A method for preparing high entropy alloy thin film based on inkjet printing and printing system

Abstract

The present invention belongs to the technical field of high entropy alloy preparation, specifically a method for preparing a high entropy alloy thin film based on inkjet printing and a printing system. Metal oxide powder and an organic solvent are mixed, and then a binder is added and mixed evenly to obtain the ink required for printing; the ink is sprayed onto the surface of a substrate to obtain an oxide liquid film; the volatile solvent in the oxide liquid film evaporates, thereby solidifying to form an oxide thin film, which is then subjected to a first heat treatment; then, under a hydrogen environment, the thin film after the first heat treatment is subjected to a second heat treatment, and the metal oxide powder is first reduced to metal and then sintered to obtain a high entropy alloy thin film. The present invention improves the dispersion uniformity of the metal oxide powder by optimizing the ink formula and improving the structure of the printing system, thereby improving the performance and printing efficiency of the obtained high entropy alloy thin film, and at the same time provides a new approach for the preparation of high entropy alloy thin films, which helps to obtain high entropy alloy thin films with excellent performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of high entropy alloy preparation, and particularly relates to a method for preparing a high entropy alloy thin film based on inkjet printing and a printing system. Background Art

[0002] High-entropy alloys (HEAs) are a new type of alloy material composed of multiple metals containing transition elements, with the atomic percentage of each component ranging from 5% to 35%. The atoms of each element in a HEA form a lattice structure through the most "disordered" patterns, resulting in a high value for the thermodynamic parameter entropy of the alloy system. The development of my country's aerospace industry has posed new challenges for high-speed and hypersonic vehicles, such as launch vehicles that require lightweight, highly reliable, and reusable vehicles. During launch and re-entry, high-speed vehicles experience extreme thermal shock in areas such as the nose cone and leading edge, necessitating high-performance thermal protection systems. High-temperature-resistant materials are the core of hypersonic vehicle thermal protection systems and the cornerstone of ultra-high-temperature thermal sealing designs. The addition of more metals to traditional alloys increases the tendency for brittle intermetallic compounds to form, embrittlement of the material. HEAs, however, due to their inclusion of transition elements, typically form simple solid solutions or amorphous phases dominated by fcc or bcc phases, exhibiting superior fracture strength, tensile strength, stability, high-temperature resistance, and wear resistance compared to traditional alloys.

[0003] The main preparation technologies for high-entropy alloy films include sputtering deposition, electrochemical deposition, evaporation coating, ion plating, etc. Usually, metal powders such as Co, Cr, Fe, Ni, Ti, and Al are mixed in proportion to obtain the ink required for printing. Due to the large number of high-entropy alloy components and complex composition, it is difficult to control the uniformity of the components using film-forming methods such as sputtering deposition, and the cost is high, and the structure of the prepared high-entropy alloy film is relatively simple. Inkjet printing puts the component mixing link in the ink mixing step, which helps to overcome the problem of poor component uniformity in the raw material preparation stage. However, the ink uniformity of inkjet printing has a great influence on the printing effect and needs to be optimized. In addition, when the existing printing system prints high-viscosity ink, the flow at the nozzle is easily affected by the solid particles inside the ink, resulting in nozzle blockage and unstable flow, which in turn affects the performance of the printed high-entropy alloy film.

[0004] Therefore, it is necessary to provide a method and a printing system for preparing high entropy alloy thin films based on inkjet printing to solve the above problems. Summary of the Invention

[0005] In response to the defects or improvement needs of the prior art, the purpose of the present invention is to provide a method and printing system for preparing high-entropy alloy films based on inkjet printing. By optimizing the ink formula, the preparation uniformity and stability of the high-entropy alloy films are synergistically improved. At the same time, a new approach is provided for the preparation of high-entropy alloy films, which helps to obtain high-entropy alloy films with excellent performance.

[0006] To achieve the above object, the present invention provides a method for preparing a high entropy alloy thin film based on inkjet printing, comprising the following steps:

[0007] S1. Mixing metal oxide powders of metal elements required to form the high entropy alloy film with an organic solvent, then adding a binder, and mixing well to obtain ink required for printing;

[0008] S2, spraying the ink onto the surface of the substrate through the nozzle of the printing system to obtain an oxide liquid film;

[0009] S3, the oxide liquid film solidifies to form an oxide thin film, which is then subjected to a first heat treatment;

[0010] S4. Under a reducing atmosphere, the oxide film after the first heat treatment is subjected to a second heat treatment, wherein the metal oxide powder is first reduced to metal and then sintered to obtain the high entropy alloy film; the second heat treatment comprises: first treating at 500-650°C for 1-3 hours, and then heating to 1000-1500°C for 0.5-1 hour.

