A method for preparing a rare earth silicate environmental barrier coating by supersonic liquid phase particle induction

Abstract

The application provides a method for preparing a rare earth silicate environmental barrier coating by supersonic liquid phase particle induction, and belongs to the technical field of environmental barrier coatings. A plurality of groups of silicate rare earth powders, a dispersing agent and a solvent are ball-milled and mixed to obtain a powder dispersion liquid, liquid phase powder particles are input into a supersonic high-energy plasma jet, and under the action of a spraying heat source, Si in the Si bonding layer on the surface of a SiC substrate is melted and accelerated to impact the Si bonding layer, and a plurality of groups of rare earth doped silicate environmental barrier coatings are effectively prepared in a liquid phase mode. The application improves the corrosion resistance by the synergistic optimization effect of the plurality of groups of rare earth doping, and can improve the service life of the coating. The application adopts yttrium and ytterbium double-group rare earth silicate materials, the ytterbium and yttrium rare earth oxides are low in cost, the rare earth silicates are high in melting point, and the corrosion resistance is excellent.

Description

Technical Field

[0001] This invention relates to the field of environmental barrier coating technology, and in particular to a method for preparing rare earth silicate environmental barrier coatings by supersonic liquid-phase particle induction. Background Technology

[0002] Environmental barrier coatings are anti-corrosion coatings that resist water, oxygen, and CMAS corrosion. They adhere to the surface of ceramic matrix composite substrates and can ensure the normal operation of the substrates in high-temperature corrosive environments. Rare earth silicates are the most promising candidate materials for thermal protection coatings on the hot-end components of next-generation high-performance aero-engines and gas turbines.

[0003] Aviation kerosene releases high temperatures and water vapor during combustion. Simultaneously, dust and sand from the atmosphere are drawn into the aircraft engine, melting, adhering to, and corroding the environmental barrier coating, especially severe in dusty weather and desert regions. Therefore, rare-earth silicate ceramic coatings in aircraft engine combustion chambers inevitably fail during application due to high-temperature water and oxygen corrosion from CMAS melt. While numerous factors contribute to this failure, the ultimate manifestation is generally excessive oxidation of the Si binder layer, resulting in an excessively thick SiO2 layer that causes coating peeling, and CMAS erosion of the rare-earth silicate material, leading to surface layer failure. Therefore, the corrosion resistance of the rare-earth silicate environmental barrier coating is the most fundamental cause of coating failure.

[0004] The synergistic effect of multi-component doping with various rare earth elements has been applied to improve the environmental corrosion resistance of silicate coatings, effectively solving the problem of coating peeling failure caused by high-temperature water vapor and CMAS. However, the available technologies for multi-component rare earth doped silicate coatings in environmental barrier coatings are currently limited, requiring sophisticated production equipment and complex and strict coating preparation conditions, resulting in unstable coating quality and low production efficiency. Summary of the Invention

[0005] In view of this, the present invention aims to provide a method for preparing rare earth silicate environmental barrier coatings induced by supersonic liquid-phase particles. The method provided by the present invention can achieve the preparation of multi-component rare earth-doped silicate environmental barrier coatings with high corrosion resistance, and has the characteristics of simple process, low cost, high efficiency, and stable coating quality and phase composition.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing rare earth silicate environmental barrier coatings induced by supersonic liquid-phase particles, comprising the following steps:

[0008] Multi-component silicate rare earth powder, dispersant, and solvent are ball-milled and mixed to obtain a powder dispersion.

[0009] The powder dispersion is introduced into a supersonic high-energy plasma jet by internal injection, and then sprayed onto the surface of a SiC substrate containing a Si binder layer by supersonic high-energy plasma liquid phase spraying, thereby obtaining a rare earth silicate environmental barrier coating on the surface of the Si binder layer.

[0010] The chemical composition of the multi-component silicate rare earth powder is (Yb 1-x / Y x )2Si2O7, where x = 0 to 1, and x is not 0 or 1.

[0011] Preferably, the particle size of the multi-component silicate rare earth powder is 50-100 μm.

[0012] Preferably, the preparation method of the multi-component silicate rare earth powder includes the following steps:

[0013] Yttrium oxide, ytterbium oxide, silicon dioxide, and an alcohol solvent are mixed to obtain a mixed slurry;

[0014] The mixed slurry was sequentially ball-milled, dried, sintered, and ground to obtain multi-component silicate rare earth powder.

