SiC-based composite ceramic and preparation method thereof

Abstract

The invention discloses SiC-based composite ceramic and a preparation method thereof. The SiC-based composite ceramic is prepared from Si and SiC, wherein SiC is a continuous matrix phase, Si is a free phase, and the free phase is distributed in the continuous matrix phase on the surface of the SiC-based composite ceramic. The preparation method comprises the following steps that 1, a mixed solid phase, organic monomers, a cross-linking agent and water are mixed and then subjected to ball milling, pre-mixed slurry is obtained, the mixed solid phase is composed of carbon black and alpha-SiC ceramic powder, the pre-mixed slurry is subjected to vacuum degassing and then mixed with an azoic compound, and mixed slurry is obtained; 2, gel casting is carried out; 3, gaseous phase siliconing sintering is carried out. The SiC-based composite ceramic has the advantages of being high in density, high in heat conductivity, low in heat expansion coefficient, excellent in polishing performance and the like; the preparation method is short in period, low in sintering temperature, free of sintering shrinking, controllable in finished product performance and capable of adapting to net-size forming of SiC-based ceramic elements in complex shapes.

Description

technical field

[0001] The invention belongs to the technical field of composite phase ceramics and its preparation, and in particular relates to a SiC-based composite phase ceramic and a preparation method thereof. Background technique

[0002] As a structural ceramic, silicon carbide has many excellent properties such as corrosion resistance, high temperature resistance, high strength, excellent thermal conductivity, and impact resistance. It is widely used in chemical, mechanical, aviation and other fields, and has always been the focus of research in the field of materials. and hotspots. However, ceramic materials are difficult to machine after sintering. People have been looking for a net-size molding method for complex-shaped ceramic components, which has become a key link to ensure the quality of ceramic components and obtain materials with practical application value.

[0003] Gel injection molding is a new technology developed on the basis of traditional grouting m...

Examples

Embodiment 1

[0033] A SiC-based composite phase ceramics of the present invention, specifically Si / SiC composite phase ceramics, including Si and SiC, wherein SiC is a continuous matrix phase, Si is a free phase, and the free phases are distributed on the surface of the SiC-based composite phase ceramics in the continuous matrix phase.

[0034] The Si / SiC composite ceramics is made of a mixed slurry sintered by gas-phase silicon infiltration. The mixed slurry is specifically composed of carbon black, α-SiC ceramic powder, acrylamide (organic monomer), N,N'-methylene bis Acrylamide (crosslinking agent), AIBA (initiator) and deionized water. After the mixed slurry is sintered by gas phase siliconization, carbon black is sintered by gas phase siliconization to generate β-SiC. β-SiC and the mixed slurry α-SiC is sintered to form a continuous SiC phase, and the gas phase silicon that has not participated in the reaction condenses in SiC on the surface of SiC-based multiphase ceramics to form a ...

Embodiment 2

[0046] A SiC-based composite phase ceramics of the present invention, specifically Si / SiC composite phase ceramics, including Si and SiC, wherein SiC is a continuous matrix phase, Si is a free phase, and the free phases are distributed on the surface of the SiC-based composite phase ceramics in the continuous matrix phase.

[0047] The Si / SiC composite ceramics is made of a mixed slurry sintered by gas-phase silicon infiltration. The mixed slurry is specifically composed of carbon black, α-SiC ceramic powder, acrylamide (organic monomer), N,N'-methylene bis Acrylamide (crosslinking agent), AIBA (initiator) and deionized water. After the mixed slurry is sintered by gas phase siliconization, carbon black is sintered by gas phase siliconization to generate β-SiC. β-SiC and the mixed slurry α-SiC is sintered to form a continuous SiC phase, and the gas phase silicon that has not participated in the reaction condenses in SiC on the surface of SiC-based multiphase ceramics to form a ...

Embodiment 3

[0055] A SiC-based composite phase ceramics of the present invention, specifically Si / SiC composite phase ceramics, including Si and SiC, wherein SiC is a continuous matrix phase, Si is a free phase, and the free phases are distributed on the surface of the SiC-based composite phase ceramics in the continuous matrix phase.

