A plasma chromium-based coating production apparatus and method employing multiple source precursors

Abstract

The application discloses a device and method for preparing plasma chromium-based coating by using multi-source precursors, which is composed of a gas cylinder, a gas supply pipeline, a gas pressure throttle valve, a flow meter, a solid flow meter, a solid heating crucible, a water bath heating pot, a gas collecting bottle, a liquid flow meter, precursor gas, a gas flow meter, a radio frequency power supply, a tubular heating furnace, a plasma reaction cavity, a power accelerator, a substrate and a gas heater. The device and method can use solid, liquid and gas multi-source precursors as raw materials to prepare chromium-based coating in an atmospheric environment. The power accelerator is used to improve the spraying efficiency and increase the bonding force between the coating and the substrate.

Description

Technical Field

[0001] This invention belongs to the field of material surface strengthening technology, and relates to a plasma chromium-based coating preparation device and method that can use multi-source precursors. Background Technology

[0002] Chromium plating is a common surface treatment technique for metals. By depositing a chromium layer onto the metal surface, it imparts corrosion resistance, wear resistance, aesthetics, electrical conductivity, thermal conductivity, optical properties, and hardness. Chromium plating is widely used in high-tech fields such as aerospace, automotive, electrical equipment, metallurgy, chemical industry, and optical instruments, providing products with superior performance and appearance. Among its most prominent characteristics, chromium plating effectively improves the corrosion resistance of metal surfaces because the chromium layer effectively isolates the metal from contact with the external environment, thereby reducing the risk of oxidation and corrosion.

[0003] Currently, common techniques for processing chromium plating on metals include electroplating, chemical plating, and physical plating. Electroplating involves electrolyzing a metal to form a chromium layer on its surface; chemical plating uses a chemical reaction to create the chromium layer. Both methods require large amounts of chemicals and electricity, causing significant environmental pollution. Physical plating deposits a chromium layer on the metal surface using physical methods, but this requires a high-vacuum environment, which greatly limits its practical application. Plasma-enhanced chemical vapor deposition (PECVD) can effectively avoid these problems.

[0004] PECVD technology is a technique used to achieve chemical vapor deposition of thin films. Its principle involves generating plasma through gas discharge within a cavity. The high-energy electrons and active free radicals in the plasma then react chemically with the precursor material to form the desired chromium-based coating. PECVD-deposited films exhibit excellent electrical properties, good substrate adhesion, and lower deposition temperatures compared to other thin film deposition techniques, making them widely used in the field of material surface coating technology.

[0005] Chinese patent CN116657244A describes a method for large-area low-temperature preparation of 1T phase CrTe2 thin films, using plasma-enhanced chemical vapor deposition (PECVD) to achieve low-temperature wafer-level CrTe2 film preparation. However, it can only use solid materials as precursors. Wang Jinwen et al., Thin Solid Films, 2008, 516 (2008)7366-7372, prepared CrO2 and Cr2O3 thin films on silicon substrates using Cr(CO)6 as a precursor. Their research found that the growth rate and composition of the deposited coatings varied under different substrate temperatures and oxygen contents. Because one of the processes in PECVD involves the diffusion and transport of various active groups to the film growth surface and tube wall, the growth rate is relatively low, at 1.4 nm / min. It is evident that existing technologies have the following problems: high requirements for the morphology of precursor materials; relatively low deposition rates; furthermore, due to the difference between the film material and the substrate surface, effective bonding is difficult to achieve at low temperatures, resulting in insufficient adhesion between the film and the substrate; if the substrate is heated, the stress of the deposited film is easily increased, which leads to a decrease in the adhesion between the film and the substrate, and further problems such as film peeling, cracking, and low corrosion resistance may occur. Summary of the Invention

[0006] To address the above problems, this invention provides a plasma chromium-based coating preparation apparatus and method that can utilize multi-source precursors. By excitation with a radio frequency power supply and heating with a tubular furnace, solid, liquid, and gaseous precursors can be used as raw materials to react with high-energy electrons and free radicals generated by plasma discharge. The reaction products are then sprayed onto the surface of a metal substrate using a dynamic acceleration system, thereby achieving the preparation of a chromium-based coating with high bonding strength on the metal surface. This invention significantly reduces the requirements for precursor materials. Through the dynamic acceleration system formed by the Laval nozzle, high bonding strength and high deposition rate between the chromium-based coating and the substrate are achieved at low temperature and atmospheric pressure in a shorter deposition time.

