A tritium-barrier alloy oxide coating and its preparation method

Abstract

The present invention belongs to the field of new material technology, and discloses an alloy oxide tritium barrier coating and a preparation method thereof. The preparation method is as follows: after pre-treating the metal substrate, a metal Cr target is sputtered by magnetron sputtering technology to deposit a layer of pure Cr primer on the surface of the metal substrate; magnetron sputtering technology is used, in a dual power supply mode, by simultaneously sputtering an Al target and a Cr target, an oxidation transition layer and an alloy oxide layer are sequentially deposited on the surface of the pure Cr primer to obtain a composite coating; the composite coating is annealed to obtain an alloy oxide tritium barrier coating containing crystalline oxides. The preparation method of the present invention can effectively alleviate the thermal mismatch problem between the coating and the substrate, and successfully form an alloy oxide tritium barrier coating with strong bonding with the substrate on the surface of the metal substrate; the preparation method of the present invention has a simple process flow, is pollution-free throughout the process, has a fast deposition speed, and saves costs; and the alloy oxide tritium barrier coating prepared by the present invention has excellent tritium and hydrogen barrier properties.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials, and in particular to an alloy oxide tritium barrier coating and a preparation method thereof. Background Art

[0002] Controlled nuclear fusion is an ideal clean energy source, attracting much attention due to its advantages in fuel reserves and minimal damage to the environment. However, in the tritium circuit of a fusion reactor, due to its small atomic number, tritium can easily penetrate and diffuse into the structure of metal materials. This not only deteriorates the material properties, causing hydrogen embrittlement and corrosion failure, resulting in radioactive contamination and economic losses, but also poses a huge safety hazard. For example, it may cause leakage and penetration of the tritium circuit during fusion reactor operation, thereby causing nuclear leakage safety issues. Applying a tritium barrier coating on the surface of tritium-related materials is an effective solution to prevent tritium leakage and tritium penetration in tritium-related materials. Metal oxides have become a hot topic in tritium barrier coating research due to their advantages such as stable chemical properties and good tritium barrier properties.

[0003] Among the commonly used oxide materials, aluminum oxide has attracted widespread attention due to its excellent tritium barrier properties, high hardness and excellent thermodynamic properties. However, aluminum oxide has a variety of phase structures, among which α-aluminum oxide has the best high-temperature chemical stability and tritium barrier properties, with a tritium barrier factor of up to 10,000. The main preparation methods used in the prior art for preparing metal oxide coatings are chemical vapor deposition and magnetron sputtering deposition. However, when chemical vapor deposition is used to prepare α-aluminum oxide, since the phase formation temperature of α-aluminum oxide is as high as 1200°C, the matrix material used to transport tritium, such as stainless steel pipes, can hardly withstand such high temperatures, resulting in the loss of matrix performance and deformation of the matrix during the actual preparation process, and thus it is difficult to effectively form a tritium barrier coating on the surface of the matrix material that transports tritium. When α-alumina is prepared by magnetron sputtering deposition, low-temperature deposition results in the coating being unable to form an α-alumina phase. The actual deposited alumina usually forms a film in an amorphous form, and the tritium barrier factor of amorphous alumina can be sharply reduced to below 50.

[0004] Based on the above, it can be seen that the above-mentioned several prior art preparation methods are difficult to effectively form a tritium-blocking coating on a base material that transports tritium. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides an alloy oxide tritium barrier coating and a preparation method thereof. The present invention utilizes magnetron sputtering technology to prepare an alloy oxide coating on the surface of stainless steel, and adopts a medium frequency / DC pulse dual power supply mode combined with a metal aluminum target and a metal chromium target for reactive co-sputtering, which can effectively inhibit target surface poisoning. At the same time, by regulating the target power, the ratio of Al and Cr elements in the coating can be adjusted. The metal base layer and the gradient oxidation transition layer in the coating act together as an intermediate transition layer, which can reduce the thermal mismatch effect between the coating and the substrate and improve the film-substrate interface bonding; the annealing treatment can effectively promote the transformation of the oxide from an amorphous state to a crystalline state, thereby improving the tritium barrier performance of the coating.

[0006] The present invention provides an alloy oxide tritium barrier coating and a preparation method thereof, which are achieved through the following technical solutions:

[0007] The present invention provides a method for preparing an alloy oxide tritium barrier coating, comprising the following steps:

[0008] Step 1: After polishing and cleaning the metal substrate, perform glow sputtering cleaning to obtain a clean metal substrate.

[0009] Step 2: In an argon atmosphere, a magnetron sputtering technique is used to deposit a layer of pure Cr primer on the surface of the clean metal substrate by sputtering a metal Cr target.

[0010] Step 3: Using magnetron sputtering technology, deposit the oxide transition layer and the alloy oxide layer in sequence:

[0011] Argon and oxygen are introduced, and magnetron sputtering technology is used. In a dual power supply mode, an Al target and a Cr target are sputtered simultaneously, and the oxygen flux is gradually increased to a stable flow within 5 minutes after the start of sputtering, so as to form a gradient-distributed oxidation transition layer on the surface of the pure Cr base layer; then, the Al target and the Cr target are continued to be sputtered simultaneously while maintaining the flow ratio of argon to oxygen, and an alloy oxide layer is deposited on the surface of the oxidation transition layer, so as to form a composite coating on the surface of the metal substrate, which consists of a pure Cr base layer, an oxidation transition layer and an alloy oxide layer from the inside to the outside.

[0012] Step 4: annealing the composite coating to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide tritium barrier coating containing crystalline oxides.

[0013] It should be noted that in step 1 above, the present invention does not limit the specific material of the metal substrate, and the metal substrate can be selected according to actual needs. For example, in some preferred embodiments of the present invention, the material of the metal substrate includes but is not limited to any one of austenitic stainless steel, low-activity martensitic stainless steel, heat-resistant steel, and high-temperature alloy.

[0014] In order to improve the bonding strength between the substrate and the coating, the present invention first polishes the metal substrate to remove impurities and defects on the surface of the metal substrate, and then cleans and removes impurities remaining during polishing. In some preferred embodiments of the present invention, the surface roughness R a If the polishing depth is less than 0.2 μm, it is considered that the impurities and defects on the surface of the metal substrate are completely removed. The present invention does not specifically limit the cleaning operation after polishing, and the cleaning can be performed according to conventional cleaning operations in the art.

