Anti-CMAS layer-column composite structure environmental barrier coating and preparation method thereof

Abstract

The invention relates to an anti-CMAS layer-column composite structure environmental barrier coating and a preparation method thereof, belongs to the technical field of high-temperature ceramic composite materials and environmental barrier coatings, and solves the problem of corrosion failure of the environmental barrier coating caused by adhesion and permeation of corrosive substances such as water vapor or CMAS and the like into the coating in the prior art. The anti-CMAS layer-column composite structure environmental barrier coating comprises a SiC-based ceramic matrix, a bonding layer, an environmental barrier intermediate layer and an anti-CMAS corrosion layer which are sequentially stacked, the anti-CMAS corrosion layer comprises a compact sub-layer and a columnar sub-layer which are stacked in sequence; the compact sub-layer is laminated on the environmental barrier intermediate layer; the columnar sub-layer is of a columnar structure. On the premise of improving the water vapor corrosion resistance of the SiC ceramic-based composite material, the wettability of CMAS on the surface of the coating can be reduced, the infiltration speed of CMAS is delayed, and the high-temperature stability and CMAS corrosion resistance of a ceramic-based structural component are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature ceramic composites and environmental barrier coatings, and particularly relates to an anti-CMAS layer-column composite structure environmental barrier coating and a preparation method thereof. Background Art

[0002] SiC f / SiC ceramic matrix composites have low density, high specific strength and excellent high-temperature mechanical properties, overcoming the disadvantages of large brittleness and poor reliability of ceramic materials, and are considered to be the most promising materials for hot-end components of next-generation aeroengines. At high temperatures, a dense SiO2 protective film is formed on the surface of SiC-based ceramic components, which can inhibit the further oxidation of the ceramic matrix. However, under actual service conditions, SiO2 reacts with water vapor in the environment to form volatile Si(OH)4, resulting in a linear decrease in the size of high-temperature components and rapid structural failure. Therefore, it is necessary to coat a structurally dense environmental barrier coating on the surface of SiC-based ceramic components to inhibit the corrosion effect of the water vapor environment. In addition, environmental corrosive substances such as volcanic ash (CMAS, chemical composition CaO-MgO-Al2O3-SiO2) in the gas environment will adhere to the surface of the components and react with the components to generate cracks, further accelerating the failure of the ceramic matrix.

[0003] Preparing an environmental barrier coating with anti-CMAS corrosion performance to improve the structural stability and long-term service performance of components is a prerequisite for the large-scale application of SiC f / SiC ceramic matrix composites. The patent application with publication number CN113860920A uses atmospheric plasma spraying to prepare an environmental barrier coating with six rare earth main element double silicates as the surface layer. The prepared coating has good high-temperature stability and anti-water vapor corrosion performance, but the preparation cost of multi-main element rare earth silicates is high and it is difficult to achieve uniform distribution of the spraying powder composition. The patent with publication number CN108486569B proposes to use plasma physical vapor deposition to prepare an environmental barrier coating and improve the anti-CMAS corrosion performance by depositing an aluminum layer, but the preparation process is complex and the bonding property between the aluminum layer and the environmental barrier coating is poor. Therefore, there is an urgent need for an environmental barrier coating with anti-CMAS corrosion and anti-water vapor corrosion effects and a simple and efficient preparation process. Summary of the Invention

[0004] In view of the above problems, the present invention provides an anti-CMAS layer-column composite structure environmental barrier coating and a preparation method thereof, which solve the problem that corrosion substances such as water vapor or CMAS adhere to and penetrate into the coating in the prior art, resulting in the corrosion failure of the environmental barrier coating.

[0005] The present invention provides an anti-CMAS layer-column composite structure environmental barrier coating, including an SiC-based ceramic matrix, an adhesive layer, an environmental barrier intermediate layer and an anti-CMAS corrosion layer which are sequentially stacked.

[0006] The anti-CMAS corrosion layer includes a dense sub-layer and a columnar sub-layer which are stacked in sequence; the dense sub-layer is stacked on the environmental barrier intermediate layer; the columnar sub-layer has a columnar structure.

[0007] Optionally, 1.5 < thickness of environmental barrier intermediate layer : thickness of bonding layer < 2.5.