[0007] The objective of this invention can be achieved through the following technical solution: a plasma chromium-based coating preparation apparatus and method using multi-source precursors. The apparatus mainly comprises a high-pressure gas source, a gas regulation and control system, a plasma reaction system, a material supply system, a power acceleration system, and a gas temperature control system. It mainly includes a gas cylinder, a gas supply pipeline, a gas pressure throttling valve, a flow meter, a solid flow meter, a solid heating crucible, a water bath heating pot, a gas collecting bottle, a liquid flow meter, precursor gas, a gas flow meter, a radio frequency power supply, a tubular heating furnace, a plasma reaction chamber, a power accelerator, a substrate, and a gas heater. The power accelerator includes a front gas chamber, a flow guide screen, a coating material outlet, a Laval nozzle, a jet, and a chromium-based coating.

[0008] Furthermore, the solid heating crucible is used to heat the solid precursor material at high temperature, causing it to sublimate into gas, with a heating temperature range of 20 ℃ to 1200 ℃.

[0009] Furthermore, the water bath heating pot is used to uniformly heat and maintain the temperature of the liquid precursor, with a heating temperature range of 20 ℃ to 99.9 ℃.

[0010] Furthermore, the gas collecting bottle is designed with a long inlet and a short outlet to hold liquid precursors and to better provide precursors for the next reaction under the action of the working carrier gas.

[0011] Furthermore, the aforementioned radio frequency power supply is used to generate a high-frequency electric field at atmospheric pressure via a radio frequency generator, thereby generating plasma in the reaction chamber. These high-frequency electric fields act on the gas, causing the gas molecules to ionize and excite, forming plasma. The radio frequency is 13.65 MHz.

[0012] Furthermore, the tubular heater is used to raise the temperature and promote the reaction between the plasma and the precursor. The heating temperature range is 20℃-1200℃.

[0013] Furthermore, the plasma reaction chamber has a length of 30 mm to 60 mm. The chamber length is a crucial parameter in the coating process, playing a vital role in coating formation. An excessively short chamber length results in the sprayed material flowing through the chamber for too short a time, failing to react sufficiently and causing the coating film to fail to meet the expected performance and quality standards. Conversely, an excessively long chamber length leads to the sprayed material flowing through the chamber for too long, causing most of the material to deposit on the inner wall of the chamber, similarly resulting in the coating failing to meet the expected performance and quality standards.

[0014] Furthermore, the accelerator accelerates the gas mixture from subsonic to sonic speeds, and then to supersonic speeds, causing a dramatic increase in the kinetic energy of the coating.

[0015] Furthermore, the aforementioned flow guide screen is characterized in that it is installed in the power accelerator and fixed at the front end of the front gas chamber and the Laval nozzle, which plays a role in fixing the plasma reaction chamber; it has a through hole, which allows the high-pressure gas in the front gas chamber to be well introduced into the Laval nozzle, and also effectively avoids the occurrence of gas backflow.

[0016] Furthermore, the Laval nozzle is characterized by a gradually narrowing inner diameter in the front half to form a contraction section, and a gradually increasing inner diameter in the rear half to form an expansion section, with a narrow throat formed at the junction of the contraction and expansion sections. Gas at the inlet flows under high pressure into the front half of the nozzle, passes through the narrow throat, and exits from the rear half. This structure allows the airflow velocity to vary with the nozzle cross-sectional area, enabling the airflow to accelerate from subsonic to sonic speeds, and even to supersonic speeds.

[0017] Furthermore, the gas heater is designed in a spiral shape to make the gas preheating more uniform and rapid.

[0018] This invention also provides a method for using a plasma chromium-based coating preparation apparatus employing a multi-source precursor. Since this apparatus is applicable to precursor states of solid, liquid, and gas, the specific steps are also divided into the following three cases: The specific steps of the chromium-based plating method when the precursor is in a solid state are as follows: Step 1: Open the solid heating crucible and heat it to a temperature of 20 ℃-1200 ℃; place the solid precursor material on the solid heating crucible; the solid precursor material is chromium acetylacetone powder, chromium chloride, and chromium hexacarbonyl. Step 2: Open the gas cylinder, pressure throttle valve, flow meter, and fixed flow meter to allow the working gas to enter the gas supply line at the pre-required pressure. The working gas is nitrogen, argon, or helium; the flow rate of the flow meter is 0.1 L / min-6 L / min; the flow rate of the fixed flow meter is 1 ml / min-100 ml / min. Step 3: Under continuous heating in the solid heating crucible, the solid is sublimated into gas, and the working gas is continuously introduced into the gas supply pipeline; the gas heater is turned on and adjusted to preheat the working carrier gas. The heating temperature of the gas heater is 100 ℃-600 ℃; Step 4: Turn on the radio frequency power supply and the tubular heating furnace. The precursor enters the furnace chamber. Under the electric field excited by the radio frequency source, the precursor decomposes into electrons, ions, and active groups. These decomposed products undergo chemical reactions to generate the initial components and by-reactants for film formation. The fixed frequency of the radio frequency power supply is 13.65 MHz; the heating temperature of the tubular heating furnace is 50 ℃-300 ℃. Step 5: The chromium-based material for the coating is generated in the plasma reaction chamber. The coating material is brought to the spray material outlet by the continuously introduced working gas. The preheated working carrier gas below is introduced into the front gas chamber to form a high-pressure chamber, where it merges with the coating material at the front end of the Laval nozzle through a guide screen, forming a high-pressure gas-solid two-phase gas. Together, they move forward axially, and through the action of the Laval nozzle, the subsonic gas is converted into supersonic gas, which is then ejected from the nozzle orifice onto the substrate, accumulating continuously to form the final chromium-based coating. The distance between the nozzle orifice and the substrate is 5 mm-25 mm.

