Improvement of Sintering Performances and Dielectric Properties of Oriented TiO2 Ceramics Using Sintering Additives

We successfully examined effects of pulverization and an addition of sintering aids on the orientation degree, sintering performances, and dielectric properties of sintered compacts of needle-like TiO2 particles. In the case of additive-free samples, an improvement in sintering performances was achieved by pulverization. However, the orientation degrees of these samples were decreased and calcination at high temperatures (≥ 1200 °C) was indispensable for obtaining an adequate relative density. On the other hand, by the addition of CuO-TiO2-Nb2O5-Ag2O type additives, the samples could be well sintered as much as 380 °C below their original sintering temperature with retaining the high orientation degrees. Moreover, high insulation resistances were achieved for samples with additives compared to that of additive-free samples and its relationship with the microstructures was discussed. Thus, this study provides an experimental investigation on improvements of sinterabilities and insulation properties of orientated TiO2 ceramics by the use of sintering additives.