Effect of CuO addition on the sintering temperature and microwave dielectric properties of CaSiO3-Al2O3 ceramics

CuO-doped CaSiO3 1 wt% Al2O3 ceramics were synthesized via a traditional solid-state reaction method, and their sintering behavior, microstructure and microwave dielectric properties were investigated. The results showed that appropriate CuO addition could accelerate the sintering process and assist the densification of CaSiO3-1 wt% Al2O3 ceramics, which could effectively lower the densification temperature from 1250 degrees C to 1050 degrees C. However, the addition of CuO undermined the microwave dielectric properties. The optimal amount of CuO addition was found to be 0.8 wt%, and the derived CaSiO3 Al2O3 ceramic sintered at 1100 degrees C presented good microwave dielectric properties of epsilon(r)=7.27, Q x f=16,850 Gliz and iota(f)= 39.53 ppm/degrees C, which is much better than those of pure CaSiO3 ceramic sintered at 1340 degrees C (Q x f= 13,109 GHz). The chemical compatibility of the above ceramic with 30 P0/70 Ag during the coliring process has also been investigated, and the result showed that there was no chemical reaction between palladium silver alloys and ceramics. (c) 2014 Chinese Materials Research Society. Production and hosting by Elsevier BA/. All rights reserved.