Fabrication of short fiber reinforced SiCN by injection molding of preceramic polymers

Pre-ceramic polymers were used as organic vehicle in this study forming a ceramic matrix after pyrolysis. Carbon short-fibers were chosen as fiber materials. Because of inadequate processing properties of the used pre-ceramic polymer blending with thermoplastic waxes and process additives was necessary. An amorphous Si-C-N network was obtained as the matrix of the short-fiber composite after pyrolysis of the polysilazene precursor. In this study the influence of different fiber types, fractions and lengths on compounding and molding has been analyzed. Torque measurements were used for characterizing the flow ability and the thermal stability of the feedstock. The resulting composite parts have been analyzed regarding their microstructure and mechanical properties.