A thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer and methods of making and using the same

Abstract

The application discloses a thermal / environmental barrier coating with an interface thermal expansion mismatch relieving layer and a preparation method and application thereof, and belongs to the technical field of thermal protection coating materials. The coating comprises, from outside to inside, a Si bonding layer, an RE12O3-2SiO2 environmental barrier coating, an interface thermal expansion mismatch relieving layer formed by a thermal shrinkage ceramic and an RE22O3-2MO-11Al2O3 ceramic composite, and an RE22O3-2MO-11Al2O3 thermal barrier coating. The coating is prepared by sequentially depositing the bonding layer, the environmental barrier coating, the interface thermal expansion mismatch relieving layer and the thermal barrier coating on the surface of a pretreated silicon carbide ceramic matrix composite by means of an atmospheric plasma spraying technology. The coating effectively relieves the thermal expansion mismatch problem at the interface between the thermal barrier coating and the environmental barrier coating, has excellent thermal cycle performance, can meet the long-time service requirement of an aero-engine hot end component under a high-temperature condition, and has wide application potential.

Description

Technical Field

[0001] This invention belongs to the technical field of thermal protective coating materials, specifically relating to a thermal / environmental barrier coating with interfacial thermal expansion mismatch, its preparation method, and its application. Background Technology

[0002] With the continuous increase in thrust-to-weight ratio, the service temperature of hot-section components in aero-engines will reach over 1400℃, far exceeding the service temperature of high-temperature alloys (<1150℃). Silicon carbide ceramic matrix composites possess advantages such as low density, high specific strength and modulus, and high-temperature resistance, and are expected to replace high-temperature alloys in aero-engine hot-section components to meet the service requirements of high thrust-to-weight ratio aero-engines. Silicon carbide ceramic matrix composites form a protective SiO2 layer on their surface in a dry oxidizing environment, preventing oxidation; however, water vapor in the aero-engine operating environment reacts with SiO2 to generate volatile SiO2. x O y This leads to weight loss and degradation of ceramic matrix composites.

[0003] Thermal / environmental barrier coatings can be used to protect silicon carbide ceramic matrix composites from vapor erosion and reduce their surface temperature. However, the coefficient of thermal expansion of existing thermal barrier coating materials is approximately 10 × 10⁻⁶. -6 K -1 It is far superior to environmental barrier coating materials (5-7×10). -6 K -1 The high coefficient of thermal expansion between the thermal barrier coating and the environmental barrier coating can easily lead to premature cracking and failure of the coating system. The introduction of an interfacial thermal expansion mismatch mitigation layer can effectively reduce the mismatch in thermal expansion coefficients between the thermal barrier coating and the environmental barrier coating. Materials for the interfacial thermal expansion mismatch mitigation layer must meet a series of requirements: a suitable coefficient of thermal expansion, high temperature resistance, excellent phase stability, chemical compatibility with both the thermal barrier coating and the environmental barrier coating materials, and resistance to water vapor corrosion. However, very few ceramic materials can meet these requirements. Therefore, research on interfacial thermal expansion mismatch mitigation layers and thermal / environmental barrier coatings incorporating such layers is crucial. Summary of the Invention

[0004] The purpose of this invention is to provide a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer, its preparation method, and its application. This effectively alleviates the problem of interfacial thermal expansion mismatch between the thermal barrier coating and the environmental barrier coating in thermal / environmental barrier coatings, and solves the problem that existing thermal / environmental barrier coating systems cannot meet the requirements for long-term service in high-temperature environments.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer is provided, comprising, from the inside out, a Si bonding layer, an RE12O3-2SiO2 environmental barrier coating, an interfacial thermal expansion mismatch mitigation layer formed by a composite of thermally shrinkable ceramic and RE22O3-2MO-11Al2O3 ceramic, and an RE22O3-2MO-11Al2O3 thermal barrier coating; wherein:

[0007] The heat-shrinkable ceramic is Lu2W3O. 12 Sc2W3O 12 and Mg2Al4Si5O 18 One of them;

[0008] The RE1 is one or more of Yb, Lu, Y, Er and Sc;

[0009] The RE2 is one or more of La, Pr, Nd, Sm, Eu, and Gd;

[0010] M is one or more of Mg, Zn, Ni and Cu.

