ADDITIVE MANUFACTURING OF SILICON CARBIDE-BASED CERAMICS BY 3-D PRINTING TECHNOLOGIES

摘要

Silicon carbide (SiC)-based materials are needed for a number of high temperature applications due to their excellent strength, thermal stability, and oxidation resistance. Fabrication of functional SiC ceramics by additive manufacturing technologies greatly reduces production time and cost, particularly for small production quantities necessary for prototype development. Two approaches which utilize 3-D printing technologies to obtain a SiC ceramic were investigated in this study. Various shapes with engineered porosity were printed using a commercially available wood filament which served as a carbonaceous preform. The printed samples were infiltrated with a pre-ceramic polymer containing dip-coat solution then pyrolyzed. The effect of solution composition on structure retention and conversion to SiC were investigated. In the second approach, pre-ceramic pastes comprised of SiC, silicon (Si), and carbon (C) particulates were evaluated as a potential extruder feedstock. Characteristic decomposition patterns in nitrogen and air were observed using thermogravimetric analysis (TGA), and X-Ray Diffraction (XRD) was used for phase identification. The effect of Si addition, SiC particle size, and pyrolysis conditions on the conversion to SiC has been studied.