It is difficult to prepare ceramic cores by traditional technology due to high dependence on mold and the difficulty of manufacturing complex structures. Additive manufacturing technology can solve these problems. In this study, the silica ceramics were prepared by selective laser sintering (SLS) based on particle grading. Adding appropriate amount of fine powder to coarse powder could improve the mechanical properties of silica ceramics. As a result, the flexural strength of silica green bodies reached a maximum of 3.20 MPa when the mass ratio of coarse powder (D₅₀ = 45.6 μm) and fine powder (D₅₀ = 23.3 μm) was 4:5. With the increase of fine powder content, the shrinkage and flexural strength of silica ceramics first increased and then decreased, while the apparent porosity showed an opposite trend. When the mass ratio was 4:5, the maximum of flexural strength was 7.15 MPa with the linear shrinkage of 4.76% and the apparent porosity of 47.28%. Compared with silica ceramics without fine powder, the flexural strength of silica ceramics increased by nearly 550% (from 1.13 MPa to 7.15 MPa) under the optimal particle grading. Therefore, the silica ceramics with good mechanical properties were prepared by SLS via optimizing the particle grading.

由于对模具的高度依赖以及制造复杂结构的难度，传统技术难以制备陶瓷芯。增材制造技术可以解决这些问题。在这项研究中，二氧化硅陶瓷是通过基于颗粒分级的选择性激光烧结 (SLS) 制备的。在粗粉中加入适量的细粉，可以提高二氧化硅陶瓷的力学性能。结果表明，当粗粉（D ₅₀  = 45.6 μm）和细粉（D ₅₀ = 23.3 μm) 为 4:5。随着细粉含量的增加，二氧化硅陶瓷的收缩率和抗弯强度先增大后减小，而表观孔隙率则呈相反趋势。当质量比为4:5时，最大弯曲强度为7.15 MPa，线收缩率为4.76%，表观气孔率为47.28%。与不含细粉的二氧化硅陶瓷相比，在最佳颗粒级配下，二氧化硅陶瓷的抗弯强度提高了近550%（从1.13 MPa提高到7.15 MPa）。因此，SLS通过优化颗粒级配制备了具有良好机械性能的二氧化硅陶瓷。