[0011] The mass ratio of thermally shrinkable ceramic to RE22O3-2MO-11Al2O3 ceramic in the interface thermal expansion mismatch mitigation layer is 1:4-3:7.

[0012] According to the above scheme, the thickness of the Si bonding layer is 50-100μm, the thickness of the RE12O3-2SiO2 environmental barrier layer is 50-100μm, the thickness of the interfacial thermal expansion mismatch mitigation layer of the thermal shrinkage ceramic and the RE22O3-2MO-11Al2O3 ceramic composite is 50-100μm, and the thickness of the RE22O3-2MO-11Al2O3 thermal barrier coating is 50-100μm.

[0013] According to the above scheme, the thermal / environmental barrier coating uses silicon carbide ceramic matrix composite material as the matrix.

[0014] A method for preparing the above-mentioned thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer is provided, comprising the following steps:

[0015] By using atmospheric plasma spraying technology, a Si bonding layer, an RE12O3-2SiO2 environmental barrier layer, an interfacial thermal expansion mismatch mitigation layer formed by the composite of thermal shrinkage ceramic and RE22O3-2MO-11Al2O3 ceramic, and an RE22O3-2MO-11Al2O3 thermal barrier coating are sequentially deposited on the surface of the pretreated silicon carbide ceramic matrix composite material, thus obtaining a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer.

[0016] According to the above scheme, the roughness of the pretreated silicon carbide ceramic matrix composite material is 4-10 μm.

[0017] According to the above scheme, the pretreatment process for silicon carbide ceramic matrix composite material is as follows: the silicon carbide ceramic matrix composite material is ground, sandblasted, then ultrasonically cleaned and dried.

[0018] Preferably, the grinding medium is a 300-800 mesh diamond grinding wheel, and the grinding wheel speed is 100-600 r / min.

[0019] Preferably, the blasting medium is 150-300 mesh corundum sand, and the compressed air pressure is 0.1-1 MPa.

[0020] Preferably, the ultrasonic cleaning time is 5-15 minutes.

[0021] According to the above scheme, when depositing the Si binder layer, the particle size of the Si powder used for spraying is 25-50μm; during the atmospheric plasma spraying process, argon and hydrogen are used as plasma, the flow rate of argon is 30-50L / min, the flow rate of hydrogen is 5-10L / min, the spraying distance is 80-120mm, the spraying current is 500-800A, and the powder feed rate is 3-8%.

[0022] According to the above scheme, when depositing the RE12O3-2SiO2 environmental barrier layer, the particle size of the RE12O3-2SiO2 powder used for spraying is 30-140μm; during the atmospheric plasma spraying process, argon and hydrogen are used as plasma, the flow rate of argon is 30-60L / min, the flow rate of hydrogen is 7-16L / min, the spraying distance is 90-150mm, the spraying current is 600-900A, and the powder feed rate is 5-15%.

[0023] According to the above scheme, when depositing the interface thermal expansion mismatch mitigation layer, the particle size of the heat shrinkable ceramic and RE22O3-2MO-11Al2O3 ceramic composite powder used for spraying is 30-50μm; during the atmospheric plasma spraying process, argon and hydrogen are used as plasma, the flow rate of argon is 30-70L / min, the flow rate of hydrogen is 5-16L / min, the spraying distance is 80-150mm, the spraying current is 500-900A, and the powder feeding rate is 10-20%.

[0024] According to the above scheme, when depositing the RE22O3-2MO-11Al2O3 thermal barrier coating, the particle size of the RE22O3-2MO-11Al2O3 powder used for spraying is 30-120μm; during the atmospheric plasma spraying process, argon and hydrogen are used as plasma, the flow rate of argon is 30-60L / min, the flow rate of hydrogen is 5-15L / min, the spraying distance is 100-150mm, the spraying current is 500-1000A, and the powder feed rate is 6-10%.