[0008] Optionally, 15 < thickness of environmental barrier intermediate layer : thickness of dense sub-layer < 25.

[0009] Optionally, 1.5 < thickness of dense sub-layer : thickness of columnar sub-layer < 2.

[0010] Optionally, the material of the SiC-based ceramic matrix is a silicon carbide matrix or a silicon carbide fiber reinforced silicon carbide ceramic matrix composite.

[0011] Optionally, the material of the bonding layer is Si.

[0012] Optionally, the material of the environmental barrier intermediate layer is Yb2Si2O7.

[0013] Optionally, the material of the dense sub-layer is Yb2SiO5.

[0014] Optionally, the columnar structure is a micro-papilla columnar structure.

[0015] On the other hand, the present invention also discloses a method for preparing the aforementioned anti-CMAS layer-column composite structure environmental barrier coating, and the specific steps are as follows:

[0016] S1: Perform sandblasting pretreatment on the SiC-based ceramic matrix;

[0017] S2: Deposit a bonding layer on the surface of the SiC-based ceramic matrix;

[0018] S3: Deposit an environmental barrier intermediate layer on the surface of the bonding layer;

[0019] S4: Use a nanosecond pulsed laser to ablate the surface of the environmental barrier intermediate layer to prepare an anti-CMAS corrosion layer including a dense sub-layer and a columnar sub-layer, and obtain the anti-CMAS layer-column composite structure environmental barrier coating.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] The present invention can improve the water vapor corrosion resistance of SiC ceramic matrix composites, reduce the wettability of CMAS on the coating surface, delay the infiltration rate of CMAS, and improve the high-temperature stability and anti-CMAS corrosion ability of ceramic matrix structural components. Description of the Drawings

[0022] Figure 1 Schematic diagram of the anti-CMAS layer-column composite structure environmental barrier coating of the present invention;

[0023] Figure 2 (a) Cross-sectional electron backscatter diffraction pattern of the anti-CMAS layer-column composite structure environmental barrier coating prepared in Example 1 of the present invention;

[0024] Figure 2 (b) is Figure 2 (a) Local enlarged view;

[0025] Figure 3 Surface electron backscatter diffraction pattern of the anti-CMAS layer-column composite structure environmental barrier coating prepared in Example 1 of the present invention;

[0026] Figure 3 (b) is Figure 3 (a) Local enlarged view;

[0027] Figure 4 (a) Contact angle of CMAS on the surface of the coating prepared in Comparative Example 1;

[0028] Figure 4 (b) Contact angle on the surface of the anti-CMAS layer-column composite structure environmental barrier coating prepared in Example 1 of the present invention. Detailed implementation manners

[0029] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In addition, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0030] A specific embodiment of the present invention, as Figures 1-4 , discloses an anti-CMAS layer-column composite structure environmental barrier coating, including a SiC-based ceramic matrix 1, an adhesive layer 2, an environmental barrier intermediate layer 3 and an anti-CMAS corrosion layer 4 which are sequentially stacked;

[0031] Further, the anti-CMAS corrosion layer 4 includes a dense sublayer 41 and a columnar sublayer 42 which are sequentially stacked; the dense sublayer 41 is stacked on the environmental barrier intermediate layer 3; the columnar sublayer 42 includes a micron papilla columnar structure.

[0032] Optionally, 1.5 < thickness of environmental barrier intermediate layer: thickness of adhesive layer < 2.5; 15 < thickness of environmental barrier intermediate layer: thickness of dense sublayer < 25; 1.5 < thickness of dense sublayer: thickness of columnar sublayer < 2.

[0033] Optionally, the material of the SiC-based ceramic matrix 1 is a silicon carbide matrix or a silicon carbide fiber reinforced silicon carbide ceramic matrix composite.

[0034] Preferably, the thickness of the bonding layer 2 is 60 μm to 125 μm; the material of the bonding layer 2 is Si. Further, the thickness of the bonding layer 2 can be, but is not limited to, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, or the range between any two of the above thicknesses, etc. Thus, the bonding layer has excellent strain tolerance, and the environmental barrier-infrared stealth coating has excellent high-temperature long-term service life.

[0035] Preferably, the thickness of the environmental barrier intermediate layer 3 is 80 μm to 150 μm; the material of the environmental barrier intermediate layer 3 is Yb2Si2O7. Further, the porosity of the environmental barrier intermediate layer 3 < 10%. Thus, the intermediate layer has excellent anti-water vapor corrosion performance.

