Microwave irradiation assisted synthesis of silicon carbide nanowhiskers

Abstract

Silicon carbide (SiC) is an important ceramic for engineering and industrial applications in harsh conditions of high temperature oxidative environment. For the synthesis of SiC in manufacturing process, conventional heating process is commonly used. In this study, SiC nanowhiskers are synthesized by microwave heating from mixture of graphite and silica. Graphite and silica in the ratio of 3:1 were mixed in ultrasonic bath using ethanol as medium for one hour. The mixture was then dried on hotplate and cold pressed uniaxially into a pellet die. The pellet was then heated by using laboratory microwaves oven to 1400°C at heating rate of 20°C /min and temperature was kept for 30 minutes. Scanning electron microscopy (SEM) showed that SiC nanowhiskers were successfully synthesized. X-ray diffraction (XRD) pattern indicated SiC phase was present after the mixture of graphite and silicon dioxide (SiO2) were exposed to microwave irradiation. Electron microscopy analysis showed that the SiC formed was in the form of nanowhiskers.