Vat photopolymerization enabling precise construction of Si3N4/ Si3N4-BN bioinspired ceramics with high damage tolerance

Bioinspired ceramics are highly required because of their excellent damage-tolerance; however, the rapid construction of laminated ceramics with low layer-thickness and high shape-accuracy is still a challenge. Here, we proposed an approach to construct Si 3 N 4 laminated ceramic based on vat photopolymerization and flaky BN toughening. The matrix slurry and interface slurry were distributed alternatively during vat photopolymerization; thus, the layer thickness of the laminated ceramics could be controlled by adjusting the slurry compositions and exposure parameters. With the increase of solid content, the fracture toughness of the laminated ceramics increased from 6.87 ± 0.35 MPa m 1/2 to 10.23 ± 0.31 MPa m 1/2 . Such increase could be ascribed to the step-by-step fracture at the layer boundaries, the crack deflection and branching by the flaky BN phase, as well as the self-reinforcing by the elongated β-Si 3 N 4 grains. Thus, this work provides insight into the construction of laminated ceramics with high layer-precision and excellent damage-tolerance.