[0036] Further, the thickness of the environmental barrier intermediate layer can be, but is not limited to, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, or the range between any two of the above thicknesses, etc. When the thickness of the environmental barrier intermediate layer is within the above range, it has excellent anti-water vapor corrosion performance and good strain tolerance. Optionally, the material of the dense sublayer 41 is Yb2SiO5, and the thickness is 3 μm to 10 μm. Further, the thickness of the dense sublayer 41 can be, but is not limited to, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or the range between any two of the above thicknesses, etc. When the thickness of the dense sublayer is within the above range, it has excellent effect of preventing the infiltration of molten CMAS, can significantly improve the anti-CMAS corrosion effect, and at the same time, the interfacial stress between the dense sublayer and the environmental barrier intermediate layer is small, and the interfacial bonding performance is good. Optionally, the material of the columnar sublayer 42 is SiO2 and / or Yb2SiO5; the columnar sublayer 42 includes a plurality of micron papilla columnar structures, and the axes of the plurality of micron papilla columnar structures are arranged side by side perpendicular to the surface of the dense sublayer 41; 1 < height of the micron papilla columnar structure: diameter of the micron papilla columnar structure < 4; 2.5 < diameter of the micron papilla columnar structure: spacing of the micron papilla columnar structures < 10.

[0037] Preferably, the diameter of the micron papilla columnar structure is 0.5 μm to 5 μm, the height is 2 μm to 5 μm, and the spacing is 0.2 μm to 0.5 μm.

[0038] It is understandable that the height of the micro-papillary columnar structure is the thickness of the columnar sublayer.

[0039] Furthermore, the diameter of the micro-papillary columnar structure can be, but is not limited to, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, or the range between any two of the above diameters, etc.; the height of the micro-papillary columnar structure can be, but is not limited to, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, or the range between any two of the above heights, etc.; the spacing of the micro-papillary columnar structure can be, but is not limited to, 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, 0.5 μm, or the range between any two of the above spacings, etc.

[0040] Furthermore, the relationship between the molten CMAS contact angle and the diameter, height, and spacing of the micro-papillary columnar structure and the thickness of the dense sublayer is as follows:

[0041] θ = 55.99 ± 3.96*D + 10.84*T2 + 52.46*L + 4.2*T1 ± 1.57*T2 2

[0042] Where, θ is the molten CMAS contact angle, in °; D is the width of the micro-papillary columnar structure, in μm; T2 is the height of the micro-papillary columnar structure, which is also the thickness of the columnar sublayer, in μm; L is the spacing of the micro-papillary columnar structure, in μm; T1 is the thickness of the dense sublayer, in μm.

[0043] It is understandable that referring to Figure 4 the angles marked in the middle two figures of

[0044] are the contact angles. The contact angle refers to the angle between the solid-liquid interface, passing through the liquid interior, to the gas-liquid interface at the three-phase junction of solid, liquid, and gas.

[0045] It should be noted that the "diameter of the micro-papillary columnar structure" mentioned in the context refers to the longest straight-line distance between two points on the edge of the columnar cavity in a plane perpendicular to the thickness direction of the dense sublayer.

[0046] The anti-CMAS layer-column composite structure environmental barrier coating of the present invention, under high-temperature service conditions, the bonding layer is rapidly oxidized to form a dense SiO2 film, and the environmental barrier intermediate layer blocks the corrosion of the SiO2 layer by high-temperature water vapor. The two jointly inhibit the degradation of the SiC matrix in the high-temperature service environment. The columnar sub-layer has a micron papilla columnar structure, which can reduce the wettability of molten CMAS on the coating surface and reduce the adhesion of CMAS on the coating surface. The dense sub-layer inhibits the infiltration process of molten CMAS, improving the CMAS corrosion resistance of the coating. The anti-CMAS layer-column composite structure environmental barrier coating provided by the present invention has excellent water vapor corrosion resistance and CMAS corrosion resistance.

