Supersonic airflow enhanced plasma spraying gun head

Abstract

The utility model discloses a supersonic airflow enhanced plasma spraying gun head. The supersonic airflow enhanced plasma spraying gun head comprises a base and a fairing which covers the base and is detachably connected with the base, a rear flow dividing body is coaxially arranged on the base, the outer wall of the rear flow dividing body is coaxially sleeved with a communicated inner flow dividing body through a threaded structure, the outer wall part of the inner flow dividing body is sleeved with an outer flow dividing body, the inner wall of the inner flow dividing body is in threaded connection with a communicated inner electrode, and the outer wall part of the outer flow dividing body is sleeved with an outer electrode. A gas flow channel allowing process gas to flow is reserved between the outer wall of the inner electrode and the inner wall of the outer electrode, the outer electrode partially protrudes out of the fairing, and a circular seam structure allowing high-pressure gas to be sprayed out is reserved between the outer wall of the outer electrode and the inner wall of the fairing. Air resistance borne by molten ceramic powder during casting is reduced or eliminated, kinetic energy of particles when the particles reach the surface of a base material is improved, and spraying efficiency is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of plasma spray gun heads, in particular to a supersonic airflow enhanced plasma spray gun head. Background Art

[0002] The substrates of the electrical electrostatic chucks that fix glass and silicon wafers in the FPD and semiconductor etching processes, as well as various components in the equipment cavity, are often made of metal materials. In order to meet the insulation and corrosion resistance during use, a layer of ceramic material with a certain thickness needs to be sprayed on the surface of the metal substrate. Because ceramic materials generally have a high melting point, high-energy plasma spraying is required to fully melt the ceramic powder as the raw material and then spray it onto the target substrate surface.

[0003] At present, ceramic powder with a particle size D50 of 30 microns is commonly used as raw material for spraying in an atmospheric environment. Because it is different from the process of sintering ceramics that slowly forms under high temperature and high pressure, the ceramic layer formed by spraying will have a porosity of about 3%. Although the ceramic coating made by this process can meet the requirements of complex chemical environment and high-voltage insulation in the etching process, as the industry's requirements for component weather resistance and service life continue to increase, the ceramic coating made by conventional APS process has become increasingly difficult to meet the requirements.

[0004] In order to spray a denser ceramic coating to meet the increasingly stringent requirements for performance and life, it is necessary to increase the speed at which the ceramic powder is melted and projected onto the substrate surface, or use ceramic powder with finer particles for spraying. Traditional plasma spray guns rely on the process gas injected into the spray gun to be ionized by the arc to produce a high-energy plasma beam, which melts the ceramic powder and pushes it for projection. If more process gas is injected to increase the initial projection velocity of the ceramic powder, the energy density of the generated plasma beam will decrease, and the ceramic powder cannot be effectively melted, thus affecting the density of the coating.

[0005] When using ceramic powder with finer particles for spraying, because traditional APS uses gas to transport ceramic powder, particles that are too fine are difficult to transport in the pipeline with gas, and cannot meet the requirements of stable powder supply during the spraying process. In order to solve the problem of small-particle powder transportation, liquid plasma spraying (SPS) technology is increasingly being used. It uses volatile liquid as a carrier, which can stably transport ceramic powder with a particle size D50 of about 5 microns, so that a ceramic coating with a porosity of less than 1% can be sprayed. However, because the powder particles used are too small and have low kinetic energy, they are very easy to lose speed during the ejection process after melting, resulting in the film formation rate in the actual spraying process being much lower than that of APS spraying, which greatly reduces production efficiency and limits the application of this process on large-size components.

[0006] Therefore, it is necessary to provide a supersonic airflow enhanced plasma spraying gun head to solve the above problems. Utility Model Content

[0007] In order to overcome the above shortcomings, the purpose of the utility model is to provide a supersonic airflow enhanced plasma spray gun head, which reduces or eliminates the air resistance encountered by the molten ceramic powder during ejection, increases the kinetic energy of the particles when they reach the surface of the substrate, and ensures the spraying efficiency.

