Mechanical properties of ZrB2–SiC(ZrSi2) ceramics

Mechanical properties of ZrB2–SiC and ZrB2–ZrSi2–SiC ceramics in the temperature range from 20 to 1400 °C were studied. It was found that the introduction of zirconium silicide resulted in pore-free ceramics having bending strengths of 400–500 MPa over a wide range of boride–carbide compositions. Zirconium silicide additive did not lead to significant strength and hardness changes at low temperature, but essentially increased Weibull modulus, and, therefore, the reliability of the ceramics. However, zirconium silicide additions resulted in noticeably reduced bending strength in ZrB2–SiC based composites at 1400 °C.