[0047] The above-mentioned anti-CMAS layer-column composite structure environmental barrier coating includes a bonding layer, an environmental barrier intermediate layer, and an anti-CMAS corrosion layer sequentially laminated on the surface of the SiC-based ceramic matrix. The bonding layer is rapidly oxidized in a high-temperature environment to form a protective SiO2 layer. The SiO2 layer and the environmental barrier intermediate layer act together to delay the corrosion and degradation of the ceramic matrix under high-temperature water vapor and oxidation, improving the stability and service safety of the component. The anti-CMAS corrosion layer includes a dense sub-layer and a columnar sub-layer. On the one hand, the micron papilla columnar structure in the columnar sub-layer is similar to the lotus leaf structure and has superhydrophobic properties, reducing the wettability and adhesion of molten CMAS on the coating surface at high temperatures; on the other hand, the dense sub-layer closes the infiltration channel of molten CMAS, further improving the CMAS corrosion resistance of the coating; furthermore, the dense sub-layer can further improve the water vapor corrosion resistance of the environmental barrier intermediate layer.

[0048] On the other hand, the present invention provides a method for preparing an anti-CMAS layer-column composite structure environmental barrier coating, and the specific steps are as follows:

[0049] S1: Perform sandblasting pretreatment on the SiC-based ceramic matrix;

[0050] S2: Deposit a bonding layer on the surface of the SiC-based ceramic matrix;

[0051] In some embodiments of the present invention, the method for preparing the bonding layer includes the atmospheric plasma spraying method.

[0052] Optionally, the atmospheric plasma spraying current is 550A - 650A;

[0053] Optionally, the atmospheric plasma spraying power is 38kW - 42kW;

[0054] Optionally, the argon gas flow rate used in the atmospheric plasma spraying is 32slpm - 38slpm;

[0055] Optionally, the hydrogen gas flow rate used in the atmospheric plasma spraying is 7slpm - 10slpm;

[0056] Optionally, the powder feeding rate of the atmospheric plasma spraying is 20 g / min to 30 g / min;

[0057] Optionally, the distance of the atmospheric plasma spraying is 85 mm to 110 mm.

[0058] S3: Depositing an environmental barrier intermediate layer on the surface of the bonding layer;

[0059] In some embodiments of the present invention, the method for preparing the environmental barrier intermediate layer includes the atmospheric plasma spraying method.

[0060] The relational expression between the processing technology and the porosity of the environmental barrier intermediate layer is:

[0061] Y = 1.83 + 2.44*P + 0.16*F + -0.9*S + -0.03*P 2

[0062] Wherein, Y is the porosity of the environmental barrier intermediate layer, in %; P is the spraying power, in kW; F is the powder feeding rate, in g / min; S is the spraying distance, in mm.

[0063] Optionally, the current of the atmospheric plasma spraying is 600 A to 800 A;

[0064] Optionally, the power of the atmospheric plasma spraying is 42 kW to 48 kW;

[0065] Optionally, the argon gas flow rate of the atmospheric plasma spraying is 32 slpm to 45 slpm;

[0066] Optionally, the hydrogen gas flow rate of the atmospheric plasma spraying is 8 slpm to 14 slpm;

[0067] Optionally, the powder feeding rate of the atmospheric plasma spraying is 25 g / min to 35 g / min;

[0068] Optionally, the distance of the atmospheric plasma spraying is 85 mm to 120 mm.

[0069] S4: Ablating the surface of the environmental barrier intermediate layer by using a nanosecond pulsed laser to prepare an anti-CMAS corrosion layer including a dense sub-layer and a columnar sub-layer, and obtaining the anti-CMAS layer-column composite structure environmental barrier coating.

[0070] The relational expression between the processing technology and the thicknesses of the dense sub-layer and the columnar sub-layer is:

[0071] T1 = -0.62 + -0.15*V + 2.36*N + 0.37*W + -0.22*N 2 ;

[0072] T2 = 8.1 +- 0.47 * V + N + 0.41 * W;

[0073] Among them, T1 is the thickness of the dense sublayer, T2 is the thickness of the columnar sublayer, with the unit of μm; V is the laser scanning speed, with the unit of mm / s; N is the laser repetition times; W is the laser energy density, with the unit of J / mm 2 .

