Microstructural and Microchemical Characterization of Silicon Carbide and Silicon Carbonitride Ceramic Fibers Produced from Polymer Precursors

Several continuous SiC and SiC/N-based ceramic fibers prepared from different polymer precursors have been characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and high-resolution electron microscopy (HREM). Methods to prepare longitudinal as well as cross-sectional thin specimens from brittle ceramic fibers were developed to facilitate HREM and EELS studies. Lattice images clearly showed nanometer-sized crystallites, as well as amorphous regions. Microchemical analysis using EELS permitted study of the form and distribution of the various chemical species within the fibers.