High-Precision and High-Strength Sic Ceramic Green Body by Stereolithography: Slurry Design and Defect Control

Abstract

High absorbance and high refractive index have always been obstacles to the wide application of silicon carbide ceramics in stereolithography technology. Aiming at the problems of low curing thickness, high viscosity, and poor stability of SiC photosensitive slurry, this study developed a novel resin system with HDDA, TMPTA, DPHA, and PEG200 (volume ratio= 2:6:1:1), incorporating anti-settling agents and plasticizers to enhance the performance of the slurry. The effects of resin system on the preparation of SiC ceramics by stereolithography were analyzed, focusing on the properties of slurry, forming precision, and mechanical properties of the green body. The optimized slurry exhibited a dynamic viscosity below 3 Pa·s, a sedimentation height (<1% in 24 hours), and a single-layer curing thickness of 85 μm. High precision and excellent surface quality SiC mirrors was prepared by stereolithography 3D printing and sintered by reactive melt infiltration process (RMI) at 1600 ℃ in Ar2. The optimization strategy of SiC slurry proposed in this work provides a feasibility for the preparation of high-precision and high-strength SiC mirrors, which is expected to promote the application of SiC ceramics in the aerospace field.

Keywords: Stereolithography, Silicon carbide (SiC), Ceramic slurry, Curing thickness, Stability