Preparation and characterization of high-temperature resistant ZrC-ZrB2 nanocomposite ceramics derived from single-source precursor

In order to prepare ZrC-ZrB2 nanocomposite ceramics with high temperature stability from single-source precursors, the reactions of ZrCl4, allyl amine, allyl-MgCl and borahe were employed to synthesize suitable precursors. The meliorated ZrNCB precursor had favorable solubility and higher ceramic yield (68.8 wt%), which was then transformed to ZrC-ZrB2 ceramics at different temperatures. The main phase of the ceramics was amorphous at 1000 degrees C. As the temperature increased, the amorphous phases started to crystallize, resulting in the appearance of ZrC and ZrB2 peaks. The content of ZrC and ZrB2 phases was relatively high in the nanocomposite ceramics at 1600 degrees C (over 80 wt%). The ZrC-ZrB2 nanocomposite ceramics showed good high temperature stability up to 2000 degrees C. Oxidation test indicated that an oxide layer was formed on the ceramic surface at 1700 degrees C under air to prevent further oxidation of the ceramics. With excellent high temperature and oxidation resistances, the ZrC-ZrB2 nanocomposite ceramics have potential application for advanced rocket engines and nuclear industry. (C) 2016 Elsevier Ltd. All rights reserved.