[0011] Furthermore, the metal oxide powder comprises, by mass percentage, 15-25% Fe2O3, 15-25% NiO, 15-25% Co3O4, 15-25% Cr2O3, and 15-25% Al2O3. Preferably, the metal oxide powder comprises, by mass percentage, 18-22% Fe2O3, 18-22% NiO, 18-22% Co3O4, 18-22% Cr2O3, and 18-22% Al2O3.

[0012] Furthermore, the adhesive is polylactic acid-glycolic acid copolymer.

[0013] Furthermore, the solvent is a mixture of dichloromethane, dibutyl phthalate and 2-butoxyethanol.

[0014] Furthermore, the amount of metal oxide powder added to the ink is 25-35%.

[0015] Furthermore, the mass ratio of dibutyl phthalate to 2-butoxyethanol is (1.8-2.2):1.

[0016] Furthermore, the volume ratio of the metal oxide powder to the binder in the ink is (6-8):3.

[0017] Furthermore, the viscosity of the ink is controlled at 15 to 30 cP, and the viscosity is adjusted by adjusting the amount of dichloromethane.

[0018] Furthermore, the ink preparation method is as follows: first, dichloromethane is added to a mixture of dibutyl phthalate and 2-butoxyethanol; then, metal oxide powder is added to the mixture by stirring or shaking; and finally, the mixture is mixed with a polylactic acid-glycolic acid copolymer solution dissolved in dichloromethane to obtain the ink required for printing; wherein, the amount of dichloromethane added is adjusted according to the viscosity of the ink so that the viscosity of the ink is controlled at 15-30 cP.

[0019] Furthermore, the temperature of the first heat treatment is 280-320° C., and the time is 0.5-1 h;

[0020] And / or, the reducing atmosphere is hydrogen.

[0021] Furthermore, the printing system includes an ink cartridge and a plurality of nozzles arranged at intervals at the bottom of the ink cartridge; each nozzle is equipped with a microchannel, and the microchannel is a Tesla valve structure; a piezoelectric element is provided on the upper part of the ink cartridge for generating pressure to cause the ink to be ejected from the nozzle through the microchannel.

[0022] Furthermore, during the printing process, the nozzle moves in coordination with the substrate, and the printed ink droplets are deposited on the surface of the substrate to form an oxide liquid film.

[0023] The present invention also provides a printing system, comprising an ink cartridge and a plurality of nozzles arranged at intervals at the bottom of the ink cartridge; each nozzle is connected to the ink cartridge through a microchannel, and the microchannel is a Tesla valve structure; a piezoelectric element is provided on the upper part of the ink cartridge for generating pressure to cause ink to be ejected from the nozzle through the microchannel.

[0024] Furthermore, the piezoelectric element is a piezoelectric ceramic, which is arranged inside the ink cartridge and is in direct contact with the ink;

[0025] Each of the microchannels comprises a number of pipeline branches that are alternately arranged and connected; each pipeline branch has two pipelines, one of which is a forward straight channel that is inclined; and the other is a bend that is bent into a semi-circular shape and is connected back to the forward straight channel.

[0026] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0027] 1. The present invention uses metal oxide powder as raw material and helps to obtain uniform and fluid ink by adding adhesives and organic solvents, which facilitates inkjet printing and effectively solves the problem of difficult mixing of metal oxide raw materials; in addition, metal oxide powder has lower cost and better stability than elemental powder. Combined with the subsequent heat treatment reduction process, it helps to regulate the morphology of high-entropy alloy films. Therefore, the present invention provides a new approach for the preparation of high-entropy alloy films. The method is simple and easy to operate, low in cost, high in efficiency, and easy to promote and apply.

[0028] 2. The present invention performs the reduction and sintering of the metal oxide components simultaneously, effectively simplifying the preparation process of the high-entropy alloy thin film. During the heat treatment, as the temperature gradually increases, the binder begins to decompose, and the metal oxide powder is subsequently reduced to metal. When the temperature reaches the peak, the metal reduction and sintering proceed simultaneously, and the different metal particles diffuse and bond to form a high-entropy alloy thin film.

