CVD (Chemical Vapor Deposition) SiC/SiO2 gradient antioxidant composite coating and preparation method thereof

Abstract

The invention discloses a CVD SiC / SiO2 gradient antioxidant composite coating and a preparation method thereof. The CVD (Chemical Vapor Deposition) SiC / SiO2 gradient antioxidant composite coating is mainly used for long-time antioxidant protection of graphite, a C / C composite material and an easily oxidized ceramic-based material (such as a C / C-ceramic composite material, C / ceramic composite material, carbide ceramics and the like). The coating is prepared by adopting a chemical vapor deposition (CVD) method and has good controllability and designability. The coating comprises a SiC coating, a SiO2 coating and a SiC and a SiO2 co-deposition coating. The coating is formed by a gradient or is a multilayer composite gradient coating which is formed by multiple gradients; the multilayer composite gradient coating is sequentially SiC / SiC-SiO2 / SiO2 coating from inside to outside, or sequentially SiC / SiC-SiO2 / SiC-SiO2 / SiC-SiO2 / SiO2 coating, or sequentially SiC / SiC-SiO2 / SiO2 / SiO2-SiC / SiC / SiC-SiO2 / SiO2......SiC / SiC-SiO2 / SiO2, or SiC / SiC- SiO2 / SiO2-SiC / SiC-SiO2 / ...... / SiO2-SiC / SiC-SiO2 / SiO2, or SiC / SiC-SiO2 / SiC-SiO2 / SiO2- SiC / SiC-SiO2 / ....... / SiC-SiO2 / SiC-SiO2 / SiO2, or is only a SiC-SiO2 codepostion coating. The prepared gradient composite coating has good long-time oxidation resistance at the temperature of from a room temperature to 1700 DEG C.

Description

technical field

[0001] The invention relates to a gradient anti-oxidation composite coating of graphite, C / C composite material and ceramic base material and a preparation method thereof, which provide long-term anti-oxidation protection in the temperature range from room temperature to 1700°C. Background technique

[0002] Graphite, C / C composite materials and ceramic-based materials (such as C / C-ceramic composite materials, C / ceramic composite materials, and carbide ceramics) have a series of advantages such as excellent high temperature resistance, ablation resistance, and wear resistance. Especially under inert atmosphere or vacuum conditions, it still has good strength, modulus and other mechanical properties at high temperatures, so it has broad application prospects in the field of aerospace. However, in an oxidizing atmosphere, these materials will be oxidized rapidly, resulting in catastrophic damage to the material, which greatly restricts its application. Therefo...

Examples

Embodiment 1

[0036] SiC / SiC~SiO 2 / SiO 2 Preparation of composite coating

[0037] After the graphite substrate was polished with No. 600 SiC sandpaper, it was cleaned with distilled water and absolute ethanol in sequence, and then dried in an oven at 100°C for 12 hours before use.

[0038] (1) Preparation of SiC coating

[0039] Place the surface-treated graphite substrate in a chemical vapor deposition furnace with CH 3 SiCl 3 -H 2 -Ar system preparation, where CH 3 SiCl 3 (MTS) is the Si source, the water bath is kept at a constant temperature of 30-35°C, and the 2 Bubble the carrier gas into the CVD furnace. The deposition temperature is 1100° C., the deposition pressure is 700 Pa, and the deposition time is 1 h.

[0040] (2)SiC~SiO 2 Coating Preparation

[0041] Maintain process parameter and process condition in step (1), pass into carbon dioxide gas, keep CO 2 / H 2 The flow ratio is 0.47, the deposition time is 10h, and SiC~SiO is prepared by deposition 2 coating.

[...

Embodiment 2

[0047] SiC / SiC-SiO 2 / SiO 2 Preparation of composite coating

[0048] After the base material was polished with No. 600 SiC sandpaper, it was ultrasonically cleaned with distilled water and absolute ethanol in turn, and then dried in an oven at 100°C for 12 hours before use.

[0049] (1) Preparation of SiC coating

[0050] Place the surface-treated substrate material in a chemical vapor deposition furnace with CH 3 SiCl 3 -H 2 -Ar system preparation, where CH 3 SiCl 3 (MTS) is the Si source, the water bath maintains a constant temperature of 34.5 ° C, and the H 2 Bubble the carrier gas into the CVD furnace. The deposition temperature is 900° C., the deposition pressure is 10 kPa, and the deposition time is 10 h.

[0051] (2) SiC-SiO 2 Coating preparation

[0052] Keep process parameters and process conditions in step (1), feed carbon dioxide gas, and gradually CO 2 / H 2 The flow ratio was increased from 0.32 to 1.28, the deposition time was 10h, and SiC-SiO was pr...

Embodiment 3

[0057] SiC / SiC-SiO 2 / SiC~SiO 2 / SiC-SiO 2 / SiO 2 Preparation of composite coating

[0058] After the base material was polished with No. 600 SiC sandpaper, it was ultrasonically cleaned with distilled water and absolute ethanol in turn, and then dried in an oven at 100°C for 12 hours before use.

