In situ synthesis of ZrC/SiC nanocomposite via carbothermic reduction of binary xerogel

Nano-sized powder composite of zirconium carbide/silicon carbide (ZrC/SiC) was successfully synthesized via a combined sol gel/carbothermic reduction techniques. A sol containing zirconium from zirconium n-propoxide (ZTP) as well as a sol containing silicon from tetraethoxy orthosilicate (TEOS) was separately prepared. The two sols were mixed together for preparing a binary gel containing both. The produced binary xerogel was subjected to a carbothermic reduction reaction at temperature of 1500 degrees C for 3 h. The synthesized powder was characterized from compositional as well as morphological point of views using XRD, FT-IR, XPS, SEM and TEM analysis. The XRD data revealed that the powder composite consisted of pure ZrC/SiC was produced. This data was confirmed by presence of main planes (0 1 0) and (0 1 1) for ZrC and (1 1 1) plane for SIC, respectively. Moreover, XPS with help of FT-IR data show obviously that the ZrC/SiC composite was formed with traces of zirconium oxycarbide. Furthermore, SEM and TEM images confirmed that cubic nano-sized ZrC particles of size similar to 40 nm and hexagonal beta-SiC nano-rods of size similar to 50 nm were obtained. In addition, the thermogravimetric analysis of the produced nanocomposite revealed the high homogeneity in the particle size distribution. Based on the obtained data, a mechanism of nanocomposite formation was postulated. (C) 2014 Elsevier B.V. All rights reserved.