[0019] The specific steps of the chromium-based plating method when the precursor is in a liquid state are as follows: Step 1: Prepare a precursor solution with a concentration of 0.1-10 g / ml; the precursor solution is a mixture of chromium oxide powder and tetraethyl orthosilicate solution; Step 2: Sonicate the precursor solution in an ultrasonic instrument for 30 min-90 min to mix thoroughly; Step 3: Turn on the water bath and adjust the temperature to 70 ℃; place the gas collecting bottle containing the fully mixed precursor solution in the water bath for preheating for 10 min-20 min. Step 4: Open the gas cylinder, pressure throttle valve, flow meter, and liquid flow meter to allow the working gas to enter the gas supply line at the pre-required pressure. The working gas is nitrogen, argon, or helium, and the flow rate of the flow meter is 0.1 L / min-6 L / min; the flow rate of the liquid flow meter is 1 ml / min-100 ml / min. Step 5: Under the continuous heating of the water bath, the working gas is continuously introduced into the gas supply pipeline in a long-in, short-out manner; the gas heater is turned on and adjusted to preheat the working carrier gas. The heating temperature of the gas heater is 100 ℃-600 ℃; Step 6: Turn on the radio frequency power supply and the tubular heating furnace. The precursor enters the furnace cavity. Under the action of the electric field excited by the radio frequency source, the precursor decomposes into electrons, ions, and active groups. The fixed frequency of the radio frequency power supply is 13.65 MHz; the heating temperature of the tubular heating furnace is 50 ℃-300 ℃. Step 7: The chromium-based material for the coating is generated in the plasma reaction chamber. The coating material is brought to the spray material outlet by the continuously introduced working gas. The preheated working carrier gas below is introduced into the front gas chamber to form a high-pressure chamber. It merges with the coating material at the front end of the Laval nozzle through the guide screen to form a high-pressure gas-solid two-phase gas. Together, they move forward along the axial direction. Through the action of the Laval nozzle, the subsonic gas is converted into supersonic gas and sprayed from the nozzle orifice onto the substrate. The distance between the nozzle orifice and the substrate is 5 mm-25 mm.

[0020] The specific steps of the chromium-based plating method when the precursor is in a gaseous state are as follows: Step 1: Open the gas cylinder, pressure throttle valve, flow meter, and gas flow meter to allow the working gas to enter the gas supply line at the pre-required pressure. The working gas is nitrogen, argon, or helium; the flow rate of the flow meter is 0.1 L / min-6 L / min; the flow rate of the gas flow meter is 1 ml / min-100 ml / min. Step 2: Turn on the precursor gas switch to introduce the precursor gas into the gas supply line. The precursor gas is a gaseous chromium-containing compound. Turn on and adjust the gas heater to preheat the working carrier gas. The heating temperature of the gas heater is 100 ℃-600 ℃. Step 3: Turn on the radio frequency power supply and the tubular heating furnace. The precursor gas enters the furnace chamber and, under the influence of the electric field excited by the radio frequency source, decomposes into electrons, ions, and active groups. The fixed frequency of the radio frequency power supply is 13.65MHz; the heating temperature of the tubular heating furnace is 20℃-1200℃. Step 4: The chromium-based material used for the coating is generated in the plasma reaction chamber. The coating material is brought to the spray material outlet by the continuously introduced working gas. The preheated working carrier gas below is introduced into the front gas chamber to form a high-pressure chamber. It merges with the coating material at the front end of the Laval nozzle through the guide screen to form a high-pressure gas-solid two-phase gas. Together, they move forward along the axial direction. Through the action of the Laval nozzle, the subsonic gas is converted into supersonic gas and sprayed from the nozzle orifice onto the substrate. The distance between the nozzle orifice and the substrate is 5 mm-25 mm.

[0021] The beneficial effects of this invention are as follows: (1) The present invention realizes that in an atmospheric environment, a multi-source precursor, including solid, liquid and gas, can be used to react with the precursor using high-energy electrons and active groups generated by plasma discharge to deposit a chromium-based coating on a metal substrate.