[0008] In order to achieve the above purpose, the technical solution adopted by the utility model is: a supersonic airflow enhanced plasma spray gun head, including a base and a fairing covered thereon and detachably connected thereto; a rear splitter fluid is coaxially arranged on the base, and a connected inner splitter fluid is coaxially sleeved on the outer wall of the rear splitter fluid through a threaded structure, an outer splitter fluid is sleeved on the outer wall portion of the inner splitter fluid, and a connected inner electrode is threadedly connected on the inner wall, an outer electrode is sleeved on the outer wall portion of the outer splitter fluid, an airflow channel for process gas flow is reserved between the outer wall of the inner electrode and the inner wall of the outer electrode, the outer electrode partially protrudes from the fairing, and an annular gap structure for high-pressure gas to be ejected is reserved between its outer wall and the inner wall of the fairing.

[0009] Furthermore, the base is connected to the rear fluid divider through an isolation ring, and the portion of the inner fluid divider that is close to the base and not in contact with the rear fluid divider abuts against the isolation ring. The isolation ring can insulate the base from the inner fluid divider.

[0010] It should be noted that the isolation ring can also isolate external dust, particles and foreign matter, reduce unnecessary wear of parts, and thus improve the operating efficiency of the machine. That is, while the isolation ring insulates the base from the inner divider fluid, it can also protect the rear divider fluid and the inner divider fluid, thereby avoiding wear between the above two components and the base.

[0011] Furthermore, the outer electrode is at least partially provided with a cooling ring through a threaded structure, and the base, the inner fluid distributor, the outer fluid distributor, the cooling ring and the outer electrode are sequentially connected to form two cooling water channels for circulating cooling water. The threaded structure allows the outer electrode and the cooling ring to be easily disassembled, making it convenient for users to replace parts and assemble and use.

[0012] The two cooling water channels are respectively a water inlet channel and a water outlet channel, which can cool various parts on the spray gun head after long-term use, ensuring that the parts will not be deformed due to high temperature, while also ensuring sufficient ionization of the process gas and the working efficiency of the spray gun head.

[0013] Furthermore, the base is provided with a cooling water outlet, a process gas inlet and a high-pressure gas inlet, and the process gas flows through the inner split fluid, the outer split fluid and the airflow channel formed between the inner electrode and the outer electrode in sequence through the process gas inlet and is ejected from the outer electrode nozzle. The inner electrode is connected to a negative pressure power supply, and the outer electrode is connected to a positive pressure power supply. After flowing through the airflow channel between the inner electrode and the outer electrode, the process gas can be fully ionized into high-energy plasma and ejected from the nozzle on the outer electrode.

[0014] Furthermore, a cooling water inlet hole connected to the cooling water outlet hole is provided in the middle of the rear splitter fluid along its axial direction, and the rear splitter fluid includes a water inlet end and a diversion end, the water inlet end is connected to the first water inlet through hole on the inner splitter fluid, and the diversion end is provided with a cooling water diversion hole in a direction perpendicular to the axial direction, and the cooling water diversion hole is connected to the second water inlet through hole on the inner splitter fluid. The cooling water flows into the rear splitter fluid through the cooling water outlet hole on the base, and when flowing through the diversion end on the rear splitter fluid, part of the cooling water flows into the inner electrode through the water inlet end to cool the inside of the inner electrode, and the other part flows into the second water inlet through hole.

[0015] Furthermore, an annular cavity 1 and an annular cavity 2 are respectively arranged between the diversion end and the water inlet end and the inner diversion body, the inner diversion body also includes a hollow boss, the water inlet hole 1 is located in the boss, and a water outlet is arranged inside the boss around the water inlet hole 1, the inner electrode is located between the inner wall of the boss and the outer wall of the water outlet, a plurality of water outlet holes 1 are opened on the water outlet along its height direction, and a water outlet hole 2 connected to the water outlet hole 1 is opened on the side of the inner diversion body away from the water inlet hole 2.

