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Digital light processing 3D printing can be applied to fabricate complex silicon nitride (Si 3 N 4) components. However, because of the surface hydroxyl groups and large refractive index, it is still a foremost challenge to realize a stable photosensitive Si 3 N 4 slurry with combined benefits of low viscosity and large curing depth. In this study, we propose a new formulation strategy to prepare Si 3 N 4 slurry. Starting from the optimization of monomer ratio, we have systematically optimized powder particle size, dispersant and photoinitiator on the rheological properties and curing properties of Si 3 N 4 slurry. Specifically, we have fabricated a stable photosensitive Si 3 N 4 slurry (48 vol%) with a viscosity of 2.09 Pa s (30 s−1), a critical curing energy of 126.09 mJ/cm2 and a maximum curing depth of 80 µm. Finally, based on this optimized slurry, we have successfully obtained complex Si 3 N 4 green body with no defect, which demonstrates great potential to fabricate arbitrary complex ceramic components for various applications. [ABSTRACT FROM AUTHOR]

In this study, four types of triply periodic minimal surface (TPMS) were implemented to create cellular ceramics via digital light processing (DLP) technology, namely p-cell, gyroid, IWP and s14. The mechanical properties of these TPMS structures were investigated experimentally. Results showed that compressive strength of TPMS structures increases with relative density. IWP and s14 structures exhibit similar mechanical response under stress. In general, all TPMS structures can sustain >2% strain without failure and the compressive strength followed the order of s14 > IWP > gyroid > p-cell. The s14 structure can reach a high compressive strength of 105 MPa at a structural density of 30.5 % while gyroid structure can provide a compressive strength of 5.6 MPa at a very low structural density of 6.7 %. The porosity dependence of Young's modulus of sintered zirconia TPMS demonstrated that the Pabst-Gregorova exponential relation can provide a better prediction than the classical Gibson-Ashby model. [ABSTRACT FROM AUTHOR]

The development of photosensitive slurries for additive manufacturing has attracted great interest due to their correlation with the final properties of the fabricated parts. This paper focus on the printing quality control in digital light processing (DLP) 3D printing of advanced ceramics. Systematic experiments were performed to assess the effects of the exposure time and printing angle on the three-point bending strength of the fabricated samples. The exposure time affected the bending strength of the printed zirconia ceramic dramatically. When the weak exposure time is 1 s and the strong exposure time is 13 s, the average bending strength can reach 580 MPa while Weibull modulus can reach 8.84. Meanwhile, the printing angle also affected the bending strength mechanical sample printed at 45° exhibits the worst performance. [ABSTRACT FROM AUTHOR]