A yttrium-based coating

Abstract

The present invention provides a yttrium-based coating, and the yttrium-based coating includes an atmospheric plasma spraying bottom layer; the atmospheric plasma spraying coating is obtained by spraying spherical yttrium-based materials onto the surface of a substrate by means of atmospheric plasma spraying; the preparation method of the spherical yttrium-based materials includes: (1) mixing yttrium-based composite powder, a solvent, a binder and a dispersant to obtain a yttrium-based composite slurry; (2) granulating the yttrium-based composite slurry to obtain yttrium-based composite particles; (3) sintering the yttrium-based composite particles to obtain yttrium-based agglomerated particles; (4) spheroidizing the yttrium-based agglomerated particles in step (3) to obtain the spherical yttrium-based materials. By optimizing the spraying raw materials of the yttrium-based coating, the present invention uses spherical yttrium-based materials with a smooth surface morphology, good fluidity and a concentrated powder particle size distribution as raw materials, so that the yttrium-based coating has high density, hardness and uniformity.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor device fabrication, specifically relates to the preparation of semiconductor device coatings, and particularly relates to a yttrium-based coating. Background Art

[0002] In semiconductor manufacturing processes, in order to perform high-integration microfabrication on substrate circuits such as silicon wafers, the plasma dry etching process has become increasingly important. It is necessary to use materials with excellent plasma resistance as chamber components, or to form a coating film on the surface of the components with a substance having excellent plasma resistance to extend the life of the components. Therefore, semiconductor etching equipment components must use ceramic materials with high hardness, high wear resistance, high dielectric strength, high corrosion resistance, and good chemical stability to cover the inner wall of the chamber. This coating is particularly important for exhibiting corrosion resistance to a wide variety of halogen-containing plasmas.

[0003] CN107946163A discloses a chamber component for a plasma processing chamber device. The chamber component includes a main body having an outer layer containing yttrium oxide, and a coating formed on the main body, wherein the coating contains a yttrium fluoride-containing material, and discloses a method for manufacturing a chamber component used in a plasma processing environment, including: immersing the main body of the chamber component having an outer layer formed of yttrium oxide in a wet coating solution containing at least one ammonium salt and HF; reacting fluoride ions from the wet coating solution with yttrium oxide from the chamber component; and forming a coating containing a fluorinated yttrium oxide material.

[0004] CN113913783A discloses a deposited coating containing both yttrium fluoride oxide and a metal oxide. The coating can be prepared by the following method: using atomic layer deposition technology to place a non-fluorinated yttrium oxide precursor coating on a surface, and subsequently followed by a step of fluorinating the precursor through a fluorine annealing step to produce yttrium fluoride oxide. The precursor coating contains yttrium oxide and a metal oxide. The fluorine annealing step converts a substantial portion of the yttrium oxide into yttrium fluoride oxide, yttrium oxyfluoride, or a combination of these to form a resulting coating containing a combination of a metal oxide (which is non-fluorinated) and yttrium fluoride oxide.

[0005] CN116695048A discloses a yttrium-based spray coating and a manufacturing method thereof. By thermally spraying yttrium oxide, yttrium fluoride, or yttrium oxyfluoride onto a substrate to form a coating with a thickness of 10 - 500 μm, and chemically cleaning the coating with a cleaning solution of organic acid, inorganic acid, or a mixture thereof until the number of particles with a size of less than 300 nm on the surface of the coating becomes no more than 5 particles / mm 2, thus obtaining a yttrium-based sprayed coating. The yttrium-based sprayed coating exhibits high corrosion resistance even in a halogen gas plasma atmosphere and prevents the exfoliation of yttrium-based particles during the etching process.

[0006] Based on the strict requirements for the corrosion resistance of yttrium-based coatings against a wide variety of halogen-containing plasmas, it is particularly important to develop a yttrium-based material that can form a yttrium-based coating with high density, hardness, and uniformity. Summary of the Invention

[0007] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a yttrium-based coating. The present invention optimizes the spraying raw materials of the yttrium-based coating. First, granulation is performed on a submicron-sized ultra-fine yttrium-based composite powder composed of submicron-sized yttrium oxyfluoride and submicron-sized yttrium fluoride. Then, spheroidization and densification treatment are performed on the obtained yttrium-based agglomerated particles. The prepared spherical yttrium-based material has a smooth spherical morphology on the surface, good fluidity, and a concentrated powder particle size distribution. The yttrium-based coating using this as the raw material has high density, hardness, and uniformity.

[0008] To achieve the purpose of this invention, the present invention adopts the following technical solutions:

[0009] In the first aspect, the present invention provides a yttrium-based coating. The yttrium-based coating includes an atmospheric plasma spraying bottom layer. The atmospheric plasma spraying coating is obtained by spraying the spherical yttrium-based material onto the surface of a substrate through the method of atmospheric plasma spraying. In the spherical yttrium-based material, the mass percentage of fluorine element is 15%-20%, and the D50 particle size of the spherical yttrium-based material is 10μm - 50μm. The spherical yttrium-based material is prepared by the following preparation method. The preparation method includes: (1) mixing a yttrium-based composite powder, a solvent, a binder, and a dispersant to obtain a yttrium-based composite slurry. The yttrium-based composite powder includes submicron-sized yttrium oxyfluoride and submicron-sized yttrium fluoride. (2) Granulating the yttrium-based composite slurry in step (1) to obtain yttrium-based composite particles. (3) Sintering the yttrium-based composite particles in step (2) to obtain yttrium-based agglomerated particles. (4) Spheroidizing the yttrium-based agglomerated particles in step (3) to obtain the spherical yttrium-based material. In the yttrium-based composite powder in step (1), the D50 particle size of submicron-sized yttrium oxyfluoride and submicron-sized yttrium fluoride is independently 0.1μm - 1μm. The spheroidizing treatment method in step (4) includes plasma spheroidizing treatment. The process of the plasma spheroidizing treatment includes: adding the yttrium-based agglomerated particles in step (3) into a plasma jet to be melted to obtain yttrium-based droplets, and spraying the yttrium-based droplets into a cooling medium to obtain the spherical yttrium-based material.

[0010] In the present invention, the spraying raw materials of the yttrium-based coating are optimized. Using spherical yttrium-based materials with a smooth surface, good fluidity, and a concentrated powder particle size distribution as raw materials, the yttrium-based coating has high density, hardness, and uniformity, and at the same time has high electrical insulation and corrosion resistance. Moreover, the dense coating reduces the generation and transfer of fine particles, which is beneficial to resisting the etching of plasma exposure.

