Fabrication of monolithic rGO/SiC(O) nanocomposite ceramics via precursor (polycarbosilane-vinyltriethoxysilane-graphene oxide) route

In this contribution, a technique based on molding polycarbosilane-vinyltriethoxysilane-graphene oxide (PCSVTES-GO) precursors synthesized by chemical modification was introduced to fabricate monolithic rGO/SiC(O) nanocomposite ceramics. Results reveal that the monoliths pyrolyzed at different temperatures (1100-1500 degrees C) consist of beta-SiC nanocrystals homogeneously embedded in amorphous SiOxCy/C-free, and multilayered rGO nanosheets composited with beta-SiC/SiOxCy/C-free. Their nanocomposite structure provides an ingenious strategy for constructing complexes with good integrity, high ceramic yield and low linear shrinkage. This improvement is primarily attributed to the presence of GO (as graft polymers and sintering additives) which enlarges the crosslinking structure of precursors and inhibits the growth of beta-SiC nanocrystals during the pyrolysis process. The final rGO/SiC(O) monoliths sintered at 1200 degrees C with higher hardness (19.81 GPa), satisfying ceramic yield (80.98%) and linear shrinkage (25.23%) promise to be candidates for making complex-shaped ceramic components in a simple and economical manner.