[0022] (2) By using a power accelerator, the airflow is accelerated from subsonic speed to sonic speed or even supersonic speed, which greatly improves the spraying power, reduces the spraying time, and greatly improves the spraying efficiency. With the support of kinetic energy, the coating and the substrate are effectively bonded, and the bonding force between the coating and the substrate is also significantly improved. Attached Figure Description

[0023] Figure 1 This is a diagram of a plasma chromium-based coating preparation apparatus that can use multi-source precursors, as described in an embodiment of the present invention. Figure 2 for Figure 1 A schematic diagram of the structure of the medium-power acceleration system; Figure 3 This is a system configuration diagram of a plasma chromium-based coating preparation apparatus and method using multi-source precursors, as described in an embodiment of the present invention. Figure 4 This is a SEM image of the coating surface in Example 2 of the present invention; Figure 5 This is a micron-sized scratch test image of the coating surface in Example 2 of the present invention.

[0024] In the picture, 1. Gas cylinder; 2. Gas supply pipeline; 3. Gas pressure throttle valve; 4. Flow meter; 5. Solid flow meter; 6. Solid heating crucible; 7. Water bath heating pot; 8. Gas collecting bottle; 9. Liquid flow meter; 10. Precursor gas; 11. Gas flow meter; 12. Radio frequency power supply; 13. Tubular furnace; 14. Plasma reaction chamber; 15. Power accelerator; 16. Substrate; 17. Gas heater; 150. Front gas chamber; 151. Flow guide screen; 152. Spray material outlet; 153. Laval nozzle; 154. Jet; 155. Chromium-based coating; Detailed implementation method: The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0025] Example 1, as Figure 1 As shown in the figure, a plasma chromium-based coating preparation device using multi-source precursors according to an embodiment of the present invention includes a gas cylinder (1), a gas supply pipeline (2), a gas pressure throttle valve (3), a flow meter (4), a solid flow meter (5), a solid heating crucible (6), a water bath heating pot (7), a gas collecting bottle (8), a liquid flow meter (9), a precursor gas (10), a gas flow meter (11), a radio frequency power supply (12), a tubular heating furnace (13), a plasma reaction chamber (14), a power accelerator (15), a substrate (16), and a gas heater (17). The solid heating crucible (6), water bath heating pot (7), and the gas collecting bottle (8) and precursor gas (10) placed on it are connected to the gas cylinder (1) via a gas supply pipeline (2) at the left end under the control of the gas pressure throttle valve (3) and the special flow meter, and connected to the radio frequency power supply (12) and the tubular heating furnace (13) via a gas supply pipeline (2) at the right end; the right end of the tubular heating furnace (13) is connected to the plasma reaction chamber (14); the left end of the gas heater (17) is connected to the gas cylinder (1) via a gas supply pipeline (2) under the control of the gas pressure throttle valve (3) and the flow meter (4), and connected to the power accelerator (15) at the right end; the left end of the power accelerator (15) receives the precursor material and gas from the tubular heating furnace (13) and the gas heater (17), and the right end forms a high-pressure gas-solid two-phase gas for spraying; like Figure 2As shown, the power acceleration system includes a front gas chamber (150), a flow guide screen (151), a spray material outlet (152), a Laval nozzle (153), a jet (154), and a chromium-based coating (155); wherein, the flow guide screen (151) is installed in the power accelerator (15) and is fixed at the front end of the front gas chamber (150) and the Laval nozzle (153), and plays a role in fixing the plasma reaction chamber (14); the flow guide screen (151) has a through hole, which allows the high-pressure gas in the front gas chamber (150) to enter the Laval nozzle (153).

[0026] like Figure 3 As shown in the figure, the present invention provides a system configuration diagram of a plasma chromium-based coating preparation device and method that can use multi-source precursors, including a high-pressure gas source, a gas regulation and control system, a plasma reaction system, a feeding system, a power acceleration system, and a gas temperature control system.

[0027] The method of using the plasma chromium-based coating preparation device with multi-source precursors of the present invention is as follows: First, open the solid heating crucible (6) and set the heating temperature to 230 °C. Select chromium acetylacetone powder as the solid precursor material and place it on the solid heating crucible (6). Then, open the gas cylinder (1), the gas pressure throttle valve (3), the flow meter (4), and the solid flow meter (5) to introduce working gas nitrogen into the gas supply line (2) at a pressure of 1.5 MPa. The flow rate of the flow meter (4) is 3 L / min; the flow rate of the solid flow meter (5) is 80 ml / min. Then, under the continuous heating of the solid heating crucible (6), the chromium acetylacetone powder is sublimated into gas, and nitrogen is continuously introduced into the gas supply line (2). At the same time, the heating temperature of the gas heater (17) is set to 300 °C. Turn on the radio frequency power supply (12) and the tubular furnace (13). The sublimated chromium acetylacetone reacts chemically with the plasma to generate the initial components and by-reactants for film formation. The radio frequency power supply (12) uses a fixed frequency of 13.65 MHz; the heating temperature of the tubular heating furnace (13) is 230 ℃. Then, it is fully reacted in a plasma reaction chamber (14) with a length of 50 mm to generate the chromium-based material used for the coating. It comes to the spray material outlet (152) with the continuously introduced nitrogen gas. The preheated working carrier gas below is introduced into the front gas chamber (150) to form a high-pressure chamber. It merges with the coating material at the front end of the Laval nozzle (153) through the guide screen (151) to form a high-pressure gas-solid two-phase gas. Together, they move forward along the axis. Through the action of the Laval nozzle (153), the subsonic gas is converted into supersonic gas and sprayed from the nozzle to the substrate (16) 20 mm away. It accumulates continuously to form the final chromium-based coating (155).