[0011] In the present invention, the chemical formula of the spherical yttrium-based material can be expressed as Y a O b F c , where a≥b and c≥b; in the spherical yttrium-based material, the mass percentage of fluorine element is 15%-20%, for example, it can be 15%, 16%, 17%, 18%, 19% or 20%, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable; the D50 particle size of the spherical yttrium-based material is 10μm - 50μm, for example, it can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0012] The present invention selects submicron yttrium oxyfluoride and submicron yttrium fluoride to prepare spherical yttrium-based materials. The submicron particle size can effectively improve the density of the prepared yttrium-based coating. The addition of yttrium fluoride is beneficial to reducing the combination of YO groups and F groups in an F atmosphere, enabling the prepared coating particles to be more closely and firmly bonded, not easily transferred, and reducing the possibility of degradation. Therefore, the addition of yttrium fluoride is beneficial to improving the mechanical properties and strength of the prepared yttrium-based coating, and the coating exhibits excellent plasma resistance. The submicron ultra-fine yttrium-based composite powder is agglomerated to a suitable size to ensure that the spherical yttrium-based material can be normally transported during the coating processing and can be fully accelerated during flight in the plasma jet. The spheroidization and densification treatments avoid the situation during the coating processing that due to the too large specific surface area of the spherical yttrium-based material, heat cannot be evenly transferred to the internal primary powder, resulting in the inability of the internal primary powder to melt while the surface primary powder remelts, and further leading to a loose coating structure.

[0013] In the present invention, through the plasma spheroidization treatment of yttrium-based agglomerated particles, the prepared spherical yttrium-based material has a smooth spherical morphology, good fluidity, and a concentrated powder particle size distribution, which is beneficial to forming a yttrium-based coating with high density, hardness, and uniformity during the spraying process.

[0014] In the yttrium-based composite powder described in step (1), the D50 particle size of sub-micron yttrium oxyfluoride is 0.1 μm - 1 μm. For example, it can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm, including but not limited to the listed values. Other unlisted values within the numerical range are equally applicable. Preferably, it is 0.3 μm - 0.7 μm.

[0015] In the yttrium-based composite powder described in step (1), the D50 particle size of sub-micron yttrium fluoride is 0.1 μm - 1 μm. For example, it can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm, including but not limited to the listed values. Other unlisted values within the numerical range are equally applicable. Preferably, it is 0.3 μm - 0.7 μm.

[0016] Preferably, in the method for preparing the spherical yttrium-based material, in the yttrium-based composite slurry described in step (1), by weight, it includes:

[0017] 100 parts of yttrium-based composite powder;

[0018] 3 parts - 10 parts of solvent;

[0019] 100 parts - 200 parts of binder;

[0020] 3 parts - 11 parts of dispersant.

[0021] In the yttrium-based composite slurry described in step (1) of the present invention, by weight, it includes 3 parts - 10 parts of solvent. For example, it can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts, 100 parts - 200 parts of binder. For example, it can be 100 parts, 110 parts, 120 parts, 130 parts, 140 parts, 150 parts, 160 parts, 170 parts, 180 parts, 190 parts or 200 parts, 3 parts - 11 parts of dispersant. For example, it can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts or 11 parts. The contents of the above components in the yttrium-based composite slurry of the present invention include but are not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0022] Preferably, in the method for preparing the spherical yttrium-based material, in the yttrium-based composite powder described in step (1), the mass percentage of sub-micron yttrium oxyfluoride is 80% - 90%. For example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89% or 90%, including but not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0023] Preferably, in the method for preparing the spherical yttrium-based material, in the yttrium-based composite powder in step (1), the mass percentage of submicron yttrium fluoride is 10%-20%, for example, it can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0024] Preferably, in the method for preparing the spherical yttrium-based material, in the yttrium-based composite slurry in step (1), the binder includes any one or a combination of at least two of polyvinyl alcohol, polyvinylpyrrolidone, methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxypropylcellulose, starch or phenolic resin. Typical but non-limiting combinations include polyvinyl alcohol and polyvinylpyrrolidone, methylcellulose and ethylcellulose, sodium carboxymethylcellulose and hydroxypropylcellulose, hydroxypropylcellulose and starch, or starch and phenolic resin.

[0025] Preferably, in the method for preparing the spherical yttrium-based material, in the yttrium-based composite slurry in step (1), the dispersant includes any one or a combination of at least two of sodium stearate, fatty alcohol polyoxyethylene ether, sodium polyacrylate, polyacrylamide, polyethylene glycol or ethanol. Typical but non-limiting combinations include the combination of sodium stearate and fatty alcohol polyoxyethylene ether, the combination of sodium polyacrylate and polyacrylamide, or the combination of polyethylene glycol and ethanol.

[0026] Preferably, in the method for preparing the spherical yttrium-based material, in the yttrium-based composite slurry in step (1), the solvent includes deionized water.

[0027] Preferably, in the method for preparing the spherical yttrium-based material, in step (1), the preparation method of the yttrium-based composite powder includes mechanical mixing.

[0028] In the present invention, the yttrium-based composite powder is prepared by conventional mechanical mixing, such as mechanical stirring or ball milling, which will not be specifically limited.

[0029] Preferably, in the method for preparing the spherical yttrium-based material, in step (1), the preparation method of the yttrium-based composite slurry includes high-energy ball milling.

[0030] In the present invention, a yttrium-based composite slurry is prepared by high-energy ball milling. The ball milling medium is yttrium oxide ceramic balls with a diameter of Φ = 8 mm, the ball-to-material ratio is 2:(3 - 8), for example, it can be 2:3, 2:4, 2:5, 2:6, 2:7 or 2:8, the ball milling time is 6 h - 12 h, for example, it can be 6 h, 7 h, 8 h, 9 h, 10 h, 11 h or 12 h, and the ball milling speed is 200 rpm - 600 rpm, for example, it can be 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, 550 rpm or 600 rpm. The process parameters of the above high-energy ball milling include but are not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0031] Preferably, in the method for preparing the spherical yttrium-based material, the granulation method in step (2) includes spray drying.

