Textured Piezoelectric Ceramics Printed With Baffled Nozzles

ABSTRACT This study aims to enhance additive manufacturing of ceramics with crystallographically aligned microstructures, known as textured ceramics. Additive manufacturing is pursued because it addresses limitations of the current standard process, tape casting. However, circular nozzles typical of the direct ink writing (DIW) process fail to align particles effectively, resulting in poor alignment and suboptimal properties. To address this, we investigate nozzles with internal baffles for orienting (BT) platelets in a lead magnesium niobate‐lead zirconate titanate (PMN‐PZT) ceramic paste. Nine nozzle designs were assessed using computational fluid dynamics (CFD), and printed parts were characterized for texture quality and piezoelectric properties. Smaller outlet gap heights and additional baffles improved texture quality, with the aspect‐ratio‐16, three‐baffle nozzle being most effective, achieving properties on par with tape cast material and consistent with CFD predictions. Traditional texture characterization using X‐ray diffraction (XRD) with the Lotgering factor (LF) was laborious and less correlated with piezoelectric coefficient than microstructural analysis. A Gaussian‐process‐based algorithm was used to digitally optimize nozzle geometry and print speed using the CFD model, which converged on a design favoring maximal print speed and nozzle length, with minimal height and width.