Silicon Carbide Coated Graphite Derived from Chlorine Free Preceramic Polymer Precursor

抄録

Graphite is widely used in electronic industry due to its excellent electrical and thermal properties. However, graphite starts to oxidize around 350°C which seriously degrades its properties. SiC coating can be applied to graphite to improve its high temperature oxidation resistance. In this research, SiC coating on graphite was made via preceramic polymer using a polymethylphenylsilane. 20% of polymethylphenylsilane in hexane solution was coated onto graphite by dip coating method. After coating, thermal oxidation was carried out at 200°C for crosslink of the preceramic polymer and the sample were pyrolysized at 1200°C under nitrogen to convert the preceramic polymer to SiC film. The phase formation, stiochiometry and microstructure of the SiC coating after pyrolysis were investigated using low angle XRD and FESEM etc. Oxidation resistance up to 600°C was evaluated.