Journal of the American Ceramic Society, Vol.93, No.12, 4153-4157, 2010
Microstructure and Mechanical Properties of Zirconium Diboride Obtained by Aqueous Tape Casting Process and Hot Pressing
Aqueous ZrB(2) suspensions with different content of B(4)C were prepared for tape casting. After drying, the green tapes were laminated and hot pressed. It was shown that the mechanical properties of the sintered bodies increased with the increase in B(4)C content, while the ZrB(2) grain size decreased correspondingly. High sintering temperature also results in ZrB(2) ceramics with higher relative density and larger grain size. The ZrB(2) samples with 8 wt% B(4)C sintered at 1900 degrees C had a relative density of 95.9 +/- 2.0% and an average grain size of 2.80 +/- 0.98 mu m. The flexural strength, elastic modulus, Vickers hardness, and fracture toughness were 512.4 +/- 63.9 MPa and 378.5 +/- 43.7, 16.5 +/- 0.7 GPa, and 2.76 +/- 0.11 MPa center dot m1/2, respectively. Scanning electron microscopy and transmission electron microscopy showed a fine and homogeneous microstructure with a clear grain boundary. The fracture mode was mainly intragranular type.