[0015] It can be understood that since the glow sputtering cleaning process and the magnetron sputtering process using magnetron sputtering technology are both carried out in the magnetron sputtering equipment, the present invention first installs the polished and cleaned metal substrate on the working turntable in the vacuum chamber of the magnetron sputtering equipment, and places the various target materials required for deposition on the target position in the magnetron sputtering vacuum chamber, and then performs the glow sputtering cleaning process and subsequent magnetron sputtering in sequence.

[0016] To facilitate glow sputtering cleaning and subsequent magnetron sputtering, the present invention places a metal Al target and a Cr target on target positions within a magnetron sputtering vacuum chamber. The Al target is connected to a medium-frequency power supply, and the Cr target is connected to a DC pulse power supply. This ensures that during the subsequent magnetron sputtering process, a pure Cr primer layer is first deposited on the clean metal substrate surface by sputtering the Cr target. Then, in dual-power mode, an oxide transition layer and an alloy oxide layer are sequentially deposited on the surface of the pure Cr primer layer by simultaneously sputtering the Al and Cr targets.

[0017] The present invention performs glow sputtering cleaning on the surface of the metal substrate after polishing and cleaning to further remove impurities such as oil, dust, oxides, rust, welding slag and sweat on the surface of the metal substrate, thereby facilitating the improvement of the bonding strength between the subsequently deposited coating and the substrate.

[0018] In some preferred embodiments of the present invention, when performing glow sputtering cleaning treatment, the vacuum chamber of the magnetron sputtering equipment is first evacuated to <0.005Pa, and then argon gas is introduced into the vacuum chamber of the magnetron sputtering equipment to a pressure of 0.4Pa~2.0Pa. A bipolar pulse power supply is used, and the bias voltage applied to the substrate is -200V~1000V, and the treatment is carried out for at least 5 minutes.

[0019] In the above step 2, the present invention first uses magnetron sputtering technology in an argon atmosphere to deposit a layer of pure Cr primer on the surface of a clean metal substrate by sputtering a metal Cr target, so as to reduce the thermal mismatch effect between the coating and the substrate through the pure Cr primer, thereby improving the film-substrate interface bonding.

[0020] In some preferred embodiments of the present invention, when depositing the pure Cr base layer, the gas pressure is 0.2Pa~1.6Pa, the bias voltage applied to the substrate is -30V~300V, and the sputtering time is 5min~15min, so as to deposit a layer of pure Cr base layer with a thickness of 50nm~200nm on the surface of the metal substrate, thereby reducing the thermal mismatch effect between the coating and the substrate through the pure Cr base layer of this thickness, thereby improving the film-substrate interface bonding.

[0021] In order to address the drawback that coatings deposited by low-temperature magnetron sputtering are difficult to effectively achieve tritium-barrier effects, the present invention takes into account that the tritium-barrier factor of chromium oxide is as high as 100 to 3000, and that chromium oxide and α-alumina have the same close-packed hexagonal structure (i.e., hcp crystal structure), with very close lattice parameters. Moreover, chromium oxide has a low crystallization temperature and can obtain a crystal structure at 450°C, making it easy to prepare by magnetron sputtering. Therefore, the present invention proposes to use an Al target and a Cr target as sputtering targets, taking advantage of the fact that chromium oxide is easy to prepare and has extremely close lattice parameters to α-alumina. By simultaneously sputtering the Al target and the Cr target, the chromium oxide formed by the sputtering of the Cr target induces the α-alumina crystals, promoting the sputtering of the Al target to form α-alumina, and then forming a tritium-barrier coating composed of chromium oxide and α-alumina on the surface of the pure Cr base layer.

[0022] In step 3 above, the present invention forms a tritium barrier coating composed of chromium oxide and α-aluminum oxide on the surface of the metal substrate by sequentially depositing an oxide transition layer and an alloy oxide layer on the surface of the pure Cr base layer, thereby further improving the film-substrate interface bonding strength. In some preferred embodiments of the present invention, the oxide transition layer and the alloy oxide layer are sequentially deposited on the surface of the pure Cr base layer by the following steps:

[0023] 3.1) Deposition of oxide transition layer:

[0024] Argon and oxygen are introduced into the vacuum chamber of the magnetron sputtering equipment. Magnetron sputtering technology is used. In the dual power supply mode of medium frequency power supply and DC pulse power supply, Al target and Cr target are sputtered simultaneously. The argon flux is kept constant during sputtering, and the oxygen flux is gradually increased to a stable flow rate within 5 minutes after the start of sputtering. Since the argon flux is constant and the oxygen content is gradually increased during the magnetron sputtering process, an oxide transition layer with a gradient oxygen content can be deposited on the surface of the pure Cr base layer.

[0025] The present invention forms a gradient-distributed oxidation transition layer on the pure Cr base layer, which not only avoids the situation where the metal of the pure Cr base layer is converted into metal oxide due to excessive exposure of the pure Cr base layer to oxygen, thereby causing a thermal mismatch effect between the coating and the substrate; moreover, the gradient-distributed oxidation transition layer and the pure Cr base layer can act synergistically and serve as an intermediate transition layer between the metal substrate and the alloy oxide layer. The components of the intermediate transition layer are distributed in a gradient, which can effectively improve the bonding ability between different coatings, thereby further improving the film-substrate interface bonding strength, and effectively reducing the problem of coating shedding caused by the thermal mismatch effect between the coating and the substrate.

[0026] 3.2) Deposition of alloy oxide layer:

[0027] The present invention simultaneously sputters an Al target and a Cr target by maintaining the oxygen flux at a stable flow rate, that is, maintaining a stable flow ratio of argon to oxygen, so as to further deposit and form an alloy oxide layer with uniform composition and dense structure on the surface of the gradient-distributed oxidation transition layer, that is, forming a composite coating of a pure Cr base layer, an oxidation transition layer and an alloy oxide layer from the inside to the outside on the surface of the metal substrate, that is, forming a gradient distribution of thermal expansion coefficient on the surface of the metal substrate, thereby effectively improving the membrane-substrate interface bonding strength.

[0028] In the above 3.1), the present invention achieves a gradient distribution of the oxide transition layer composition by gradually increasing the amount of oxygen during the preparation of the oxide transition layer. This also effectively prevents surface poisoning of the target material. In some preferred embodiments of the present invention, when the oxygen flux reaches a stable flow rate, the flow ratio of argon to oxygen is 3 to 7:1.

