Property enhancement of 3D-printed alumina ceramics using vacuum infiltration

A combination of powder-bed inkjet 3D-printing and vacuum infiltration was utilized for manufacturing alumina ceramic components with enhanced mechanical and physical properties. 3D-printed parts were vacuum infiltrated with highly concentrated slurries to improve the green density followed by sintering for densification. The effect of infiltrant solid loading on the physical and mechanical properties of the produced parts was investigated using Archimedes' method, mercury porosimetry, microCT, 4-point bend test and surface profilometery. In case of parts with small size below 1.5 cm thickness, higher slurry concentration leads to improved density, lowered porosity, enhanced mechanical properties and improved surface finish. However, due to high viscosity of concentrated slurries and incomplete infiltration, thicker parts exhibit lower density at higher infiltrant concentration. The present work provides an effective approach for enhancing properties of inkjet 3D-printed ceramics.