Synthesis of Silicon Carbide Nanowhiskers from Graphite and Silica of Different Ratio by Microwave Irradiation Assisted Synthesis

In this paper, the effect of ratio of silicon dioxide and graphite for the synthesis of silicon carbide nanowhiskers by microwaves heating was reported. The mixtures of SiO2 and graphite with different ratio were prepared by ultrasonic mixing using ethanol as medium. The mixtures were dried on hotplate and cold pressed by using hydraulic hand press uniaxially into a pellet die. The mixture in the form of pellet were heated up to 1400 °C at heating rate of 20 °C/min and soaked for 30 minutes. Scanning electron microscopy was used to study the morphology of sample of each different ratio of mixture. It was found that almost complete conversion of graphite and silica to silicon carbide nanowhiskers was observed for sample of mixture SiO2 and graphite in the ratio of 1:3. Result from x-ray diffraction analysis also indicated that single β-SiC phase was present in the diffractogram of silicon carbide nanowhiskers synthesized from mixture SiO2 and graphite in the ratio of 1:3.