Environmental barrier coating as well as preparation method and application thereof

Abstract

The invention provides an environmental barrier coating. The environmental barrier coating is composed of a SiC bonding layer, a mullite middle layer and an ytterbium silicate outer coating, which coat a C / SiC composite material and are sequentially arranged from inside to outside. The C / SiC composite material coated by a SiC coating is prepared by a secondary chemical vapor deposition (CVD) method; the mullite middle layer is prepared by combining a sol-gel method with an air spraying technology, and the ytterbium silicate outer coating is prepared by combining a solid phase sintering technology with an air spraying technology. Through a smart EBC coating system and a preparation process, the ytterbium silicate outer coating is prepared by combining a solid phase sintering technology withan air spraying technology for the first time, the mullite middle layer and the ytterbium silicate outer coating are tightly combined, and the coating is compact and free of cracks. The traditional sol-gel process is improved to a great extent, the defects of cracking, peeling and poor binding force in the sintering process of a coating prepared through a traditional sol-gel method are maximallyovercome, and the use requirements of large components and special-shaped parts can be met.

Description

technical field

[0001] The invention relates to the technical field of preparation of high-temperature anti-oxidation / anti-corrosion composite coatings, and more specifically relates to an environmental barrier coating and its preparation method and application. Background technique

[0002] A high thrust-to-weight ratio is one of the hallmarks of a high-performance aeroengine. Increasing the temperature at the inlet of the engine turbine and reducing the density of materials can significantly increase its thrust-to-weight ratio. At present, the application temperature of traditional superalloy materials is close to the limit. Compared with traditional high-temperature alloy materials, C / SiC composite materials have the advantages of low density, high hardness, excellent high-temperature mechanical properties, and strong thermal shock resistance. C / SiC composite materials have high specific strength and can be maintained at 1600 ° C without It is an ideal high-temperature s...

Examples

preparation example Construction

[0045] The environmental barrier coating disclosed by the invention is composed of a SiC bonding layer, a mullite middle layer and an ytterbium silicate outer coating which are coated on a C / SiC composite material and arranged in sequence from the inside to the outside. Its preparation method comprises the following steps:

[0046] S1. Preparation of SiC bonding layer by secondary chemical vapor deposition

[0047] The surface of the C / SiC composite material was smoothed with sandpaper, ultrasonically cleaned and dried, and then placed in a chemical vapor deposition furnace; the deposition gas source (MTS), carrier gas (hydrogen) and dilution gas (argon) were continuously fed, Control the temperature in the furnace at 1050°C~1200°C; after the first deposition, turn the sample 180° in the vertical direction for the second deposition, and cool down with the furnace to obtain a SiC bonding layer-coated C / SiC composite material sample ; Specifically, the pressure in the depositio...

Embodiment 1

[0058] The preparation method of the environmental barrier coating of the present embodiment comprises the following steps:

[0059] S1. Preparation of SiC bonding layer by secondary chemical vapor deposition

[0060] The surface of the C / SiC composite material was smoothed with sandpaper, cleaned ultrasonically and dried, and then placed in a chemical vapor deposition furnace; trichloromethylsilane (MTS), hydrogen and argon were continuously fed, and the temperature in the furnace was controlled at 1100 ℃, the pressure in the furnace is 0.3~0.6kPa, the flow rate of trichloromethylsilane (MTS) is 800~1000mL / min, the flow rate of hydrogen gas is 1500~2500mL / min, the flow rate of argon gas is 1500~2500mL / min; the first deposition After 25 hours, turn the sample vertically 180° o Carry out the second deposition, the total deposition time is 50h, and obtain the SiC bonding layer-coated C / SiC composite material sample of the second deposition with furnace cooling;

[0061] S2. Pr...

