Enhanced mechanical, dielectric and microwave absorption properties of cordierite based ceramics by adding Ti₃SiC₂ powders

Cordierite ceramics doped with different contents of Ti₃SiC₂ are successfully fabricated by hot-pressed sintering process. The influences of Ti₃SiC₂ addition on the properties of the ceramics are investigated. No chemical reactions occur between the Ti₃SiC₂ and cordierite phases during the sintering process. The dispersed Ti₃SiC₂ powders inhibit the densification process of the ceramics and improve the sintering temperature. The ceramic sintered at higher temperature has larger complex permittivity and dielectric loss value when the Ti₃SiC₂ content is fixed, which is attributed to its higher density. As for the dense ceramics, the flexural strength and complex permittivity are both enhanced with the increasing Ti₃SiC₂ content. The permittivity of the ceramic doped with 20 wt% Ti₃SiC₂ is observed to increase dramatically because of the surge of electric conductivity. The ceramic doped with 15 wt% Ti₃SiC₂ presents the optimal microwave absorption property. The effective absorption bandwidth of 9.7-12.4 GHz is obtained for the ceramic in 1.6 mm thickness, and the minimum absorption peak is -16.4 dB at the matching frequency 11.1 GHz.