Densification and properties of barium zirconate ceramics by addition of P2O5

The influences of P₂O₅ doping on the sintering behavior, phase formation and properties of barium zirconate ceramics were investigated. Unmodified BaZrO₃ was difficult to densify, even at 1600 °C. Only a porous microstructure could be obtained. However, doping BaZrO₃ with P₂O₅ markedly enhances its sinterability. 94.2% of theoretical density was achieved with the inclusion of 4 mol% P₂O₅ sintered at 1600 °C for 4 h. The bending strength of the samples sintered at 1600 °C for 4 h was improved by almost 8 times by the addition of 4 mol% P₂O₅. The average bending strength of 152.3 ± 16.7 MPa was obtained. The Vickers hardness of 4 mol% P₂O₅ modified BaZrO₃ reaches 8.8 ± 0.4 GPa.