[0016] The above-mentioned part of the cooling water entering the inner electrode flows into the ring cavity two through the water outlet through hole one, and the ring cavity two is connected to the water outlet through hole two. Therefore, the cooling water entering the inner electrode can flow to the base through the water outlet through hole one, the ring cavity two and the water outlet through hole two in sequence, and be discharged through the cooling water outlet hole on the base.

[0017] Furthermore, the external fluid distribution includes a boss, an air inlet hole 2 connected to the air inlet hole 1, and two water inlet holes 3 and water outlet holes 3 respectively connected to the water inlet hole 2 and the water outlet hole 2. A plurality of air inlet holes connected to the air inlet hole 2 are provided on the boss, and the cooling ring includes a water inlet hole 4 and a water outlet hole 4 respectively connected to the water inlet hole 3 and the water outlet hole 3.

[0018] Furthermore, it also includes a locking bolt, which passes through the base, the inner splitter fluid and the outer splitter fluid in sequence and is connected to the cooling ring, and a sleeve is provided on the part of the locking bolt that contacts the inner splitter fluid. The sleeve is provided to insulate the base from the splitter fluid, so that the rear splitter fluid can connect the inner electrode to the negative electrode of the power supply through the inner splitter fluid, ensuring that there is no interference between the positive and negative electrodes of the power supply.

[0019] The base, the inner distributor fluid, the outer distributor fluid and the cooling ring are assembled and fixed together by setting locking bolts, which is simple to assemble and convenient for workers to assemble and use for spraying.

[0020] Furthermore, the fairing includes a gas filling portion, a convergent section, a throat and an expansion section which are integrally formed, and the convergent section, the throat and the expansion section together constitute a Laval tube structure. The Laval tube structure is configured to accelerate the high-pressure gas entering the gas filling portion from the base to a supersonic speed and then eject it along the surface of the outer electrode.

[0021] Beneficial effects of the utility model:

[0022] In the utility model, the base, the rear flow divider, the inner flow divider, the outer flow divider, the inner electrode, the outer electrode and the fairing cooperate with each other, and a limited space for accommodating high-pressure gas is formed between the base and the fairing on which the cover is arranged, and the ceramic powder flow stream after being fully heated and melted is mixed into the supersonic airflow, which effectively reduces or eliminates the air resistance encountered by the molten ceramic powder during ejection, improves the kinetic energy of the particles when reaching the surface of the substrate, and ensures the spraying efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is an isometric view of the overall structure of an embodiment of the utility model;

[0024] Figure 2 This is a schematic cross-sectional view of the overall structure of an embodiment of the utility model;

[0025] Figure 3 It is a partial structural cross-sectional schematic diagram of an embodiment of the utility model;

[0026] Figure 4 It is a partial structural isometric view of an embodiment of the utility model;

[0027] Figure 5 This is an isometric view of the overall structure of the rear splitter body according to an embodiment of the utility model;

[0028] Figure 6 This is an isometric view of the overall structure of the internal dividing fluid of an embodiment of the utility model;

[0029] Figure 7 This is an isometric view of the overall structure of the external split fluid according to an embodiment of the present utility model;

[0030] In the figure: 1. base; 101. cooling water outlet hole; 102. process gas inlet; 103. high-pressure gas inlet; 2. rear distributor; 21. cooling water inlet hole; 22. cooling water distributor hole; 23. annular cavity one; 24. annular cavity two; 3. isolation ring; 4. inner distributor; 41. water inlet hole one; 42. water inlet hole two; 43. water outlet; 44. water outlet hole one; 45. water outlet hole two; 5. outer distributor; 51. water outlet hole three; 52. water inlet hole three; 54. air inlet hole two; 55. air inlet hole; 6. inner electrode; 7. cooling ring; 71. water inlet hole four; 72. water outlet hole four; 8. outer electrode; 9. fairing; 91. gas filling part; 92. convergent section; 93. throat; 94. expansion section; 10. locking bolt. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0032] See attached Figures 1 to 7 As shown, a supersonic airflow enhanced plasma spray gun head in this embodiment includes a base 1 and a fairing 9 which is arranged on the base 1 and is detachably connected to the base 1; a rear splitter 2 is coaxially arranged on the base 1, and a connected inner splitter 4 is coaxially sleeved on the outer wall of the rear splitter 2 through a threaded structure, an outer splitter 5 is sleeved on the outer wall portion of the inner splitter 4, and a connected inner electrode 6 is threadedly connected on the inner wall, an outer electrode 8 is sleeved on the outer wall portion of the outer splitter 5, an airflow channel for process gas flow is reserved between the outer wall of the inner electrode 6 and the inner wall of the outer electrode 8, the outer electrode 8 partially protrudes from the fairing 9, and an annular gap structure for high-pressure gas to be ejected is reserved between its outer wall and the inner wall of the fairing 9.

