A surface coating for silicon carbide whiskers

A mullite coating process has been conducted to form an electrically insulating layer on the surface of the silicon carbide whiskers for whisker reinforcement application by a chemical deposition and hydrolysis. The phase, structure, morphology and electrically insulating property of the coated silicon carbide whiskers have been investigated by using x-ray diffraction, scanning electron microscopy, transmission electron microscopy and electrical measurement. The study indicates that a crystalline mullite coating layer is formed after heat-treating the precursor coating at elevated temperature. The formed mullite coating significantly increases the electrical resistance of the silicon carbide whiskers.