[0032] In the present invention, the yttrium-based composite slurry is granulated by spray drying. The feeding speed of spray drying granulation is 80 mL / min - 160 mL / min, for example, it can be 80 mL / min, 90 mL / min, 100 mL / min, 110 mL / min, 120 mL / min, 130 mL / min, 140 mL / min, 150 mL / min or 160 mL / min, the inlet air temperature is 160 °C - 300 °C, for example, it can be 160 °C, 170 °C, 180 °C, 190 °C, 200 °C, 210 °C, 220 °C, 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, 280 °C, 290 °C or 300 °C, and the outlet air temperature is 120 °C - 180 °C, for example, it can be 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C or 180 °C. The process parameters of the above spray drying include but are not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0033] Preferably, in the method for preparing the spherical yttrium-based material, after the granulation in step (2), it further includes screening the yttrium-based composite particles to D 50 The particle size is 10 μm - 50 μm, for example, it can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0034] Preferably, in the preparation method of the spherical yttrium-based material, the sintering temperature in step (3) is 800°C - 1200°C. For example, it can be 800°C, 820°C, 840°C, 860°C, 880°C, 900°C, 920°C, 940°C, 960°C, 980°C, 1000°C, 1020°C, 1040°C, 1050°C, 1080°C, 1090°C, 1100°C, 1120°C, 1140°C, 1160°C, 1180°C or 1200°C, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0035] Preferably, in the preparation method of the spherical yttrium-based material, the sintering in step (3) is carried out in a vacuum environment, and the vacuum degree of the vacuum environment is 10 -2 -10 -3 Pa. For example, it can be 10 -3 Pa, 20 -3 Pa, 30 -3 Pa, 40 -3 Pa, 50 -3 Pa, 60 -3 Pa, 70 -3 Pa, 80 -3 Pa, 90 -3 Pa or 10 -2 Pa, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0036] Preferably, in the preparation method of the spherical yttrium-based material, the sintering time in step (3) is 0.2h - 2h. For example, it can be 0.2h, 0.3h, 0.4h, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0037] Preferably, in the preparation method of the spherical yttrium-based material, after the sintering in step (3), it further includes screening the yttrium-based agglomerated particles to a D 50 particle size of 10μm - 50μm. For example, it can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0038] Preferably, in the preparation method of the spherical yttrium-based material, after the spheroidization treatment in step (4), it further includes screening the spherical yttrium-based material to a D 50The particle size is 10 μm - 50 μm, and for example, it can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0039] In the preparation method of the spherical yttrium-based material of the present invention, the yttrium-based agglomerated particles described in step (3) are injected into the plasma jet generated by an AxialⅢ high-power plasma spray gun in an external powder feeding manner for melting. The powder feeding amount is 80 g / min - 160 g / min, and for example, it can be 80 g / min, 90 g / min, 100 g / min, 110 g / min, 120 g / min, 130 g / min, 140 g / min, 150 g / min or 160 g / min. The molten droplets are sprayed into the cooling medium until the powder is cooled to room temperature, and the spherical yttrium-based material is prepared.

[0040] Preferably, in the preparation method of the spherical yttrium-based material, during the plasma spheroidization process, the distance between the emission position of the plasma jet and the cooling medium is 500 mm - 800 mm. For example, it can be 500 mm, 520 mm, 540 mm, 560 mm, 580 mm, 600 mm, 610 mm, 620 mm, 630 mm, 640 mm, 650 mm, 660 mm, 670 mm, 680 mm, 690 mm, 700 mm, 720 mm, 740 mm, 760 mm, 780 mm or 800 mm, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable, and preferably it is 600 mm to 700 mm.

[0041] The distance between the emission position of the plasma jet and the cooling medium in the present invention refers to the distance from the ejection outlet of the plasma spray gun to the surface of the refrigerant, and the distance is set to 500 mm to 800 mm, so as to spray the molten YOF-based droplets onto the refrigerant without loss, to improve the yield and make it have a rapid cooling effect. When the distance is too small, the loss of the solvent and powder caused by the spraying pressure increases. When the distance is too large, due to the influence of the spraying angle, the yield on the surface of the refrigerant decreases, and it is difficult to achieve a sufficient rapid cooling effect.

[0042] Preferably, in the preparation method of the spherical yttrium-based material, during the plasma spheroidization process, the emission power of the plasma jet is 60 kW - 80 kW. For example, it can be 60 kW, 62 kW, 64 kW, 66 kW, 68 kW, 70 kW, 72 kW, 74 kW, 76 kW, 78 kW or 80 kW, including but not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0043] Preferably, in the method for preparing the spherical yttrium-based material, during the plasma spheroidization treatment, the cooling medium includes nitrogen and / or argon.

[0044] In the present invention, the cooling medium can be nitrogen and / or argon. When the cooling medium is selected as nitrogen, argon can simultaneously serve as the protective atmosphere gas for the powder.

[0045] In the present invention, a yttrium-based coating is prepared by an atmospheric plasma spraying method. During the spraying process, part of Y-F will decompose at high temperatures, and Y combines with O to form YOF, thereby preparing a yttrium-based coating with excellent plasma resistance. The preparation steps specifically include:

[0046] (a) Cleaning the substrate with alcohol, drying it, and then performing surface sandblasting roughening and activation treatment; (b) Spraying the spherical yttrium-based material on the surface of the substrate treated in step (a) by atmospheric plasma spraying (APS) to obtain a yttrium-based coating.

[0047] The drying temperature in step (a) is 60°C - 100°C, for example, it can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C. The sandblasting pressure in step (a) is 0.1MPa - 0.4MPa, for example, it can be 0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa or 0.4MPa. The sandblasting distance in step (a) is 30mm - 150mm, for example, it can be 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm or 150mm. The sandblasting angle in step (a) is 70° - 90°, for example, it can be 70°, 75°, 80°, 85° or 90°. The sandblasting material in step (a) uses 120# alumina white fused alumina grit. Among the process parameters for pre-treating the substrate in the above step (a), it includes but is not limited to the listed values, and other unlisted values within the value range are equally applicable.