[0074] Optionally, the central wavelength of the laser of the pulsed laser is 355 nm;

[0075] Optionally, the pulse width of the laser of the pulsed laser is 10 ns to 20 ns;

[0076] Optionally, the laser energy density of the pulsed laser is 0.5 J / mm 2 ~5 J / mm 2 ;

[0077] Optionally, the repetition frequency of the pulsed laser is 10 kHz to 30 kHz;

[0078] Optionally, the scanning speed of the pulsed laser is 5 mm / s to 20 mm / s;

[0079] Optionally, the spot overlap rate of the pulsed laser is 20% to 50%;

[0080] Optionally, the scanning repetition times of the pulsed laser is 3 times to 5 times.

[0081] The present invention uses nanosecond pulsed laser to ablate the surface of the environmental barrier intermediate layer. In some ablated areas, melting occurs, and after cooling and solidification, a dense structure is formed, effectively suppressing the infiltration of CMAS along the cracks; in some ablated areas, decomposition and vaporization occur, and after cooling and deposition, a micro-mastoid columnar structure is formed, which has superhydrophobic properties, can reduce the wettability of CMAS on the coating surface, reduce the attachment of CMAS, and further improve the CMAS corrosion resistance of the coating. At the same time, the preparation method is simple and efficient, has strong repeatability, flexible and controllable process parameters, and low preparation cost.

[0082] In some embodiments, the preparation method of the adhesive layer includes the atmospheric plasma spraying method.

[0083] As a possible embodiment, when preparing the adhesive layer, the spraying current of the atmospheric plasma spraying is 550 A to 650 A; for example, it can be but not limited to 500 A, 510 A, 530 A, 550 A, 570 A, 590 A, 600 A, 610 A, 630 A, 650 A or the range between any two of the above spraying currents, etc.

[0084] In some alternative embodiments, when preparing the adhesive layer, the spraying power of atmospheric plasma spraying is 38 kW to 42 kW; for example, it can be, but is not limited to, 38 kW, 39 kW, 40 kW, 41 kW, 42 kW, or the range between any two of the above powers, etc.

[0085] In some of these embodiments, when preparing the adhesive layer, the gas used in atmospheric plasma spraying includes argon. Further optionally, the argon gas flow rate is 32 slpm to 38 slpm; for example, it can be, but is not limited to, 32 slpm, 33 slpm, 34 slpm, 35 slpm, 36 slpm, 37 slpm, 38 slpm, or the range between any two of the above flow rates, etc.

[0086] In some exemplary embodiments, when preparing the adhesive layer, the gas used in atmospheric plasma spraying includes hydrogen. As a non-limiting example, the hydrogen gas flow rate is 7 slpm to 10 slpm; for example, it can be, but is not limited to, 7 slpm, 7.5 slpm, 8 slpm, 8.5 slpm, 9 slpm, 9.5 slpm, 10 slpm, or the range between any two of the above flow rates, etc.

[0087] In some embodiments, when preparing the adhesive layer, the powder feeding rate of atmospheric plasma spraying is 20 g / min to 30 g / min; for example, it can be, but is not limited to, 20 g / min, 22 g / min, 24 g / min, 26 g / min, 28 g / min, 30 g / min, or the range between any two of the above powder feeding rates, etc.

[0088] In some alternative embodiments, when preparing the adhesive layer, the spraying distance of atmospheric plasma spraying is 85 mm to 110 mm; for example, it can be, but is not limited to, 85 mm, 86 mm, 88 mm, 90 mm, 92 mm, 94 mm, 96 mm, 98 mm, 100 mm, 102 mm, 104 mm, 106 mm, 108 mm, 110 mm, or the range between any two of the above distances, etc.

[0089] In some embodiments, the method for preparing the environmental barrier intermediate layer includes atmospheric plasma spraying.

[0090] In some alternative embodiments, when preparing the intermediate layer, the spraying current of atmospheric plasma spraying is 600 A to 800 A; for example, it can be, but is not limited to, 600 A, 620 A, 640 A, 680 A, 700 A, 720 A, 740 A, 760 A, 780 A, 800 A, or the range between any two of the above spraying currents, etc.

[0091] In some alternative embodiments, when preparing the intermediate layer, the spraying power of atmospheric plasma spraying is 42 kW to 48 kW; for example, it can be, but is not limited to, 42 kW, 43 kW, 44 kW, 45 kW, 46 kW, 47 kW, 48 kW, or the range between any two of the above powers, etc.

