Design of Layered Architectures for Modulating the Anisotropy and Mechanical Properties of Vat‐Photopolymerized Alumina

ABSTRACT Layer‐by‐layer vat photopolymerization (VPP) introduces intrinsic anisotropy, which is particularly evident in the pronounced differences in three‐point bending strength and fracture toughness. To address this issue, this study proposes and validates an alternating interlaminar Gyroid deposition printing strategy. The method divides a 3D model into two complementary substructures ( N ‐type: Gyroid lattice and its complementary lattice; T ‐type: Gyroid lattice and a solid block) and alternately prints them on odd and even layers, thereby reconstructing interlayer bonding and producing an interlocked, staggered laminated microarchitecture. This work systematically examined the effects of the N ‐ and T ‐type printing strategies and lattice wall thickness on the anisotropic behavior and mechanical properties of alumina ceramics. Compared with control samples, the N ‐type samples exhibited significantly mitigated anisotropy and leading to a substantial improvement in fracture toughness. Specifically, the fracture toughness increased by 35.89% and 68.89% in the X and Z directions, respectively. The anisotropy reduction rates for three‐point bending strength and fracture toughness reached 88.64% and 84.15%, respectively. In contrast, the T ‐type configuration produced greater gains in bending strength (increases of 58.26% and 42.37% in X and Z, respectively). Microstructural characterization indicates that the interlocked laminated geometry promotes crack deflection, blunting, and multilayer delamination, thereby increasing fracture‐energy dissipation.