The in-situ exothermic reactions between ZrC, B₄C and Si accelerate the charge densification and had allowed to sinter nonporous ZrB₂-SiC ultrahigh-temperature ceramics within 6 minutes at 1750 °C. The developed reactive sintering route, at hot pressing - 1830°C and 30 MPa, has been successfully used for obtaining ZrB₂-SiC ceramics containing 8 vol.% of multi-wall carbon nanotubes (MW-CNT). Carbon nanotubes survived the hot pressing and could be clearly observed in the sintered ceramics. The CNT addition essentially improved the ceramic fracture toughness from 4.3 MPa∙m^1/2 for pure ZrB₂-SiC matrix to 6.8 MPa∙m^1/2 for ZrB₂-SiC-CNT.

REACTIVE HOT PRESSING ROUTE FOR DENSE ZrB₂-SiC AND ZrB₂-SiC-CNT ULTRA-HIGH TEMPERATURE CERAMICS.

Oleksii Popov, Jozef Vleugels, Eldar Zeynalov,Vladimir Vishnyakov.

Journal of European Ceramic Society IF –CA, 40(15), 5012-5019(2020).