[0015] Preferably, the ball mill rotates at a speed of 200–400 r / min for 24–30 h.

[0016] The sintering temperature is 1500–1600℃, and the time is 2–6 hours.

[0017] Preferably, the dispersant is polyethylene glycol;

[0018] The content of the multi-component silicate rare earth powder in the powder dispersion is 10-30 wt.%, and the content of the dispersant is 5-20 wt.%.

[0019] Preferably, the step of introducing the powder dispersion into a supersonic high-energy plasma jet via internal injection and then spraying it onto the surface of a SiC substrate containing a Si binder layer using supersonic high-energy plasma liquid phase spraying includes:

[0020] The powder dispersion is injected into the powder feeding position of the plasma spray gun through a peristaltic pump, and then sprayed onto the surface of the SiC substrate containing the Si binder layer using supersonic high-energy plasma.

[0021] Preferably, the liquid flow rate of the peristaltic pump is 18–22 mL / min. -1 The pipe diameter is 1.1 to 1.5 mm, and the liquid pressure is 0.1 to 0.3 MPa.

[0022] Preferably, the parameters for the supersonic high-energy plasma liquid phase spraying include:

[0023] The spraying power is 52-55kW;

[0024] The spraying distance is 50-60mm;

[0025] The distance between the liquid injection point and the nozzle is 10–20 mm;

[0026] The feed rate is 18–22 mL / min. -1 .

[0027] This invention provides a rare earth silicate environmental barrier coating prepared by the above method.

[0028] Preferably, the thickness of the rare earth silicate environmental barrier coating is 100–300 μm.

[0029] This invention provides a method for preparing a rare earth silicate environmental barrier coating using supersonic liquid-phase particle induction, comprising the following steps: ball milling and mixing multi-component rare earth silicate powder, dispersant, and solvent to obtain a powder dispersion; spraying the powder dispersion onto the surface of a SiC substrate containing a Si binder layer using supersonic high-energy plasma liquid-phase technology, thereby obtaining a rare earth silicate environmental barrier coating on the surface of the Si binder layer; the chemical composition of the multi-component rare earth silicate powder is (Yb 1-x / Y x The formula is 2Si₂O₇, where x = 0 to 1, and x is not 0 or 1. This invention introduces liquid-phase powder particles into a supersonic high-energy plasma jet, where they melt and are accelerated by impact under the action of a spraying heat source to achieve efficient preparation of multi-component rare-earth-doped silicate environmental barrier coatings. In this invention, the liquid-phase sample can be injected into the spray gun via a peristaltic pump, and melted and impacted on the substrate surface under the action of a supersonic high-energy plasma heat source. The advantage of liquid-phase delivery of multi-component rare-earth silicate ceramic particles is that it reduces the granulation step and avoids the volatilization of silica in the silicate ceramic powder into the air during the spraying process.

[0030] Because the corrosion resistance of environmental barrier coatings decreases due to ceramic layer degradation in high-temperature water vapor and CMAS corrosive environments, this invention improves corrosion resistance through the synergistic optimization effect of multi-component rare earth doping, thereby extending the service life of the coating. This invention uses yttrium and ytterbium bicomponent rare earth silicate materials. Ytterbium and yttrium rare earth oxides are low-cost, and their rare earth silicates have high melting points and excellent corrosion resistance. This invention provides a theoretical basis for the composition, structure, and process design of environmental barrier coatings with low ceramic layer degradation rates, high corrosion resistance, and high reliability. Its advantages lie in its simple process, low cost, ease of control, and high production efficiency, providing technical support for the surface protection of high-performance environmental barrier coatings urgently needed for next-generation aero-engines and other critical national equipment.

[0031] The composition of the multi-component silicate rare earth powder of this invention is (Yb 1-x / Y xYb₂Si₂O₇, where x = 0 to 1, and x is not 0 or 1, is used in this invention to maintain a single β-type structure in this multi-component rare earth silicate by controlling the Y content. Compared to pure Yb₂Si₂O₇ and Y₂Si₂O₇ rare earth silicate environmental barrier coatings without rare earth elements, (Yb₂Si₂O₇) 1-x / Y x The high phase stability of 2Si2O7 is expected to significantly improve its resistance to high-temperature water vapor and CMAS corrosion, ultimately extending the service life of environmental barrier coatings. Detailed Implementation

[0032] This invention provides a method for preparing rare earth silicate environmental barrier coatings induced by supersonic liquid-phase particles, comprising the following steps:

[0033] Multi-component silicate rare earth powder, dispersant, and solvent are ball-milled and mixed to obtain a powder dispersion.