[0092] In some of these embodiments, when preparing the intermediate layer, the gas used in atmospheric plasma spraying includes argon. Further optionally, the argon gas flow rate is 32 slpm to 45 slpm; for example, it can be, but is not limited to, 32 slpm, 34 slpm, 36 slpm, 38 slpm, 40 slpm, 41 slpm, 43 slpm, 45 slpm, or the range between any two of the above flow rates, etc.

[0093] In some exemplary embodiments, when preparing the intermediate layer, the gas used in atmospheric plasma spraying includes hydrogen. As a non-limiting example, the hydrogen gas flow rate is 8 slpm to 14 slpm; for example, it can be, but is not limited to, 8 slpm, 9 slpm, 10 slpm, 11 slpm, 12 slpm, 13 slpm, 14 slpm, or the range between any two of the above flow rates, etc.

[0094] In some alternative embodiments, when preparing the intermediate layer, the powder feeding rate of atmospheric plasma spraying is 25 g / min to 35 g / min; for example, it can be, but is not limited to, 25 g / min, 26 g / min, 27 g / min, 28 g / min, 29 g / min, 30 g / min, 31 g / min, 32 g / min, 33 g / min, 34 g / min, 35 g / min, or the range between any two of the above powder feeding rates, etc.

[0095] In some of these embodiments, when preparing the intermediate layer, the spraying distance of atmospheric plasma spraying is 85 mm to 120 mm; for example, it can be, but is not limited to, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, or the range between any two of the above distances, etc.

[0096] In some embodiments, pulsed laser is used to ablate the surface of the environmental barrier intermediate layer.

[0097] In some alternative embodiments, when performing the ablation treatment, the central wavelength of the laser of the pulsed laser is 355 nm.

[0098] In some exemplary embodiments, when performing ablation treatment, the laser pulse width of the pulsed laser is 10 ns to 20 ns; for example, it can be, but is not limited to, 10 ns, 12 ns, 14 ns, 16 ns, 18 ns, 20 ns, or the range between any two of the above pulse widths, etc.

[0099] As a possible embodiment, when performing ablation treatment, the laser energy density of the pulsed laser is 0.5 J / mm 2 ~5 J / mm 2 ; for example, it can be, but is not limited to, 0.5 J / mm 2 、1.0 J / mm 2 、1.5 J / mm 2 、2.0 J / mm 2 、2.5 J / mm 2 、3.0 J / mm 2 、3.5 J / mm 2 、4.0 J / mm 2 、4.5 J / mm 2 、5.0 J / mm 2 or the range between any two of the above powers, etc.

[0100] In some alternative embodiments, when performing ablation treatment, the repetition frequency of the pulsed laser is 10 kHz to 30 kHz; for example, it can be, but is not limited to, 10 kHz, 12 kHz, 14 kHz, 16 kHz, 18 kHz, 20 kHz, 22 kHz, 24 kHz, 26 kHz, 28 kHz, 30 kHz, or the range between any two of the above frequencies, etc.

[0101] As a possible embodiment, when performing ablation treatment, the scanning speed of the pulsed laser is 5 mm / s to 20 mm / s; for example, it can be, but is not limited to, 5 mm / s, 7 mm / s, 9 mm / s, 10 mm / s, 12 mm / s, 14 mm / s, 16 mm / s, 18 mm / s, 20 mm / s, or the range between any two of the above speeds, etc.

[0102] In some alternative embodiments, when performing ablation treatment, the number of scanning repetitions of the pulsed laser is 3 to 5 times; for example, it can be, but is not limited to, 3 times, 4 times, 5 times, or the range between any two of the above values, etc.

[0103] Example 1

[0104] S1: Select a SiC ceramic with a size of 20×20×8 mm 3 as the substrate, and perform sandblasting pretreatment on the SiC ceramic substrate. The sandblasting pressure is 4.5 MPa, and the sandblasting time is 240 seconds.

[0105] S2: The bonding layer is prepared on the surface of the pretreated SiC ceramic matrix by atmospheric plasma spraying. Set the serpentine spraying path and the corresponding spraying parameters. After preheating the SiC matrix to 200 °C, start the gun. The spraying powder used is Si powder, and the powder particle size D50 is 54 μm. The spraying parameters are as follows: spraying current is 620 A, spraying power is 42 kW, argon gas flow rate is 36 slpm, hydrogen gas flow rate is 8 slpm, powder feeding rate is 28 g / min, spraying distance is 90 mm, and the thickness of the Si bonding layer is about 97 μm.

