Fabrication of a high-performance film of CaO–B2O3–SiO2 glass-ceramic via surface modification with titanate coupling agent

Abstract

In this work, the titanate coupling agent KR-TTS was used in tape casting of CaO–B2O3–SiO2 (CBS) glass-ceramics to obtain a high-performance dielectric tape. The functional group ((RO)m) of KR-TTS could directly react with the hydroxyl (–OH) of the CBS powders, which made the feature of powders from hydrophilicity into hydrophobicity. The modification mechanism of the modifier KR-TTS was illuminated by infrared absorption spectrum and contact angle of powders with modifier KR-TTS. The optimum amount of KR-TTS was determined by the rheological properties of suspensions, the density and the tensile strength of the green samples, the density and dielectric properties of the sintering samples sintered at 835 °C. The surface modification of CBS glass-ceramic by KR-TTS has made a substantial breakthrough in improving the densification and the mechanical performance of the green tapes. When the amount of KR-TTS was 1.0 wt%, the stability of slurry and the properties of the green samples had been greatly improved. The density of the green samples with 1.0 wt% KR-TTS reached 1.59 g/cm3 and the tensile strength of the green samples reached 2.43 MPa. The sintering sample with 1.0 wt% KR-TTS realized sintering densification and performed better dielectric properties. The sintering density reached to 2.51 g/cm3. The permittivity and dielectric loss were εr = 5.92 and tanδ = 13 × 10−4 at 10 GHz.