Effect of Powder Type on Slurries for Additive Manufacturing of Sodium Potassium Niobate Piezoceramics

ABSTRACT

Due to its enhanced design flexibility, additive manufacturing (AM) is a game‐changing technology for piezoelectric ceramics. Still, to achieve a high‐quality ceramic by AM, slurry preparation is critical. Piezoceramics based on potassium sodium niobate [(K, Na)NbO ₃ ] (KNN) are challenging to densify and therefore require extra care during slurry preparation, including adjustments for differences in the starting powder. This work presents slurries for vat photopolymerization (VPP) AM of lead‐free piezoelectric ceramics based on KNN. Powders made of two different synthesis methods, solid‐state synthesis and spray pyrolysis, with different particle morphology and size distribution, were used to formulate highly loaded non‐aqueous slurries. The rheological properties were highly dependent on powder characteristics, but suitable rheological performance could be achieved for both powders. The densities of the sintered KNN were ∼93%–94%, which is in the range typical for conventionally produced KNN, and all samples show reasonable ferroelectric and piezoelectric response for this material system. These results demonstrate the feasibility of VPP for KNN‐based piezoceramics and provide practical guidelines for slurry design based on powder characteristics.