Effect of solid loading on the electrical properties of PZT-based porous piezoelectric ceramics produced by DIW 3D printing

Compared with conventional dry-pressing and sintering, which can yield high densification but are limited in constructing complex architectures, Direct ink writing (DIW) offers greater structural design flexibility. In this work, Gd/Sr co-doped PZT ceramics (Pb 0.97 Gd 0.01 Sr 0.02 Zr 0.53 Ti 0.47 O 3 ) were selected as the research material. Slurries with varying solid loadings (78–81 wt%) were prepared, and ceramic samples with a special lattice structure were fabricated via DIW, followed by binder burnout and sintering. The microstructure, electrical properties, and thermal characteristics of the samples were systematically analyzed to explore the effects of solid loading on printing stability, densification, and electrical performance. The results show that increasing the solid loading significantly promotes ceramic densification and enhances polarization response. The sample with 80 wt% solid loading exhibited the optimal performance, achieving a high relative density of 94%, d 33 of 302 pC/N, k p of 0.517, Q m of 53.17, and a slightly increased T C of 345 °C. This composition displayed a well-defined domain structure and superior polarization alignment, confirming the synergistic improvement in microstructure and electromechanical coupling. Using the optimized 80 wt% composition, complex PZT architectures were reliably printed with excellent fidelity, establishing a clear solid-loading–microstructure–performance correlation and confirming the feasibility of DIW for functional piezoelectric devices.