Effect of photosensitive resins on the properties of vat photopolymerization-based 3D printed alumina ceramics

Stereolithography-based three-dimensional printing fabricates objects through ultraviolet-induced layerwise curing of photosensitive resins. This study systematically evaluated alumina ceramic parts fabricated using four distinct photosensitive resin systems. Key parameters including slurry viscosity, debinding/sintering behavior, microstructure, and mechanical properties were analyzed. Rheological tests revealed that ceramic slurries exhibited non-Newtonian fluid characteristics, with viscosity significantly influenced by resin composition. Lumi React Hard & Detailed resin (resin A) produced the lowest slurry viscosity (0.386 Pa s). Directional sintering shrinkage rates for resin A demonstrated minimal anisotropy (9.5%‒16.5%). Post-sintering characterization showed bulk density (1.82‒2.37 g/cm³), porosity (40.3‒56.6 vol%), and bending strength (8.9‒14.6 MPa) variations across resin systems. Resins A and D (standard blends) yielded superior bending strength, correlating with optimized crosslinking and polymerization patterns observed in microstructural analysis. The findings establish resin selection as a critical determinant of ceramic part performance, providing technical guidance for stereolithography-based ceramic manufacturing optimization. This work demonstrates the feasibility of tailoring material properties through photosensitive resin formulation engineering, expanding functional ceramic applications in additive manufacturing.