[0106] S3: The intermediate layer is prepared on the surface of the bonding layer by atmospheric plasma spraying. The spraying powder used is ytterbium pyrosilicate (Yb2SiO5), and the powder particle size D50 is 46 μm. The spraying path is the same as that of the bonding layer. After heating the matrix with the bonding layer to 200 °C, start the gun. The spraying parameters are: spraying current is 720 A, gun power is 46 kW, argon gas flow rate is 42 slpm, hydrogen gas flow rate is 12 slpm, powder feeding rate is 33 g / min, spraying distance is 100 mm, and the thickness of the intermediate layer is about 140 μm.

[0107] S4: Set the processing parameters of the laser to ablate the environmental barrier intermediate layer, and the scanning path is a serpentine path. The laser ablation parameters are: pulse width is 10 ns, laser energy density is 4 J / mm 2 , repetition frequency is 10 kHz, scanning speed is 10 mm / s, scanning repetition times is 3 times, spot overlap rate is 40%, and an environmental barrier coating with an anti-CMAS layer-column composite structure is obtained after treatment.

[0108] Comparative Example 1

[0109] The preparation method of Comparative Example 1 is similar to that of Example 1, except that: in Comparative Example 1, there is no step S4, the environmental barrier intermediate layer is not ablated, and there is no anti-CMAS corrosion layer on the surface of the intermediate layer.

[0110] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. 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 should be covered by the protection scope of the present invention.

Claims

1. An anti-CMAS layer-column composite structure environmental barrier coating, characterized in that: It includes a SiC-based ceramic substrate, an adhesive layer, an environmental barrier intermediate layer and an anti-CMAS corrosion layer which are stacked in sequence; The anti-CMAS corrosion layer comprises a dense sublayer and a columnar sublayer which are stacked in sequence; the dense sublayer is stacked on the environmental barrier intermediate layer; and the columnar sublayer is a columnar structure.

2. The anti-CMAS layer-column composite structure environmental barrier coating according to claim 1, characterized in that: 1.5<Environmental barrier intermediate layer thickness: Adhesive layer thickness <2.

5.

3. The anti-CMAS layer-column composite structure environmental barrier coating according to claim 1, characterized in that: 15<Thickness of environmental barrier intermediate layer: Thickness of dense sublayer<25.

4. The anti-CMAS layer-column composite structure environmental barrier coating according to claim 1, characterized in that: 1.5<thickness of dense sublayer: thickness of columnar sublayer<2.

5. The anti-CMAS layer-column composite structure environmental barrier coating according to claim 1, characterized in that: The material of the SiC-based ceramic matrix is ​​a silicon carbide matrix or a silicon carbide fiber reinforced silicon carbide ceramic-based composite material matrix.

6. The anti-CMAS layer-column composite structure environmental barrier coating according to claim 1, characterized in that: The material of the adhesive layer is Si.

7. The anti-CMAS layer-column composite structure environmental barrier coating according to claim 1, characterized in that: The material of the environmental barrier intermediate layer is Yb2Si2O7.

8. The anti-CMAS layer-column composite structure environmental barrier coating according to claim 1, characterized in that: The material of the dense sublayer is Yb2SiO5.

9. The anti-CMAS layer-column composite structure environmental barrier coating according to any one of claims 1 to 8, characterized in that: The columnar structure is a micron-mastoid columnar structure.

10. A method for preparing the anti-CMAS layer-column composite structure environmental barrier coating according to any one of claims 1 to 9, characterized in that: The specific steps are as follows: S1: sandblasting pretreatment of SiC-based ceramic substrate; S2: depositing an adhesive layer on the surface of the SiC-based ceramic substrate; S3: depositing an environmental barrier intermediate layer on the surface of the adhesive layer; S4: ablating the surface of the environmental barrier intermediate layer by using nanosecond pulse laser to prepare an anti-CMAS corrosion layer including a dense sublayer and a columnar sublayer, thereby obtaining the anti-CMAS layer-column composite structure environmental barrier coating.

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