[0033] After the cable is connected, the flow divider 2 connects the inner electrode 6 to the negative pole of the power supply through the inner flow divider 4, and the corresponding outer electrode 8 is connected to the positive pole of the power supply. The process gas is filled from the base 1, and flows through the inner flow divider 4 and the outer flow divider 5 in sequence, and then enters the air flow channel left between the outer wall of the inner electrode 6 and the inner wall of the outer electrode 8. The tip of the inner electrode 6 discharges to the outer electrode 8 and generates an arc, so that the process gas in the air flow channel is fully ionized into a high-energy plasma beam, and finally ejected from the nozzle on the outer electrode 8, and the ceramic powder is sprayed into the plasma beam to form a ceramic powder stream; the fairing 9 passes high-pressure gas, and the high-pressure gas is ejected from the above-mentioned annular seam structure, so that the formed ceramic powder stream is mixed in the high-pressure gas, and a supersonic airflow is formed when the high-pressure gas is ejected, so that the ceramic powder stream can follow the supersonic airflow to hit the surface of the substrate at high speed, and form a denser ceramic coating on the surface of the substrate, thereby ensuring the spraying effect.

[0034] It should be noted that the base 1, fairing 9, rear splitter 2, inner splitter 4, outer splitter 5, inner electrode 6 and outer electrode 8 are all coaxially arranged, and the outer electrode 8 is entirely covered outside the inner electrode 6. Specifically, the nozzle on the outer electrode 8 protrudes from the fairing 9, and the nozzle is connected to the above-mentioned airflow channel.

[0035] In order to improve the density of the sprayed ceramic coating, the traditional APS spray system needs to introduce an SPS powder supply system to replace the original powder supply system, which requires a large number of pipelines and control lines to be changed, and the control of the new powder supply system needs to be introduced into the original spray control system. However, the plasma spray gun head of the present application can directly replace the original gun head, and only the supply of high-pressure gas is required to improve the density of the ceramic coating, which greatly simplifies the transformation process.

[0036] For the spraying device that has used the SPS powder supply system, the plasma spray gun head of the present application can greatly increase the film forming rate when spraying ultra-dense coatings, increase the film forming speed, thereby effectively improving production efficiency and reducing production costs, while also making it feasible to spray ultra-dense coatings on large-sized parts.

[0037] Furthermore, the base 1 is connected to the rear splitter body 2 via an isolation ring 3, and the portion of the inner splitter body 4 that is close to the base 1 and not in contact with the rear splitter body 2 abuts against the isolation ring 3. The isolation ring 3 can insulate the base 1 from the inner splitter body 4.

[0038] It should be noted that the isolation ring 3 can also isolate external dust, particles and foreign matter, reduce unnecessary wear of parts, and thus improve the operating efficiency of the machine. That is, while the isolation ring 3 insulates the base 1 from the inner divider fluid 4, it can also protect the rear divider fluid 2 and the inner divider fluid 4, thereby avoiding wear between the above two components and the base 1.

[0039] The outer electrode 8 is at least partially provided with a cooling ring 7 through a threaded structure, and the base 1, the inner fluid divider 4, the outer fluid divider 5, the cooling ring 7 and the outer electrode 8 are sequentially connected to form two cooling water channels for circulating cooling water. The threaded structure allows the outer electrode 8 and the cooling ring 7 to be easily disassembled, making it convenient for users to replace parts and assemble and use.

