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

Direct ink writing (DIW) of Al 2 O 3 -ZrO 2 -SiO 2 (AZS) refractories for glass-contact applications is limited despite advances in ceramic DIW processing. Water-based inks for AZS-32 (51.0 wt% Al 2 O 3 , 32.5 wt% ZrO 2 , 16.5 wt% SiO₂) and AZS-40 (47.5 wt% Al 2 O 3 , 40.0 wt% ZrO 2 , 12.5 wt% SiO 2 ) 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 ZrO 2 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.