Abstract

ZrB² has a melting temperature of 3245℃ and a low density of 6.1 g/cm³ , which makes this a candidate for application to ultra-high temperature over 2000℃. Beside these properties, ZrB₂ has excellent resistance to thermal shock and oxidation compared with other non-oxide engineering ceramics. This paper reviewed briefly 2 research examples, which are related to densification and properties of ZrB₂-based ceramics for ultra-high temperature applications. In the first section, the effect of B₄C addition on the densification and properties of ZrB₂-based ceramics is shown. ZrB₂-20 vol.% SiC system was selected as a basic composition and B₄C or C was added to this system in some extents. With sintered bodies, densification behavior and hightemperature (up to 1400℃) properties such as bending strength and hardness are examined. In the second section, the effect of the SiC size on the microstructures and physical properties is shown. ZrB₂-SiC ceramics are fabricated by using various SiC sources in order to investigate the grain-growth inhibition and the mechanical/thermal properties of ZrB₂-SiC.

• Keywords: Zirconium Diboride (붕화지르코늄),Ultra-high Temperature Ceramics (초고온세라믹스),Densification (치밀화),Properties (물성)