[0048] The current of the plasma spraying described in step (b) is 300A - 500A, for example, it can be 300A, 350A, 400A, 450A or 500A. The voltage of the plasma spraying described in step (b) is 40V - 65V, for example, it can be 40V, 45V, 50V, 55V, 60V or 65V. The flow rate of the auxiliary gas for the plasma spraying described in step (b) is 1L / min - 10L / min, for example, it can be 1L / min, 2L / min, 3L / min, 4L / min, 5L / min, 6L / min, 7L / min, 8L / min, 9L / min or 10L / min. The scanning speed of the plasma spraying described in step (b) is 150m / min. The energy of the plasma flame is adjusted by adjusting the current and the auxiliary gas. The powder feeding rate is 20L / min - 100g / min, for example, it can be 20L / min, 30L / min, 40L / min, 50L / min, 60L / min, 70L / min, 80L / min, 90L / min or 100L / min. The flow rate of the powder feeding carrier gas for the plasma spraying described in step (b) is 2.0L / min - 12.0L / min, for example, it can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11L / min or 12L / min. The main gas flow rate of the plasma spraying described in step (b) is 25L / min - 70L / min, for example, it can be 20L / min, 30L / min, 35L / min, 40L / min, 45L / min, 50L / min, 55L / min, 60L / min, 65L / min or 70L / min. The spraying distance of the plasma spraying described in step (b) is 100mm - 200mm, for example, it can be 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm or 200mm. The spraying angle of the plasma spraying described in step (b) is 80° - 90°, for example, it can be 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°, 88°, 89° or 90°. During the spraying process of the plasma spraying described in step (b), the temperature of the substrate surface is 50°C - 120°C, for example, it can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C. Among the above process parameters, it includes but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0049] By regulating the current and voltage of the plasma spraying in step (b), the power of the plasma spraying is adjusted. During the spraying process, Y-F will decompose at high temperature, and Y will combine with O, further regulating the composition ratio of the spherical yttrium-based material to improve the density, hardness, and plasma resistance of the prepared coating. However, if the power of the plasma spraying is too high, the powder particles will be excessively melted into molten droplet particles, splash and impact on the surface of the substrate, and quickly deposit and cool and shrink to form a stressed structure, resulting in the generation of shrinkage cracks.

[0050] Preferably, the yttrium-based coating further includes a suspension plasma spraying coating; the suspension plasma spraying coating is sprayed with the yttrium-based composite powder described in step (1) onto the surface of the air plasma spraying coating by the method of suspension plasma spraying.

[0051] The present invention selects an air plasma spraying coating with low preparation cost as the bottom layer and a suspension plasma spraying coating with higher density as the top layer, and uses a submicron ultra-fine yttrium-based composite powder including submicron yttrium oxyfluoride and submicron yttrium fluoride as the raw material for suspension plasma spraying. While reducing the cost, the performance of the yttrium-based coating is significantly improved, making its denseness better, the corrosion resistance to plasma etching gas more excellent, and further improving the service life.

[0052] The specific process parameters of the suspension plasma spraying in the present invention are well-known in the art and will not be particularly limited. Exemplarily, the method for preparing the suspension slurry for suspension plasma spraying in the present invention includes mixing the yttrium-based composite powder with deionized water, anhydrous ethanol, a dispersant polyvinylpyrrolidone, and ammonium citrate. The mass fraction of the solid powder accounts for 10%-40% of the total mass of the slurry, for example, it can be 10%, 15%, 20%, 25%, 30%, 35%, or 40%. The dispersant polyvinylpyrrolidone is 1%-1.5%, stabilizing the suspension by steric hindrance. The volume ratio of water to ethanol is 1:1, and ammonium citrate is 0.25%-0.5%.

[0053] The present invention uses an AxialⅢ spray gun for suspension plasma spraying. The process parameters of the suspension plasma spraying include:

[0054] The flow rate of the main gas Ar for suspension plasma spraying is 40 L / min - 75 L / min, for example, it can be 40 L / min, 45 L / min, 50 L / min, 55 L / min, 60 L / min, 65 L / min, 70 L / min or 75 L / min; the flow rate of the auxiliary gas H2 for suspension plasma spraying is 6 L / min - 20 L / min, for example, it can be 6 L / min, 8 L / min, 10 L / min, 12 L / min, 14 L / min, 16 L / min, 18 L / min or 20 L / min; the voltage for suspension plasma spraying is 65 V - 80 V, for example, it can be 65 V, 67 V, 69 V, 70 V, 72 V, 74 V, 76 V, 78 V or 80 V; the current for suspension plasma spraying is 400 A - 550 A, for example, it can be 400 A, 420 A, 440 A, 460 A, 480 A, 500 A, 510 A, 520 A, 530 A, 540 A or 550 A; the slurry amount for suspension plasma spraying is 25 mL / min - 65 mL / min, for example, it can be 25 mL / min, 30 mL / min, 35 mL / min, 40 mL / min, 45 mL / min, 50 mL / min, 55 mL / min, 60 mL / min or 65 mL / min, the spraying distance for suspension plasma spraying is 60 mm - 150 mm, for example, it can be 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm or 150 mm, and during the suspension plasma spraying process, it also includes cooling from the back of the substrate using nitrogen or compressed air, and the pressure of the cooling gas is 0.3 MPa - 0.5 MPa, for example, it can be 0.3 MPa, 0.32 MPa, 0.34 MPa, 0.36 MPa, 0.38 MPa, 0.4 MPa, 0.42 MPa, 0.44 MPa, 0.46 MPa, 0.48 MPa or 0.5 MPa, to ensure that the surface temperature of the coating and the substrate is lower than 150 °C. Among the above process parameters, it includes but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] (1) The yttrium-based coating provided by the present invention has high density, hardness and uniformity, and at the same time has high electrical insulation and corrosion resistance, and the dense coating reduces the generation and transfer of fine particles, which is beneficial to resisting the etching of plasma exposure;

[0057] (2) By optimizing the spraying raw materials of the yttrium-based coating, the present invention uses spherical yttrium-based materials with a smooth surface, good fluidity, moderate particle size, and concentrated powder particle size distribution as raw materials, ensuring that the spherical yttrium-based materials can be normally transported during the coating processing, and can be fully accelerated during flight in the plasma jet, avoiding the situation during the coating processing where the specific surface area of the spherical yttrium-based materials is too large, resulting in uneven heat transfer to the internal primary powder, making the internal primary powder unable to melt while the surface primary powder remelts, thereby leading to a loose coating structure;

[0058] (3) The present invention selects submicron yttrium oxyfluoride and submicron yttrium fluoride as raw materials for preparing spherical yttrium-based materials. The submicron particle size can effectively improve the density of the prepared yttrium-based coating. The addition of yttrium fluoride is beneficial to reducing the combination of YO groups with F groups in an F atmosphere, enabling the prepared coating particles to be more closely and firmly bonded, less likely to transfer, and reducing the possibility of degradation. Therefore, the addition of yttrium fluoride is beneficial to improving the mechanical properties and strength of the prepared yttrium-based coating, and the coating exhibits excellent plasma resistance. Description of the Drawings

[0059] Figure 1 is the SEM image of the yttrium-based agglomerated particles without spheroidization treatment in Preparation Example 1.

[0060] Figure 2 is the SEM image of the spherical yttrium-based materials after spheroidization treatment in Preparation Example 1.

[0061] Figure 3 is the SEM image of the surface of the yttrium-based coating prepared in Example 1.

[0062] Figure 4 is the SEM image of the cross-section of the yttrium-based coating prepared in Example 1.

