A high-entropy alloy-based filler metal and a method of in-situ repair of a metal film

Abstract

The application relates to the technical field of film repairing, and particularly discloses a high-entropy alloy-based filler metal and a method for in-situ repairing of a metal film. The high-entropy alloy-based filler metal is AlCrCoYMX; wherein M is at least one selected from Pd, Ni or Fe; and X is at least one selected from Zr, Zn, Cu, Ag or Mo. The high-entropy alloy-based filler metal can be applied to various metal films, has excellent high-temperature stability and interface compatibility, ensures that the hydrogen purity after repairing is relatively high, and the film life is significantly prolonged. Moreover, the in-situ repairing method can effectively solve the problems that, in the prior art, the operation of repairing the metal film is complex, in-situ repairing cannot be realized, the compatibility after repairing with the original metal film is poor, and the repairing is not complete.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of film repair, and in particular to a high-entropy alloy-based filler metal and a method for repairing a metal film in situ. BACKGROUND

[0002] Dense metal films are widely used in key fields such as hydrogen separation and purification, and their permeation selectivity is a core indicator of performance. However, such films are prone to defects such as pinholes and cracks during preparation and use, which not only reduces the purity of hydrogen, but also shortens the service life of the film. At the same time, the preparation cost of metal films is relatively high, and direct disposal will cause significant economic losses, so it is of great practical significance to repair the defects of metal films to extend their service life.

[0003] However, the existing repair technologies still have obvious shortcomings: for example, the palladium composite film defect repair method reported in the prior art requires the introduction of silicon source vapor and oxidizing atmosphere on both sides of the film, which is a complicated operation process, and additional film contamination and new defects may be introduced during manual operation; there are also disclosed dense film defect filling methods, which can achieve basic repair of dense film defects, but require disassembly of the film assembly, which does not well adapt to the in-situ repair needs of palladium composite films in hydrogen separation scenarios; there are also reported methods for on-site online automatic repair of metal film separators, which focus on the in-situ repair scenario of metal films, but the way of natural diffusion of inorganic metal compounds to contact the surface of the film cannot achieve precise identification and targeted repair of the defect position.

[0004] Overall, the existing repair strategies have obvious shortcomings in terms of operation convenience, adaptability to hydrogen separation scenarios, and other aspects, making it difficult to efficiently and in-situ solve the defect problems of metal films in hydrogen separation applications. Therefore, developing a more suitable in-situ repair technology for hydrogen separation scenarios, which is simple to operate and has higher repair efficiency, has become a key issue that needs to be broken through in the current field. SUMMARY

[0005] In view of this, the present application provides a high-entropy alloy-based filler metal and a method for repairing a metal film in situ. The high-entropy alloy-based filler metal can be applied to various metal films, has excellent high-temperature stability and interface compatibility, ensures that the hydrogen purity after repair is high and the film life is significantly extended. Moreover, the method for repairing a metal film in situ provided by the present application effectively solves the problems of complex operation, inability to achieve in-situ repair, poor compatibility with the original metal film after repair, and incomplete repair in the prior art.

[0006] To achieve the above-mentioned application purposes, the present application adopts the following technical solutions:

[0007] The first aspect of the present invention provides a high-entropy alloy-based solder, wherein the high-entropy alloy-based solder is AlCrCoYMX; wherein M is selected from at least one of Pd, Ni or Fe; and X is selected from at least one of Zr, Zn, Cu, Ag or Mo.

[0008] Compared to existing technologies, this invention designs a high-entropy alloy-based solder, wherein the high-entropy alloy-based solder is AlCrCoYMX; wherein M is selected from at least one of Pd, Ni, or Fe; and X is selected from at least one of Zr, Zn, Cu, Ag, or Mo. The high-entropy alloy-based solder exhibits a random solid solution distribution of metal atoms, which maintains the activity of active elements, inhibits the precipitation of brittle intermetallic compounds, and forms a low-melting-point eutectic phase. This reduces the soldering temperature and prevents deformation or grain coarsening of the metal film due to high-temperature thermal stress, thus affecting its subsequent use. Furthermore, the random solid solution of the high-entropy alloy-based solder provided by this invention strongly hinders element diffusion and possesses excellent corrosion resistance, oxidation resistance, wear resistance, and high-temperature stability, which helps the repaired metal film remain stable under high-temperature or corrosive environments.

