Temperature-dependent microstructure and phase evolution of iron-containing SiC fibers

Oxygen-free silicon carbide (SiC) fibers were prepared by using polycarbosilane and iron pentacarbonyl [Fe(CO)(5)] as the' raw material. The developments in microstructure and phase of the fibers upon the selected heat-treated temperatures were studied by XRD, FTlR, DTA-TG, SEM, and TEM techniques. The results revealed that the sintering of SiC fibers was promoted by introducing small amount of Fe. The iron-containing nanoparticles existed in the form of alpha-Fe in the SiC fibers pyrolyzed below 1000 degrees C. Above 1200 degrees C, most of the iron-containing nanoparticles existed in the form of Fe3Si. The SiC grains became obviously coarse above 1600 degrees C due to the decomposition of SiCxOy. After being sintered at 1800 degrees C, the final iron-containing SiC fibers were oxygen-free and remained dense. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.