Effects of CaSiO3 addition on sintering behavior and microwave dielectric properties of Al2O3 ceramics

The effects of CaSiO3 addition on the sintering behavior and microwave dielectric properties of Al2O3 ceramics have been investigated. The addition of CaSiO3 into Al2O3 ceramics resulted in the emergence of Ca2Al2SiO7 and CaAl2Si2O8, which acting as liquid sintering aids can effectively lower the sintering temperature of Al2O3 ceramic. The Q × f value of Al2O3–CaSiO3 ceramics decreased with the CaSiO3 addition increasing because of the lower Q × f value of Ca2Al2SiO7 and CaAl2Si2O8. Compared with the pure CaSiO3 ceramic, the Al2O3–CaSiO3 ceramic with 20 wt% CaSiO3 addition possessed good dielectric properties of ɛr = 9.36 and Q × f = 13,678 GHz at the similar sintering temperature.