Fabrication of high density BaTiO۳ ceramics by gel casting

Here, high-density ceramics of ۹۸% or more of the theoretical density are fabricated through the gel casting wet-forming method after a two-step sintering. A well-known commercially available submicron BaTiO۳ powder was used as the starting material. So, other researchers can re-use our research outcomes easily, instead of performing new experiments. For comparison, one sample was prepared by the conventional uniaxial pressing of the BaTiO۳ powder and sintered similarly. Powder deagglomeration improved the quality of the gel casted samples. However, an extremely deagglomerated BaTiO۳ powder was not required to obtain high-density ceramics because the starting powder was homogenized effectively upon gel casting. Small amounts of ISOBAM, an alkaline hydrosoluble copolymer of isobutylene and maleic anhydride, was used both the dispersant and gelling agent. High solid content, ۷۰ - ۸۰wt.%, BaTiO۳ gels were produced for this purpose. In contrast to previous works, no other organic additive was required for the gel formation. It was found by scanning electron microscopy that improved microstructural development is responsible for the enhanced density of the gel cast BaTiO۳ ceramics.