[0034] The powder dispersion is introduced into a supersonic high-energy plasma jet by internal injection, and then sprayed onto the surface of a SiC substrate containing a Si binder layer by supersonic high-energy plasma liquid phase spraying, thereby obtaining a rare earth silicate environmental barrier coating on the surface of the Si binder layer.

[0035] The chemical composition of the multi-component silicate rare earth powder is (Yb 1-x / Y x )2Si2O7, where x=0~1.

[0036] In this invention, the chemical composition of the multi-component silicate rare earth powder is (Yb 1-x / Y x )2Si2O7, where x = 0 to 1, and x is not 0 or 1; specifically, x = 0.2, 0.5 or 0.8.

[0037] In this invention, the particle size of the multi-component silicate rare earth powder is preferably 50–100 μm, more preferably 60–80 μm. In this invention, the preparation method of the multi-component silicate rare earth powder preferably includes the following steps:

[0038] Yttrium oxide, ytterbium oxide, silicon dioxide, and an alcohol solvent are mixed to obtain a mixed slurry;

[0039] The mixed slurry was sequentially ball-milled, dried, sintered, and ground to obtain multi-component silicate rare earth powder.

[0040] In this invention, the alcohol solvent is preferably anhydrous ethanol; the molar ratio of the total molar amount of yttrium oxide and ytterbium oxide to silicon dioxide is preferably 1:1 to 1.2, more preferably 1:1.15.

[0041] In this invention, the rotational speed of the ball mill is preferably 200-400 r / min, more preferably 300 r / min; the time is preferably 24-30 h, more preferably 26-28 h.

[0042] In this invention, the drying temperature is preferably 60-100°C, more preferably 70-80°C; the drying time is preferably 24-48 hours, more preferably 36 hours.

[0043] In this invention, the sintering temperature is preferably 1500-1600℃, more preferably 1550℃, and the sintering time is preferably 2-6h, more preferably 4-5h.

[0044] In this invention, the material is preferably passed through a 200-mesh sieve after grinding.

[0045] This invention involves ball milling and mixing multi-component silicate rare earth powder, a dispersant, and a solvent to obtain a powder dispersion. In this invention, the dispersant is preferably polyethylene glycol, and the molecular weight of the polyethylene glycol is preferably 300-2000. In this invention, the solvent is preferably anhydrous ethanol and / or deionized water.

[0046] In this invention, the ball milling speed is preferably 200-400 r / min, more preferably 300 r / min; the time is preferably 24-30 h, more preferably 26-28 h.

[0047] In this invention, the content of the multi-component silicate rare earth powder in the powder dispersion is preferably 10-30 wt.%, more preferably 15-25 wt.%, and even more preferably 20 wt.%; the content of the dispersant is preferably 5-20 wt.%, more preferably 10-15 wt.%.

[0048] After obtaining the powder dispersion, the present invention introduces the powder dispersion into a supersonic high-energy plasma jet via internal injection, and then sprays it onto the surface of a SiC substrate containing a Si binder layer using supersonic high-energy plasma liquid phase spraying, thereby obtaining a rare earth silicate environmental barrier coating on the surface of the Si binder layer. Before the spraying, the present invention preferably subjectes the powder dispersion to ball milling and magnetic stirring. The ball milling rate is preferably 300–500 r / min, more preferably 400 r / min; the time is preferably 2–4 h, more preferably 3 h; the magnetic stirring rate is preferably 50–60 r / min, more preferably 55 r / min.

[0049] In this invention, the step of introducing the powder dispersion into a supersonic high-energy plasma jet via internal injection and then spraying it onto the surface of a SiC substrate containing a Si binder layer using supersonic high-energy plasma liquid phase spraying preferably includes:

[0050] The powder dispersion is injected into the plasma spray gun via a peristaltic pump, and the supersonic high-energy plasma of the powder dispersion is sprayed onto the surface of the SiC substrate containing the Si binder layer using the plasma spray gun.