[0063] Figure 5 is the SEM image of the surface of the yttrium-based coating prepared in Example 16. Detailed Embodiments

[0064] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0065] Preparation Example 1:

[0066] This preparation example provides a method for preparing spherical yttrium-based materials, and the preparation method is as follows:

[0067] (1) By mass, 100 parts of yttrium-based composite powder, 7 parts of water, 150 parts of polyvinyl alcohol, and 8 parts of ethanol are mixed. 100 parts of yttrium oxide ceramic balls with a diameter of Φ = 8 mm are added, and high-energy ball milling is carried out for 8 h at a ball milling speed of 400 rpm to obtain a yttrium-based composite slurry. In the yttrium-based composite powder, the mass percentage of yttrium oxyfluoride is 85%, the D50 particle size is 0.45 μm, the mass percentage of yttrium fluoride is 15%, and the D50 particle size is 0.55 μm;

[0068] (2) The yttrium-based composite slurry prepared in step (1) is granulated by spray drying. The feeding speed of spray drying granulation is 120 mL / min, the inlet air temperature is 200 °C, and the outlet air temperature is 150 °C to obtain yttrium-based composite particles. The prepared yttrium-based composite particles are sieved to a D50 particle size of 37 μm;

[0069] (3) The yttrium-based composite particles obtained in step (2) are sintered at 1050 °C for 0.65 h to obtain yttrium-based agglomerated particles. The prepared yttrium-based agglomerated particles are sieved to a D50 particle size of 37 μm;

[0070] (4) By means of external powder feeding, the yttrium-based agglomerated particles obtained in step (3) are injected into the plasma jet generated by an AxialⅢ high-power plasma spray gun for melting. The powder feeding rate is 120 g / min, and the molten droplets are sprayed into the cooling medium until the powder cools to room temperature to prepare spherical yttrium-based materials. Among them, the distance between the emission position of the plasma jet and the cooling medium is 650 mm, the emission power of the plasma jet is 70 kW, and the cooling medium is nitrogen. The prepared spherical yttrium-based materials are sieved to a D50 particle size of 37 μm.

[0071] The spherical yttrium-based materials prepared in this preparation example have a D50 particle size of 37 μm and a mass percentage of fluorine element of 17.5%.

[0072] The SEM image of the yttrium-based agglomerated particles prepared in step (3) of this preparation example is as Figure 1 shown, and the SEM image of the spherical yttrium-based materials after spheroidization treatment in step (4) is as Figure 2 shown.

[0073] Preparation Example 2:

[0074] This preparation example provides a preparation method of spherical yttrium-based materials, and the preparation method is as follows:

[0075] (1) By mass parts, 100 parts of yttrium-based composite powder, 3 parts of water, 100 parts of polyvinyl alcohol and 3 parts of ethanol are mixed. 80 parts of yttrium oxide ceramic balls with Φ = 8 mm are added, and high-energy ball milling is carried out. The ball milling time is 10 h and the ball milling speed is 500 rpm to obtain a yttrium-based composite slurry; in the yttrium-based composite powder, the mass percentage of yttrium oxyfluoride is 80%, the D50 particle size is 0.3 μm, the mass percentage of yttrium fluoride is 20%, and the D50 particle size is 0.7 μm;

[0076] (2) The yttrium-based composite slurry prepared in step (1) is granulated by spray drying. The feeding speed of spray drying granulation is 80 mL / min, the inlet air temperature is 280 °C, and the outlet air temperature is 160 °C to obtain yttrium-based composite particles; the prepared yttrium-based composite particles are screened to a D50 particle size of 11 μm;

[0077] (3) The yttrium-based composite particles obtained in step (2) are sintered at 800 °C for 2 h to obtain yttrium-based agglomerated particles; the prepared yttrium-based agglomerated particles are screened to a D50 particle size of 11 μm;

[0078] (4) By using the external powder feeding method, the yttrium-based agglomerated particles obtained in step (3) are injected into the plasma jet generated by an AxialⅢ high-power plasma spray gun for melting. The powder feeding amount is 90 g / min, and the molten droplets are sprayed into the cooling medium until the powder is cooled to room temperature to prepare spherical yttrium-based materials. Among them, the distance between the emission position of the plasma jet and the cooling medium is 600 mm, the emission power of the plasma jet is 60 kW, and the cooling medium is nitrogen. The prepared spherical yttrium-based materials are screened to a D50 particle size of 11 μm.

[0079] The spherical yttrium-based material prepared in this preparation example has a D50 particle size of 11 μm and a mass percentage of fluorine element of 20%.

[0080] Preparation Example 3:

[0081] This preparation example provides a method for preparing a spherical yttrium-based material, and the preparation method is as follows:

[0082] (1) By mass parts, 100 parts of yttrium-based composite powder, 10 parts of water, 200 parts of polyvinyl alcohol and 11 parts of ethanol are mixed. 110 parts of yttrium oxide ceramic balls with Φ = 8 mm are added, and high-energy ball milling is carried out. The ball milling time is 6 h and the ball milling speed is 600 rpm to obtain a yttrium-based composite slurry; in the yttrium-based composite powder, the mass percentage of yttrium oxyfluoride is 90%, the D50 particle size is 0.7 μm, the mass percentage of yttrium fluoride is 10%, and the D50 particle size is 0.3 μm;

[0083] (2) Granulate the yttrium-based composite slurry prepared in step (1) by spray drying. The feeding speed for spray drying granulation is 160 mL / min, the inlet air temperature is 300 °C, and the outlet air temperature is 180 °C to obtain yttrium-based composite particles. Screen the prepared yttrium-based composite particles to a D50 particle size of 49 μm;

[0084] (3) Sinter the yttrium-based composite particles obtained in step (2) at 1200 °C for 0.2 h to obtain yttrium-based agglomerated particles. Screen the prepared yttrium-based agglomerated particles to a D50 particle size of 49 μm;

[0085] (4) Using the external powder feeding method, inject the yttrium-based agglomerated particles obtained in step (3) into the plasma jet generated by an AxialⅢ high-power plasma spray gun for melting. The powder feeding rate is 150 g / min, and the molten droplets are sprayed into the cooling medium until the powder cools to room temperature to prepare spherical yttrium-based materials. Among them, the distance between the emission position of the plasma jet and the cooling medium is 700 mm, the emission power of the plasma jet is 79 kW, and the cooling medium is nitrogen. Screen the prepared spherical yttrium-based materials to a D50 particle size of 49 μm.

[0086] The spherical yttrium-based material prepared in this preparation example has a D50 particle size of 49 μm and a mass percentage of fluorine element of 15%.

