Reaction Mechanism of Silicon Carbide Ceramics Derived from Woods
木材陶瓷化反应机理的研究

The process of reaction of silicon carbide ceramics derived from wood was investigated. The reaction mechanism was also analyzed. The results show that the temperature of silicon infiltration determines the ultimate microstructure of SiC ceramics. Porous SiC materials are formed at lower temperature, while at higher temperature, compact Si/SiC composite materials formed. The process of silicon-carbon reaction can be described as three steps: (1) Melted Si ascends via capillary of charcoal and reacts with contacted carbon forming silicon carbide. (2) The thickness of SiC layer increases toward carbon layer till the end. (3) Reaction-formed SiC will re-crystallize in the later stage of the reaction, and the ultimate microstructure is composed of large size of polygonal SiC and free Si.