Synthesis of Zirconium Diboride Based Ultra High Temperature Ceramics Via Preceramic Route

The present work focuses on the synthesis of ZrB2 based ceramics via a preceramic route, which involves the preparation of ceramic slurry with Zirconium silicate or zircon (ZrSiO4), boron carbide (B4C), phenolic resin and ethanol as the raw materials in stoichiometric amounts. The slurry is cured and then pyrolysed at 1500 degrees C and 1650 degrees C in argon atmosphere under a well-defined heating schedule. The heat treated samples were analysed by XRD (X-Ray Diffraction), Fourier Transform Infrared (FT-IR) spectroscopy, particle shape and size analyzer and Scanning Electron Microscopy (SEM). Complete conversion of the reactants to ZrB2-SiC occurred at 1650 degrees C, while the XRD and IR spectra of sample pyrolysed at 1500 degrees C indicated the presence of zircon along with silica. SEM images of ZrB2-SiC powder showed coral like microstructure with an average particle size of 6.6 mu m.