Dielectric and mechanical properties of TiB₂/ZrO₂ composites

TiB₂/ZrO₂ composites were prepared by hot-pressed sintering method, the dielectric performance between 8.2 and 12.4 GHz and mechanical properties of the composites were studied, the mechanism of polarization and loss were discussed. The result show that TiB₂ deteriorate the sintering character of the composites; Dielectric loss can not be detected obviously in ZrO₂ matrix, and vibrations of the valence electrons in ZrO₂ are responsible for polarization in the matrix. TiB₂ local networks increase the real part of dielectric constant and loss. Hardness of the composites decreases with the volume fraction rise of TiB₂. Flexural strength and fracture toughness of the composite increase firstly and then decrease with the volume fraction rise of TiB₂, which is caused both by relative density, grain size of the matrix and the toughening effect of TiB2.