[0029] In some preferred embodiments of the present invention, when depositing the oxide transition layer and the alloy oxide layer, the gas pressure is 0.1Pa~1Pa, and the bias voltage applied to the substrate is -30V~200V, so as to achieve uniform distribution of aluminum oxide and chromium oxide and improve the bonding strength between the formed aluminum oxide and chromium oxide and the underlying substrate and coating.

[0030] When depositing the alloy oxide layer, the deposition duration can be adjusted according to the actual desired thickness of the alloy oxide layer. For example, in some preferred embodiments of the present invention, when an alloy oxide layer with a thickness of 0.1 μm to 2 μm is required, the deposition time is 10 min to 600 min.

[0031] In some preferred embodiments of the present invention, when depositing the oxide transition layer and the alloy oxide layer, the total sputtering power of the Al and Cr targets is 100 W to 5000 W. The power ratio of the Al and Cr targets can be selected according to process requirements for sputtering. For example, in some more preferred embodiments of the present invention, the atomic ratio of Al to Cr in the formed alloy oxide tritium barrier coating can be adjusted by regulating the power ratio of the Al and Cr targets.

[0032] The present invention also subjects the composite coating formed by magnetron sputtering to an annealing treatment to promote the transformation of the oxide from an amorphous state to a crystalline state, such as converting amorphous chromium oxide into crystalline chromium oxide, thereby improving the tritium barrier properties of the coating. In some preferred embodiments of the present invention, the annealing temperature is 200°C to 800°C, and the annealing time is 10 minutes to 360 minutes.

[0033] The present invention also provides an alloy oxide tritium barrier coating prepared by the above preparation method, wherein the atomic ratio of Al element to Cr element in the alloy oxide tritium barrier coating is 1-2:1-9.

[0034] It should be noted that the alloy oxide tritium barrier coating prepared by the above method of the present invention is composed of a pure Cr base layer, an oxidized transition layer and an alloy oxide layer from the surface of the substrate to the outside, and has a gradient-distributed composite structure. Among them, the pure Cr base layer and the gradient-distributed oxidized transition layer can reduce the thermal mismatch effect between the coating and the substrate, thereby improving the film-substrate interface bonding, and has a dense structure and does not contain hydrogen elements, which can avoid the adverse effects of hydrogen embrittlement on the substrate. The alloy oxide layer on the surface contains crystalline metal oxides, which can effectively improve the tritium and hydrogen barrier properties of the substrate.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention cleans the metal substrate by performing a glow sputtering cleaning process after polishing and cleaning the metal substrate. Then, a pure Cr primer layer is deposited on the surface of the cleaned metal substrate using magnetron sputtering technology. Then, using magnetron sputtering technology, in a dual power supply mode of a medium frequency power supply and a direct current pulse power supply, an Al target and a Cr target are reactively co-sputtered, the argon flux is kept constant during sputtering, and the oxygen flux is gradually increased to a stable flow rate within 5 minutes after the start of sputtering. Since the oxygen content gradually increases during the magnetron sputtering process, an oxidized transition layer with a gradient oxygen content can be deposited on the surface of the pure Cr primer layer. Then, through the synergistic effect of the gradient-distributed oxidized transition layer and the pure Cr primer layer, the thermal mismatch effect between the coating and the substrate is further reduced, thereby further improving the film-substrate interface bonding strength. Then, the present invention simultaneously sputters an Al target and a Cr target by maintaining a stable oxygen flux, that is, maintaining a stable flow ratio of argon to oxygen, thereby further depositing a uniform and dense alloy oxide layer on the surface of the gradient-distributed oxide transition layer. This further forms a composite coating on the surface of the metal substrate, comprising, from the inside out, a pure Cr base layer, an oxide transition layer, and an alloy oxide layer. The composite coating is then annealed to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide barrier coating containing crystalline oxides.

[0037] The preparation method of the present invention successfully creates an alloy oxide tritium barrier coating on a metal substrate, resolving the thermal mismatch between existing aluminum oxide-based tritium barrier coatings and the metal substrate. Furthermore, the alloy oxide tritium barrier coating of the present invention exhibits strong adhesion to the metal substrate, effectively improving the tritium and hydrogen barrier properties of the metal substrate. Furthermore, the preparation method of the present invention is simple, pollution-free, and has a fast deposition rate, resulting in cost savings.

[0038] The preparation method of the present invention is applicable to nonferrous metals such as austenitic stainless steel, low-activity martensitic stainless steel, heat-resistant steel, and high-temperature alloys.

[0039] The present invention adopts a medium frequency / DC pulse dual power supply mode combined with a metal aluminum target and a metal chromium target for reactive co-sputtering, which can effectively suppress target surface poisoning. At the same time, by regulating the target power, the ratio of Al and Cr elements in the coating can be adjusted, and a specific composition with an Al / Cr atomic ratio between 2:1 and 1:9 can be prepared.

[0040] The alloy oxide tritium barrier coating prepared by the present invention comprises a pure Cr base layer, an oxidized transition layer and an alloy oxide layer in order from the substrate surface outward, and has a composite structure with a gradient distribution. The pure Cr base layer and the gradient-distributed oxidized transition layer can reduce the thermal mismatch effect between the coating and the substrate, thereby improving the film-substrate interface bonding. The coating has a dense structure and does not contain hydrogen elements, which can avoid the adverse effects of hydrogen embrittlement on the substrate. In addition, the alloy oxide layer on the surface contains crystalline metal oxides, which can effectively improve the tritium and hydrogen barrier properties of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a surface scanning electron microscope image of the coating of Comparative Example 1.

[0042] Figure 2 This is a cross-sectional scanning electron microscope image of the coating of Comparative Example 1.

[0043] Figure 3 This is a surface scanning electron microscope image of the coating of Comparative Example 2.

[0044] Figure 4 Surface scanning electron microscope image of the coating of Example 1.

[0045] Figure 5 Surface scanning electron microscope image of the coating of Example 2.

[0046] Figure 6 Surface scanning electron microscope image of the coating of Example 3.

[0047] Figure 7 This is the XRD spectrum of the coating on the surface of Example 1. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be described clearly and completely below.

[0049] Example 1

[0050] This embodiment provides a method for preparing an alloy oxide tritium barrier coating, comprising the following steps:

[0051] Step 1: After polishing and cleaning the metal substrate, perform glow sputtering cleaning to obtain a clean metal substrate:

[0052] 1.1) In this embodiment, a 316L stainless steel substrate is used as the metal substrate. After polishing and cleaning, a polished 316L stainless steel substrate is obtained.