[0051] In this invention, the liquid flow rate of the peristaltic pump is preferably 18–22 mL / min. -1 More preferably 20 mL·min -1 The preferred pipe diameter is 1.1–1.5 mm, more preferably 1.2–1.4 mm; the preferred liquid pressure is 0.1–0.3 MPa, more preferably 0.2 MPa. In this invention, a powder dispersion is injected into a plasma spray gun using a peristaltic pump. The powder dispersion melts in a supersonic high-energy plasma jet and accelerates to impact the surface of the SiC substrate onto which the Si bonding layer is applied, thus obtaining a rare-earth silicate environmental barrier coating.

[0052] In this invention, the thickness of the Si bonding layer in the SiC substrate containing the Si bonding layer is preferably 60–100 μm, more preferably 70–80 μm; this invention does not have any special requirements on the thickness of the SiC substrate. In this invention, the method for preparing the SiC substrate containing the Si bonding layer preferably includes the following steps:

[0053] A Si binder layer was deposited on a SiC substrate with a roughness of 2–3 μm using supersonic high-energy plasma spraying technology. Specific parameters included:

[0054] The spraying power is preferably 38-42kW, more preferably 39-40kW;

[0055] The spraying distance is preferably 90-120mm, and more preferably 100-110mm.

[0056] In this invention, the preferred parameters for the supersonic high-energy plasma liquid phase spraying of the rare earth silicate environmental barrier coating include:

[0057] The spraying power is preferably 52-55kW, more preferably 53-54kW;

[0058] The spraying distance is preferably 50-60mm, more preferably 55mm;

[0059] The distance between the liquid injection point and the nozzle is preferably 10-20 mm, more preferably 15 mm;

[0060] The preferred feed rate is 18–22 mL / min. -1 More preferably 20 mL·min -1 .

[0061] This invention provides a rare earth silicate environmental barrier coating prepared by the above method. In this invention, the rare earth silicate environmental barrier coating is attached to the surface of a SiC substrate containing a Si binder layer, specifically in the following positional relationship: SiC substrate - Si binder layer - rare earth silicate environmental barrier coating.

[0062] In this invention, the thickness of the rare earth silicate environmental barrier coating is preferably 100-300 μm.

[0063] The following detailed description of the method for preparing rare earth silicate environmental barrier coatings induced by supersonic liquid-phase particles provided by the present invention, with reference to specific embodiments, should not be construed as limiting the scope of protection of the present invention.

[0064] Example 1

[0065] A method for preparing rare earth silicate environmental barrier coatings induced by supersonic liquid-phase particles comprises the following steps:

[0066] (1) Rare earth oxides and SiO2 were uniformly mixed at a molar ratio of 1:1 using mechanical alloying. The rare earth oxides were yttrium oxide and ytterbium oxide, with a molar ratio of 1:1. The mixture was stirred with anhydrous ethanol at a mass ratio of 1:4 to form a slurry. The slurry was then ball-milled at 400 r / min for 24 h. After drying the slurry, it was sintered at 1500 °C for 2 h to obtain pure yttrium-doped ytterbium silicate powder. The powder was then ground and passed through a 200-mesh sieve to obtain a multi-component rare earth silicate powder with a particle size between 50 and 100 μm, and the composition was YbYSi2O7.

[0067] (2) YbYSi2O7 silicate powder, anhydrous ethanol and polyethylene glycol (PEG 600) were mixed in a mass ratio of 1:4:1 and then ball-milled at 400 r / min for 24 h to obtain a powder dispersion.

[0068] (3) The powder dispersion is injected into the plasma spray gun using a peristaltic pump with a flow rate of 20 mL / min. -1 The pipe diameter is 1.2 mm, and the liquid pressure is 0.2 MPa. The supersonic liquid-phase plasma spraying process parameters are adjusted as follows: spraying power is 52 kW, spraying distance is 50 mm, the distance between the liquid injection position and the nozzle is 10 mm, and the feed rate is 20 mL / min. -1 The powder dispersion is melted and accelerated in a supersonic high-energy plasma jet to impact the surface of the SiC substrate with the sprayed Si adhesive layer, resulting in a rare earth silicate environmental barrier coating with a thickness of 300 μm.

