DLP-based additive manufacturing of hollow 3D structures with surface activated silicone carbide-polymer composite

Additive manufacturing (AM) has revolutionized the fabrication of ceramic (Silicon Carbide, SiC)-polymer composites, offering enhanced material properties such as lighter weight, toughness, and thermal characteristics. Despite these advancements, a significant knowledge gap persists in effectively processing SiC with high solid loading to achieve desired mechanical and thermal behaviors. This paper addresses this gap by exploring material properties and addressing two major challenges: adequate rheology and avoiding printing failure for excessive separation force in photopolymerization-based AM processes. In this study, high solid loading SiC-polymer composite resins were successfully developed for direct light projection (DLP)-based AM. Resin processability was determined by rheological properties and curing parameters, with resin preparation involving orthogonal optimization of compositions to achieve suitable viscosity, stability, and homogeneity. Experimental determination of photocuring parameters (curing time and critical exposure) was also conducted. Viscosity was found to increase with particle size reduction, with higher solid loading resulting in exponential viscosity growth. Additionally, a 3D part with a hollow structure and fine resolution, featuring densified uniform particle distribution, was successfully fabricated. This study further developed a DLP prototype and SiC-polymer composites with varied particle size and loading concentrations were additively manufactured. The influence of SiC particles on compressive strength and thermal conductivity of the 3D printed samples was investigated. Results revealed a proportional relationship between compressive strength, thermal conductivity, and solid loading, demonstrating significant improvements compared to pure polymer matrices. This study provides a material basis for polymerization-based 3D printing of porous structures, demonstrating the potential for advanced applications in various industries.