[0029] 3. The present invention utilizes a microchannel nozzle with a Tesla valve structure to enable the forward-flowing ink to pass smoothly, effectively prevent clogging, and facilitate obtaining a high-entropy alloy film with better film-forming effect; through the movement and coordination of the ink cartridge and the substrate, the droplet landing position can be precisely controlled, the implementation method is simple and convenient, and the printing results are accurate and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of the process for preparing a high entropy alloy thin film constructed according to a preferred embodiment of the invention;

[0031] Figure 2 It is a schematic structural diagram of the inkjet printing system of the present invention;

[0032] Figure 3 It is a schematic diagram of the microchannel structure of the inkjet printing system;

[0033] Figure 4 The following are actual images of the metal powder and ink used in the examples.

[0034] Reference numerals

[0035] 1-Ink cartridge, 11-Piezoelectric element, 12-Microchannel, 13-Nozzle, 2-Ink, 21-Ink droplet, 22-Ink line, 23-Ink film, 3-Light source, 4-XY moving platform, 5-High-speed camera, 6-Controller. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0037] Problems such as uneven composition of high entropy alloy films and easy clogging of existing nozzles when printing inks with high viscosity will affect the performance of the printed high entropy alloy films and reduce printing efficiency. In view of this, the present invention first provides a method for preparing high entropy alloy films based on inkjet printing, such as Figure 1-3 As shown, the following steps are included:

[0038] S1. Mixing metal oxide powders of metal elements required to form the high entropy alloy film with an organic solvent, then adding a binder, and mixing well to obtain ink required for printing;

[0039] S2. Spraying the ink onto the surface of the substrate through the nozzle of the printing system to obtain an oxide liquid film. During this process, the ink forms ink droplets through the nozzle and is deposited on the substrate under the action of gravity. At the same time, the XY moving platform (the substrate is placed on the XY moving platform) is adjusted to print the desired oxide liquid film.

[0040] S3, the volatile solvent in the oxide liquid film gradually evaporates, thereby solidifying to form a stable oxide film, which is then subjected to a first heat treatment; after the oxide liquid film is solidified and subjected to the first heat treatment, the solvent and the binder begin to be thermally degraded and removed, forming a solid oxide film containing a large number of small pores;

[0041] S4. Then, in a hydrogen environment, the film after the first heat treatment is subjected to a second heat treatment, where the metal oxide powder is first reduced to metal and then sintered to obtain a high entropy alloy film.

[0042] The present invention uses metal oxide powder as the starting material, prepares a uniform ink, then prints the resulting film and then thermally reduces it to produce a high-entropy alloy thin film. This process improves the stability and safety of the metal oxide powder, reduces costs, and facilitates widespread application. The metal oxide powder also exhibits improved dispersibility in organic solvents. During subsequent thermal reduction, oxygen is released from the metal oxide to produce a single-element high-entropy alloy thin film. When the temperature is further increased during sintering, interdiffusion and bonding occur between the different metal particles, contributing to the regulation and improvement of the high-entropy alloy structure.

[0043] The quality of the high-entropy alloy film finally obtained by the present invention is mainly determined by the composition of the metal oxides in the ink and the sintering temperature and time, and these factors are relatively easy to control. Therefore, the high-entropy alloy film is highly controllable and convenient for large-scale application.

[0044] The metal oxide powder is a mixture of oxides corresponding to the metal components in the final high-entropy alloy film. Preferably, the metal oxide powder comprises, by mass, 15-25% Fe2O3, 15-25% NiO, 15-25% Co3O4, 15-25% Cr2O3, and 15-25% Al2O3. Preferably, the metal oxide powder comprises, by mass, 18-22% Fe2O3, 18-22% NiO, 18-22% Co3O4, 18-22% Cr2O3, and 18-22% Al2O3. More preferably, the metal oxide powder comprises, by mass, 20% Fe2O3, 20% NiO, 20% Co3O4, 20% Cr2O3, and 20% Al2O3. The purity and particle size of the metal oxide powder also affect the film formation and sintering effects. The purity is controlled to be greater than 99% and the particle size to be less than 5 μm.

[0045] The binder is a polylactic acid-glycolic acid copolymer, which ensures the stability of the printing process and maintains the shape of the final printed film. The volume ratio of the metal oxide powder to the binder in the ink is (6-8):3, preferably 7:3 (for example, the volume of the metal oxide powder and the binder can be measured by placing them in a measuring cylinder). The amount of metal oxide powder added to the ink is 25-35%. If the amount of metal oxide powder added is too small, the porosity of the solid oxide film may be too high when the binder and organic solvent are removed, affecting the density of the high-entropy alloy film obtained by sintering; if the amount of metal oxide powder added is too large, its dispersibility will deteriorate, which is not conducive to printing a uniform oxide liquid film, thereby affecting the uniformity and stability of the high-entropy alloy film.

