솔-젤 공정으로 제조된 SiO2-C 복합 전구체를 사용하여 열탄소환원법에 의한 β-SiC 분말 합성에 금속 Si 첨가가 미치는 영향

Abstract

The objective of this study was to develop a synthesis process for β-SiC powders to reduce the synthesis temperature and to control the particle size and to prevent particle agglomeration of the synthesized β-SiC powders. A phenol resin and TEOS were used as the starting materials for the carbon and Si sources, respectively. SiO₂-C hybrid precursors with various C/Si mole ratios were fabricated using a conventional sol-gel process. β-SiC powders were synthesized by a carbothermal reduction process using SiO₂-C hybrid precursors with various C/Si mole ratios (1.6 ~ 2.5) fabricated using a sol-gel process. In this study, the effects of excess carbon and the addition of Si powders to the SiO₂-C hybrid precursor on the synthesis temperature and particle size of β-SiC were examined. It was found that the addition of metallic Si powders to the SiO₂/C hybrid precursor with excess carbon reduced the synthesis temperature of the β-SiC powders to as low as 1300℃. The synthesis temperature for β-SiC appeared to be reduced with an increase of the C/Si mole ratio in the SiO₂-C hybrid precursor by a direct carburization reaction between Si and excess carbon.