[0059] (1) Preparation of SiC coating

[0060] Place the surface-treated substrate material in a chemical vapor deposition furnace with CH 3 SiCl 3 -H 2 Ar system preparation, where CH 3 SiCl 3 (MTS) is the Si source, the water bath maintains a constant temperature of 30.5 ° C, and the H 2 Bubble the carrier gas into the CVD furnace. The deposition temperature is 1300° C., the deposition pressure is 700 Pa, and the deposition time is 4 hours.

[0061] (2) SiC-SiO 2 Coating Preparation

[0062] Keep process parameters and process conditions in step (1), feed carbon dioxide gas, and gradually CO 2 / H 2 The flow ratio was changed from 1.28 to 0.32, the deposition time wa...

technical field

[0001] The invention relates to a gradient anti-oxidation composite coating of graphite, C / C composite material and ceramic base material and a preparation method thereof, which provide long-term anti-oxidation protection in the temperature range from room temperature to 1700°C. Background technique

[0002] Graphite, C / C composite materials and ceramic-based materials (such as C / C-ceramic composite materials, C / ceramic composite materials, and carbide ceramics) have a series of advantages such as excellent high temperature resistance, ablation resistance, and wear resistance. Especially under inert atmosphere or vacuum conditions, it still has good strength, modulus and other mechanical properties at high temperatures, so it has broad application prospects in the field of aerospace. However, in an oxidizing atmosphere, these materials will be oxidized rapidly, resulting in catastrophic damage to the material, which greatly restricts its application. Therefo...

Examples

Embodiment 1

[0036] SiC / SiC~SiO 2 / SiO 2 Preparation of composite coating

[0037] After the graphite substrate was polished with No. 600 SiC sandpaper, it was cleaned with distilled water and absolute ethanol in sequence, and then dried in an oven at 100°C for 12 hours before use.

[0038] (1) Preparation of SiC coating

[0039] Place the surface-treated graphite substrate in a chemical vapor deposition furnace with CH 3 SiCl 3 -H 2 -Ar system preparation, where CH 3 SiCl 3 (MTS) is the Si source, the water bath is kept at a constant temperature of 30-35°C, and the 2 Bubble the carrier gas into the CVD furnace. The deposition temperature is 1100° C., the deposition pressure is 700 Pa, and the deposition time is 1 h.

[0040] (2)SiC~SiO 2 Coating Preparation

[0041] Maintain process parameter and process condition in step (1), pass into carbon dioxide gas, keep CO 2 / H 2 The flow ratio is 0.47, the deposition time is 10h, and SiC~SiO is prepared by deposition 2 coating.

[...

Embodiment 2

[0047] SiC / SiC-SiO 2 / SiO 2 Preparation of composite coating

[0048] After the base material was polished with No. 600 SiC sandpaper, it was ultrasonically cleaned with distilled water and absolute ethanol in turn, and then dried in an oven at 100°C for 12 hours before use.

[0049] (1) Preparation of SiC coating

[0050] Place the surface-treated substrate material in a chemical vapor deposition furnace with CH 3 SiCl 3 -H 2 -Ar system preparation, where CH 3 SiCl 3 (MTS) is the Si source, the water bath maintains a constant temperature of 34.5 ° C, and the H 2 Bubble the carrier gas into the CVD furnace. The deposition temperature is 900° C., the deposition pressure is 10 kPa, and the deposition time is 10 h.

[0051] (2) SiC-SiO 2 Coating preparation

[0052] Keep process parameters and process conditions in step (1), feed carbon dioxide gas, and gradually CO 2 / H 2 The flow ratio was increased from 0.32 to 1.28, the deposition time was 10h, and SiC-SiO was pr...

Embodiment 3

[0057] SiC / SiC-SiO 2 / SiC~SiO 2 / SiC-SiO 2 / SiO 2 Preparation of composite coating

[0058] After the base material was polished with No. 600 SiC sandpaper, it was ultrasonically cleaned with distilled water and absolute ethanol in turn, and then dried in an oven at 100°C for 12 hours before use.

[0059] (1) Preparation of SiC coating

[0060] Place the surface-treated substrate material in a chemical vapor deposition furnace with CH 3 SiCl 3 -H 2 Ar system preparation, where CH 3 SiCl 3 (MTS) is the Si source, the water bath maintains a constant temperature of 30.5 ° C, and the H 2 Bubble the carrier gas into the CVD furnace. The deposition temperature is 1300° C., the deposition pressure is 700 Pa, and the deposition time is 4 hours.

[0061] (2) SiC-SiO 2 Coating Preparation

[0062] Keep process parameters and process conditions in step (1), feed carbon dioxide gas, and gradually CO 2 / H 2 The flow ratio was changed from 1.28 to 0.32, the deposition time wa...

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