[0046] The organic solvent is preferably a mixture of dichloromethane, dibutyl phthalate, and 2-butoxyethanol. The mass ratio of dibutyl phthalate to 2-butoxyethanol is (1.8-2.2):1, preferably 2:1. The viscosity of the ink is preferably 30 cP, which can be adjusted by adjusting the amount of dichloromethane. The surface tension of the ink is preferably 31 mN / m. Research in the present invention has shown that this combination of organic solvents is more conducive to the uniform dispersion of metal oxide powders.

[0047] Specifically, the ink is prepared by first adding dichloromethane to a mixture of dibutyl phthalate and 2-butoxyethanol; then adding metal oxide powder to the mixture by stirring or shaking; and finally mixing the mixture with a polylactic acid-glycolic acid copolymer solution dissolved in dichloromethane to obtain the ink required for printing; wherein the amount of dichloromethane added is adjusted according to the viscosity of the ink so that the viscosity of the ink is controlled within a range of 15 to 30 cP.

[0048] Due to the volatile nature of dichloromethane, ink preparation should usually be carried out in a fume hood.

[0049] like Figure 4 As shown, the ink preparation method of the present invention enables the metal oxide particles to be evenly dispersed in the organic solvent, which is conducive to ultimately obtaining a high-entropy alloy film with uniform composition. In addition, the ink has good fluidity and can be smoothly sprayed from the nozzle.

[0050] In step S3, the temperature of the first heat treatment is 280-320°C and the time is 0.5-1h;

[0051] In step S4, the second heat treatment involves initially treating the metal at 500-650°C for 1-3 hours, followed by heating to 1000-1500°C for 0.5-1 hour. As the heat treatment temperature continues to rise and reaches its peak, metal reduction and sintering proceed simultaneously. Under the influence of high-temperature sintering, the different metal particles diffuse and bond over time, forming a dense high-entropy alloy phase within the metal.

[0052] As a preferred embodiment of the present invention, the structure of the printing system (inkjet printing system) in step S2 is improved, such as Figure 2 As shown, it mainly includes a printing unit and a deposition unit. The printing unit mainly includes an ink cartridge 1 and a plurality of nozzles 13 arranged at intervals at the bottom of the ink cartridge 1; each nozzle 13 is provided with a microchannel 12, and the microchannel 12 is preferably provided with a Tesla valve structure, such as Figure 3 As shown, a piezoelectric element 11 is provided on the top of the ink cartridge 1 to generate pressure to eject ink from a nozzle 13 through a microchannel 12 to a deposition unit, forming an oxide liquid film. The deposition unit is preferably configured as an XY movable platform 4 for fixing the substrate. By moving the XY movable platform 4, the deposition position of the oxide liquid film can be synchronously adjusted.

[0053] Specifically, piezoelectric element 11 is a piezoelectric ceramic disposed within ink cartridge 1 and in direct contact with the ink. Piezoelectric element 11 is connected to a drive device that applies a driving voltage to piezoelectric element 11, causing it to deform and generate downward pressure, forcing ink from microchannel 12 to nozzle 13.

[0054] like Figure 3As shown, each microchannel 12 comprises several alternatingly connected branch lines. Each branch has two lines: one is a straight, inclined forward channel; the other is a curved channel, curved into a semi-circular shape and connected back to the straight forward channel. The structural design of the microchannels 12 in this printing system enables unidirectional ink flow at the nozzle 13. This allows ink flowing in the forward direction (toward the nozzle 13) to pass smoothly, while suppressing reverse flow, effectively alleviating the risk of ink clogging at the nozzle.

[0055] In particular, the printing system also includes a controller 6 and a high-speed camera 5. The ink cartridge 1 and the XY movable platform 4 are respectively connected to the controller 6. When the driving voltage is applied to the piezoelectric element 11, the piezoelectric element 11 deforms, thereby pressurizing the ink to eject the ink. By controlling the amplitude and period of the input voltage and other parameters through the controller 6, the size and dripping speed of the ink droplets can be accurately controlled, thereby achieving high-precision printing. At the same time, the program control of the controller 6 can accurately control the movement of the ink cartridge 1 and the substrate on the XY movable platform 4, which can effectively speed up the film printing speed. The high-speed camera 5 is set on the side of the XY movable platform 4 to monitor the fusion between the ink droplets and the printed line, and uses this as a reference to adjust the movement speed of the XY movable platform 4 and the dripping speed of the ink droplets to achieve precise control of the printed film.