[0040] The two cooling water channels are respectively a water inlet channel and a water outlet channel, which can cool various parts on the spray gun head after long-term use, ensuring that the parts will not be deformed due to high temperature, while also ensuring sufficient ionization of the process gas and the working efficiency of the spray gun head.

[0041] The base 1 is provided with a cooling water outlet 101, a process gas inlet 102 and a high-pressure gas inlet 103. The process gas flows through the inner split fluid 4, the outer split fluid 5 and the air flow channel formed between the inner electrode 6 and the outer electrode 8 in sequence through the process gas inlet 102 and is ejected from the nozzle of the outer electrode 8. The inner electrode 6 is connected to a negative voltage of the power supply, and the outer electrode 8 is connected to a positive voltage of the power supply. After flowing through the air flow channel between the inner electrode 6 and the outer electrode 8, the process gas can be fully ionized into high-energy plasma and ejected from the nozzle on the outer electrode 8.

[0042] A cooling water inlet hole 21 connected to the cooling water outlet hole 101 is provided in the middle of the rear splitter body 2 along its axial direction. The rear splitter body 2 includes a water inlet end and a diversion end. The water inlet end is connected to the first water inlet through hole 41 on the inner splitter body 4. The diversion end is provided with a cooling water diversion hole 22 along the vertical axial direction. The cooling water diversion hole 22 is connected to the second water inlet through hole 42 on the inner splitter body 4. The cooling water flows into the rear splitter body 2 through the cooling water outlet hole 101 on the base 1. When flowing through the diversion end on the rear splitter body 2, part of the cooling water flows into the inner electrode 6 through the water inlet end to cool the inner electrode 6, and the other part flows into the second water inlet through hole 42.

[0043] An annular cavity 1 23 and an annular cavity 24 are respectively arranged between the diversion end and the water inlet end and the inner diversion body 4. The inner diversion body 4 also includes a hollow boss. The water inlet through hole 1 41 is located in the boss, and a water outlet portion 43 is arranged inside the boss around the water inlet through hole 1 41. The inner electrode 6 is located between the inner wall of the boss and the outer wall of the water outlet portion 43. A plurality of water outlet through holes 1 44 are opened on the water outlet portion 43 along its height direction. A water outlet through hole 2 45 connected to the water outlet through hole 1 44 is opened on the side of the inner diversion body 4 away from the water inlet through hole 2 42.

[0044] The above-mentioned part of the cooling water entering the inner electrode 6 flows into the annular cavity 24 through the water outlet through hole 1 44, and the annular cavity 24 is connected to the water outlet through hole 2 45. Therefore, the cooling water entering the inner electrode 6 can flow to the base 1 through the water outlet through hole 1 44, the annular cavity 24 and the water outlet through hole 2 45 in sequence, and be discharged through the cooling water outlet hole 101 on the base 1.

[0045] The external flow divider 5 includes a boss, an air inlet hole 2 54 connected to the air inlet hole 1, and two water inlet holes 3 52 and water outlet holes 3 51 connected to the water inlet hole 2 42 and the water outlet hole 2 45 respectively. A plurality of air inlet holes 55 connected to the air inlet hole 2 54 are provided on the boss, and the cooling ring 7 includes a water inlet hole 4 71 and a water outlet hole 4 72 connected to the water inlet hole 3 52 and the water outlet hole 3 51 respectively.

[0046] The specific air inlet channel is as follows: the process gas enters from the process gas inlet 102 on the base 1, flows through the air inlet hole 1 on the inner divider fluid 4, and flows into the air flow channel between the inner electrode 6 and the outer electrode 8 through the air inlet hole 2 54 and the air inlet through hole 55 on the outer divider fluid 5. In the air flow channel, the tip of the inner electrode 6 discharges to the outer electrode 8 to generate an arc, and finally the ionized high-energy plasma is ejected through the nozzle on the outer electrode 8. The ceramic powder is ejected from the powder supply nozzle arranged externally, mixed into the above-mentioned ejected high-energy plasma, and is fully heated and melted to form a ceramic powder stream.

