Optimisation of curing models and ultra-high-precision forming strategy in vat photopolymerization of silica-based ceramic modified by graphene
Yongkang Yang, Xiqing Xu, Boran Wang, Shiyuan Li, Ziqi Jia, Xusen Guo, Shuhuai Wang, Shuxin Niu, Xin Li
Abstract
Vat photopolymerization (VPP) 3D printing technology is suited for intricate ceramic core forming due to its design freedom. However, solving the lateral over-cure width while formation is crucial. Graphene was used in VPP-3D printing of silica-based ceramic cores to examine its effects on forming and sintering, and a desirable curing coefficient was presented to evaluate the forming accuracy of single layer. A straightforward model using a modified Beer–Lambert law based on exposure time rather than exposure power predicts the effect of graphene on the VPP process at consistent curing depth and exposure time and clarifies how the curing process affects flexural strength and surface quality. The optimal graphene content was determined by double bond conversion rate, structural anisotropy, and mechanical properties. Increasing graphene concentration reduces curing sensitivity and exposure time threshold, allowing more liquid phase to cure and improving double bond conversion and interlayer bonding. However, excess graphene increases the conversion rate and stress concentration of green body. According to microstructural studies, extra graphene enhanced the likelihood of crack reformation after sintering. The ceramic cores had optimal forming and sintering capabilities with 0.6 wt.‰ graphene content. The approach offers significant insights for enhancing VPP ceramic 3D printing.