[0087] Preparation Example 4:

[0088] This preparation example provides a method for preparing spherical yttrium-based materials, and the preparation method is as follows:

[0089] (1) By mass, mix 100 parts of yttrium-based composite powder, 7 parts of water, 150 parts of polyvinylpyrrolidone, and 8 parts of ethanol, add 100 parts of yttrium oxide ceramic balls with Φ = 8 mm, and perform high-energy ball milling for 8 h at a ball milling speed of 400 rpm to obtain a yttrium-based composite slurry. In the yttrium-based composite powder, the mass percentage of yttrium oxyfluoride is 85%, the D50 particle size is 0.1 μm, the mass percentage of yttrium fluoride is 15%, and the D50 particle size is 0.1 μm;

[0090] (2) Granulate the yttrium-based composite slurry prepared in step (1) by spray drying. The feeding speed for spray drying granulation is 120 mL / min, the inlet air temperature is 200 °C, and the outlet air temperature is 150 °C to obtain yttrium-based composite particles. Screen the prepared yttrium-based composite particles to a D50 particle size of 37 μm;

[0091] (3) Sinter the yttrium-based composite particles obtained in step (2) at 1050 °C for 0.65 h to obtain yttrium-based agglomerated particles. Screen the prepared yttrium-based agglomerated particles to a D50 particle size of 37 μm;

[0092] (4) By adopting the external powder feeding method, the yttrium-based agglomerated particles obtained in step (3) are injected into the plasma jet generated by an AxialⅢ high-power plasma spray gun for melting. The powder feeding rate is 120 g / min, and the molten droplets are sprayed into the cooling medium until the powder is cooled to room temperature to prepare spherical yttrium-based materials. Among them, the distance between the emission position of the plasma jet and the cooling medium is 500 mm, the emission power of the plasma jet is 70 kW, and the cooling medium is nitrogen. The prepared spherical yttrium-based materials are sieved to a D50 particle size of 37 μm.

[0093] The D50 particle size of the spherical yttrium-based materials prepared in this preparation example is 37 μm, and the mass percentage of fluorine element is 16%.

[0094] Preparation Example 5:

[0095] This preparation example provides a method for preparing spherical yttrium-based materials, and the preparation method is as follows:

[0096] (1) By mass, 100 parts of yttrium-based composite powder, 7 parts of water, 150 parts of starch, and 8 parts of ethanol are mixed, and 100 parts of yttrium oxide ceramic balls with Φ = 8 mm are added, and high-energy ball milling is carried out. The ball milling time is 8 h, and the ball milling speed is 400 rpm to obtain yttrium-based composite slurry; in the yttrium-based composite powder, the mass percentage of yttrium oxyfluoride is 85%, the D50 particle size is 1 μm, the mass percentage of yttrium fluoride is 15%, and the D50 particle size is 1 μm;

[0097] (2) The yttrium-based composite slurry prepared in step (1) is granulated by spray drying. The feeding speed of spray drying granulation is 120 mL / min, the inlet air temperature is 200 °C, and the outlet air temperature is 150 °C to obtain yttrium-based composite particles; the prepared yttrium-based composite particles are sieved to a D50 particle size of 37 μm;

[0098] (3) The yttrium-based composite particles obtained in step (2) are sintered at 1050 °C for 0.65 h to obtain yttrium-based agglomerated particles; the prepared yttrium-based agglomerated particles are sieved to a D50 particle size of 37 μm;

[0099] (4) By adopting the external powder feeding method, the yttrium-based agglomerated particles obtained in step (3) are injected into the plasma jet generated by an AxialⅢ high-power plasma spray gun for melting. The powder feeding rate is 120 g / min, and the molten droplets are sprayed into the cooling medium until the powder is cooled to room temperature to prepare spherical yttrium-based materials. Among them, the distance between the emission position of the plasma jet and the cooling medium is 800 mm, the emission power of the plasma jet is 70 kW, and the cooling medium is nitrogen. The prepared spherical yttrium-based materials are sieved to a D50 particle size of 37 μm.

[0100] The D50 particle size of the spherical yttrium-based material obtained in this preparation example is 37 μm, and the mass percentage of fluorine element is 19%.

[0101] Preparation Example 6:

[0102] This preparation example provides a method for preparing a spherical yttrium-based material. Except that the D50 particle size of yttrium fluoride is 1.5 μm, the rest are the same as those in Preparation Example 1.

[0103] Preparation Example 7:

[0104] This preparation example provides a method for preparing a spherical yttrium-based material. Except that the D50 particle size of yttrium oxyfluoride is 1.5 μm, the rest are the same as those in Preparation Example 1.

[0105] Preparation Example 8:

[0106] This preparation example provides a method for preparing a spherical yttrium-based material. Except that the D50 particle sizes of both yttrium fluoride and yttrium oxyfluoride are 1.5 μm, the rest are the same as those in Preparation Example 1.

[0107] Preparation Example 9:

[0108] This preparation example provides a method for preparing a spherical yttrium-based material. Except that 60 parts by mass of a binder is added to the yttrium-based composite slurry, the rest are the same as those in Preparation Example 1.

[0109] Preparation Example 10:

[0110] This preparation example provides a method for preparing a spherical yttrium-based material. Except that 250 parts by mass of a binder is added to the yttrium-based composite slurry, the rest are the same as those in Preparation Example 1.

[0111] Preparation Example 11:

[0112] This preparation example provides a method for preparing a spherical yttrium-based material. Except that the emission power of the plasma jet in step (4) is 45 kW, the rest are the same as those in Preparation Example 1.

[0113] Preparation Example 12:

[0114] This preparation example provides a method for preparing a spherical yttrium-based material. Except that the emission power of the plasma jet in step (4) is 90 kW, the rest are the same as those in Preparation Example 1.

[0115] Preparation Example 13:

[0116] This preparation example provides a method for preparing a spherical yttrium-based material. Except that the distance between the emission position of the plasma jet and the cooling medium in step (4) is 400 mm, the rest are the same as those in Preparation Example 1.

[0117] Preparation Example 14:

[0118] This preparation example provides a method for preparing a spherical yttrium-based material. Except that the distance between the emission position of the plasma jet and the cooling medium in step (4) is 900 mm, the rest are the same as those in Preparation Example 1.

[0119] Comparative Preparation Example 1:

[0120] This comparative preparation example provides a method for preparing yttrium-based agglomerated particles. Except that step (4) is not carried out, that is, the spheroidization treatment is not carried out, the rest are the same as those in Preparation Example 1.