[0047] One of the two cooling water channels is a water inlet channel. The cooling water enters the rear splitter body 2 and is divided into two parts when passing through the cooling water splitter hole 22. One part flows through the water inlet hole 1 41 and then enters the inner electrode 6 to cool the inner electrode 6. While cooling, it flows into the water outlet hole 2 45 through the water outlet hole 1 44 on the inner splitter body 4. The other part flows into the water inlet hole 2 42, and then flows into the sealed chamber formed by the cooling ring 7 and the outer electrode 8 through the water inlet hole 3 52 and the water inlet hole 4 71 to cool the outer electrode 8. The other part is a water outlet channel. The cooling water for cooling the outer electrode 8 enters the water outlet hole 2 45 on the inner splitter body 4 through the water outlet hole 4 72 and the water outlet hole 3 51 in turn, and finally is discharged from the cooling water outlet hole 101 after merging with the cooling water flowing out of the water outlet hole 1 44. The discharged cooling water can circulate into the rear splitter body 2 for cooling again.

[0048] It also includes a locking bolt 10, which passes through the base 1, the inner splitter 4 and the outer splitter 5 in sequence and is connected to the cooling ring 7, and a sleeve is provided on the part of the locking bolt 10 that contacts the inner splitter 4. The sleeve is provided to insulate the base 1 from the splitter, so that the rear splitter 2 can connect the inner electrode 6 to the negative pole of the power supply through the inner splitter 4, ensuring that there is no interference between the positive and negative poles of the power supply.

[0049] The base 1, the inner flow divider 4, the outer flow divider 5 and the cooling ring 7 are assembled and fixed together by setting the locking bolts 10, which is simple to assemble and convenient for workers to assemble and use for spraying.

[0050] The fairing 9 includes a gas filling portion 91, a convergent section 92, a throat 93 and an expansion section 94 which are integrally formed, and the convergent section 92, the throat 93 and the expansion section 94 together form a Laval tube structure. The Laval tube structure can accelerate the high-pressure gas entering the gas filling portion 91 from the base 1 to a supersonic speed and then eject it along the surface of the outer electrode 8.

[0051] Working principle: The base 1 is provided with a cooling water outlet 101, a process gas inlet 102 and a high-pressure gas inlet 103, and the rear splitter 2 is provided with a cooling water inlet 21. Therefore, when using the spray gun head, a water cable is connected to the cooling water inlet 21, and the cooling water flows through the rear splitter 2 and the inner splitter 4 in sequence through the water cable and then enters the inner electrode 6, and is introduced into the negative power supply electrode in the inner electrode 6. The base 1 is connected to the cooling ring 7 through the locking bolt 10, and the outer electrode 8 is connected to the positive power supply electrode. The circulating cooling water is discharged from the cooling water outlet 101;

[0052] The process gas is introduced from the process gas inlet 102 on the base 1, and the high-pressure gas is introduced into the chamber formed by the base 1 and the fairing 9 from the four high-pressure gas inlets 103. The process gas passes through the first inlet hole on the inner flow divider 4, the second inlet hole 54 on the outer flow divider 5, and the inlet hole 55 in sequence, and then enters the gap between the outer wall of the inner electrode 6 and the inner wall of the outer electrode 8. The tip of the inner electrode 6 discharges to the outer electrode 8 to generate an arc, so that the process gas flowing through the above gap is fully ionized into high-energy plasma, and is ejected from the nozzle on the outer electrode 8;

[0053] The ceramic powder sprayed from the external supply nozzle is sprayed into the high-energy plasma beam sprayed from the outer electrode 8, and the high-energy plasma fully heats and melts it, and then mixes it into the supersonic airflow sprayed from the gap between the fairing 9 and the outer electrode 8. The fully melted ceramic powder flow hits the surface of the substrate at high speed along the supersonic airflow to form a denser ceramic coating, thereby ensuring the spraying effect.