[0009] High mixing entropy and lattice distortion endow the solder melt with excellent wettability and uniform solidification ability, making it less prone to the formation of coarse precipitates in the weld. This facilitates the formation of a uniform joint between the metal film and the substrate, improving repair quality. Moreover, the high-entropy alloy-based solder provided by this invention is applicable to various metal film materials, such as palladium-based, nickel-based, or iron-based metal films. By selecting different high-entropy alloy-based solders according to the different metal film materials, the quality and reliability of the repair joint can be significantly improved by optimizing interface compatibility, performance synergy, and process adaptability.

[0010] Preferably, the molar ratio of each element in the high-entropy alloy-based brazing filler metal is 1:1:1:1:1:1.

[0011] Preferably, the high-entropy alloy-based solder is any one of AlCrCoYPdCu, AlCrCoYPdAg, AlCrCoYNiZr, or AlCrCoYFeMo.

[0012] A second aspect of the present invention provides a method for in-situ repair of a metal film, specifically comprising the following steps:

[0013] Step 1: Inspect the metal film and mark the location of defects;

[0014] Step 2: Ball mill the high-entropy alloy-based brazing filler metal described in the first aspect of the present invention to obtain powdered brazing filler metal;

[0015] Step 3: Disperse the powdered solder in an organic alcohol mixed solvent to obtain a paste solder; apply the paste solder to the defects in the metal film, and heat it to a temperature above the liquidus line of the paste solder and below the melting point of the film material under a protective atmosphere, keep it at the temperature, cool it, and test it to obtain the repaired metal film.

[0016] The in-situ repair method for metal films provided by this invention achieves efficient in-situ repair of defects in dense metal films through an integrated process of precise defect location, selection of high-entropy alloy-based solder, and in-situ high-temperature liquefaction filling. This invention utilizes the high-temperature liquefaction characteristics and capillary action of high-entropy alloy-based solder to complete the dense filling of defects in the film module in situ, avoiding the problems of complex operation, inability to achieve in-situ repair, poor compatibility with the original metal film, and incomplete repair in the prior art.

[0017] Preferably, in step one, vacuum leak detection or gas chromatography is used to detect defects.

[0018] Preferably, in step one, the metal film is any one of palladium-based metal film, nickel-based metal film, or iron-based metal film.

[0019] Preferably, in step two, the ball-to-material ratio of the ball mill is 10:1-20:1, the ball mill speed is 250-450 rpm, and the ball milling time is 10-20 h.

[0020] Preferably, in step three, the organic alcohol mixed solvent is a mixture of ethanol and terpineol in a volume ratio of 1:1 to 1:1.5.

[0021] Preferably, in step three, the mass ratio of the high-entropy alloy-based brazing filler metal to the organic alcohol mixed solvent is 7:3-7:4.

[0022] Preferably, in step three, the protective atmosphere is a mixture of high-purity argon, hydrogen, and argon, a mixture of oxygen and argon, or a mixture of nitrogen and hydrogen.

[0023] More preferably, when the metal film is a palladium-based metal film, in step three, the protective atmosphere is a mixture of high-purity argon and hydrogen and argon.

[0024] More preferably, when the metal film is a palladium-based metal film, in step three, high-purity argon is used in the heating stage and a mixture of hydrogen and argon is used in the heat preservation stage; wherein, in the mixture of hydrogen and argon, the volume of hydrogen accounts for 40%-60% of the volume of the mixture.