[0069] Example 2

[0070] A method for preparing rare earth silicate environmental barrier coatings induced by supersonic liquid-phase particles comprises the following steps:

[0071] (1) Rare earth oxides and SiO2 were uniformly mixed at a molar ratio of 1:1.15 using a mechanical alloying method. The rare earth oxides consisted of yttrium oxide and ytterbium oxide at a molar ratio of 1:4. The mixture was then stirred with anhydrous ethanol at a mass ratio of 1:4 to form a slurry. The slurry was then ball-milled at 400 r / min for 24 h. After drying, the slurry was sintered at 1500 °C for 2 h to obtain pure yttrium-doped ytterbium silicate powder. The powder was then ground and passed through a 200-mesh sieve to obtain a multi-component rare earth silicate powder with a particle size between 50 and 100 μm. The composition was Yb 1.6 Y 0.4 Si2O7.

[0072] (2) Yb 1.6 Y 0.4 Si2O7 silicate powder, anhydrous ethanol and polyethylene glycol (PEG 600) were mixed in a mass ratio of 1:4:1 and then ball-milled at 400 r / min for 24 h to obtain a powder dispersion.

[0073] (3) The powder dispersion is injected into the plasma spray gun using a peristaltic pump with a flow rate of 20 mL / min. -1 The pipe diameter is 1.2 mm, and the liquid pressure is 0.2 MPa. The supersonic liquid-phase plasma spraying process parameters are adjusted as follows: spraying power is 52 kW, spraying distance is 60 mm, the distance between the liquid injection position and the nozzle is 15 mm, and the feed rate is 20 mL / min. -1 The powder dispersion is melted and accelerated in a supersonic high-energy plasma jet to impact the surface of the SiC substrate with the sprayed Si adhesive layer, resulting in a rare earth silicate environmental barrier coating with a thickness of 300 μm.

[0074] Example 3

[0075] A method for preparing rare earth silicate environmental barrier coatings induced by supersonic liquid-phase particles comprises the following steps:

[0076] (1) Rare earth oxides and SiO2 were uniformly mixed at a molar ratio of 1:1.2 using mechanical alloying. The rare earth oxides were yttrium oxide and ytterbium oxide at a molar ratio of 1:1. The mixture was stirred with anhydrous ethanol at a mass ratio of 1:4 to form a slurry. The slurry was then ball-milled at 400 r / min for 24 h. After drying the slurry, it was sintered at 1500 °C for 2 h to obtain pure yttrium-doped ytterbium silicate powder. The powder was then ground and passed through a 200-mesh sieve to obtain multi-component rare earth silicate powder with a particle size between 50 and 100 μm, and the composition was YbYSiO5.

[0077] (2) YbYSiO5 silicate powder, anhydrous ethanol and polyethylene glycol (PEG 600) were mixed in a mass ratio of 1:4:1 and then ball-milled at 400 r / min for 24 h to obtain a powder dispersion.

[0078] (3) The powder dispersion is injected into the plasma spray gun using a peristaltic pump with a flow rate of 20 mL / min. -1 The pipe diameter is 1.2 mm, and the liquid pressure is 0.2 MPa. The supersonic liquid-phase plasma spraying process parameters are adjusted as follows: spraying power is 55 kW, spraying distance is 60 mm, distance between the liquid injection position and the nozzle is 20 mm, and feed rate is 20 mL / min. -1 The powder dispersion is melted and accelerated in a supersonic high-energy plasma jet to impact the surface of the SiC substrate with the sprayed Si adhesive layer, resulting in a rare earth silicate environmental barrier coating with a thickness of 300 μm.

[0079] Comparative Example 1

[0080] (1) Ytterbium oxide and SiO2 were uniformly mixed at a molar ratio of 1:1.1 by mechanical alloying. The mixture was then mixed with anhydrous ethanol at a mass ratio of 1:4 to form a slurry. The slurry was then ball-milled at 400 r / min for 24 h. After drying, the slurry was sintered at 1500℃ for 2 h and then ground and passed through a 200-mesh sieve to obtain pure ytterbium pyrosilicate powder with a particle size between 50 and 100 μm.

[0081] (2) Yb2Si2O7 silicate powder, deionized water and polyethylene glycol (PEG 600) were mixed in a mass ratio of 1:4:1 and then ball-milled at 400 r / min for 24 h to obtain a powder dispersion.

