Fabrication of barium titanate by binder jetting additive manufacturing technology

Fabrication of barium titanate (BaTiO3) specimens was accomplished with binder jetting additive manufacturing, and build parameters (e.g., binder saturation and layer thickness) and sintering profiles were modified to optimize the density achieved and the crystal structures obtained in the 3D printed parts. Surface and cross sectional grain morphology was characterized by scanning electron microscopy (SEM) revealing grain growth on localized areas of BTO fabricated specimens after sintering. Crystal structure was analyzed by X-ray diffraction (XRD) where the presence of a hexagonal phase was observed for BaTiO3 only when sintered at 1400 °C. The dielectric constant of the fabricated BaTiO3 specimens sintered at 1260 °C was obtained by using a Ku-band wave-guide and vector network analyzer setup in which the relative permittivity was measured from 8.6 to 6.23 for a frequency range of 12.4–18 GHz, respectively. When sintered at 1400 °C for 4 h, a density of 3.93 g/cm3 was obtained, which corresponds to 65.2% of the theoretical density. Piezoelectric properties exhibited a d33 value of 74.1 for specimens also sintered at 1400 °C. Results reported in this paper demonstrate the feasibility of BTO as a binder jetting material for 3D printed dielectric structures, ceramic capacitors and gas and pressure sensors.