[0025] More preferably, when the metal film is a nickel-based metal film, in step three, the protective atmosphere is a mixture of oxygen and argon or a mixture of hydrogen and argon.

[0026] More preferably, when the metal film is a nickel-based metal film, in step three, the protective atmosphere is a mixture of oxygen and argon; wherein the oxygen content in the mixture is ≤5ppm.

[0027] More preferably, when the metal film is a nickel-based metal film, in step three, the protective atmosphere is a mixture of hydrogen and argon; wherein, hydrogen accounts for 10-20% of the volume of the mixture.

[0028] More preferably, when the metal film is an iron-based metal film, in step three, the protective atmosphere is a mixture of nitrogen and hydrogen; wherein nitrogen accounts for 30%-50% of the volume of the mixture.

[0029] Preferably, when the metal film is a palladium-based metal film, in step three, the temperature above the liquidus line of the solder paste and below the melting point of the film is 600-900℃.

[0030] Preferably, when the metal film is a nickel-based metal film, in step three, the temperature above the liquidus line of the solder paste and below the melting point of the film is 1000-1100℃.

[0031] Preferably, when the metal film is an iron-based metal film, in step three, the temperature above the liquidus line of the solder paste and below the melting point of the film is 750-950℃.

[0032] Preferably, in step three, the heat preservation time is 30-60 minutes.

[0033] In summary, this invention provides a method for in-situ repair of metal films using a high-entropy alloy-based solder. It achieves efficient repair of defects in dense metal films through an integrated process of precise defect location, selection of the high-entropy alloy-based solder, and in-situ high-temperature liquefaction filling. This invention utilizes the high-temperature liquefaction characteristics and capillary action of the high-entropy alloy-based solder to achieve dense filling of defects in the film module in situ. This avoids the problems of complex metal film repair operations, inability to achieve in-situ repair, poor compatibility with the original metal film, and incomplete repair in existing technologies. Furthermore, this invention improves the stability and durability of the repaired metal film through the compositional matching design of the high-entropy alloy-based solder and the metal film. Attached Figure Description

[0034] Figure 1 The images show a comparison of the surface morphology of the metal film before and after in-situ repair using the high-entropy alloy-based solder AlCrCoYPdCu provided in Example 1. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment provides a high-entropy alloy-based solder AlCrCoYPdCu and a method for in-situ repair of metal films, the details of which are as follows:

[0038] Step 1: Use the vacuum leak detection method to inspect the Pb-Cu film, and mark the defect location as a crack with a length of about 0.3 mm;

[0039] Step 2: Select the raw material components of high-entropy alloy brazing filler metal AlCrCoYPdCu according to the metal film material. Weigh each raw material component according to the design ratio, mix them evenly, and ball mill them under an inert atmosphere. Set the ball-to-material ratio to 15:1, the ball milling speed to 400 rpm, and the ball milling time to 15 hours. Dry the filler metal and pass it through a 200-mesh sieve to obtain powdered brazing filler metal.

[0040] Step 3: Mix the powdered brazing filler metal with a mixed solvent of ethanol / terpineol (volume ratio 1:1) at a mass ratio of 7:3 to form a paste. Use a micro-injector to inject the paste brazing filler metal into the metal film defect to completely cover the metal film defect. Let it stand for 10 minutes to evaporate the solvent.

[0041] The metal membrane was kept in the separation device. High-purity Ar gas was introduced before the temperature was raised to 300°C. When the temperature was raised to 800°C, a mixture of Ar gas and H2 gas was introduced, in which H2 accounted for 40% of the volume of the mixture. After holding at this temperature for 1 hour, the temperature was allowed to drop naturally. After the temperature dropped to 600°C, the hydrogen purity was tested and found to be 99.999%. The device operated continuously for 2000 hours without any leaks.