[0082] (3) The powder dispersion is injected into the plasma spray gun using a peristaltic pump with a flow rate of 20 mL / min. -1 The pipe diameter is 1.2 mm, and the liquid pressure is 0.2 MPa. The supersonic liquid-phase plasma spraying process parameters are adjusted as follows: spraying power is 52 kW, spraying distance is 60 mm, the distance between the liquid injection position and the nozzle is 15 mm, and the feed rate is 20 mL / min. -1 The powder dispersion is melted and accelerated in a supersonic high-energy plasma jet to impact the SiC substrate surface with the sprayed Si binder layer, resulting in a ytterbium pyrosilicate surface layer with a thickness of 300 μm.

[0083] Comparative Example 2

[0084] (1) Yttrium oxide and SiO2 were uniformly mixed at a molar ratio of 1:1.1 by mechanical alloying. The mixture was then mixed with anhydrous ethanol at a mass ratio of 1:4 to form a slurry. The slurry was then ball-milled at 400 r / min for 24 h. After drying the slurry, it was sintered at 1500 °C for 2 h. The slurry was then ground and passed through a 200-mesh sieve to obtain yttrium silicate powder with a particle size between 50 and 100 μm.

[0085] (2) Y2Si2O7 silicate powder, deionized water and polyethylene glycol (PEG 600) were mixed in a mass ratio of 1:4:1 and then ball-milled at 400 r / min for 24 h to obtain a powder dispersion.

[0086] (3) The powder dispersion is injected into the plasma spray gun using a peristaltic pump with a flow rate of 20 mL / min. -1 The pipe diameter is 1.2 mm, and the liquid pressure is 0.2 MPa. The supersonic liquid-phase plasma spraying process parameters are adjusted as follows: spraying power is 52 kW, spraying distance is 60 mm, the distance between the liquid injection position and the nozzle is 15 mm, and the feed rate is 20 mL / min. -1 The powder dispersion is melted and accelerated in a supersonic high-energy plasma jet to impact the SiC substrate surface with the sprayed Si adhesive layer, resulting in a yttrium silicate surface layer with a thickness of 300 μm.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing rare earth silicate environmental barrier coatings induced by supersonic liquid-phase particles, comprising the following steps: Multicomponent rare earth silicate powder, dispersant, and solvent are ball-milled and mixed to obtain a powder dispersion; the dispersant is polyethylene glycol; the content of multicomponent rare earth silicate powder in the powder dispersion is 10~30 wt.%, and the content of dispersant is 5~20 wt.%; the chemical composition of the multicomponent rare earth silicate powder is (Yb 1-x / Y x )2Si2O7, where x = 0~1, and x is not 0 or 1; The powder dispersion is injected into the powder feeding position of the plasma spray gun through a peristaltic pump, and then sprayed onto the surface of the SiC substrate containing the Si binder layer using supersonic high-energy plasma to obtain a rare earth silicate environmental barrier coating on the surface of the Si binder layer. The peristaltic pump has a liquid flow rate of 18~22 mL·min. -1 The pipe diameter is 1.1~1.5 mm, and the liquid pressure is 0.1~0.3 MPa; The parameters of the supersonic high-energy plasma spraying include: The spraying power is 52~55 kW; The spraying distance is 50~60 mm; The distance between the liquid injection point and the nozzle is 10~20 mm; The feed rate is 18~22 mL·min -1 .

2. The method according to claim 1, characterized in that, The particle size of the multi-component silicate rare earth powder is 50~100 μm.

3. The method according to claim 1, characterized in that, The preparation method of the multi-component silicate rare earth powder includes the following steps: Yttrium oxide, ytterbium oxide, silicon dioxide, and an alcohol solvent are mixed to obtain a mixed slurry; The mixed slurry was sequentially ball-milled, dried, sintered, and ground to obtain multi-component silicate rare earth powder.

4. The method according to claim 3, characterized in that, The mixed slurry is subjected to ball milling, drying, sintering and grinding in sequence, wherein the ball milling speed is 200~400 r / min and the time is 24~30 h; The sintering temperature is 1500~1600 ℃, and the time is 2~6 h.

5. The rare earth silicate environmental barrier coating prepared by the method according to any one of claims 1 to 4.

6. The rare earth silicate environmental barrier coating according to claim 5, characterized in that, The thickness of the rare earth silicate environmental barrier coating is 100~300 μm.