Polycrystalline alumina ceramic fabrication using digital stereolithographic light process

Abstract ⍺-alumina powder with an average particle size of 180 nm was dispersed into a photosensitive resin to prepare slurry with a solid content of 40 vol% in this study. The main defects in fabricating high-performance alumina ceramics using digital light processing (DLP) 3D printing are crossing cracks resulting from the tensile stress induced by constrained shrinkage during polymerization and delamination arising from insufficient adhesion between the printed layers. The different photocurable resin systems and different amounts of plasticizer, PEG400, effects on the defect formation, sintered density, and mechanical strength were investigated. It was observed that the optimal resin composition was made up of monomer (1,6-hexanediol diacrylate) and oligomer (Bisphenol A epoxy acrylate) at the ratio of 4:1. For the slurry with binder/plasticizer of 8:2, the sintered body defects can be completely eliminated and the sintered density and average flexural strength can reach 94% and 340 MPa, respectively.