[0042] This invention also includes surface morphology tests on the metal film before and after in-situ repair, and the results are as follows: Figure 1 As shown; Figure 1 The results showed that before repair, the metal membrane surface had numerous pinhole defects, which significantly reduced the hydrogen separation purity and shortened the membrane's lifespan. After repair, the pinhole defects on the metal membrane surface completely disappeared, resulting in a smooth and dense surface morphology. This result directly demonstrates that the high-entropy alloy-based brazing filler metal provided by this invention, through in-situ high-temperature liquefaction filling, can effectively achieve dense repair of defects. Furthermore, the repaired area exhibits good interfacial compatibility with the substrate membrane material, with no coarse precipitates forming, ensuring that the repaired metal membrane maintains high hydrogen purity and structural stability during long-term operation.

[0043] Example 2

[0044] This embodiment provides a high-entropy alloy-based solder AlCrCoYPdAg and a method for in-situ repair of metal films, the details of which are as follows:

[0045] Step 1: Use the vacuum leak detection method to test the Pb-Ag membrane, and mark the defect location as a micropore;

[0046] Step 2: Select the raw material components of the high-entropy alloy brazing filler metal AlCrCoYPdAg according to the metal film material. Weigh each raw material component according to the design ratio, mix them evenly, and ball mill them under an inert atmosphere. Set the ball-to-material ratio to 20:1, the ball milling speed to 400 rpm, and the ball milling time to 18 hours. Dry the filler metal and pass it through a 200-mesh sieve to obtain powdered brazing filler metal.

[0047] Step 3: Mix the powdered brazing filler metal with a mixed solvent of ethanol / terpineol (volume ratio 1:1) at a mass ratio of 7:4 to form a paste. Use a micro-injector to inject the paste brazing filler metal into the metal film defect to completely cover the metal film defect. Let it stand for 10 minutes to evaporate the solvent.

[0048] The metal membrane was kept in the separation device. High-purity Ar gas was introduced before the temperature was raised to 300°C. When the temperature was raised to 880°C, a mixture of Ar gas and H2 gas was introduced, in which H2 accounted for 60% of the volume of the mixture. The pressure was maintained at 10 bar. After holding at this temperature for 1 hour, the temperature was allowed to drop naturally. After cooling to 600°C, the hydrogen purity was tested and found to be 99.999%. The device operated continuously for 2000 hours without any leaks.

[0049] Example 3

[0050] This embodiment provides a high-entropy alloy-based solder AlCrCoYNiZr and a method for in-situ repair of metal films, the details of which are as follows:

[0051] Step 1: Use the vacuum leak detection method to inspect the nickel alloy (Inconel 625) hollow fiber membrane, and mark the defect location as 2-3 pinholes;

[0052] Step 2: Select the raw material components of high-entropy alloy brazing filler metal AlCrCoYNiZr according to the metal film material. Weigh each raw material component according to the design ratio, mix them evenly, and ball mill them in an inert atmosphere. Set the ball-to-material ratio to 15:1, the ball milling speed to 400 rpm, and the ball milling time to 12 hours. Dry the filler metal and pass it through a 200-mesh sieve to obtain powdered brazing filler metal.

[0053] Step 3: Mix the powdered brazing filler metal with a mixed solvent of ethanol / terpineol at a mass ratio of 7:3 to form a paste. Use a micro-injector to inject the paste brazing filler metal into the metal film defect to completely cover the defect. Let it stand for 10 minutes to evaporate the solvent.

[0054] The metal membrane is held in the separation device with a low-oxygen argon atmosphere as the protective atmosphere, wherein the oxygen content is ≤5ppm and the pressure is 15bar. The temperature is raised to 1100℃ and held for 1 hour, then naturally cooled down. After cooling to 600℃, the hydrogen purity is tested and reaches 99.999%. The device has been running continuously for 1000 hours without any leaks.