[0025] This invention provides an application of the aforementioned thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer in the field of hot-end components of aero-engines.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] 1. This invention provides a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer. The interfacial thermal expansion mismatch mitigation layer is formed by selecting a suitable heat-shrinkable ceramic and combining it with RE22O3-2MO-11Al2O3 ceramic. The resulting interfacial thermal expansion mismatch mitigation layer has a thermal expansion coefficient of 6.5-8.0 × 10⁻⁶. -6 K -1 The RE12O3-2SiO2 environmental barrier coating (4.8-6.0×10) -6 K -1 ) and RE22O3-2MO-11Al2O3 thermal barrier coating (8.5-9.6×10 -6 K -1 The method can effectively alleviate the problem of thermal expansion mismatch between the thermal barrier coating and the environmental barrier coating in the thermal / environmental barrier coating; the resulting thermal / environmental barrier coating has excellent thermal cycling performance, with a thermal cycling life of not less than 600 cycles at 1400℃, which can meet the requirements of long-term service under high temperature conditions for hot-end components of aero-engines and has broad application potential.

[0028] 2. This invention provides a method for preparing a thermal / environmental barrier coating. The method employs atmospheric plasma spraying technology to prepare a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer on the surface of a silicon carbide ceramic matrix composite material. Compared with existing technologies such as physical vapor deposition, chemical vapor deposition, and low-pressure plasma spraying, the equipment and process used in this invention for preparing the coating are simple, low-cost, and easy to industrialize and apply. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer prepared in Example 1 of the present invention.

[0030] Figure 2 This is a schematic flowchart of the method for preparing a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer in Embodiment 1 of the present invention.

[0031] Figure 3 This is a cross-sectional morphology diagram of the thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer prepared in Example 1 of the present invention. Detailed Implementation

[0032] To better understand the present invention, the following description, in conjunction with the accompanying drawings in the embodiments, further illustrates the content of the present invention, but the present invention is not limited to the following embodiments.

[0033] Figure 1 This is a schematic cross-sectional view of a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer prepared on the surface of a silicon carbide ceramic matrix composite material according to Embodiment 1 of the present invention. As shown in the figure, the coating has a four-layer structure, consisting of, from the silicon carbide ceramic matrix composite material outwards, a Si bonding layer, an RE12O3-2SiO2 environmental barrier coating, an interfacial thermal expansion mismatch mitigation layer formed by the composite of heat-shrinkable ceramic and RE22O3-2MO-11Al2O3 ceramic, and a RE2O3-2MO-11Al2O3 thermal barrier coating; wherein:

[0034] The heat-shrinkable ceramic is Lu2W3O. 12 Sc2W3O 12 and Mg2Al4Si5O 18 RE1 is one or more of Yb, Lu, Y, Er and Sc; RE2 is one or more of La, Pr, Nd, Sm, Eu and Gd; and M is one or more of Mg, Zn, Ni and Cu.

[0035] The mass ratio of heat-shrinkable ceramic to RE22O3-2MO-11Al2O3 ceramic in the interface thermal expansion mismatch mitigation layer is 1:4 to 3:7. This invention reveals that when heat-shrinkable ceramic and RE22O3-2MO-11Al2O3 ceramic are used in the above-mentioned proportions, the resulting interface thermal expansion mismatch mitigation layer has a thermal expansion coefficient between that of a thermal barrier coating and an environmental barrier coating, effectively mitigating the interfacial thermal expansion mismatch problem between the thermal barrier coating and the environmental barrier coating in thermal / environmental barrier coatings.

[0036] Figure 2 This is a flowchart illustrating a method for preparing a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer on the surface of a silicon carbide ceramic matrix composite material according to Embodiment 1 of the present invention. The method includes the following steps:

[0037] (1) The silicon carbide ceramic matrix composite material is subjected to grinding and sandblasting pretreatment. The grinding process conditions are: 300-800 mesh diamond grinding wheel, grinding wheel speed is 100-600 r / min; the sandblasting process conditions are: 150-300 mesh corundum sand, compressed air pressure is 0.1-1 MPa.

[0038] (2) The pretreated silicon carbide ceramic matrix composite material was ultrasonically cleaned and dried;

[0039] (3) A Si bonding layer, an RE12O3-2SiO2 environmental barrier layer, an interfacial thermal expansion mismatch mitigation layer formed by thermal shrinkage ceramic and RE22O3-2MO-11Al2O3 ceramic composite, and an RE22O3-2MO-11Al2O3 thermal barrier coating are sequentially deposited on the surface of silicon carbide ceramic matrix composite material by atmospheric plasma spraying technology.

