Dielectric and Mechanical Properties of BZT-xBCT Piezoceramics Modified by Nano SiO2 Additive

Lead-free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 piezoceramics with nano SiO2 additive were prepared by conventional solid oxide sintering method. The samples were fabricated by means of cold isostatic pressing and sintering was performed at 1350 °C for 4 h in the air. The phase structure and microstructure were studied via X-ray diffraction technique and field emission scanning electron microscopy. The room-temperature dielectric properties and the variations in the temperature ranging from 23 to 160 °C were measured using a high-precision LCR meter. The mechanical properties such as Vickers hardness and compressive strength were investigated. The obtained results showed that nano SiO2 addition produced dense and uniform microstructures with larger grains than pure BCZT. The Curie temperature of undoped BCZT increased to about 25 °C through the incorporation of 0.75 mol% SiO2 and then, the mechanical properties considerably improved. Accordingly, BCZT piezoceramic with nano SiO2 additive enjoys viable properties, which makes it widely applicable.