics, and no diffraction peaks of crystalline phase were observed. This indicates that even after high-temperature heat treatment, the coating still maintains the phase structure characteristics dominated by amorphous SiO2.

[0068] Performance testing

[0069] The performance of the enamel coating sample prepared in Example 1 and the coating samples prepared in Comparative Examples 1-4 were tested. Information on the comparative examples is as follows:

[0070] Comparative Example 1: Using Chinese low-activation martensitic steel without any coating.

[0071] Comparative Example 2: A typical SiO2 tritium-barrier coating was prepared on a low-activation martensitic steel substrate in China using magnetron sputtering. The preparation method was as follows: Before sputtering, the substrate was polished to ensure a smooth surface. Sputtering process parameters: the target material was high-purity SiO2 (99.99%), the working gas was high-purity Ar (99.99%), the chamber pressure was maintained at 0.23 Pa, an AC sputtering power supply was used with a power setting of 250 W, and the total sputtering time was 5 h, ultimately obtaining a coating with a thickness of approximately 2 μm.

[0072] Comparative Example 3: A typical Al2O3 tritium-barrier coating was prepared on a low-activation martensitic steel substrate in China using magnetron sputtering technology. The preparation method was as follows: before sputtering, the substrate was polished to ensure a smooth surface. The sputtering process parameters were as follows: the target material was high-purity Al2O3 (99.99%), the working gas was high-purity Ar (99.99%), the chamber pressure was maintained at 0.23 Pa, an AC sputtering power supply was used with a power setting of 250 W, and the total sputtering time was 5 h, ultimately obtaining a coating with a thickness of approximately 2 μm.

[0073] Comparative Example 4: The preparation method of Comparative Example 4 is the same as that of Example 1, except that the formulation of the amorphous enamel tritium barrier coating material is as follows: based on the total mass of 100%, it includes 50% SiO2, 9% Al2O3, 8% TiO2, 14% CaO, 9% Na2O, 5% BaO, 5% B2O3, and unavoidable impurities. The total mass of unavoidable impurities does not exceed 0.5% of the total mass of the glaze powder raw materials.

[0074] 1. Hydrogen isotope permeation test

[0075] The tritium barrier properties of the coating were studied using an ultra-high vacuum hydrogen permeation performance testing system. The system consists of a vacuum chamber, a monitoring system, and auxiliary equipment. The specific experimental steps are as follows: The enamel coating sample was installed into the testing system, ensuring the coating surface faced the upstream high-pressure side. Both parts of the apparatus were evacuated to approximately 1 × 10⁻⁶. -6 The pressure is 120-130 kPa, followed by the introduction of hydrogen or deuterium gas into the upstream chamber at a pressure of 120-130 kPa. The test temperature is controlled within the range of 573-873 K. The hydrogen signal permeating through the sample into the downstream chamber is dynamically monitored by a stage IV mass spectrometer installed on the downstream low-pressure side, and the hydrogen permeation flux is calculated using a calibration factor obtained from a hydrogen standard leak.

[0076] See results Figure 6 Calculations show that the tritium barrier factor of this enamel coating can reach over 1300 at 500 ℃ and over 800 at 600 ℃, significantly higher than comparative examples 1-3. The enamel coating exhibits excellent tritium barrier properties at high temperatures.

[0077] Figure 7 The image shows the energy dispersive spectroscopy (EDS) scan of the enamel coating from Example 1 after a hydrogen permeation test. It can be observed that the elemental composition of the coating did not change significantly, confirming the excellent stability of the enamel coating under long-term hydrogen permeation conditions.

[0078] Figure 8 The XRD pattern of the enamel coating prepared in Example 1 after hydrogen permeation testing is shown. It can be seen that the phase structure of the coating did not change significantly, confirming the excellent stability of the enamel coating under long-term hydrogen permeation conditions.

[0079] 2. Corrosion test of liquid lead-lithium alloy

[0080] This experiment employed a static immersion method, completely immersing each sample in a 550 °C liquid lead-lithium alloy and conducting a 5000-h isothermal corrosion test under an argon protective atmosphere. Before and after corrosion, the samples were ultrasonically cleaned to remove surface contaminants, dried, and their mass changes were measured using an analytical balance with an accuracy of 0.1 mg.

