Understanding ink design and printing dynamics of extrusion-based 3D printing: Defect-free dense piezoelectric ceramics

The formulation and trade-off between a control rheological ink and its printability are significant challenges for designing a defect-free extrusion-based 3D printed feedstock of piezoelectric materials. In this study, we explore different strategies, including ink design, printing dynamics, and densification behaviors, to successfully manufacture a dense 3D-printed lead zirconate titanate (PZT) ceramic using material extrusion. First, PZT inks of different solid volumes (50–55 vol%) were designed using an aqueous binder system, and their rheological behaviors were evaluated. Second, the printing dynamics, that is, extrusion pressure, nozzle size, and printing speed, were optimized for printing an optimal ink without defects. Finally, the printed specimens were sintered at 1100–1300 °C in a lead-rich atmosphere. The specimens achieved a relative density of ∼97.59 %, which is close to conventional die-pressed PZT density ∼ 97.79 %, and exhibited similar piezoelectric behavior. This high-density 3D-printed PZT with tailorable design feasibility has potential applications in sensors, actuators, and energy harvesters.