[0040] In the process of preparing the Si adhesive layer, argon and hydrogen are used as plasmas, with an argon flow rate of 30-50 L / min, a hydrogen flow rate of 5-10 L / min, a spraying distance of 80-120 mm, a spraying current of 500-800 A, a powder feeding rate of 3-8%, and a Si powder particle size of 25-50 μm.

[0041] In the preparation of the RE12O3-2SiO2 environmental barrier coating, argon and hydrogen were used as plasmas, with an argon flow rate of 30-60 L / min, a hydrogen flow rate of 7-16 L / min, a spraying distance of 90-150 mm, a spraying current of 600-900 A, a powder feed rate of 5-15%, and a RE12O3-2SiO2 powder particle size of 30-140 μm.

[0042] In the process of preparing the interfacial thermal expansion mismatch mitigation layer formed by the composite of heat-shrinkable ceramic and RE22O3-2MO-11Al2O3 ceramic, argon and hydrogen were used as plasmas, with an argon flow rate of 30-70 L / min and a hydrogen flow rate of 5-16 L / min. The spraying distance was 80-150 mm, the spraying current was 500-900 A, the powder feeding rate was 10-20%, and the particle size of the composite powder of heat-shrinkable ceramic and RE22O3-2MO-11Al2O3 ceramic was 30-50 μm.

[0043] In the preparation of the RE22O3-2MO-11Al2O3 thermal barrier coating, argon and hydrogen were used as plasmas, with an argon flow rate of 30-60 L / min and a hydrogen flow rate of 5-15 L / min. The spraying distance was 100-150 mm, the spraying current was 500-1000 A, the powder feed rate was 6-10%, and the particle size of the RE22O3-2MO-11Al2O3 powder was 30-120 μm.

[0044] Example 1

[0045] A method for preparing a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer includes the following steps:

[0046] (1) The silicon carbide ceramic matrix composite material was pretreated by grinding and sandblasting. The grinding process conditions were: 300-mesh diamond grinding wheel, grinding wheel speed of 200 r / min; the sandblasting process conditions were: 200-mesh corundum sand, compressed air pressure of 0.5 MPa; the surface roughness of the silicon carbide ceramic matrix composite material after pretreatment was measured to be 8 μm using a roughness tester.

[0047] (2) The pretreated silicon carbide ceramic matrix composite material was ultrasonically cleaned in 98% alcohol for 10 min and then dried at 120°C.

[0048] (3) A Si bonding layer was prepared on the surface of a silicon carbide ceramic matrix composite material that had been ultrasonically cleaned and dried by atmospheric plasma spraying technology. The particle size of the Si powder used for spraying was 25-50 μm, and the thickness of the Si bonding layer was 100 μm. The spraying process parameters were: argon flow rate of 30 L / min, hydrogen flow rate of 5 L / min, spraying distance of 80 mm, spraying current of 500 A, and powder feeding rate of 3%.

[0049] (4) An environmental barrier coating of Lu2O3-2SiO2 was prepared on the surface of the Si bonding layer by atmospheric plasma spraying technology. The particle size of the Lu2O3-2SiO2 powder used for spraying was 30-140μm, and the thickness of the Lu2O3-2SiO2 environmental barrier coating was 100μm. The spraying process parameters were: argon flow rate of 40L / min, hydrogen flow rate of 7L / min, spraying distance of 90mm, spraying current of 600A, and powder feeding rate of 5%.

[0050] (5) An interfacial thermal expansion mismatch mitigation layer was prepared on the surface of a Lu2O3-2SiO2 environmental barrier coating using atmospheric plasma spraying technology. The interfacial thermal expansion mismatch mitigation layer consisted of thermally shrinkable Lu2W3O3 with a mass ratio of 1:4. 12 It is composed of La2O3-2ZnO-11Al2O3. The particle size of the composite powder used for spraying is 30-50μm, and the thickness of the interfacial thermal expansion mismatch mitigation layer is 100μm. The spraying process parameters are: argon flow rate of 30L / min, hydrogen flow rate of 6L / min, spraying distance of 80mm, spraying current of 600A, and powder feeding rate of 10%.