[0081] Figure 9 The graph shows the weight change of each coated sample after 5000 h of corrosion in molten lead-lithium alloy at 550 ℃. The test results show that after 5000 h of corrosion, the weight loss rate of the enamel coating is only 0.02%, which is much lower than that of comparative examples 1-3. It can be seen that the enamel coating can effectively improve the corrosion resistance of the material to molten lead-lithium alloy.

[0082] In addition, the coating of Comparative Example 4 was observed using XRD patterns. (See XRD pattern for reference.) Figure 10The diffraction peaks of the crystalline phase are clearly visible in the figure. This result indicates that the addition of excessive nucleating agent (TiO2) will impair the amorphous formation ability of the coating, making it difficult to maintain its amorphous structure characteristics.

[0083] Example 2

[0084] The preparation method of Example 2 is the same as that of Example 1, except that the formulation of the amorphous enamel tritium barrier coating material is as follows: based on a total mass of 100%, it includes 55% SiO2, 12% Al2O3, 4% TiO2, 13% CaO, 8% Na2O, 4% BaO, 4% B2O3, and unavoidable impurities. The total mass of unavoidable impurities does not exceed 0.5% of the total mass of the glaze powder raw materials.

[0085] like Figure 11 As shown, the enamel coating prepared in Example 2 has a smooth and flat surface with a glassy luster; the coating and the base alloy have good matching coefficients of thermal expansion, and the interface between the two is well bonded, exhibiting excellent adhesion; the coating is dense internally, with a compact and uniform cross-sectional structure and no obvious grain characteristics; no microcrystalline precipitation occurs within the coating, maintaining an amorphous structure. XRD results show that the enamel coating is amorphous. Hydrogen isotope permeation experiments show that at 500 °C, the tritium barrier factor of this enamel coating can reach over 1300; at 600 °C, the tritium barrier factor can reach over 800. Corrosion experiments show that after 5000 h of corrosion, the weight loss rate of the enamel coating is only 0.02%. It can be seen that the enamel coating has excellent tritium barrier performance and resistance to molten lead-lithium corrosion.

[0086] Example 3

[0087] The preparation method of Example 3 is the same as that of Example 1, except that the formulation of the amorphous enamel tritium barrier coating material is as follows: based on a total mass of 100%, it includes 45% SiO2, 8% Al2O3, 6% TiO2, 17% CaO, 12% Na2O, 6% BaO, 6% B2O3, and unavoidable impurities. The total mass of unavoidable impurities does not exceed 0.5% of the total mass of the glaze powder raw materials.

[0088] like Figure 12As shown, the enamel coating prepared in Example 3 has a smooth and flat surface with a glassy luster; the coating and the base alloy have good matching thermal expansion coefficients, and the interface between the two is well bonded, exhibiting excellent adhesion; the coating is dense internally, with a compact and uniform cross-sectional structure and no obvious grain characteristics; no microcrystalline precipitation occurs within the coating, maintaining an amorphous structure. XRD results show that the enamel coating is amorphous. Hydrogen isotope permeation experiments show that at 500 °C, the tritium barrier factor of this enamel coating can reach over 1300; at 600 °C, the tritium barrier factor can reach over 800. Corrosion experiments show that after 5000 h of corrosion, the weight loss rate of the enamel coating is only 0.02%. It can be seen that the enamel coating has excellent tritium barrier performance and resistance to molten lead-lithium corrosion.

[0089] Example 4

[0090] The amorphous enamel tritium-blocking coating material and preparation method in Example 4 are the same as in Example 1, except that the coating thickness is 70 μm.

[0091] like Figure 13 As shown, the prepared enamel-coated tritium-blocking coating has a smooth and flat surface with a glassy luster; the coating and the base alloy have good matching thermal expansion coefficients, and the interface between the two is well bonded, exhibiting excellent adhesion; the coating is dense internally, with a compact and uniform cross-sectional structure and no obvious grain characteristics; no microcrystals precipitate within the coating, maintaining an amorphous structure. XRD results show that the enamel coating is amorphous. Hydrogen isotope permeation experiments show that at 500 °C, the tritium-blocking factor of this enamel coating can reach over 1300; at 600 °C, the tritium-blocking factor can reach over 800. Corrosion experiments show that after 5000 h of corrosion, the weight loss rate of the enamel coating is only 0.02%. It can be seen that the enamel coating has excellent tritium-blocking performance and resistance to molten lead-lithium corrosion.