[0053] 1.2) The polished metal substrate is dried and mounted on a workpiece turret in a magnetron sputtering vacuum chamber. Two Al targets and one Cr target are placed on target positions within the magnetron sputtering vacuum chamber. The Al targets are connected to a medium frequency power supply, and the Cr targets are connected to a DC pulse power supply.

[0054] 1.3) Evacuate the vacuum chamber of the magnetron sputtering equipment to 5×10 -3 Pa, and then argon gas was introduced to control the gas pressure to 0.5 Pa. The bias voltage applied to the substrate was -800 V, and the substrate was cleaned by glow sputtering for 10 minutes to obtain a clean metal substrate.

[0055] Step 2: In an argon atmosphere, magnetron sputtering technology is used to deposit a layer of pure Cr primer on the surface of the clean metal substrate by sputtering a metal Cr target:

[0056] Argon gas was introduced into the vacuum chamber, the Cr target was turned on, the working pressure was controlled to be 0.6 Pa, the bias voltage applied to the substrate was -150 V, the sputtering time was 10 min, and a layer of pure Cr primer was deposited on the surface of the clean metal substrate.

[0057] Step 3: Using magnetron sputtering technology, deposit the oxide transition layer and the alloy oxide layer in sequence:

[0058] 3.1) Deposition of oxide transition layer:

[0059] By introducing argon and oxygen into the vacuum chamber of the magnetron sputtering equipment, magnetron sputtering technology was used. In the dual power supply mode of medium frequency power supply and DC pulse power supply, the working gas pressure was controlled to 0.6 Pa, the bias voltage applied to the substrate was -200 V, the metal Al target and the metal Cr target were turned on, the total power was adjusted to 4000 W, and the power ratio of the metal Al target and the metal Cr target was 3:1. By sputtering the Al target and the Cr target at the same time, the argon flux was kept constant during sputtering, and the oxygen flux was gradually increased to an argon-oxygen partial pressure ratio of 3:1 within 5 minutes after the start of sputtering, and an oxide transition layer with a gradient oxygen content was deposited on the surface of the pure Cr base layer.

[0060] 3.2) Deposition of alloy oxide layer:

[0061] The argon-oxygen partial pressure ratio was maintained at 3:1, and the Al target and the Cr target were sputtered simultaneously under the above-mentioned magnetron sputtering conditions for 180 min to further deposit an alloy oxide layer on the surface of the gradient-distributed oxide transition layer, thereby obtaining a composite coating consisting of a pure Cr base layer, an oxide transition layer, and an alloy oxide layer from the inside to the outside.

[0062] 3.3) After coating, stop ventilation and maintain vacuum until the substrate temperature is ≤60℃.

[0063] Step 4: annealing the composite coating to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide tritium barrier coating containing crystalline oxides.

[0064] The annealing atmosphere was air, the heating rate was 5°C / min, the annealing temperature was 600°C, the holding time was 2h, and then the product was cooled to room temperature in the furnace.

[0065] After testing, the thickness of the alloy oxide tritium barrier coating obtained in this embodiment is 2.98 μm. In addition, the atomic percentage of aluminum is 60.7% and the atomic percentage of chromium is 29.3% in the metal element composition of the alloy oxide tritium barrier coating in this embodiment.

[0066] Example 2

[0067] This embodiment provides a method for preparing an alloy oxide tritium barrier coating, comprising the following steps:

[0068] Step 1: After polishing and cleaning the metal substrate, perform glow sputtering cleaning to obtain a clean metal substrate:

[0069] 1.1) In this embodiment, a 316L stainless steel substrate is used as the metal substrate. After polishing and cleaning, a polished 316L stainless steel substrate is obtained.

[0070] 1.2) The polished metal substrate is dried and mounted on a workpiece turret in a magnetron sputtering vacuum chamber. Two Al targets and one Cr target are placed on target positions within the magnetron sputtering vacuum chamber. The Al targets are connected to a medium frequency power supply, and the Cr targets are connected to a DC pulse power supply.

[0071] 1.3) Evacuate the vacuum chamber of the magnetron sputtering equipment to 5×10 -3 Pa, and then argon gas was introduced to control the gas pressure to 0.5 Pa. The bias voltage applied to the substrate was -800 V, and the substrate was cleaned by glow sputtering for 10 minutes to obtain a clean metal substrate.

[0072] Step 2: In an argon atmosphere, magnetron sputtering technology is used to deposit a layer of pure Cr primer on the surface of the clean metal substrate by sputtering a metal Cr target:

[0073] Argon gas was introduced into the vacuum chamber, the Cr target was turned on, the working pressure was controlled to be 0.6 Pa, the bias voltage applied to the substrate was -150 V, the sputtering time was 10 min, and a layer of pure Cr primer was deposited on the surface of the clean metal substrate.

[0074] Step 3: Using magnetron sputtering technology, deposit the oxide transition layer and the alloy oxide layer in sequence:

[0075] 3.1) Argon and oxygen were introduced into the vacuum chamber of the magnetron sputtering equipment, and magnetron sputtering technology was used. In the dual power supply mode of the medium frequency power supply and the direct current pulse power supply, the working gas pressure was controlled to 0.6 Pa, the bias voltage applied to the substrate was -200 V, the metal Al target and the metal Cr target were turned on, the total power was adjusted to 4000 W, and the power ratio of the metal Al target to the metal Cr target was 1:3. By sputtering the Al target and the Cr target simultaneously, the argon flux was maintained constant during sputtering, and the oxygen flux was gradually increased to an argon-oxygen partial pressure ratio of 3:1 within 5 minutes after the start of sputtering, and an oxide transition layer with a gradient oxygen content was deposited on the surface of the pure Cr base layer.

[0076] 3.2) Maintaining the argon-oxygen partial pressure ratio at 3:1, the Al target and the Cr target were sputtered simultaneously under the above magnetron sputtering conditions for 180 min, thereby further depositing an alloy oxide layer on the surface of the gradient-distributed oxide transition layer to obtain a composite coating consisting of a pure Cr base layer, an oxide transition layer, and an alloy oxide layer from the inside out.

[0077] 3.3) After coating, stop ventilation and maintain vacuum until the substrate temperature is ≤60℃.

