Preparation of Silicon Carbide Ceramics from Bamboo Charcoal by High-Temperature Silicon Infiltration

Bamboo charcoal, silica, and phenol-formaldehyde resin were mixed powders that were heated at temperatures from 1,500°C to 1,800°C in an argon atmosphere to produce a silicon carbide (SiC) ceramic. Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDXA) were used to monitor heat flow and physical, chemical, and structural changes during the formation of the ceramic. The DSC results indicated that during firing, endothermic reactions occurred below 800°C, after which exothermic reactions dominated. FTIR study suggested conversion of Si-O bonds to Si-C bonds at temperatures above 1,500°C. SEM and EDXA showed that the microstructure of the bamboo charcoal was observable in the ceramic structure and that the surface of the ceramic material contained a high proportion of Si. X-ray diffractometry analysis indicated that the ceramics obtained by firing above 1,650°C mainly consisted of SiC with trace amounts of elemental carbon and silicon.