Pre-calcination and suspension optimization for high-performance La2Zr2O7 ceramics based digital light processing (DLP) vat photopolymerization

Pyrochlore-type zirconates, particularly La 2 Zr 2 O 7 , are considered highly promising materials for high-temperature applications owing to their excellent thermal and mechanical properties. However, the fabrication of high-performance La 2 Zr 2 O 7 ceramics with complex geometries remains challenging. In this study, dense La 2 Zr 2 O 7 ceramics with complex structures were fabricated via digital light processing (DLP) vat photopolymerization. The entire process was systematically examined, from raw material powder pre-calcination, suspension formulation optimization (including the selection of surface modifier KH570 and dispersant KOS110), rheological and curing behavior control, to green body debinding and final sintering. The results indicated that the La 2 O 3 /ZrO 2 powders pre-calcined at 1100 °C significantly suppressed cracking during the debinding process. By using 1 wt% KH570 as a surface modifier and 2 wt% KOS110 as a dispersant, a ceramic suspension with 35 vol% solid loading, low viscosity, and good stability could be obtained. The La 2 Zr 2 O 7 ceramic sintered at 1600 °C for 6 h achieved a high relative density of 99.23 %, a flexural strength of 257 ± 27 MPa, and a thermal conductivity of 3.4 W/m·K. The XRD and Raman analyses confirmed the improved crystallinity with increasing sintering temperature, and the observed changes in peak intensity were attributed to the densification and microstructural evolution. Finally, the complex La 2 Zr 2 O 7 ceramic structures were successfully fabricated, demonstrating the high shaping precision and the compact, uniform microstructure. This study provides an experimental basis for manufacturing high-performance La 2 Zr 2 O 7 ceramics using DLP technology.