[0051] (6) A La2O3-2ZnO-11Al2O3 thermal barrier coating was prepared on the surface of the interfacial thermal expansion mismatch mitigation layer by atmospheric plasma spraying technology. The particle size of the La2O3-2ZnO-11Al2O3 powder used for spraying was 30-120μm, and the thickness of the La2O3-2ZnO-11Al2O3 thermal barrier coating was 100μm. The spraying process parameters were: argon flow rate of 30L / min, hydrogen flow rate of 6L / min, spraying distance of 100mm, spraying current of 600A, and powder feeding rate of 6%.

[0052] Figure 3 The figure shows the cross-sectional morphology of the thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer prepared in Example 1. As can be seen from the figure, the coatings are well bonded to each other and to the substrate, and no obvious delamination cracks were observed.

[0053] The thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer prepared in this embodiment was subjected to thermal cycling performance testing. The test conditions were: holding at 1400℃ in a tube furnace for 5 minutes, followed by air cooling for 30 seconds, until the coating peeled off more than 10%, which was defined as failure. The results showed that the thermal / environmental barrier coating with the interfacial thermal expansion mismatch mitigation layer in this embodiment had a thermal cycling life of 670 cycles.

[0054] Comparative Example 1

[0055] Comparative Example 1 and Example 1 show that a Si bonding layer, a Lu2O3-2SiO2 environmental barrier coating, and a La2O3-2ZnO-11Al2O3 thermal barrier coating were deposited on the surface of a silicon carbide ceramic matrix composite material using atmospheric plasma spraying technology. The specific steps are as follows:

[0056] (1) The silicon carbide ceramic matrix composite material was pretreated by grinding and sandblasting. The grinding process conditions were: 300-mesh diamond grinding wheel, grinding wheel speed of 200 r / min; the sandblasting process conditions were: 200-mesh corundum sand, compressed air pressure of 0.5 MPa; the surface roughness of the silicon carbide ceramic matrix composite material after pretreatment was measured to be 8 μm using a roughness tester.

[0057] (2) The pretreated silicon carbide ceramic matrix composite material was ultrasonically cleaned in 98% alcohol for 10 min and then dried at 120°C.

[0058] (3) A Si bonding layer was prepared on the surface of a silicon carbide ceramic matrix composite material that had been ultrasonically cleaned and dried by atmospheric plasma spraying technology. The particle size of the Si powder used for spraying was 25-50 μm, and the thickness of the Si bonding layer was 100 μm. The spraying process parameters were: argon flow rate of 30 L / min, hydrogen flow rate of 5 L / min, spraying distance of 80 mm, spraying current of 500 A, and powder feeding rate of 3%.

[0059] (4) An environmental barrier coating of Lu2O3-2SiO2 was prepared on the surface of the Si bonding layer by atmospheric plasma spraying technology. The particle size of the Lu2O3-2SiO2 powder used for spraying was 30-140μm, and the thickness of the Lu2O3-2SiO2 environmental barrier coating was 100μm. The spraying process parameters were: argon flow rate of 40L / min, hydrogen flow rate of 7L / min, spraying distance of 90mm, spraying current of 600A, and powder feeding rate of 5%.

[0060] (5) A La2O3-2ZnO-11Al2O3 thermal barrier coating was prepared on the surface of a Lu2O3-2SiO2 environmental barrier coating by atmospheric plasma spraying technology. The particle size of the La2O3-2ZnO-11Al2O3 powder used for spraying was 30-120μm, and the thickness of the La2O3-2ZnO-11Al2O3 thermal barrier coating was 100μm. The spraying process parameters were: argon flow rate of 30L / min, hydrogen flow rate of 6L / min, spraying distance of 100mm, spraying current of 600A, and powder feeding rate of 6%.

[0061] The thermal / environmental barrier coating prepared in this comparative example was tested using the same test method as in Example 1, and its thermal cycle life was 263 cycles.