[0078] Step 4: annealing the composite coating to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide tritium barrier coating containing crystalline oxides.

[0079] The annealing atmosphere was air, the heating rate was 5°C / min, the annealing temperature was 600°C, the holding time was 2h, and then the product was cooled to room temperature in the furnace.

[0080] The test showed that the thickness of the tritium-barrier alloy oxide coating obtained in this embodiment was 2.93 μm. The atomic percentage of aluminum and the atomic percentage of chromium in the tritium-barrier alloy oxide coating in this embodiment was 21.8% and 78.2%, respectively.

[0081] Example 3

[0082] This embodiment provides a method for preparing an alloy oxide tritium barrier coating, comprising the following steps:

[0083] Step 1: After polishing and cleaning the metal substrate, perform glow sputtering cleaning to obtain a clean metal substrate:

[0084] 1.1) In this embodiment, a 316L stainless steel substrate is used as the metal substrate. After polishing and cleaning, a polished 316L stainless steel substrate is obtained.

[0085] 1.2) The polished metal substrate is dried and mounted on a workpiece turret in a magnetron sputtering vacuum chamber. Two Al targets and one Cr target are placed on target positions within the magnetron sputtering vacuum chamber. The Al targets are connected to a medium frequency power supply, and the Cr targets are connected to a DC pulse power supply.

[0086] 1.3) Evacuate the vacuum chamber of the magnetron sputtering equipment to 5×10 -3 Pa, and then argon gas was introduced to control the gas pressure to 0.5 Pa. The bias voltage applied to the substrate was -800 V, and the substrate was cleaned by glow sputtering for 10 minutes to obtain a clean metal substrate.

[0087] Step 2: In an argon atmosphere, magnetron sputtering technology is used to deposit a layer of pure Cr primer on the surface of the clean metal substrate by sputtering a metal Cr target:

[0088] Argon gas was introduced into the vacuum chamber, the Cr target was turned on, the working pressure was controlled to be 0.6 Pa, the bias voltage applied to the substrate was -150 V, the sputtering time was 10 min, and a layer of pure Cr primer was deposited on the surface of the clean metal substrate.

[0089] Step 3: Using magnetron sputtering technology, deposit the oxide transition layer and the alloy oxide layer in sequence:

[0090] 3.1) By introducing argon and oxygen into the vacuum chamber of the magnetron sputtering equipment, magnetron sputtering technology is used. In the dual power supply mode of the medium frequency power supply and the direct current pulse power supply, the working gas pressure is controlled to 0.6 Pa, the bias voltage applied to the substrate is -200 V, the metal Al target and the metal Cr target are turned on, the total power is adjusted to 4000 W, and the power ratio of the metal Al target to the metal Cr target is 1:1. By sputtering the Al target and the Cr target simultaneously, the argon flux is maintained constant during sputtering, and the oxygen flux is gradually increased to an argon-oxygen partial pressure ratio of 3:1 within 5 minutes after the start of sputtering, an oxide transition layer with a gradient oxygen content is deposited on the surface of the pure Cr base layer.

[0091] 3.2) Maintaining the argon-oxygen partial pressure ratio at 3:1, the Al target and the Cr target were sputtered simultaneously under the above magnetron sputtering conditions for 180 min, thereby further depositing an alloy oxide layer on the surface of the gradient-distributed oxide transition layer to obtain a composite coating consisting of a pure Cr base layer, an oxide transition layer, and an alloy oxide layer from the inside out.

[0092] 3.3) After coating, stop ventilation and maintain vacuum until the substrate temperature is ≤60℃.

[0093] Step 4: annealing the composite coating to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide tritium barrier coating containing crystalline oxides.

[0094] The annealing atmosphere was air, the heating rate was 5°C / min, the annealing temperature was 600°C, the holding time was 2h, and then the product was cooled to room temperature in the furnace.

[0095] After testing, the thickness of the alloy oxide tritium barrier coating obtained in this embodiment is 2.89 μm. In addition, the atomic percentage of aluminum is 45.8%, and the atomic percentage of chromium is 54.2%.

[0096] Example 4

[0097] This embodiment provides a method for preparing an alloy oxide tritium barrier coating, comprising the following steps:

[0098] Step 1: After polishing and cleaning the metal substrate, perform glow sputtering cleaning to obtain a clean metal substrate:

[0099] 1.1) In this embodiment, a 304L stainless steel substrate is used as the metal substrate. After polishing and cleaning, a polished 304L stainless steel substrate is obtained.

[0100] 1.2) The polished metal substrate is dried and mounted on a workpiece turret in a magnetron sputtering vacuum chamber. Two Al targets and one Cr target are placed on target positions within the magnetron sputtering vacuum chamber. The Al targets are connected to a medium frequency power supply, and the Cr targets are connected to a DC pulse power supply.

[0101] 1.3) Evacuate the vacuum chamber of the magnetron sputtering equipment to 5×10 -3 Pa, and then argon gas was introduced to control the gas pressure to 0.5 Pa. The bias voltage applied to the substrate was -800 V, and the substrate was cleaned by glow sputtering for 10 minutes to obtain a clean metal substrate.

[0102] Step 2: In an argon atmosphere, magnetron sputtering technology is used to deposit a layer of pure Cr primer on the surface of the clean metal substrate by sputtering a metal Cr target:

[0103] Argon gas was introduced into the vacuum chamber, the Cr target was turned on, the working pressure was controlled to be 0.6 Pa, the bias voltage applied to the substrate was -150 V, the sputtering time was 10 min, and a layer of pure Cr primer was deposited on the surface of the clean metal substrate.

[0104] Step 3: Using magnetron sputtering technology, deposit the oxide transition layer and the alloy oxide layer in sequence:

[0105] 3.1) By introducing argon and oxygen into the vacuum chamber of the magnetron sputtering equipment, magnetron sputtering technology is used. In the dual power supply mode of the medium frequency power supply and the direct current pulse power supply, the working gas pressure is controlled to 0.6 Pa, the bias voltage applied to the substrate is -200 V, the metal Al target and the metal Cr target are turned on, the total power is adjusted to 3000 W, and the power ratio of the metal Al target to the metal Cr target is 2:1. By sputtering the Al target and the Cr target simultaneously, the argon flux is maintained constant during sputtering, and the oxygen flux is gradually increased to an argon-oxygen partial pressure ratio of 4:1 within 5 minutes after the start of sputtering, an oxide transition layer with a gradient oxygen content is deposited on the surface of the pure Cr base layer.

