Fabrication of Three-Dimensional Piezoelectric Ceramics Using the Dispenser System

Abstract

We fabricated lead-free (K,Na,Li)NbO3 (KNLN) and BaTiO3 (BT) piezoelectric ceramics using a dispenser system. After dissolving polyvinyl butyral in ethanol, a paste for extrusion was fabricated by mixing KNLN or BT ceramic powders. After several times of paste extrusion with a dispenser system, degreasing was performed at 650°C. The KNLN moldings were sintered, at 1,100–1,170°C, and sintering of BT moldings were performed by two-step sintering at 1,320°C and 1,150°C. From the x-ray diffraction pattern, the fabricated KNLN ceramics had a perovskite structure. The density of the KNLN and BT moldings fabricated by the dispenser system was 3.94 and 5.42 g/cm3, respectively. In addition, the BT moldings had the dielectric constant εr = 1.95 × 103. The Curie temperature of the BT moldings was confirmed at about 125°C, as with the BT piezoelectric ceramics fabricated by uniaxial pressure molding. The BT moldings had the piezoelectric constant d33 = 60 pC/N. The fabrication methods studied in this work provided the potential to fabricate simple three-dimensional piezoelectric ceramic devices for applications in acoustic wave sensors.