Preparation of high-density green body based on binder jetting 3D printing using spheroidized SiC powder

Abstract

Silicon carbide (SiC) ceramic stands as a critical material in the realm of high-performance engineering ceramics. However, Crafting SiC ceramics with intricate structures and superior mechanical properties presents notable challenges in shaping, sintering, and processing. Binder jetting (BJ) additive manufacturing has the outstanding advantages of high forming efficiency and no thermal deformation, especially suitable for printing complex structure SiC components.; however, BJ printed green bodies often exhibit low density, resulting in high residual silicon content and diminished strength of the final components. In this work, we introduce a novel strategy to fabricate high-strength SiC components with complex geometries by improving the density of printed SiC green bodies. This method involves modifying the morphology of SiC powder through the molten salt method to increase the density of BJ 3D printed green bodies from 1.24 ± 0.13 g/cm³ to 2.01 ± 0.03 g/cm³, followed by a reactive melt infiltration process. The resulting RB-SiC ceramics display exceptional flexural strength, averaging 280.60 ± 33.05 MPa, and an elastic modulus of 294.67 ± 4.90 GPa. These values represent some of the highest for flexural strength and elastic modulus reported among 3D-printed SiC composites. With its robust mechanical performance and streamlined fabrication process, this strategy holds substantial promise for the production of structural SiC ceramics.