[0028] Example 2, as Figure 1As shown in the figure, a plasma chromium-based coating preparation device using multi-source precursors according to an embodiment of the present invention includes a gas cylinder (1), a gas supply pipeline (2), a gas pressure throttle valve (3), a flow meter (4), a solid flow meter (5), a solid heating crucible (6), a water bath heating pot (7), a gas collecting bottle (8), a liquid flow meter (9), a precursor gas (10), a gas flow meter (11), a radio frequency power supply (12), a tubular heating furnace (13), a plasma reaction chamber (14), a power accelerator (15), a substrate (16), and a gas heater (17). The solid heating crucible (6), water bath heating pot (7), and the gas collecting bottle (8) and precursor gas (10) placed on it are connected to the gas cylinder (1) via a gas supply pipeline (2) at the left end under the control of the gas pressure throttle valve (3) and the special flow meter, and connected to the radio frequency power supply (12) and the tubular heating furnace (13) via a gas supply pipeline (2) at the right end; the right end of the tubular heating furnace (13) is connected to the plasma reaction chamber (14); the left end of the gas heater (17) is connected to the gas cylinder (1) via a gas supply pipeline (2) under the control of the gas pressure throttle valve (3) and the flow meter (4), and connected to the power accelerator (15) at the right end; the left end of the power accelerator (15) receives the precursor material and gas from the tubular heating furnace (13) and the gas heater (17), and the right end forms a high-pressure gas-solid two-phase gas for spraying; like Figure 2 As shown, the power acceleration system includes a front gas chamber (150), a flow guide screen (151), a spray material outlet (152), a Laval nozzle (153), a jet (154), and a chromium-based coating (155); wherein, the flow guide screen (151) is installed in the power accelerator (15) and is fixed at the front end of the front gas chamber (150) and the Laval nozzle (153), and plays a role in fixing the plasma reaction chamber (14); the flow guide screen (151) has a through hole, which allows the high-pressure gas in the front gas chamber (150) to enter the Laval nozzle (153).

[0029] like Figure 3 As shown in the figure, the present invention provides a system configuration diagram of a plasma chromium-based coating preparation device and method that can use multi-source precursors, including a high-pressure gas source, a gas regulation and control system, a plasma reaction system, a feeding system, a power acceleration system, and a gas temperature control system.

[0030] The method of using the plasma chromium-based coating preparation device with multi-source precursor of the present invention is as follows: Specifically, a mixture of chromium oxide powder with a concentration of 0.1 g / ml and tetraethyl orthosilicate solution is prepared as a precursor solution; the solution is ultrasonicated in an ultrasonic instrument for 60 min to mix thoroughly; then, the water bath heating pot (7) is turned on and the temperature is adjusted to 70 ℃; the gas collecting bottle (8) of the solution is placed in the water bath heating pot (7) for preheating for 15 min; at the same time, the gas cylinder (1), the gas pressure throttle valve (3), the flow meter (4) and the liquid flow meter (9) are turned on to introduce working gas nitrogen into the gas supply pipeline (2) at a pressure of 1.5 MPa. The flow rate of the flow meter (4) is 3 L / min; the flow rate of the liquid flow meter (9) is 80 ml / min; then, under the continuous heating of the water bath heating pot, nitrogen gas is continuously introduced into the gas supply pipeline in a long-in-short-out manner; at the same time, the heating temperature of the gas heater (17) is set to 300 °C; the radio frequency power supply (12) and the tubular heating furnace (13) are turned on, and the precursor reacts chemically with the plasma to generate the initial components and by-reactants for film formation. The radio frequency power supply (12) uses a fixed frequency of 13.65 MHz; the heating temperature of the tubular heating furnace (13) is 230 °C. Then, a full reaction is carried out in a plasma reaction chamber (14) with a length of 50 mm to generate the chromium-based material used for the coating. This material is then introduced to the spray material outlet (152) along with continuously introduced nitrogen gas. The preheated working carrier gas below is introduced into the front gas chamber (150) to form a high-pressure chamber. This high-pressure chamber is formed by the coating material passing through a guide screen (151) and merging with the coating material at the front end of the Laval nozzle (153) to form a high-pressure gas-solid two-phase gas. This gas moves forward along the axial direction and, through the action of the Laval nozzle (153), the subsonic gas is converted into supersonic gas. This gas is then sprayed from the nozzle opening to the substrate (16) at a distance of 20 mm. The gas accumulates continuously to form the final chromium-based coating (155). To further observe the surface morphology of the coating in Example 2 of this invention, such as... Figure 4 The SEM images shown indicate that the coating is uniform and dense; the micron-level scratch test results on the coating surface are as follows. Figure 5 As shown, the film-substrate adhesion force is >10 N, indicating that there is a high adhesion force between the coating and the substrate.