[0056] The Si / SiC composite ceramics is made of a mixed slurry sintered by gas-phase silicon infiltration. The mixed slurry is specifically composed of carbon black, α-SiC ceramic powder, acrylamide (organic monomer), N,N'-methylene bis Acrylamide (crosslinking agent), AIBA (initiator) and deionized water. After the mixed slurry is sintered by gas phase siliconization, carbon black is sintered by gas phase siliconization to generate β-SiC. β-SiC and the mixed slurry α-SiC is sintered to form a continuous SiC phase, and the gas phase silicon that has not participated in the reaction condenses in SiC on the surface of SiC-based multiphase ceramics to form a ...

technical field

[0001] The invention belongs to the technical field of composite phase ceramics and its preparation, and in particular relates to a SiC-based composite phase ceramic and a preparation method thereof. Background technique

[0002] As a structural ceramic, silicon carbide has many excellent properties such as corrosion resistance, high temperature resistance, high strength, excellent thermal conductivity, and impact resistance. It is widely used in chemical, mechanical, aviation and other fields, and has always been the focus of research in the field of materials. and hotspots. However, ceramic materials are difficult to machine after sintering. People have been looking for a net-size molding method for complex-shaped ceramic components, which has become a key link to ensure the quality of ceramic components and obtain materials with practical application value.

[0003] Gel injection molding is a new technology developed on the basis of traditional grouting m...

Examples

Embodiment 1

[0033] A SiC-based composite phase ceramics of the present invention, specifically Si / SiC composite phase ceramics, including Si and SiC, wherein SiC is a continuous matrix phase, Si is a free phase, and the free phases are distributed on the surface of the SiC-based composite phase ceramics in the continuous matrix phase.

[0034] The Si / SiC composite ceramics is made of a mixed slurry sintered by gas-phase silicon infiltration. The mixed slurry is specifically composed of carbon black, α-SiC ceramic powder, acrylamide (organic monomer), N,N'-methylene bis Acrylamide (crosslinking agent), AIBA (initiator) and deionized water. After the mixed slurry is sintered by gas phase siliconization, carbon black is sintered by gas phase siliconization to generate β-SiC. β-SiC and the mixed slurry α-SiC is sintered to form a continuous SiC phase, and the gas phase silicon that has not participated in the reaction condenses in SiC on the surface of SiC-based multiphase ceramics to form a ...

Embodiment 2

[0046] A SiC-based composite phase ceramics of the present invention, specifically Si / SiC composite phase ceramics, including Si and SiC, wherein SiC is a continuous matrix phase, Si is a free phase, and the free phases are distributed on the surface of the SiC-based composite phase ceramics in the continuous matrix phase.

[0047] The Si / SiC composite ceramics is made of a mixed slurry sintered by gas-phase silicon infiltration. The mixed slurry is specifically composed of carbon black, α-SiC ceramic powder, acrylamide (organic monomer), N,N'-methylene bis Acrylamide (crosslinking agent), AIBA (initiator) and deionized water. After the mixed slurry is sintered by gas phase siliconization, carbon black is sintered by gas phase siliconization to generate β-SiC. β-SiC and the mixed slurry α-SiC is sintered to form a continuous SiC phase, and the gas phase silicon that has not participated in the reaction condenses in SiC on the surface of SiC-based multiphase ceramics to form a ...

Embodiment 3

[0055] A SiC-based composite phase ceramics of the present invention, specifically Si / SiC composite phase ceramics, including Si and SiC, wherein SiC is a continuous matrix phase, Si is a free phase, and the free phases are distributed on the surface of the SiC-based composite phase ceramics in the continuous matrix phase.

[0056] The Si / SiC composite ceramics is made of a mixed slurry sintered by gas-phase silicon infiltration. The mixed slurry is specifically composed of carbon black, α-SiC ceramic powder, acrylamide (organic monomer), N,N'-methylene bis Acrylamide (crosslinking agent), AIBA (initiator) and deionized water. After the mixed slurry is sintered by gas phase siliconization, carbon black is sintered by gas phase siliconization to generate β-SiC. β-SiC and the mixed slurry α-SiC is sintered to form a continuous SiC phase, and the gas phase silicon that has not participated in the reaction condenses in SiC on the surface of SiC-based multiphase ceramics to form a ...

Images