[0056] In some preferred embodiments, the structural characteristic parameters of the ink (such as ink viscosity, metal oxide powder content, etc.) can be associated with the structural parameters of the controller 6, and the size and dripping speed of the ink droplets and the substrate movement speed can be regulated according to the structural characteristic parameters of the ink, thereby obtaining a high-entropy alloy film with better film formation and sintering effects.

[0057] The method for preparing a high entropy alloy thin film based on inkjet printing of the present invention is described below through specific examples.

[0058] (1) The printing system used in this embodiment is as follows Figure 2 As shown, the apparatus comprises a printing unit and a deposition unit. The droplet printing unit comprises an ink cartridge 1, a piezoelectric element 11, a microchannel structure 12, a nozzle 13, ink 2, and ink droplets 21; the droplet deposition unit comprises an ink line 22, an ink film 23, a light source 3, an XY motion platform 4, and a high-speed camera 5. In this example, the piezoelectric element 11 is a piezoelectric ceramic, and the light source 3 is a high-intensity LED. Under the influence of gravity, ink droplets 21 ejected from the nozzle 13 vertically impact the substrate on the XY motion platform 4. Adjacent ink droplets 21 fuse during spreading to form ink lines 22, and adjacent ink lines 22 fuse to form ink films 23.

[0059] like Figure 3As shown, the microchannel 12 connects the ink 2 to one end of the nozzle 13. Under the action of the piezoelectric element 11, the ink 2 at the top flows through the microchannel structure 12 toward the nozzle 13, where it is ejected under pressure to form ink droplets. The unique structural design of the microchannel 12 creates a significant difference between the forward and reverse flows of the ink 2. When the piezoelectric element 11 deforms and generates downward pressure, the ink 2 can flow smoothly from top to bottom through the microchannel 12 without resistance. When the piezoelectric element 11 stops deforming, negative pressure forms inside the ink cartridge 1, causing the ink 2 to flow in the reverse direction. However, if the ink 2 flows in the reverse direction into the microchannel 12, it will be divided into two paths at the first intersection and converge at the second intersection. This time, the two paths of ink 2 flow in opposite directions, creating significant resistance. As the number of intersections increases, the flow of ink 2 slows rapidly, allowing only forward flow through the microchannel 12 and making reverse flow difficult. This structural design effectively alleviates the problem of ink 2 clogging at the nozzle 13.

[0060] Before use, the focus and aperture of the high-speed camera should be adjusted so that a bright and uniform real image can be observed.

[0061] (2) Based on the above-mentioned printing system, a high entropy alloy film is prepared, such as Figure 1 As shown, the details are as follows:

[0062] First, dichloromethane is added to a mixture of dibutyl phthalate and 2-butoxyethanol (mass ratio is 2:1); then, metal oxide powder is added to the mixed solvent by stirring; finally, the mixture is mixed with a polylactic acid-glycolic acid copolymer solution dissolved in dichloromethane to obtain the ink required for printing; wherein, the viscosity of the ink is adjusted by adding an amount of dichloromethane to control the viscosity of the ink at 30 cP. The metal oxide powder includes Fe2O3 20%, NiO 20%, Co3O4 20%, Cr2O3 20% and Al2O3 20% by mass percentage. In the final ink, the volume ratio of metal oxide powder to binder is 7:3, and the mass content of metal oxide powder is preferably 30%. As Figure 4 As shown, it can be seen that the obtained ink has good dispersibility and moderate viscosity, which helps to improve the quality of the printed high entropy alloy film.

[0063] After the prepared ink is printed by the inkjet printing system, the required oxide liquid film is printed on the substrate. The volatile solvent in the oxide liquid film gradually evaporates, thereby solidifying to form a stable oxide film, which is subjected to the first heat treatment (in this embodiment, it is treated at 300°C for 1 hour), and then the printed oxide film is heat treated in a hydrogen environment. When the temperature rises to 600°C, the polylactic acid-glycolic acid decomposes and detaches from the film. At this time, the metal oxide powder begins to be reduced to metal, accompanied by the production of water; when the temperature continues to rise to a peak temperature of 1000°C, the reduction and sintering of the metal proceed simultaneously. Under the action of high-temperature sintering, as time passes, different metal particles diffuse and combine with each other, forming a dense high-entropy alloy phase inside. The composition of the metal oxide in the ink and the sintering temperature and time determine the quality of the final high-entropy alloy film.