[0031] Example 3, as Figure 1As shown in the figure, a plasma chromium-based coating preparation device using multi-source precursors according to an embodiment of the present invention includes a gas cylinder (1), a gas supply pipeline (2), a gas pressure throttle valve (3), a flow meter (4), a solid flow meter (5), a solid heating crucible (6), a water bath heating pot (7), a gas collecting bottle (8), a liquid flow meter (9), a precursor gas (10), a gas flow meter (11), a radio frequency power supply (12), a tubular heating furnace (13), a plasma reaction chamber (14), a power accelerator (15), a substrate (16), and a gas heater (17). The solid heating crucible (6), water bath heating pot (7), and the gas collecting bottle (8) and precursor gas (10) placed on it are connected to the gas cylinder (1) via a gas supply pipeline (2) at the left end under the control of the gas pressure throttle valve (3) and the special flow meter, and connected to the radio frequency power supply (12) and the tubular heating furnace (13) via a gas supply pipeline (2) at the right end; the right end of the tubular heating furnace (13) is connected to the plasma reaction chamber (14); the left end of the gas heater (17) is connected to the gas cylinder (1) via a gas supply pipeline (2) under the control of the gas pressure throttle valve (3) and the flow meter (4), and connected to the power accelerator (15) at the right end; the left end of the power accelerator (15) receives the precursor material and gas from the tubular heating furnace (13) and the gas heater (17), and the right end forms a high-pressure gas-solid two-phase gas for spraying; like Figure 2 As shown, the power acceleration system includes a front gas chamber (150), a flow guide screen (151), a spray material outlet (152), a Laval nozzle (153), a jet (154), and a chromium-based coating (155); wherein, the flow guide screen (151) is installed in the power accelerator (15) and is fixed at the front end of the front gas chamber (150) and the Laval nozzle (153), and plays a role in fixing the plasma reaction chamber (14); the flow guide screen (151) has a through hole, which allows the high-pressure gas in the front gas chamber (150) to enter the Laval nozzle (153).

[0032] like Figure 3 As shown in the figure, the present invention provides a system configuration diagram of a plasma chromium-based coating preparation device and method that can use multi-source precursors, including a high-pressure gas source, a gas regulation and control system, a plasma reaction system, a feeding system, a power acceleration system, and a gas temperature control system.

[0033] The method of using the plasma chromium-based coating preparation device with multi-source precursors of the present invention is as follows: Specifically, the gas cylinder (1), the gas pressure throttle valve (3), the flow meter (4), and the gas flow meter (11) are opened, and the working gas nitrogen is introduced into the gas supply line (2) at a pressure of 1.5 MPa. The flow rate of the flow meter (4) is 3 L / min; the flow rate of the gas flow meter (11) is 80 ml / min; then, the precursor gas (10) switch is turned on, and the gaseous chromium-containing compound is introduced into the gas supply line (2). The heating temperature of the gas heater (17) is set to 300 °C; the radio frequency power supply (12) and the tubular furnace (13) are turned on, and the gaseous chromium-containing compound reacts chemically with the plasma to generate the initial components and by-reactants for film formation. The radio frequency power supply (12) uses a fixed frequency of 13.65 MHz; the heating temperature of the tubular furnace (13) is 230 °C. Then, the reaction is carried out in a plasma reaction chamber (14) with a length of 50 mm to generate the chromium-based material used for the coating. The material is brought to the spray material outlet (152) with the continuously introduced nitrogen gas. The preheated working carrier gas below is introduced into the front gas chamber (150) to form a high-pressure chamber. It is combined with the coating material through the guide screen (151) at the front end of the Laval nozzle (153) to form a high-pressure gas-solid two-phase gas. They move forward together along the axis. Through the action of the Laval nozzle (153), the subsonic gas is converted into supersonic gas and sprayed from the nozzle to the substrate (16) 20 mm away. They accumulate continuously to form the final chromium-based coating (155).