[0055] Example 4

[0056] This embodiment provides a high-entropy alloy-based solder AlCrCoYFeMo and a method for in-situ repair of metal films, the details of which are as follows:

[0057] Step 1: The Fe-Cr-Al film is tested using the vacuum leak detection method, and the defect location is marked as two micro-cracks with a length of 0.1 mm;

[0058] Step 2: Select the raw material components of the high-entropy alloy brazing filler metal AlCrCoYFeMo according to the metal film material. Weigh each raw material component according to the design ratio, mix them evenly, and ball mill them under an inert atmosphere. Set the ball-to-material ratio of ball milling to 10:1, the ball milling speed to 450 rpm, and the ball milling time to 13 hours. Dry the filler metal and pass it through a 200-mesh sieve to obtain powdered brazing filler metal.

[0059] Step 3: Mix the powdered brazing filler metal with a mixed solvent of ethanol / terpineol (volume ratio 1:1) at a mass ratio of 7:3 to form a paste. Use a micro-injector to inject the paste brazing filler metal into the metal film defect to completely cover the metal film defect. Let it stand for 10 minutes to evaporate the solvent.

[0060] The metal membrane is kept in the separation device, and a mixture of N2 and H2 is passed through it, with H2 accounting for 40% of the volume of the mixture. The temperature is then raised to 950°C, held for 1 hour, and then allowed to cool naturally. After the temperature drops to 600°C, the hydrogen purity is tested and found to be 99.999%. The device has been running continuously for 5000 hours without any leaks.

[0061] Comparative Example 1

[0062] This comparative example provides a repair solder for palladium-based metal films and a method for in-situ repair of the metal film. It uses commercially available BCuP-5 solder, incorporating 15% pure palladium powder by weight of the solder. The specific steps include:

[0063] Step 1: Use the vacuum leak detection method to inspect the Pb-Cu film, and mark the defect location as a crack with a length of about 0.25 mm;

[0064] Step 2: Weigh the components of the repair brazing filler metal according to the design ratio, mix them evenly, and ball mill them in an inert atmosphere. Set the ball-to-material ratio to 15:1, the ball mill speed to 400 rpm, and the ball milling time to 15 hours. Dry the filler metal and pass it through a 200-mesh sieve to obtain powdered brazing filler metal.

[0065] Step 3: Mix the powdered brazing filler metal with a mixed solvent of ethanol / terpineol (volume ratio 1:1) at a mass ratio of 7:3 to form a paste. Use a micro-injector to inject the paste brazing filler metal into the metal film defect to completely cover the metal film defect. Let it stand for 10 minutes to evaporate the solvent.

[0066] The metal membrane was kept in the separation device, and high-purity Ar gas was introduced before the temperature was raised to 300°C. When the temperature was raised to 800°C, a mixture of Ar gas and H2 gas was introduced, in which H2 accounted for 40% of the volume of the mixture. After holding at this temperature for 1 hour, the temperature was allowed to drop naturally. After the temperature dropped to 600°C, the hydrogen purity was tested and found to be 99.995%. Scanning electron microscopy showed that the cracks were densely filled. After 200 hours of continuous operation, a leak appeared.

[0067] Comparative Example 2

[0068] This comparative example provides a repair solder for nickel alloy films and a method for in-situ repair of metal films, using Ni-Cr-Al solder (Ni: 72wt%, Cr: 18wt%, and 10wt% Al), specifically including the following steps:

[0069] Step 1: Use the vacuum leak detection method to inspect the nickel alloy (Inconel 625) hollow fiber membrane, and mark the defect location as 1-2 pinholes;

[0070] Step 2: Weigh the components of the repair brazing filler metal according to the design ratio, mix them evenly, and ball mill them in an inert atmosphere. Set the ball-to-material ratio to 15:1, the ball mill speed to 400 rpm, and the ball milling time to 12 hours. Dry the filler metal and pass it through a 200-mesh sieve to obtain powdered brazing filler metal.

[0071] Step 3: Mix the powdered brazing filler metal with a mixed solvent of ethanol / terpineol at a mass ratio of 7:3 to form a paste. Use a micro-injector to inject the paste brazing filler metal into the metal film defect to completely cover the defect. Let it stand for 10 minutes to evaporate the solvent.