[0062] Comparative Example 2

[0063] Comparative Example 2, compared to Example 1, describes the deposition of a Si bonding layer and a heat-shrinkable ceramic Lu2W3O layer on the surface of a silicon carbide ceramic matrix composite material using atmospheric plasma spraying technology. 12 The specific steps for forming an interfacial thermal expansion mismatch mitigation layer, a Lu2O3-2SiO2 environmental barrier coating, and a La2O3-2ZnO-11Al2O3 thermal barrier coating by combining La2O3-2ZnO-11Al2O3 ceramic (mass ratio 1:9) are as follows:

[0064] (1) The silicon carbide ceramic matrix composite material was pretreated by grinding and sandblasting. The grinding process conditions were: 300-mesh diamond grinding wheel, grinding wheel speed of 200 r / min; the sandblasting process conditions were: 200-mesh corundum sand, compressed air pressure of 0.5 MPa; the surface roughness of the silicon carbide ceramic matrix composite material after pretreatment was measured to be 8 μm using a roughness tester.

[0065] (2) The pretreated silicon carbide ceramic matrix composite material was ultrasonically cleaned in 98% alcohol for 10 min and then dried at 120°C.

[0066] (3) A Si bonding layer was prepared on the surface of a silicon carbide ceramic matrix composite material that had been ultrasonically cleaned and dried by atmospheric plasma spraying technology. The particle size of the Si powder used for spraying was 25-50 μm, and the thickness of the Si bonding layer was 100 μm. The spraying process parameters were: argon flow rate of 30 L / min, hydrogen flow rate of 5 L / min, spraying distance of 80 mm, spraying current of 500 A, and powder feeding rate of 3%.

[0067] (4) An environmental barrier coating of Lu2O3-2SiO2 was prepared on the surface of the Si bonding layer by atmospheric plasma spraying technology. The particle size of the Lu2O3-2SiO2 powder used for spraying was 30-140μm, and the thickness of the Lu2O3-2SiO2 environmental barrier coating was 100μm. The spraying process parameters were: argon flow rate of 40L / min, hydrogen flow rate of 7L / min, spraying distance of 90mm, spraying current of 600A, and powder feeding rate of 5%.

[0068] (5) Heat-shrinkable ceramic Lu2W3O3 with a mass ratio of 1:9 was prepared on the surface of an environmental barrier coating of Lu2O3-2SiO2 by atmospheric plasma spraying technology. 12 The interfacial thermal expansion mismatch mitigation layer formed by the composite of La2O3-2ZnO-11Al2O3 ceramics was sprayed with a composite powder particle size of 30-50μm and a thickness of 100μm. The spraying process parameters were: argon flow rate of 30L / min, hydrogen flow rate of 6L / min, spraying distance of 80mm, spraying current of 600A, and powder feeding rate of 10%.

[0069] (6) A La2O3-2ZnO-11Al2O3 thermal barrier coating was prepared on the surface of the interfacial thermal expansion mismatch mitigation layer by atmospheric plasma spraying technology. The particle size of the La2O3-2ZnO-11Al2O3 powder used for spraying was 30-120μm, and the thickness of the La2O3-2ZnO-11Al2O3 thermal barrier coating was 100μm. The spraying process parameters were: argon flow rate of 30L / min, hydrogen flow rate of 6L / min, spraying distance of 100mm, spraying current of 600A, and powder feeding rate of 6%.

[0070] The thermal / environmental barrier coating prepared in this comparative example was tested using the same test method as in Example 1. The results showed that due to the heat shrinkage of the ceramic Lu2W3O 12 The inappropriate composite ratio of La2O3-2ZnO-11Al2O3 ceramics resulted in a thermal expansion coefficient of the interfacial thermal expansion mismatch mitigation layer being greater than that of the La2O3-2ZnO-11Al2O3 thermal barrier coating and the Lu2O3-2SiO2 environmental barrier coating. Consequently, the thermal / environmental barrier coating prepared in this comparative example had a thermal cycle life of only 181 cycles.