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Those skilled in the art will recognize that the present invention can have variations within the parameter range. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A plasma chromium-based coating preparation apparatus that can utilize multi-source precursors, characterized in that: It consists of a high-pressure gas source, a gas regulation and control system, a plasma reaction system, a feeding system, a power acceleration system and a gas temperature control system; including a gas cylinder (1), a gas supply pipeline (2), a gas pressure throttle valve (3), a flow meter (4), a solid flow meter (5), a solid heating crucible (6), a water bath heating pot (7), a gas collecting bottle (8), a liquid flow meter (9), a precursor gas (10), a gas flow meter (11), a radio frequency power supply (12), a tubular heating furnace (13), a plasma reaction chamber (14), a power accelerator (15), a substrate (16), and a gas heater (17); in, The solid heating crucible (6), water bath heating pot (7), and the gas collecting bottle (8) and precursor gas (10) placed on it are connected to the gas cylinder (1) via a gas supply pipeline (2) at the left end under the control of the gas pressure throttle valve (3) and the special flow meter, and connected to the radio frequency power supply (12) and the tubular heating furnace (13) via a gas supply pipeline (2) at the right end; the right end of the tubular heating furnace (13) is connected to the plasma reaction chamber (14); the left end of the gas heater (17) is connected to the gas cylinder (1) via a gas supply pipeline (2) under the control of the gas pressure throttle valve (3) and the flow meter (4), and connected to the power accelerator (15) at the right end; the left end of the power accelerator (15) receives the precursor material and gas from the tubular heating furnace (13) and the gas heater (17), and the right end forms a high-pressure gas-solid two-phase gas for spraying; The power accelerator (15) consists of a front gas chamber (150), a flow guide screen (151), a spray material outlet (152), a Laval nozzle (153), and a jet (154). The flow guide screen (151) is installed in the power accelerator (15) and is fixed at the front end of the front gas chamber (150) and the Laval nozzle (153), which plays a role in fixing the plasma reaction chamber (14). The flow guide screen (151) has a through hole, which allows the high-pressure gas in the front gas chamber (150) to pass through. In the Laval nozzle (153), gas backflow is effectively avoided; the inner diameter of the first half of the Laval nozzle (153) gradually decreases to form a contraction section, and the inner diameter of the second half gradually increases to form an expansion section. A narrow throat is formed at the junction of the contraction section and the expansion section. The gas at the inlet flows into the first half of the nozzle under high pressure, passes through the narrow throat, and escapes from the second half. This structure allows the airflow speed to change with the change of the nozzle cross-sectional area, so that the airflow can be accelerated from subsonic to sonic speed, and even to supersonic speed.

2. The plasma chromium-based coating preparation apparatus using multi-source precursors according to claim 1, characterized in that, The solid heating crucible (6) heats the solid precursor at a temperature range of 20 ℃ to 1200 ℃; the water bath heating pot (7) heats the liquid precursor at a temperature range of 20 ℃ to 99.9 ℃; the gas collecting bottle (8) has a long inlet and short outlet structure; the radio frequency power supply (12) provides energy to the plasma reactor at a frequency of 13.65 MHz; the tubular heating furnace (13) is used to raise the temperature and promote the reaction between the plasma and the precursor, with a heating temperature range of 20 ℃ to 1200 ℃; the plasma reaction chamber (14) has a length of 30 mm to 60 mm; the gas heater (17) preheats the gas more uniformly and rapidly, and has a spiral winding structure.

3. A method of using the plasma chromium-based coating preparation apparatus for employing multi-source precursors as described in any one of claims 1-2, characterized in that, When the current driver is solid, the method includes the following steps: Step 1: Open the solid heating crucible (6) and heat it to a temperature of 20 ℃-1200 ℃; place the solid precursor material on the solid heating crucible (6); the solid precursor material includes chromium acetylacetone powder, chromium chloride, and chromium hexacarbonyl. Step 2: Open the gas cylinder (1), the gas pressure throttle valve (3), the flow meter (4), and the fixed flow meter (5) to introduce the working gas into the gas supply pipeline (2) at the pre-required gas pressure; the working gas is nitrogen, argon, or helium, and the flow rate of the flow meter is 0.1 L / min-6 L / min; the flow rate of the fixed flow meter is 1 ml / min-100 ml / min; Step 3: Under the continuous heating of the solid heating crucible (6), the solid is sublimated into gas. As the working gas is continuously introduced into the gas supply pipeline (2), the gas heater (17) is turned on and adjusted to preheat the working carrier gas. The heating temperature of the gas heater (17) is 100 ℃-600 ℃. Step 4: Turn on the radio frequency power supply (12) and the tubular heating furnace (13). The precursor enters the furnace cavity. Under the action of the electric field excited by the radio frequency source, the precursor decomposes into electrons, ions and active groups. The fixed frequency of the radio frequency power supply (12) is 13.65 MHz. The heating temperature of the tubular heating furnace (13) is 20 ℃-1200 ℃. Step 5: The chromium-based coating is generated in the plasma reaction chamber (14) and arrives at the spray material outlet (152) with the continuously introduced working gas; the preheated working carrier gas below is introduced into the front gas chamber (150) to form a high-pressure chamber, which merges with the coating material at the front end of the Laval nozzle (153) through the guide screen (151) to form a high-pressure gas-solid two-phase gas, which moves forward along the axial direction. Through the action of the Laval nozzle (153), the subsonic gas is converted into supersonic gas and sprayed from the nozzle opening onto the substrate (16) and coated on the substrate; the distance between the nozzle opening and the substrate is 5 mm-25 mm.