[0072] The metal membrane was kept in the separation device with a low-oxygen argon gas as the protective atmosphere, wherein the oxygen content was ≤5ppm and the pressure was 15bar. The temperature was raised to 1100℃ and held for 1 hour, then naturally cooled down. After cooling to 600℃, the hydrogen purity was tested and found to be 99.997%. No leaks were found after 200 hours of continuous operation, but leaks appeared after 500 hours of operation.

[0073] Comparative Example 3

[0074] This comparative example provides a repair solder for iron-based alloy films and a method for in-situ repair of metal films, using FeNiCrBSi solder. The FeNiCrBSi solder contains the following elemental mass percentages: Fe: 42%, Ni: 33%, Cr: 21%, B: 2.5%, and Si: 1.5%. Specifically, it includes the following:

[0075] Step 1: The Fe-Cr-Al film is tested using the vacuum leak detection method, and the defect location is marked as two micro-cracks with a length of 0.1 mm;

[0076] Step 2: Weigh each raw material component according to the design ratio, mix them evenly, and ball mill them under an inert atmosphere. Set the ball-to-material ratio to 10:1, the ball mill speed to 450 rpm, and the ball milling time to 13 hours. Dry the mixture and pass it through a 200-mesh sieve to obtain powdered brazing filler metal.

[0077] Step 3: Mix the powdered brazing filler metal with a mixed solvent of ethanol / terpineol (volume ratio 1:1) at a mass ratio of 7:3 to form a paste. Use a micro-injector to inject the paste brazing filler metal into the metal film defect to completely cover the metal film defect. Let it stand for 10 minutes to evaporate the solvent.

[0078] The metal membrane was kept in the separation device, and a mixture of N2 and H2 was passed through it, with H2 accounting for 40% of the volume of the mixture. The temperature was then raised to 950°C, held for 1 hour, and then allowed to cool down naturally. After the temperature dropped to 600°C, the hydrogen purity was tested and found to be 99.998%. The device ran continuously for 500 hours without any leaks. After 800 hours of operation, a leak reappeared at the repaired location.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of in situ repairing a metal film, characterized by: Specifically comprising the following steps: Step one, detecting the metal film, marking the defect position; Step two, ball milling the high-entropy alloy-based filler material to obtain a powdered filler material; the high-entropy alloy-based filler material is any one of AlCrCoYPdCu, AlCrCoYPdAg, AlCrCoYNiZr or AlCrCoYFeMo; the molar ratio of each element in the high-entropy alloy-based filler material is 1:1:1:1:1:1; Step three, dispersing the powdered filler material in an organic alcohol mixed solvent to obtain a paste-like filler material; coating the paste-like filler material on the defect of the metal film, heating to a temperature above the liquidus line of the paste-like filler material and below the melting point of the film material in a protective atmosphere, holding, cooling, detecting to obtain the repaired metal film; In step one, the metal film is any one of a palladium-based metal film, a nickel-based metal film or an iron-based metal film.

2. The method of in situ repairing a metal film of claim 1, wherein: In step one, the defect is detected by vacuum air leakage detection or gas chromatography detection.

3. The method of in situ repairing a metal film of claim 1 wherein: In step three, the organic alcohol mixed solvent is a mixed solvent of ethanol and terpineol at a volume ratio of 1:1-1:1.

5.

4. The method of in situ repairing a metal film of claim 1 wherein: In step three, the mass ratio of the high-entropy alloy-based filler material to the organic alcohol mixed solvent is 7:3-7:

4.

5. The method of repairing metal films in place according to claim 1 wherein: In step three, the protective atmosphere is high-purity argon, a mixed gas of hydrogen and argon, a mixed gas of oxygen and argon or a mixed gas of nitrogen and hydrogen.

6. The method of repairing a metal film in situ according to claim 1, wherein: In step three, the holding time is 30-60 min.

Images