[0106] 3.2) Maintaining an argon-oxygen partial pressure ratio of 4:1, the Al target and the Cr target were sputtered simultaneously under the above magnetron sputtering conditions for 180 min, thereby further depositing an alloy oxide layer on the surface of the gradient-distributed oxide transition layer to obtain a composite coating consisting of a pure Cr base layer, an oxide transition layer, and an alloy oxide layer from the inside out.

[0107] 3.3) After coating, stop ventilation and maintain vacuum until the substrate temperature is ≤60℃.

[0108] Step 4: performing an annealing treatment 1 on the composite coating to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide tritium barrier coating containing crystalline oxides.

[0109] The annealing atmosphere was air, the heating rate was 5°C / min, the annealing temperature was 650°C, the holding time was 2h, and then the product was cooled to room temperature in the furnace.

[0110] After testing, the thickness of the alloy oxide tritium barrier coating obtained in this embodiment is 3.07 μm. In addition, the atomic percentage of aluminum is 54.3% and the atomic percentage of chromium is 45.7% in the metal element composition of the alloy oxide tritium barrier coating in this embodiment.

[0111] Example 5

[0112] This embodiment provides a method for preparing an alloy oxide tritium barrier coating, comprising the following steps:

[0113] Step 1: After polishing and cleaning the metal substrate, perform glow sputtering cleaning to obtain a clean metal substrate:

[0114] 1.1) In this embodiment, a 304L stainless steel substrate is used as the metal substrate. After polishing and cleaning, a polished 304L stainless steel substrate is obtained.

[0115] 1.2) The polished metal substrate is dried and mounted on a workpiece turret in a magnetron sputtering vacuum chamber. Two Al targets and one Cr target are placed on target positions within the magnetron sputtering vacuum chamber. The Al targets are connected to a medium frequency power supply, and the Cr targets are connected to a DC pulse power supply.

[0116] 1.3) Evacuate the vacuum chamber of the magnetron sputtering equipment to 5×10 -3 Pa, and then argon gas was introduced to control the gas pressure to 0.5 Pa. The bias voltage applied to the substrate was -800 V, and the substrate was cleaned by glow sputtering for 10 minutes to obtain a clean metal substrate.

[0117] Step 2: In an argon atmosphere, magnetron sputtering technology is used to deposit a layer of pure Cr primer on the surface of the clean metal substrate by sputtering a metal Cr target:

[0118] Argon gas was introduced into the vacuum chamber, the Cr target was turned on, the working pressure was controlled to be 0.6 Pa, the bias voltage applied to the substrate was -150 V, the sputtering time was 10 min, and a layer of pure Cr primer was deposited on the surface of the clean metal substrate.

[0119] Step 3: Using magnetron sputtering technology, deposit the oxide transition layer and the alloy oxide layer in sequence:

[0120] 3.1) By introducing argon and oxygen into the vacuum chamber of the magnetron sputtering equipment, magnetron sputtering technology is used. In the dual power supply mode of the medium frequency power supply and the direct current pulse power supply, the working gas pressure is controlled to 0.6 Pa, the bias voltage applied to the substrate is -200 V, the metal Al target and the metal Cr target are turned on, the total power is adjusted to 5000 W, and the power ratio of the metal Al target to the metal Cr target is 1:1. By sputtering the Al target and the Cr target simultaneously, the argon flux is maintained constant during sputtering, and the oxygen flux is gradually increased to an argon-oxygen partial pressure ratio of 3:1 within 5 minutes after the start of sputtering, an oxide transition layer with a gradient oxygen content is deposited on the surface of the pure Cr base layer.

[0121] 3.2) Maintaining the argon-oxygen partial pressure ratio at 3:1, the Al target and the Cr target were sputtered simultaneously under the above magnetron sputtering conditions for 180 min, thereby further depositing an alloy oxide layer on the surface of the gradient-distributed oxide transition layer to obtain a composite coating consisting of a pure Cr base layer, an oxide transition layer, and an alloy oxide layer from the inside out.

[0122] 3.3) After coating, stop ventilation and maintain vacuum until the substrate temperature is ≤60℃.

[0123] Step 4: performing an annealing treatment 1 on the composite coating to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide tritium barrier coating containing crystalline oxides.

[0124] The annealing atmosphere was air, the heating rate was 5°C / min, the annealing temperature was 700°C, the holding time was 3h, and then the product was cooled to room temperature in the furnace.

[0125] After testing, the thickness of the alloy oxide tritium barrier coating obtained in this embodiment is 3.57 μm. In addition, the atomic percentage of aluminum is 38.2% and the atomic percentage of chromium is 61.8% in the metal element composition of the alloy oxide tritium barrier coating in this embodiment.

[0126] Comparative Example 1

[0127] This comparative example provides a method for preparing an alloy oxide tritium barrier coating, comprising the following steps:

[0128] Step 1: After polishing and cleaning the metal substrate, perform glow sputtering cleaning to obtain a clean metal substrate:

[0129] 1.1) In this embodiment, a 316L stainless steel substrate is used as the metal substrate. After polishing and cleaning, a polished 316L stainless steel substrate is obtained.

[0130] 1.2) The polished metal substrate is dried and mounted on a workpiece turret in a magnetron sputtering vacuum chamber. Two Al targets and one Cr target are placed on target positions within the magnetron sputtering vacuum chamber. The Al targets are connected to a medium frequency power supply, and the Cr targets are connected to a DC pulse power supply.

[0131] 1.3) Evacuate the vacuum chamber of the magnetron sputtering equipment to 5×10 -3 Pa, and then argon gas was introduced to control the gas pressure to 0.5 Pa. The bias voltage applied to the substrate was -800 V, and the substrate was cleaned by glow sputtering for 10 minutes to obtain a clean metal substrate.

[0132] Step 2: In an argon atmosphere, magnetron sputtering technology is used to deposit a layer of pure Cr primer on the surface of the clean metal substrate by sputtering a metal Cr target:

[0133] Argon gas was introduced into the vacuum chamber, the Cr target was turned on, the working pressure was controlled to be 0.6 Pa, the bias voltage applied to the substrate was -150 V, the sputtering time was 10 min, and a layer of pure Cr primer was deposited on the surface of the clean metal substrate.