[0064] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a high entropy alloy thin film based on inkjet printing, characterized in that: The following steps are involved: S1. Mixing metal oxide powders of metal elements required to form the high entropy alloy film with an organic solvent, then adding a binder, and mixing well to obtain ink required for printing; S2, spraying the ink onto the surface of the substrate through the nozzle of the printing system to obtain an oxide liquid film; S3, the oxide liquid film solidifies to form an oxide thin film, which is then subjected to a first heat treatment; S4. Under a reducing atmosphere, the oxide film after the first heat treatment is subjected to a second heat treatment, wherein the metal oxide powder is first reduced to metal and then sintered to obtain the high entropy alloy film; the second heat treatment comprises: first treating at 500-650° C. for 1-3 hours, then heating to 1000-1500° C. for 0.5-1 hour; The metal oxide powder comprises, by mass percentage, 15-25% Fe2O3, 15-25% NiO, 15-25% Co3O4, 15-25% Cr2O3 and 15-25% Al2O3; The adhesive is polylactic acid-glycolic acid copolymer; The organic solvent is a mixture of dichloromethane, dibutyl phthalate and 2-butoxyethanol.

2. The method for preparing a high entropy alloy thin film based on inkjet printing according to claim 1, characterized in that: The mass fraction of the metal oxide powder in the ink is 25-35%.

3. The method for preparing a high entropy alloy thin film based on inkjet printing according to claim 1, characterized in that: The mass ratio of dibutyl phthalate to 2-butoxyethanol is (1.8-2.2):1; And / or, the relative volume ratio of the metal oxide powder to the binder in the ink is (6-8):3; And / or, the viscosity of the ink is controlled at 15-30 cP, and the viscosity is adjusted by adjusting the amount of the dichloromethane.

4. The method for preparing a high entropy alloy thin film based on inkjet printing according to any one of claims 1 to 3, characterized in that: The ink is prepared by first adding dichloromethane to a mixture of dibutyl phthalate and 2-butoxyethanol; then adding metal oxide powder to the mixture by stirring or shaking; and finally mixing the mixture with a polylactic acid-glycolic acid copolymer solution dissolved in dichloromethane to obtain the ink required for printing. The amount of dichloromethane added is adjusted according to the viscosity of the ink to control the viscosity of the ink within a range of 15 to 30 cP.

5. The method for preparing a high entropy alloy thin film based on inkjet printing according to any one of claims 1 to 3, characterized in that: The first heat treatment temperature is 280-320°C and the time is 0.5-1h; And / or, the reducing atmosphere is hydrogen.

6. The method for preparing a high entropy alloy thin film based on inkjet printing according to any one of claims 1 to 3, characterized in that: The printing system includes an ink cartridge and a plurality of nozzles arranged at intervals at the bottom of the ink cartridge; each nozzle is equipped with a microchannel, and the microchannel is a Tesla valve structure; a piezoelectric element is provided on the top of the ink cartridge for generating pressure to eject ink from the nozzle through the microchannel.

7. The method for preparing a high entropy alloy thin film based on inkjet printing according to claim 6, characterized in that: During the printing process, the nozzle moves in coordination with the substrate, and the printed ink droplets are deposited on the surface of the substrate to form an oxide liquid film.

8. A printing system used in the method for preparing a high entropy alloy thin film based on inkjet printing according to any one of claims 1 to 7, characterized in that: The invention comprises an ink cartridge and a plurality of nozzles arranged at intervals at the bottom of the ink cartridge; each nozzle is connected to the ink cartridge via a microchannel, and the microchannel is a Tesla valve structure; a piezoelectric element is provided on the upper part of the ink cartridge for generating pressure to eject ink from the nozzle through the microchannel.

9. The printing system according to claim 8, characterized in that: The piezoelectric element is a piezoelectric ceramic, which is arranged inside the ink cartridge and is in direct contact with the ink; Each of the microchannels comprises a number of pipeline branches that are alternately arranged and connected; each pipeline branch has two pipelines, one of which is a forward straight channel that is inclined; and the other is a bend that is bent into a semi-circular shape and is connected back to the forward straight channel.

Images