Embodiment 2

[0069] The preparation method of the environmental barrier coating of the present embodiment comprises the following steps:

[0070] S1. Preparation of SiC bonding layer by secondary chemical vapor deposition

[0071] The surface of the C / SiC composite material was smoothed with sandpaper, ultrasonically cleaned and dried, and then placed in a chemical vapor deposition furnace; trichloromethylsilane (MTS), hydrogen and argon were continuously fed, and the temperature in the furnace was controlled at 1150 ℃, furnace pressure 0.3~0.6kPa, trichloromethylsilane (MTS) flow rate 800~1000mL / min, hydrogen flow rate 1500~2500mL / min, argon flow rate 1500~2500mL / min; first deposition 25h After that, turn the sample vertically 180 o Carry out the second deposition, the total deposition time is 50h, and obtain the SiC bonding layer-coated C / SiC composite material sample of the second deposition with furnace cooling;

[0072] S2. Preparation of mullite interlayer by sol-gel combined air s...

technical field

[0001] The invention relates to the technical field of preparation of high-temperature anti-oxidation / anti-corrosion composite coatings, and more specifically relates to an environmental barrier coating and its preparation method and application. Background technique

[0002] A high thrust-to-weight ratio is one of the hallmarks of a high-performance aeroengine. Increasing the temperature at the inlet of the engine turbine and reducing the density of materials can significantly increase its thrust-to-weight ratio. At present, the application temperature of traditional superalloy materials is close to the limit. Compared with traditional high-temperature alloy materials, C / SiC composite materials have the advantages of low density, high hardness, excellent high-temperature mechanical properties, and strong thermal shock resistance. C / SiC composite materials have high specific strength and can be maintained at 1600 ° C without It is an ideal high-temperature s...

Examples

preparation example Construction

[0045] The environmental barrier coating disclosed by the invention is composed of a SiC bonding layer, a mullite middle layer and an ytterbium silicate outer coating which are coated on a C / SiC composite material and arranged in sequence from the inside to the outside. Its preparation method comprises the following steps:

[0046] S1. Preparation of SiC bonding layer by secondary chemical vapor deposition

[0047] The surface of the C / SiC composite material was smoothed with sandpaper, ultrasonically cleaned and dried, and then placed in a chemical vapor deposition furnace; the deposition gas source (MTS), carrier gas (hydrogen) and dilution gas (argon) were continuously fed, Control the temperature in the furnace at 1050°C~1200°C; after the first deposition, turn the sample 180° in the vertical direction for the second deposition, and cool down with the furnace to obtain a SiC bonding layer-coated C / SiC composite material sample ; Specifically, the pressure in the depositio...

Embodiment 1

[0058] The preparation method of the environmental barrier coating of the present embodiment comprises the following steps:

[0059] S1. Preparation of SiC bonding layer by secondary chemical vapor deposition

[0060] The surface of the C / SiC composite material was smoothed with sandpaper, cleaned ultrasonically and dried, and then placed in a chemical vapor deposition furnace; trichloromethylsilane (MTS), hydrogen and argon were continuously fed, and the temperature in the furnace was controlled at 1100 ℃, the pressure in the furnace is 0.3~0.6kPa, the flow rate of trichloromethylsilane (MTS) is 800~1000mL / min, the flow rate of hydrogen gas is 1500~2500mL / min, the flow rate of argon gas is 1500~2500mL / min; the first deposition After 25 hours, turn the sample vertically 180° o Carry out the second deposition, the total deposition time is 50h, and obtain the SiC bonding layer-coated C / SiC composite material sample of the second deposition with furnace cooling;

[0061] S2. Pr...

Embodiment 2

[0069] The preparation method of the environmental barrier coating of the present embodiment comprises the following steps:

[0070] S1. Preparation of SiC bonding layer by secondary chemical vapor deposition

[0071] The surface of the C / SiC composite material was smoothed with sandpaper, ultrasonically cleaned and dried, and then placed in a chemical vapor deposition furnace; trichloromethylsilane (MTS), hydrogen and argon were continuously fed, and the temperature in the furnace was controlled at 1150 ℃, furnace pressure 0.3~0.6kPa, trichloromethylsilane (MTS) flow rate 800~1000mL / min, hydrogen flow rate 1500~2500mL / min, argon flow rate 1500~2500mL / min; first deposition 25h After that, turn the sample vertically 180 o Carry out the second deposition, the total deposition time is 50h, and obtain the SiC bonding layer-coated C / SiC composite material sample of the second deposition with furnace cooling;

[0072] S2. Preparation of mullite interlayer by sol-gel combined air s...

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