Direct ink writing of textured piezoelectric ceramics

Textured ceramics are often formed via tape casting in order to align platelet particles in the preferred direction, allowing the ceramic to have properties approaching those of single crystals without the complexities of growing such a crystal. However, tape casting produces significant waste material, as flat plates are machined to produce the desired geometries, e.g., rings. Additive manufacturing reduces these issues by allowing the complex geometries to be formed in the green state, thus reducing waste and improving design freedom. This presentation will discuss progress to-date on direct ink writing (DIW) of textured PMN-PZT. The focus will be on the methodology used to develop a suitable paste for printing. Development of a stable, shear thinning paste with a quick recovery time is critical. Zeta potential and rheological data were collected as a function of pH and other relevant slurry parameters such as percent solids loading and binder content. Sintered filaments and bulk parts were characterized to evaluate the efficacy of template alignment in the process as a function of slurry rheology, nozzle geometry, and print parameters.