[0121] Comparative Preparation Example 2:

[0122] This comparative preparation example provides a method for preparing a spherical yttrium-based material. Except that yttrium oxyfluoride powder is used to completely replace the yttrium-based composite powder in step (1), the rest are the same as those in Preparation Example 1.

[0123] Example 1:

[0124] This example provides a yttrium-based coating. The yttrium-based coating uses the spherical yttrium-based material prepared in Preparation Example 1 as the raw material. Through the method of atmospheric plasma spraying, a yttrium-based bottom layer is prepared, and through the method of suspension plasma spraying, a yttrium-based top layer is prepared.

[0125] The method for preparing the yttrium-based bottom layer by atmospheric plasma spraying includes:

[0126] (a) Clean the substrate with alcohol, and after drying, perform surface roughening and activation treatment by sandblasting. The drying temperature is 85 °C, the pressure of sandblasting is 0.25 MPa, the distance of sandblasting is 90 mm, the sandblasting angle is 80 °, and the sandblasting material uses 120# alumina white fused alumina grits. Among the process parameters for pretreating the substrate above, it includes but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable;

[0127] (b) Spray the spherical yttrium-based material on the surface of the substrate treated in step (a) by atmospheric plasma spraying (APS) to obtain a yttrium-based coating. The current of plasma spraying is 400 A, the voltage is 50 V, the auxiliary gas flow rate is 5 L / min, the scanning speed is 150 m / min, the energy of the plasma jet is adjusted by adjusting the current and the auxiliary gas, the powder feeding amount is 60 L / min, the powder feeding carrier gas flow rate is 8 L / min, the main gas flow rate is 45 L / min, the spraying distance is 150 mm, the spraying angle is 85 °, and during the spraying process, the temperature of the substrate surface is 80 °C.

[0128] The method for preparing the yttrium-based top layer by suspension plasma spraying includes:

[0129] (a) Mix the yttrium-based composite powder described in step (1) of Preparation Example 1 with deionized water, ethanol, dispersant polyvinylpyrrolidone, and ammonium citrate. The mass fraction of the yttrium-based composite powder accounts for 25% of the total mass of the slurry, the mass fraction of the dispersant polyvinylpyrrolidone accounts for 1% - 1.5% of the total mass of the slurry, the mass fraction of ammonium citrate accounts for 0.25% - 0.5% of the total mass of the slurry, and the volume ratio of water to ethanol is 1:1.

[0130] (b) Perform suspension plasma spraying using an AxialⅢ spray gun. The main gas Ar flow rate is 55 L / min, the secondary gas H2 flow rate is 15 L / min, the voltage is 70 V, the current is 450 A, the slurry volume is 45 mL / min, the spraying distance is 90 mm, and use compressed air to cool from the back of the substrate. The cooling gas pressure is 0.4 MPa - 0.5 MPa to ensure that the surface temperature of the coating and the substrate is lower than 150 °C.

[0131] The SEM image of the surface of the yttrium-based coating provided in this example is as shown in Figure 3 shown, and the SEM image of the cross-section is as shown in Figure 4 shown.

[0132] Example 2:

[0133] Except that the spherical yttrium-based material prepared in Preparation Example 2 is used as the raw material for the yttrium-based bottom layer and the yttrium-based composite powder in Preparation Example 2 is used as the raw material for the yttrium-based top layer in this example, the rest are the same as in Example 1.

[0134] Example 3:

[0135] Except that the spherical yttrium-based material prepared in Preparation Example 3 is used as the raw material for the yttrium-based bottom layer and the yttrium-based composite powder in Preparation Example 3 is used as the raw material for the yttrium-based top layer in this example, the rest are the same as in Example 1.

[0136] Example 4:

[0137] Except that the spherical yttrium-based material prepared in Preparation Example 4 is used as the raw material for the yttrium-based bottom layer and the yttrium-based composite powder in Preparation Example 4 is used as the raw material for the yttrium-based top layer in this example, the rest are the same as in Example 1.

[0138] Example 5:

[0139] Except that the spherical yttrium-based material prepared in Preparation Example 5 is used as the raw material for the yttrium-based bottom layer and the yttrium-based composite powder in Preparation Example 5 is used as the raw material for the yttrium-based top layer in this example, the rest are the same as in Example 1.

[0140] Example 6:

[0141] In this example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 6 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 6 as the raw material, the rest are the same as in Example 1.

[0142] Example 7:

[0143] In this example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 7 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 7 as the raw material, the rest are the same as in Example 1.

[0144] Example 8:

[0145] In this example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 8 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 8 as the raw material, the rest are the same as in Example 1.

[0146] Example 9:

[0147] In this example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 9 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 9 as the raw material, the rest are the same as in Example 1.

[0148] Example 10:

[0149] In this example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 10 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 10 as the raw material, the rest are the same as in Example 1.

[0150] Example 11:

[0151] In this example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 11 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 11 as the raw material, the rest are the same as in Example 1.

[0152] Example 12:

[0153] In this example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 12 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 12 as the raw material, the rest are the same as in Example 1.

[0154] Example 13:

[0155] In this example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 13 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 13 as the raw material, the rest are the same as in Example 1.

[0156] Example 14:

[0157] In this embodiment, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Preparation Example 14 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Preparation Example 14 as the raw material, the rest are the same as in Example 1.

[0158] Example 15:

[0159] This embodiment provides a yttrium-based coating. Except that it is formed only by atmospheric plasma spraying and does not include the top layer obtained by suspension plasma spraying, the rest are the same as in Example 1.

[0160] Example 16:

[0161] In this embodiment, except that during the preparation of the yttrium-based bottom layer, the current of plasma spraying is 650 A and the voltage is 70 V, the rest of the conditions are the same as in Example 1. The obtained coating structure is as Figure 5 shown.

[0162] Comparative Example 1:

[0163] In this comparative example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Comparative Example 1 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Comparative Preparation Example 1 as the raw material, the rest are the same as in Example 1.

[0164] Comparative Example 2:

[0165] In this comparative example, except that the yttrium-based bottom layer uses the spherical yttrium-based material prepared in Comparative Example 2 as the raw material, and the yttrium-based top layer uses the yttrium-based composite powder in Comparative Preparation Example 2 as the raw material, the rest are the same as in Example 1.

[0166] Performance test:

[0167] The hardness of the coating surface layer was measured by the Vickers microhardness method, the porosity of the bottom layer and the surface layer cross-section was measured by the metallographic microscopy method. The corrosion resistance of the coating was tested by exposing the coated specimen in a glow plasma chamber at 100 - 200 °C and filled with CF4 gas environment for 100 h and observing the surface state of the coating and the bonding state between the coating and the substrate. The surface roughness of the surface layer coating was tested by a surface profilometer. The porosity of the yttrium-based coatings prepared in all the above examples and comparative examples was tested. The test results are shown in Table 1.

