|About this Abstract
||Materials Science & Technology 2020
||Late News Poster Session
||Effect of SiC and CNT on thermal stability of HfB2–ZrB2 Based Ultra High Temperature Composites
||Shruti Dubey, Kantesh Balani, Ambreen Nisar
|On-Site Speaker (Planned)
HfB2-ZrB2 based ultra-high temperature ceramics (UHTCs) are used as protective tiles for nose cones and leading edges of the re-entry vehicles facing harsh environmental conditions. The present work assesses, the effect of SiC (20 vol %) and carbon nanotubes (CNT, 6 vol %) incorporation on the room temperature thermal stability of HfB2-ZrB2 based ceramics, consolidated via spark plasma sintering. The dissipation of heat is crucial factor concerning the thermal stability of the component under service in stringent environmental condition where temperature is >2000 °C. The thermal conductivity increased by ~> 12 % on CNT reinforcement in HfB2-ZrB2–SiC composites whereas, the oxidation temperature (Tonset) increases by > 18% with only a marginal weight gain ~0.8 %. It was observed that electrical conductivity increased by ~138 times in CNT reinforced HfB2-ZrB2–SiC composites. Despite higher electrical conductivity of ZrB2-HfB2-SiC-CNT ceramics, the phonon contribution dominated in governing the overall thermal conductivity of these composites.