Mechanical, dielectric and microwave absorption properties of TiC/cordierite composite ceramics

TiC/cordierite composite ceramics are fabricated by hot-pressed sintering process. Influences of TiC content and sintering temperature on properties of the composite ceramics are investigated. No chemical reactions occur between TiC and cordierite during the sintering process. For the ceramics sintered at 1300 °C, both the bulk density and flexural strength decrease with increasing TiC content. While the bulk density of the ceramics sintered at 1350 °C is not affected by the dispersed TiC particles, but the flexural strength increases with rising TiC content. The distances of TiC particles decrease as the content increases from 5 to 20 wt%, which is help to form conductive network and improve complex permittivity. Both the real and imaginary part of complex permittivity increase with the rising sintering temperature as well as TiC content. For the ceramics sintered at 1350 °C, the complex permittivity is improved dramatically as the TiC content rises from 15 to 20 wt%, which is ascribed to the formation of conductive network. The ceramic with 15 wt% TiC presents the most favorable microwave absorption performance. The absorption bandwidth below −5 dB is obtained in the frequency range of 8.6–11.8 GHz with a minimum value of −11.4 dB at 10 GHz.