[0071] Comparative Example 3

[0072] Comparative Example 3, compared with Example 1, describes the deposition of a Si bonding layer, an interfacial thermal expansion mismatch mitigation layer formed by the thermal shrinkage ceramic ZrW2O8 and the La2O3-2ZnO-11Al2O3 ceramic composite, a Lu2O3-2SiO2 environmental barrier coating, and a La2O3-2ZnO-11Al2O3 thermal barrier coating on the surface of a silicon carbide ceramic matrix composite material using atmospheric plasma spraying technology. The specific steps are as follows:

[0073] (1) The silicon carbide ceramic matrix composite material was pretreated by grinding and sandblasting. The grinding process conditions were: 300-mesh diamond grinding wheel, grinding wheel speed of 200 r / min; the sandblasting process conditions were: 200-mesh corundum sand, compressed air pressure of 0.5 MPa; the surface roughness of the silicon carbide ceramic matrix composite material after pretreatment was measured to be 8 μm using a roughness tester.

[0074] (2) The pretreated silicon carbide ceramic matrix composite material was ultrasonically cleaned in 98% alcohol for 10 min and then dried at 120°C.

[0075] (3) A Si bonding layer was prepared on the surface of a silicon carbide ceramic matrix composite material that had been ultrasonically cleaned and dried by atmospheric plasma spraying technology. The particle size of the Si powder used for spraying was 25-50 μm, and the thickness of the Si bonding layer was 100 μm. The spraying process parameters were: argon flow rate of 30 L / min, hydrogen flow rate of 5 L / min, spraying distance of 80 mm, spraying current of 500 A, and powder feeding rate of 3%.

[0076] (4) An environmental barrier coating of Lu2O3-2SiO2 was prepared on the surface of the Si bonding layer by atmospheric plasma spraying technology. The particle size of the Lu2O3-2SiO2 powder used for spraying was 30-140μm, and the thickness of the Lu2O3-2SiO2 environmental barrier coating was 100μm. The spraying process parameters were: argon flow rate of 40L / min, hydrogen flow rate of 7L / min, spraying distance of 90mm, spraying current of 600A, and powder feeding rate of 5%.

[0077] (5) An interfacial thermal expansion mismatch mitigation layer was prepared on the surface of the Lu2O3-2SiO2 environmental barrier coating by atmospheric plasma spraying technology. The interfacial thermal expansion mismatch mitigation layer was composed of heat-shrinkable ZrW2O8 and La2O3-2ZnO-11Al2O3 with a mass ratio of 1:4. The particle size of the composite powder used for spraying was 30-50μm, and the thickness of the interfacial thermal expansion mismatch mitigation layer was 100μm. The spraying process parameters were: argon flow rate of 30L / min, hydrogen flow rate of 6L / min, spraying distance of 80mm, spraying current of 600A, and powder feeding rate of 10%.

[0078] (6) A La2O3-2ZnO-11Al2O3 thermal barrier coating was prepared on the surface of the interfacial thermal expansion mismatch mitigation layer by atmospheric plasma spraying technology. The particle size of the La2O3-2ZnO-11Al2O3 powder used for spraying was 30-120μm, and the thickness of the La2O3-2ZnO-11Al2O3 thermal barrier coating was 100μm. The spraying process parameters were: argon flow rate of 30L / min, hydrogen flow rate of 6L / min, spraying distance of 100mm, spraying current of 600A, and powder feeding rate of 6%.

[0079] The thermal cycling performance of the thermal / environmental barrier coating prepared in this comparative example was tested using the same test method as in Example 1. The results showed that the thermal / environmental barrier coating prepared in this comparative example had a thermal cycle life of only 206 cycles, indicating that the application of unsuitable heat-shrinkable ceramics to the interfacial thermal expansion mismatch mitigation layer actually reduced the thermal cycle life of the thermal / environmental barrier coating.

[0080] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer, characterized in that, The thermal / environmental barrier coating, from the inside out, consists of a Si bonding layer, an RE12O3-2SiO2 environmental barrier coating, an interfacial thermal expansion mismatch mitigation layer formed by the composite of thermal shrinkage ceramic and RE22O3-2MO-11Al2O3 ceramic, and an RE22O3-2MO-11Al2O3 thermal barrier coating; wherein: The heat-shrinkable ceramic is Lu2W3O. 12 and Sc2W3O 12 One of them; RE1 is one or more of Yb, Lu, Y, Er and Sc; The RE2 is one or more of La, Pr, Nd, Sm, Eu, and Gd; M is Zn; The mass ratio of thermally shrinkable ceramic to RE22O3-2MO-11Al2O3 ceramic in the interface thermal expansion mismatch mitigation layer is 1:4-3:

7.

