Microstructures of a SiC-ZrC Ceramic Fiber Derived from a Polymeric Precursor.

Continuous ceramic fiber comprising silicon carbide-zirconium carbide (SiC-ZrC) binary phases was obtained through melt spinning, electron-beam curing and pyrolysis of a pre-ceramic precursor of polyzirconocenecarbosilanes (PZCS). After pyrolysis and heat treatment, ZrC particles with mean diameters of 15-20 nm were formed and homogeneously dispersed in a matrix of fine crystalline β-SiC with an average grain size of 6-10 nm. Concentration of Zr in the fiber varies from 14.

Microstructures and Properties of Ceramic Fibers of h-BN Containing Amorphous SiN.

Composite ceramic fibers comprising about 80 wt% boron nitride (h-BN) and 20 wt% SiN were fabricated through melt-spinning, electron-beam curing, and pyrolysis up to 1600 °C in atmospheres of NH and N, using a mixture of poly[tri(methylamino)borazine] (PBN) and polysilazane (PSZ). By analyzing the microstructure and composition of the pyrolyzed ceramic fibers, we found the formation of binary phases including crystalline h-BN and amorphous SiN. Further investigations confirmed that this heterogeneous microstructure can only be formed when the introduced ratio of SiN is below 30% in mass.