4. A method of using the plasma chromium-based coating preparation apparatus for multi-source precursors as described in any one of claims 1-2, characterized in that, When the precursor is in a liquid state, the method includes the following steps: Step 1: Prepare a precursor solution, wherein the precursor solution is a mixture of chromium oxide powder and tetraethyl orthosilicate solution; Step 2: Sonicate the precursor solution in an ultrasonic instrument for 30 min-90 min to mix thoroughly; Step 3: Open the water bath heating pot (7) and adjust the temperature to 70 ℃; place the gas collecting bottle containing the fully mixed precursor solution in the water bath heating pot (7) for preheating for 10 min-20 min. Step 4: Open the gas cylinder (1), the gas pressure throttle valve (3), the flow meter (4), and the liquid flow meter (9) to introduce the working gas into the gas supply pipeline (2) at the pre-required gas pressure; the working gas is nitrogen, argon, or helium, and the flow rate of the flow meter is 0.1 L / min-6 L / min; the flow rate of the liquid flow meter is 1 ml / min-100 ml / min; Step 5: Under the continuous heating of the water bath heating pot (7), the working gas is continuously introduced into the gas supply pipeline (2) in a long-in-short-out manner; turn on and adjust the gas heater (17) to preheat the working carrier gas; the heating temperature of the gas heater (17) is 100 ℃-600 ℃. Step 6: Turn on the radio frequency power supply (12) and the tubular heating furnace (13). The precursor enters the furnace cavity. Under the action of the electric field excited by the radio frequency source, the precursor decomposes into electrons, ions and active groups. The fixed frequency of the radio frequency power supply (12) is 13.65 MHz. The heating temperature of the tubular heating furnace (13) is 20 ℃-1200 ℃. Step 7: The chromium-based coating is generated in the plasma reaction chamber (14) and arrives at the spray material outlet (152) with the continuously introduced working gas; the preheated working carrier gas below is introduced into the front gas chamber (150) to form a high-pressure chamber, which merges with the coating material at the front end of the Laval nozzle (153) through the guide screen (151) to form a high-pressure gas-solid two-phase gas, which moves forward along the axial direction. Through the action of the Laval nozzle (153), the subsonic gas is converted into supersonic gas and sprayed from the nozzle opening onto the substrate (16) and coated on the substrate; the distance between the nozzle opening and the substrate is 5 mm-25 mm.

5. A method of using a plasma chromium-based coating preparation apparatus capable of employing multi-source precursors as described in any one of claims 1-2, characterized in that, When the precursor is in a gaseous state, the method includes the following steps: Step 1: Open the gas cylinder (1), gas pressure throttle valve (3), flow meter (4), and gas flow meter (11) to introduce the working gas into the gas supply pipeline (2) at the pre-required gas pressure; the working gas is nitrogen, argon, or helium, and the flow rate of the flow meter is 0.1 L / min-6 L / min; the flow rate of the liquid flow meter is 1 ml / min-100 ml / min; Step 2: Turn on the precursor gas (10) switch and introduce the precursor gas into the gas supply line (2); the precursor gas (10) is a gaseous chromium-containing compound; turn on and adjust the gas heater (17) to preheat the working carrier gas; the heating temperature of the gas heater (17) is 100 ℃-600 ℃. Step 3: Turn on the radio frequency power supply (12) and the tubular heating furnace (13). The precursor gas enters the furnace cavity. Under the action of the electric field excited by the radio frequency source, the precursor gas decomposes into electrons, ions and active groups. The fixed frequency of the radio frequency power supply (12) is 13.65 MHz. The heating temperature of the tubular heating furnace (13) is 20 ℃-1200 ℃. Step 4: The chromium-based coating is generated in the plasma reaction chamber (14) and arrives at the spray material outlet (152) with the continuously introduced working gas; the preheated working carrier gas below is introduced into the front gas chamber (150) to form a high-pressure chamber, which merges with the coating material at the front end of the Laval nozzle (153) through the guide screen (151) to form a high-pressure gas-solid two-phase gas, which moves forward along the axial direction. Through the action of the Laval nozzle (153), the subsonic gas is converted into supersonic gas and sprayed from the nozzle opening onto the substrate (16) and coated on the substrate; the distance between the nozzle opening and the substrate (16) is 5 mm-25 mm.

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