2. The thermal / environmental barrier coating according to claim 1, characterized in that, The thickness of the Si bonding layer is 50-100 μm, the thickness of the RE12O3-2SiO2 environmental barrier layer is 50-100 μm, the thickness of the interfacial thermal expansion mismatch mitigation layer of the thermal shrinkage ceramic and the RE22O3-2MO-11Al2O3 ceramic composite is 50-100 μm, and the thickness of the RE22O3-2MO-11Al2O3 thermal barrier coating is 50-100 μm.

3. The thermal / environmental barrier coating according to claim 1, characterized in that, The thermal / environmental barrier coating uses silicon carbide ceramic matrix composite material as the matrix.

4. A method for preparing a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer as described in any one of claims 1-3, characterized in that, Includes the following steps: By using atmospheric plasma spraying technology, a Si bonding layer, an RE12O3-2SiO2 environmental barrier layer, an interfacial thermal expansion mismatch mitigation layer formed by the composite of thermal shrinkage ceramic and RE22O3-2MO-11Al2O3 ceramic, and an RE22O3-2MO-11Al2O3 thermal barrier coating are sequentially deposited on the surface of the pretreated silicon carbide ceramic matrix composite material, thus obtaining a thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer.

5. The preparation method according to claim 4, characterized in that, The roughness of the pretreated silicon carbide ceramic matrix composite material is 4-10 μm.

6. The preparation method according to claim 4, characterized in that, The pretreatment process for silicon carbide ceramic matrix composites is as follows: the silicon carbide ceramic matrix composites are ground, sandblasted, ultrasonically cleaned and dried.

7. The preparation method according to claim 6, characterized in that, The grinding media is a 300-800 mesh diamond grinding wheel with a grinding wheel speed of 100-600 r / min; the sandblasting media is a 150-300 mesh corundum abrasive with a compressed air pressure of 0.1-1 MPa; and the ultrasonic cleaning time is 5-15 min.

8. The preparation method according to claim 4, characterized in that, When depositing the Si binder layer, the particle size of the Si powder used in the spraying is 25-50 μm; during atmospheric plasma spraying, argon and hydrogen are used as plasma, with an argon flow rate of 30-50 L / min, a hydrogen flow rate of 5-10 L / min, a spraying distance of 80-120 mm, a spraying current of 500-800 A, and a powder feed rate of 3-8%. When depositing the RE12O3-2SiO2 environmental barrier layer, the particle size of the RE12O3-2SiO2 powder used for spraying is 30-140 μm; during atmospheric plasma spraying, argon and hydrogen are used as plasma, with an argon flow rate of 30-60 L / min, a hydrogen flow rate of 7-16 L / min, a spraying distance of 90-150 mm, a spraying current of 600-900 A, and a powder feed rate of 5-15%. When depositing the RE22O3-2MO-11Al2O3 thermal barrier coating, the particle size of the RE22O3-2MO-11Al2O3 powder used for spraying is 30-120μm; during atmospheric plasma spraying, argon and hydrogen are used as plasma, the flow rate of argon is 30-60 L / min, the flow rate of hydrogen is 5-15 L / min, the spraying distance is 100-150 mm, the spraying current is 500-1000 A, and the powder feed rate is 6-10%.

9. The preparation method according to claim 4, characterized in that, When depositing the interface thermal expansion mismatch mitigation layer, the particle size of the heat shrinkable ceramic and RE22O3-2MO-11Al2O3 ceramic composite powder used for spraying is 30-50 μm; during atmospheric plasma spraying, argon and hydrogen are used as plasma, the flow rate of argon is 30-70 L / min, the flow rate of hydrogen is 5-16 L / min, the spraying distance is 80-150 mm, the spraying current is 500-900 A, and the powder feed rate is 10-20%.

10. The application of the thermal / environmental barrier coating with an interfacial thermal expansion mismatch mitigation layer as described in any one of claims 1-3 in the field of hot-end components of aero-engines.

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