Direct ink writing of AZS refractories: Dimensional accuracy and corrosion in molten glass

Direct ink writing (DIW) of Al2O3-ZrO2-SiO2 (AZS) refractories for glass-contact applications is limited despite advances in ceramic DIW processing. Water-based inks for AZS-32 (51.0 wt% Al2O3, 32.5 wt% ZrO2, 16.5 wt% SiO₂) and AZS-40 (47.5 wt% Al2O3, 40.0 wt% ZrO2, 12.5 wt% SiO2) were formulated at 42.3 and 55.1 vol% solid loadings for 3D printing crucibles. Post-sintering at 1630 °C, Z-direction shrinkage was 17% (AZS-32) and 11% (AZS-40), with porosities of 6.8% and 18.6%. Corrosion testing in barium crystal glass at 1450 °C for 10 h showed that higher porosity increased glass penetration and matrix dissolution. AZS-32 showed limited infiltration, while AZS-40 had deeper degradation. FTIR and XRD confirmed structural changes, increased crystallinity, mullite formation, and stable monoclinic ZrO2 supporting densification. Results demonstrate the feasibility of DIW for AZS refractories and link processing-induced porosity to corrosion behavior, guiding the design of additively manufactured glass-contact refractories.