[0092] Example 5

[0093] The amorphous enamel tritium-barrier coating material and preparation method in Example 5 are the same as in Example 1, except that the alloy substrate is CLF-1 steel.

[0094] like Figure 14 As shown, the enamel-coated tritium barrier coating prepared on the CLF-1 steel surface has a smooth and flat surface with a glassy luster. The coating and the base alloy have good matching thermal expansion coefficients, and the interface between the two is well bonded with excellent adhesion. The coating is dense internally, with a compact and uniform cross-sectional structure and no obvious grain characteristics. There are no microcrystalline precipitations within the coating, maintaining an amorphous structure.

[0095] Example 6

[0096] The amorphous enamel tritium-blocking coating material and preparation method of Example 6 are the same as those of Example 1, except that the alloy substrate is a shaped part of low-activation martensitic steel from China.

[0097] like Figure 15 As shown, the enamel tritium-barrier coating prepared on the planes and corners of irregularly shaped parts has a smooth and flat surface with a glassy luster. The coating and the base alloy have good matching coefficients of thermal expansion, and the interface between the two is well bonded with excellent adhesion. The coating is dense internally, with a compact and uniform cross-sectional structure and no obvious grain features. There is no microcrystalline precipitation within the coating, maintaining an amorphous structure.

[0098] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that 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 present invention.

Claims

1. An amorphous enamel tritium-barrier coating material resistant to molten lead-lithium corrosion, characterized in that, The coating material is a direct mixture of glaze powder raw materials or a glaze obtained by melting glaze powder raw materials. The glaze powder raw materials, based on a total mass of 100%, include 45%~55% SiO2, 8%~12% Al2O3, 4%~6% TiO2, 13%~17% CaO, 8%~12% Na2O, 4%~6% BaO, 4%~6% B2O3, and unavoidable impurities. The total mass of the unavoidable impurities does not exceed 0.5% of the total mass of the glaze powder raw materials.

2. An amorphous enamel tritium-barrier coating resistant to molten lead-lithium corrosion, characterized in that, It is prepared using the coating material as described in claim 1.

3. The amorphous enamel tritium-barrier coating resistant to molten lead-lithium corrosion as described in claim 2, characterized in that, The coating thickness is 50~300 μm.

4. The method for preparing an amorphous enamel tritium-resistant coating resistant to molten lead-lithium corrosion as described in claim 2 or 3, characterized in that, Includes the following steps: S1. The set amount of the glaze powder raw material is ball-milled and mixed, then heated and melted, and quenched with water to obtain enamel glaze. The heating and melting method is to melt at a temperature of 1450~1550 ℃ for 2~3 h. S2. Prepare the enamel glaze into enamel micro powder with a particle size of less than 20 μm; S3. Mix the enamel micro powder and dispersant at a ratio of 1 g : (10~20) mL to prepare an enamel slurry; S4. The enamel slurry is sprayed onto the desired substrate using a spraying method, dried, and then kept at a high temperature of 800~1000 ℃ for 2~5 min, followed by natural air cooling to obtain an enamel coating.

5. The preparation method according to claim 4, characterized in that, The ball milling speed is 250~350 rpm, and the ball milling is carried out until the maximum particle size of the enamel powder is less than or equal to 20 μm.

6. The preparation method according to claim 4, characterized in that, The heating and melting process involves heating from room temperature to 1450-1550 ℃ at a heating rate of 10-20 ℃ / min.

7. The preparation method according to claim 4, characterized in that, The dispersant is anhydrous ethanol or acetone.

8. The preparation method according to claim 4, characterized in that, In step S4, the drying method is to dry at a temperature of 200~300℃ until the dispersant in the coating evaporates, and the mass loss of the coating within 5 minutes does not exceed 0.1% of its initial mass.

9. The application of the amorphous enamel tritium barrier coating as described in claim 2 or 3 as a protective coating for nuclear fusion reactors.

10. The application as described in claim 9, characterized in that, The protective coating is applied to the surface of the plasma-facing component in the nuclear fusion reactor, and / or to the inner surface of the liquid lead-lithium cladding of the nuclear fusion reactor.

11. A metallic material with high tritium barrier properties, characterized in that, The surface of the metal material is coated with an amorphous enamel tritium-barrier coating as described in claim 2 or 3.

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