[0134] Step 3: Using magnetron sputtering technology, deposit the oxide transition layer and the alloy oxide layer in sequence:

[0135] 3.1) By introducing argon and oxygen into the vacuum chamber of the magnetron sputtering equipment, magnetron sputtering technology is used. In the dual power supply mode of the medium frequency power supply and the DC pulse power supply, the working gas pressure is controlled to 0.6 Pa, the bias voltage applied to the substrate is -200 V, the metal Al target and the metal Cr target are turned on, the total power is adjusted to 4000 W, and the power ratio of the metal Al target to the metal Cr target is 3:1. By sputtering the Al target and the Cr target simultaneously, the argon flux is maintained constant during sputtering, and the oxygen flux is gradually increased to an argon-oxygen partial pressure ratio of 3:1 within 5 minutes after the start of sputtering, an oxide transition layer with a gradient oxygen content is deposited on the surface of the pure Cr base layer.

[0136] 3.2) Maintaining the argon-oxygen partial pressure ratio at 3:1, the Al target and the Cr target were sputtered simultaneously under the above magnetron sputtering conditions for 180 min, thereby further depositing an alloy oxide layer on the surface of the gradient-distributed oxide transition layer to obtain a composite coating consisting of a pure Cr base layer, an oxide transition layer, and an alloy oxide layer from the inside out.

[0137] 3.3) After coating, stop ventilation and maintain vacuum until the substrate temperature is ≤60℃.

[0138] The difference between this comparative example and Example 1 is only that:

[0139] In this comparative example, no annealing treatment is performed, that is, in this comparative example, the composite coating formed on the surface of the metal substrate is used as the tritium barrier coating.

[0140] The test shows that the thickness of the tritium barrier coating of the alloy oxide obtained in this comparative example is 2.86 μm. In addition, the atomic percentage of aluminum is 62.3% and the atomic percentage of chromium is 27.7% in the metal element composition of the tritium barrier coating of the alloy oxide obtained in this comparative example.

[0141] Comparative Example 2

[0142] This comparative example provides a method for preparing an alloy oxide tritium barrier coating, comprising the following steps:

[0143] Step 1: After polishing and cleaning the metal substrate, perform glow sputtering cleaning to obtain a clean metal substrate:

[0144] 1.1) In this embodiment, a 316L stainless steel substrate is used as the metal substrate. After polishing and cleaning, a polished 316L stainless steel substrate is obtained.

[0145] 1.2) The polished metal substrate is dried and mounted on a workpiece turret in a magnetron sputtering vacuum chamber. Two Al targets and one Cr target are placed on target positions within the magnetron sputtering vacuum chamber. The Al targets are connected to a medium frequency power supply, and the Cr targets are connected to a DC pulse power supply.

[0146] 1.3) Evacuate the vacuum chamber of the magnetron sputtering equipment to 5×10 -3 Pa, and then argon gas was introduced to control the gas pressure to 0.5 Pa. The bias voltage applied to the substrate was -800 V, and the substrate was cleaned by glow sputtering for 10 minutes to obtain a clean metal substrate.

[0147] Step 2: In an argon atmosphere, magnetron sputtering technology is used to deposit a layer of pure Cr primer on the surface of the clean metal substrate by sputtering a metal Cr target:

[0148] Argon gas was introduced into the vacuum chamber, the Cr target was turned on, the working pressure was controlled to be 0.6 Pa, the bias voltage applied to the substrate was -150 V, the sputtering time was 10 min, and a layer of pure Cr primer was deposited on the surface of the clean metal substrate.

[0149] Step 3: Deposit the alloy oxide layer using magnetron sputtering technology:

[0150] 3.1) Argon and oxygen were introduced into the vacuum chamber of the magnetron sputtering equipment, and the argon-oxygen partial pressure ratio was controlled to be 3:1. Magnetron sputtering technology was used. In the dual power supply mode of the medium frequency power supply and the direct current pulse power supply, the working gas pressure was controlled to be 0.6 Pa, the bias voltage applied to the substrate was -200 V, the metal Al target and the metal Cr target were turned on, the total power was adjusted to 4000 W, and the power ratio of the metal Al target to the metal Cr target was 1:1. The Al target and the Cr target were sputtered simultaneously for a sputtering deposition time of 180 min to further deposit an alloy oxide layer on the surface of the pure Cr base layer, thereby obtaining a composite coating consisting of a pure Cr base layer and an alloy oxide layer from the inside to the outside.

[0151] 3.3) After coating, stop ventilation and maintain vacuum until the substrate temperature is ≤60℃.

[0152] Step 4: annealing the composite coating to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide tritium barrier coating containing crystalline oxides.

[0153] The annealing atmosphere was air, the heating rate was 5°C / min, the annealing temperature was 600°C, the holding time was 2h, and then the product was cooled to room temperature in the furnace.

[0154] The difference between this comparative example and Example 3 is only that:

[0155] In this comparative example, no gradient oxidation transition layer was prepared.

[0156] The test shows that the thickness of the tritium barrier alloy oxide coating obtained in this comparative example is 3.12 μm. In addition, the atomic percentage of aluminum is 42.2% and the atomic percentage of chromium is 57.8% in the metal element composition of the tritium barrier alloy oxide coating in this comparative example.

[0157] Experimental part

[0158] (1) Micromorphology test

[0159] The present invention takes the coating of Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2 as examples, and performs scanning electron microscope tests respectively, and the test results are as follows: Figures 1-6 shown.

[0160] in, Figure 1 This is a surface scanning electron microscope image of the coating of Comparative Example 1, Figure 2 is a cross-sectional scanning electron microscope image of the coating of Comparative Example 1, Figure 3 This is a surface scanning electron microscope image of the coating of Comparative Example 2. Figure 4 This is a surface scanning electron microscope image of the coating of Example 1. Figure 5 This is a surface scanning electron microscope image of the coating of Example 2. Figure 6 Surface scanning electron microscope image of the coating of Example 3.

[0161] Depend on Figure 1 and Figure 2 It can be seen that the coating composition on the surface of the unannealed coating in Comparative Example 1 is primarily in the form of amorphous oxide particles, with significant pores between the amorphous oxide particles, resulting in poor surface density. However, a metallic phase remains in the gradient oxidation transition layer in the middle of the coating, making the intermediate phase more uniform and dense than the coating surface.

