The effect of temperature and atmospheric-pressure on mechanical and electrical properties of polymer-derived SiC fibers

The polymer derived SiC fibers with high mechanical properties are mainly used as reinforcing materials for ceramic matrix composites (CMCs), which are applied in various fields. However, there is a problem that amorphous SiC fibers are decomposed by oxygen impurities and excess carbon at high temperature. In this study, SiC fibers prepared under various atmospheric-pressure near the decomposition temperature exhibited morphological gradient with various mechanical and electrical properties. In particular, the mechanical properties and electrical properties of polymer-derived SiC fibers showed an inverse correlation depending on the surface layer such as carbon-rich or amorphous SiCxOy.