[0054] The above implementation modes are only for illustrating the technical concept and features of the utility model, and their purpose is to allow people familiar with this technology to understand the content of the utility model and implement it. It cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A supersonic airflow enhanced plasma spray gun head, characterized in that: It includes a base and a fairing which is arranged on the base and is detachably connected to the base; a rear fluid distributor is coaxially arranged on the base, and a connected inner fluid distributor is coaxially sleeved on the outer wall of the rear fluid distributor through a threaded structure; an outer fluid distributor is sleeved on the outer wall of the inner fluid distributor, and a connected inner electrode is threadedly connected on the inner wall; an outer electrode is sleeved on the outer wall of the outer fluid distributor, and an air flow channel for process gas to flow is reserved between the outer wall of the inner electrode and the inner wall of the outer electrode; the outer electrode partially protrudes from the fairing, and an annular gap structure for high-pressure gas to be ejected is reserved between its outer wall and the inner wall of the fairing.

2. The supersonic airflow enhanced plasma spray gun head according to claim 1, characterized in that: The base is connected to the rear fluid divider via an isolation ring, and a portion of the inner fluid divider that is close to the base and not in contact with the rear fluid divider abuts against the isolation ring.

3. The supersonic airflow enhanced plasma spray gun head according to claim 1, characterized in that: The outer electrode is at least partially provided with a cooling ring through a threaded structure ring, and the base, the inner fluid distributor, the outer fluid distributor, the cooling ring and the outer electrode are sequentially connected to form two cooling water channels for circulating cooling water.

4. The supersonic airflow enhanced plasma spray gun head according to claim 3, characterized in that: The base is provided with a cooling water outlet, a process gas inlet and a high-pressure gas inlet. The process gas flows through the process gas inlet in sequence through the inner split fluid, the outer split fluid and the air flow channel formed between the inner electrode and the outer electrode and is ejected from the outer electrode nozzle.

5. The supersonic airflow enhanced plasma spray gun head according to claim 4, characterized in that: A cooling water inlet hole connected to the cooling water outlet hole is formed in the middle of the rear splitter fluid along its axial direction, and the rear splitter fluid includes an inlet end and a diversion end, the inlet end is connected to the first inlet through hole on the inner splitter fluid, and a cooling water diversion hole is formed in the diversion end along the direction perpendicular to the axial direction, and the cooling water diversion hole is connected to the second inlet through hole on the inner splitter fluid.

6. The supersonic airflow enhanced plasma spray gun head according to claim 5, characterized in that: An annular cavity 1 and an annular cavity 2 are respectively arranged between the diversion end and the water inlet end and the inner diversion body. The inner diversion body also includes a hollow boss. The water inlet hole 1 is located in the boss, and a water outlet is arranged inside the boss around the water inlet hole 1. The inner electrode is located between the inner wall of the boss and the outer wall of the water outlet. A plurality of water outlet holes 1 are arranged on the water outlet along its height direction. A water outlet hole 2 connected to the water outlet hole 1 is arranged on the side of the inner diversion body away from the water inlet hole 2.

7. The supersonic airflow enhanced plasma spray gun head according to claim 6, characterized in that: The external flow divider includes a boss, an air inlet hole 2 connected to the air inlet hole 1, and two water inlet holes 3 and 3 connected to the water inlet hole 2 and the water outlet hole 2 respectively. A plurality of air inlet holes connected to the air inlet hole 2 are provided on the boss, and the cooling ring includes a water inlet hole 4 and a water outlet hole 4 connected to the water inlet hole 3 and the water outlet hole 3 respectively.

8. The supersonic airflow enhanced plasma spray gun head according to claim 3, characterized in that: It also includes a locking bolt, which passes through the base, the inner flow divider and the outer flow divider in sequence and is connected to the cooling ring, and a sleeve is provided on the part of the locking bolt that contacts the inner flow divider.

9. The supersonic airflow enhanced plasma spray gun head according to claim 1, characterized in that: The fairing includes a gas filling portion, a convergent section, a throat and an expansion section which are integrally formed, and the convergent section, the throat and the expansion section together constitute a Laval tube structure.

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