Low temperature preparation of the β-CaSiO3 ceramics based on the system CaO–SiO2–BaO–B2O3

The dense β-CaSiO3 ceramics based on the system CaO–SiO2–BaO–B2O3 are fabricated by traditional solid-state preparation process at a densification temperature range of 930–970 °C. The introduction of BaO and B2O3 to the binary system CaO–SiO2 is achieved by the means of a chemical combination of H2SiO3, H3BO3, Ca (OH) 2 and Ba(OH)2·8H2O, which finally results in the formation of a hydrated barium borate phase with low melting characteristics. In turn, by a liquid phase sintering aid of the hydrated barium borate, the densification temperature of β-CaSiO3 ceramics can be decreased availably and the dense microstructure can be achieved accordingly. The β-CaSiO3 ceramics with the optimum content of BaO and B2O3 can express good mechanical strength (bending strength: 133 MPa) and excellent dielectric properties (ɛr: 6.5; loss: 5 × 10−4).