Electrical and Physical Properties of Ceramic Whiskers from the Al₂O₃-CaB₆ System

Abstract: In this study physical properties were determined for ceramic whiskers based on the Al₂O₃-CaB₆ system. Through a wet method and a sintering process between 1400 °C and 1500 °C, aluminium borate (Al₁₈B₄O₃₃) was developed from the binary Al₂O₃ (95-85 %)-CaB₆ (5-15 %) system. The whisker microstructure from interlocked fibres (between 8 and 30 µm in width) developed after the sintering process. The addition of CaB₆ at the expense of alumina at all additions resulted in an increase of the conductivity and the dielectric constant of the corresponding ceramic materials. The relationships between the phases formed, the conductivity and the dielectric values of the studied specimens were found to differ according to the complicated void structure (pores) in the specimens as detected in SEM images.