Application and evaluation of boron nitride-assisted liquid silicon infiltration for preparing Cf/SiC composites

서지정보

· 발행기관 : 한국탄소학회
· 수록지 정보 : Carbon Letters / 12권 / 2호
· 저자명 : 김진훈, EuigyungJeong, 김세영, 이영식

목차

1. Introduction
2. Experimental
3. Results and Discussion
4. Conclusions
References

초록

C/SiC composites were prepared by boron nitride (BN)-assisted liquid silicon infiltration
(LSI), and their anti-oxidation and mechanical properties were investigated. The
microstructures, bulk densities, and porosities of the C/SiC composites demonstrated
that the infiltration of liquid silicon into the composites improved them, because the
layered-structure BN worked as a lubricant. Increasing the amount of BN improved the
anti-oxidation of the prepared C/SiC composites. This synergistic effect was induced
by the assistance of BN in the LSI. More thermally stable SiC was formed in the composite,
and fewer pores were formed in the composite, which reduced inward oxygen
diffusion. The mechanical strength of the composite increased up to the addition of 3%
BN and decreased thereafter due to increased brittleness from the presence of more
SiC in the composite. Based on the anti-oxidation and mechanical properties of the
prepared composites, we concluded that improved anti-oxidation of C/SiC composites
can be achieved through BN-assisted LSI, although there may be some degradation of
the mechanical properties. The desired anti-oxidation and mechanical properties of the
composite can be achieved by optimizing the BN-assisted LSI conditions.
Key words: LSI, boron nitride, C/SiC composites, anti-oxidation, mechanical properties

영어초록

C/SiC composites were prepared by boron nitride (BN)-assisted liquid silicon infiltration(LSI), and their anti-oxidation and mechanical properties were investigated. Themicrostructures, bulk densities, and porosities of the C/SiC composites demonstratedthat the infiltration of liquid silicon into the composites improved them, because thelayered-structure BN worked as a lubricant. Increasing the amount of BN improved theanti-oxidation of the prepared C/SiC composites. This synergistic effect was inducedby the assistance of BN in the LSI. More thermally stable SiC was formed in the composite,and fewer pores were formed in the composite, which reduced inward oxygendiffusion. The mechanical strength of the composite increased up to the addition of 3%BN and decreased thereafter due to increased brittleness from the presence of moreSiC in the composite. Based on the anti-oxidation and mechanical properties of theprepared composites, we concluded that improved anti-oxidation of C/SiC compositescan be achieved through BN-assisted LSI, although there may be some degradation ofthe mechanical properties. The desired anti-oxidation and mechanical properties of thecomposite can be achieved by optimizing the BN-assisted LSI conditions.Key words: LSI, boron nitride, C/SiC composites, anti-oxidation, mechanical properties

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