[0168] Table 1

[0169]

[0170] According to the test results of the above-mentioned Embodiment 15, the present invention optimizes the spraying raw materials of the yttrium-based coating. Using spherical yttrium-based materials with a smooth surface, good fluidity, moderate particle size and concentrated powder particle size distribution as raw materials, the yttrium-based coating has high density, hardness and uniformity, and at the same time has high electrical insulation and corrosion resistance. Moreover, the dense coating reduces the generation and transfer of fine particles, which is beneficial to resist the etching of plasma exposure.

[0171] According to the test results of Embodiments 1-5, on the surface of the yttrium-based coating based on spherical yttrium-based materials, a submicron-level ultra-fine yttrium-based composite powder is sprayed by suspension plasma spraying to prepare a yttrium-based top layer, further improving the performance of the yttrium-based coating, making its denseness better, the corrosion resistance to plasma etching gas more excellent, and further improving the service life.

[0172] According to the test results of Embodiments 6 to 8, when the D50 particle size of yttrium fluoride and / or yttrium oxyfluoride for preparing spherical yttrium-based materials is 1.5 μm, that is, when the D50 particle sizes of yttrium fluoride and yttrium oxyfluoride do not meet the submicron size at the same time, the quality of the prepared coating drops significantly, the porosity increases, the hardness decreases, the roughness becomes larger, and even the coating falls off in powder form during the plasma etching process.

[0173] According to the test results of Embodiments 9-10, when the mass ratio of the binder is not within the range defined in the present invention during the process of preparing the spherical yttrium-based materials, spherical yttrium materials cannot be obtained and the bottom layer coating cannot be prepared.

[0174] In Embodiment 16, when the power of plasma spraying is too high during the process of preparing the spherical yttrium-based materials, the powder particles are excessively melted into molten droplet particle state, splash and impact on the surface of the substrate, and quickly deposit and cool and shrink to form a structure with stress, such as Figure 5 shown, shrinkage cracks appear on the surface of the coating, and the coating falls off in chunks during the plasma etching process.

[0175] According to the test results of Comparative Example 1, during the process of preparing the spherical yttrium-based materials, if no spheroidization treatment is carried out, the prepared yttrium-based agglomerated particles do not have a smooth spherical surface morphology, have poor fluidity, and the powder particle size distribution is not concentrated. Compared with Embodiment 1, the quality of the yttrium-based coating prepared therefrom becomes worse, and during the plasma etching process, local coating powder falls off.

[0176] In Comparative Example 2, if the spherical yttrium-based material only contains yttrium oxyfluoride powder and does not contain yttrium fluoride, during the plasma spraying process, it is impossible to reduce the combination of YO groups and F groups in an F atmosphere. As a result, the particles of the prepared Y2O3 coating are not tightly and firmly bonded, are prone to transfer, and increase the risk of coating degradation. Therefore, the mechanical properties and strength of the prepared yttrium-based coating decrease, and the plasma resistance becomes poor.

[0177] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A yttrium-based coating, characterized in that, The yttrium-based coating includes an air plasma spraying bottom layer; the air plasma spraying bottom layer is formed by spraying spherical yttrium-based materials onto the surface of a substrate through air plasma spraying; In the spherical yttrium-based materials, the mass percentage of fluorine element is 15%-20%, and the D50 particle size of the spherical yttrium-based materials is 10μm-50μm; The spherical yttrium-based materials are prepared by the following preparation method, and the preparation method includes: (1) Mix yttrium-based composite powder, solvent, binder and dispersant to obtain a yttrium-based composite slurry; The yttrium-based composite powder includes sub-micron yttrium oxyfluoride and sub-micron yttrium fluoride; (2) Granulate the yttrium-based composite slurry in step (1) to obtain yttrium-based composite particles; (3) Sinter the yttrium-based composite particles described in step (2) in a vacuum environment to obtain yttrium-based agglomerated particles; screen the yttrium-based agglomerated particles to D 50 The particle size is 10 μm - 50 μm; the sintering temperature is 800 °C - 1200 °C, and the sintering time is 0.2 h - 2 h; the vacuum degree of the vacuum environment is 10 -2 -10 -3 Pa; (4) Spheroidize the yttrium-based agglomerated particles in step (3) to obtain the spherical yttrium-based materials; In the yttrium-based composite powder in step (1), the D50 particle size of sub-micron yttrium oxyfluoride and sub-micron yttrium fluoride is independently 0.1μm-1μm; The spheroidizing treatment method in step (4) includes plasma spheroidizing treatment, and the process of the plasma spheroidizing treatment includes: Add the yttrium-based agglomerated particles in step (3) into a plasma jet for melting to obtain yttrium-based droplets, and the yttrium-based droplets are sprayed into a cooling medium to obtain the spherical yttrium-based materials; the emission power of the plasma jet is 60kW-80kW.

2. The yttrium-based coating according to claim 1, characterized in that, In the preparation method of the spherical yttrium-based materials, in the yttrium-based composite slurry in step (1), by weight, it includes: 100 parts of yttrium-based composite powder; 3 parts - 10 parts of solvent; 100 parts - 200 parts of binder; 3 parts - 11 parts of dispersant.

3. The yttrium-based coating according to claim 1, characterized in that, In the preparation method of the spherical yttrium-based materials, in the yttrium-based composite powder in step (1), the mass percentage of sub-micron yttrium oxyfluoride is 80%-90%, and the mass percentage of sub-micron yttrium fluoride is 10%-20%.

4. The yttrium-based coating according to claim 1, characterized in that, In the preparation method of the spherical yttrium-based materials, the preparation method of the yttrium-based composite slurry in step (1) includes high-energy ball milling.

5. The yttrium-based coating according to claim 1, characterized in that, In the preparation method of the spherical yttrium-based materials, the granulating method in step (2) includes spray drying.

6. The preparation method according to claim 1, wherein In the preparation method of the spherical yttrium-based materials, during the plasma spheroidizing treatment process, the distance between the emission position of the plasma jet and the cooling medium is 500mm-800mm.

7. The yttrium-based coating according to claim 1, characterized in that, The yttrium-based coating further includes a suspension plasma spraying coating; the suspension plasma spraying coating is formed by spraying the yttrium-based composite powder in step (1) onto the surface of the air ion spraying bottom layer through suspension plasma spraying.

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