Low-temperature fabrication of high-specific strength SiC-based ceramics via photopolymerization 3D printing with controllable anisotropy
Piao Qu, Guozhen Liang, Muhammad Irfan Hussain, Muhammad Hanif, Muhammad Hamza, Kaibin Huang, Yan Lou, Zhangwei Chen
Abstract
Abstract The combination of silicon carbide (SiC) ceramics and stereolithography technology shows promise for manufacturing complex-shaped SiC components, expanding application possibilities. However, high sintering temperature and structural-performance anisotropy limit the practical use of 3D-printed SiC components. Herein, a novel method is introduced to produce high-specific-strength SiC-based ceramics at a relatively low temperature of 1 100 ℃. A mixed SiC/SiO 2 slurry (30% SiO 2 and 70% SiC by volume) with a solid loading of up to 40% was prepared to improve UV light penetration and printability. Additionally, incorporating a high content of methyl-phenyl-polysiloxane (PSO) solution (75% by weight) enabled low-temperature pyrolysis of SiC/SiO 2 /PSO ceramics. The SiC/SiO 2 /PSO ceramic lattices after pyrolysis achieved a specific strength as high as (1.03 × 10 5 ) N·m·kg −1 and a density of 1.75 g·cm −3 , outperforming similar SiC-based lattices structures of similar porosities. The bending strength of (95.49 ± 8.79) MPa was comparable to that of ceramics sintered at 1 400 ℃ or higher. Notably, the addition of the silicon carbide oxide (SiOC) phase reduced anisotropy, lowering the transverse and longitudinal compression strength ratios from 1.87 to 1.08, and improving mechanical properties by 79%. This improvement is attributed to SiOC shrinkage, promoting a uniform distribution of sintered components, resulting in a more robust and balanced material structure. This method offers valuable insight into the additive manufacturing (AM) of SiC-based ceramics at lower temperatures and provides new guidance for controlling anisotropy in 3D-printed ceramic parts.