3D printing of high-purity complex SiC structures based on stereolithography

Complex Silicon carbide (SiC) structures are hardly achievable via traditional manufacturing methods, while stereolithography 3D printing technology effectively shapes sophisticated structures with high precision. However, it is a huge challenge to prepare SiC slurry for stereolithography 3D printing with excellent curing ability due to the increased light absorption of SiC powder. Therefore, a novel approach to fabricating high-purity SiC structures is proposed in this study based on the stereolithography 3D printing process, where SiO2 powder is used as an additive to increase the curing thickness from 27.8 μm to 53.0 μm. Moreover, phenolic epoxy resin (PEA) is introduced as a carbon source to transform SiO2 to SiC during sintering. As a result, there is almost no SiO2 phase or SiOC remaining in the final parts when the addition of PEA reaches 50 wt% related to the resin weight after sintering at 1600oC for 4 hours. Based on the SiC/SiO2/PEA slurry systems prepared, high-purity silicon carbide with complex structures can be successfully fabricated in one step without any pre-oxidation or precursor impregnation processes. This approach provides valuable insights into additive manufacturing of high-purity complex SiC structures.