[0162] Depend on Figure 3 It can be seen that compared with Figure 1 It can be seen that after annealing, no oxide particles are present on the surface of the non-gradient oxide transition layer coating, indicating that annealing is indeed beneficial for promoting the conversion of amorphous oxides on the coating surface into crystalline oxides. However, the coating of Comparative Example 2 exhibits obvious cracks and macroscopically exhibits flaking.

[0163] Depend on Figure 4 It can be seen that the coating components on the coating surface of Example 1 are mainly present in the form of dense crystalline oxides. Figure 3 and Figure 1 It can be seen that Example 1 performs annealing treatment on the basis of the coating of Comparative Example 1, thereby transforming the oxide on the surface of the coating from an amorphous state to a crystalline state, thereby improving the tissue density of the coating. This shows that annealing treatment plays a very important role in promoting the transformation of the oxide from an amorphous state to a crystalline state, thereby improving the tissue density of the coating, and the crystalline metal oxide on the surface is beneficial to improving the tritium and hydrogen barrier properties of the substrate.

[0164] Depend on Figure 5It can be seen that the coating surface of Example 2 is similar to that of Example 1, and both have dense texture.

[0165] Depend on Figure 6 It can be seen that the coating surface of Example 3 is similar to that of Example 1, and both have dense tissue. Figure 6 and Figure 3 It can be seen that after Example 3 adds a gradient oxidation transition layer on the basis of Comparative Example 2, the bonding between the coating and the substrate is significantly improved, avoiding the occurrence of thermal mismatch effect, which indicates that the formation of the gradient oxidation transition layer has an important influence on improving the bonding strength between the coating and the substrate.

[0166] (2) XRD test

[0167] The present invention takes the coating on the surface of Example 1 as an example, and performs XRD test on it, and the test results are as follows Figure 7 shown.

[0168] Figure 7 This is the XRD spectrum of the coating on the surface of Example 1. It can be seen that the coating on the surface of Example 1 contains crystalline chromium oxide and does not contain hydrogen. This indicates that annealing can indeed promote the transformation of the oxide from an amorphous state to a crystalline state, thereby improving the density of the coating tissue, and thus helping to improve the tritium and hydrogen barrier properties of the substrate.

[0169] (3) Tritium resistance performance test

[0170] The present invention uses a hydrogen barrier performance test instead of a tritium barrier test. Referring to the method in the prior art CN115747775A, the present invention uses a gas-driven hydrogen permeation test device and an electrochemical hydrogen permeation device to evaluate the hydrogen barrier and hydrogen permeation resistance of the coatings prepared in Examples 1 to 5 and Comparative Example 2. The results show that the hydrogen permeation resistance factors of the coatings prepared in Examples 1 to 5 of the present invention are all >200, indicating that the alloy oxide tritium barrier coating prepared by the preparation method of the present invention has good hydrogen barrier performance. The hydrogen permeation resistance factor of Comparative Example 2 is 43, which is greatly reduced compared to the hydrogen permeation resistance factors of Examples 1 to 5. This further verifies that the formation of the gradient oxidation transition layer has an important influence on improving the bonding strength between the coating and the substrate.

[0171] Obviously, the above embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. A method for preparing an alloy oxide tritium barrier coating, characterized in that: The following steps are involved: Pretreatment of metal substrate: After polishing and cleaning the metal substrate, glow sputtering cleaning is performed to obtain a clean metal substrate; Deposition of pure Cr base layer: In an argon atmosphere, magnetron sputtering technology is used to deposit a layer of pure Cr base layer on the surface of a clean metal substrate by sputtering a metal Cr target; Adopting magnetron sputtering technology, sequentially depositing an oxide transition layer and an alloy oxide layer: introducing argon and oxygen, using magnetron sputtering technology, in dual power supply mode, by simultaneously sputtering an Al target and a Cr target, and gradually increasing the oxygen flux to a stable flow rate within 5 minutes after the start of sputtering, so as to form a gradient-distributed oxide transition layer on the surface of the pure Cr base layer; Subsequently, the Al target and the Cr target are sputtered simultaneously while maintaining the flow ratio of argon to oxygen, thereby depositing an alloy oxide layer on the surface of the oxidized transition layer, thereby forming a composite coating on the surface of the metal substrate, which includes, from the inside to the outside, a pure Cr base layer, an oxidized transition layer, and an alloy oxide layer; Annealing treatment: performing annealing treatment on the composite coating to transform the oxide on the surface of the composite coating from an amorphous state to a crystalline state, thereby obtaining an alloy oxide tritium barrier coating containing crystalline oxides.

2. The preparation method according to claim 1, wherein When depositing the oxide transition layer and the alloy oxide layer, the Al target is sputtered using a medium frequency power supply mode, and the Cr target is sputtered using a direct current pulse power supply mode.

3. The preparation method according to claim 1, wherein When the oxygen flux reaches a stable flow rate, the flow ratio of argon to oxygen is 3~7:

1.

4. The preparation method according to claim 1, wherein When depositing the oxidation transition layer and the alloy oxide layer, the gas pressure is 0.1 Pa to 1 Pa, and the bias voltage applied to the substrate is -30 V to 200 V.

5. The preparation method according to claim 1, wherein When depositing the alloy oxide layer, the deposition time is 10 min to 600 min.

6. The preparation method according to claim 1, wherein When depositing the oxidation transition layer and the alloy oxide layer, the total sputtering power of the Al target and the Cr target is 100W-5000W.

7. The preparation method according to claim 1, wherein When depositing the pure Cr base layer, the gas pressure is 0.2 Pa to 1.6 Pa, and the bias voltage applied to the substrate is -30 V to 300 V; The thickness of the pure Cr base layer is 50nm~200nm.

8. The preparation method according to claim 1, wherein During the glow sputtering cleaning process, the vacuum is first evacuated to <0.005 Pa, and then argon gas is introduced to a pressure of 0.4 Pa to 2.0 Pa. A bipolar pulse power supply is used, and the bias voltage applied to the substrate is -200 V to 1000 V. The process is carried out for at least 5 minutes.

9. The preparation method according to claim 1, wherein The annealing temperature of the annealing treatment is 200° C. to 800° C., and the annealing holding time is 10 min to 360 min.

10. An alloy oxide tritium barrier coating prepared by the preparation method according to any one of claims 1 to 9, characterized in that: In the alloy oxide tritium barrier coating, the atomic ratio of Al element to Cr element is 1-2:1-9.

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