Innovative procedure for 3D printing of hybrid silicon carbide/carbon fiber nanocomposites

A novel route to fabricating hybrid ceramic matrix composites has been developed. The fabrication is based on the unique combination of additive manufacturing (AM), a preceramic polymer, and a chopped carbon fiber precursor. After introducing the photoinitiator to the preceramic polymer formulation, a photosensitive resin was introduced. The resulting resin was loaded with distinct weight percentages of stabilized polyacrylonitrile nanofiber-the carbon fiber precursor. These formulations were 3D printed, cured, and converted to ceramic phases using a pyrolysis cycle. The end objective of the pyrolysis cycle is the conversion of the polycarbosilane resin into a silicon carbide matrix and the transformation of the PAN polymer into reinforcing carbon nanofibers within one cycle. The results of this work showed that ceramic matrix composite components can be successfully fabricated using a suitable combination of 3D printing, resin formulation, and processing cycle. The pyrolyzed ceramic hybrid composite was fully dense with nearly linear shrinkage and a shiny, smooth surface. Approximately 60% retained weight after pyrolysis to 1350 degrees C was confirmed by thermogravimetric analysis. In terms of crystallography, the ceramic matrix composite displayed three coexisting phases including silicon carbide, silicon oxycarbide, and turbostratic carbon. The results showed this combination of material and processes has a high potential for fabricating hybrid composites with high-temperature performance and improved mechanical properties combined with complex geometries.