A Novel Binder-Assisted Atmospheric Sintering Route for Silicon Carbide (SiC) Production.

Silicon carbide (SiC) is a high-performance ceramic known for its exceptional thermal and mechanical stability, yet its conventional synthesis requires high temperatures and inert atmospheres, leading to substantial cost and energy demands. This study introduces a potentially sustainable binder-assisted atmospheric sintering technique for β-SiC formation from SiO2 and activated carbon, eliminating the need for vacuum or protective gas environments. Using a hybrid graphite-mullite insulation system with sacrificial carbon barriers, β-SiC was successfully synthesized at temperatures as low as 1350 °C. The hybrid insulation acts as a passive getter, creating a localized reducing atmosphere, while the UF resin residue creates a carbon skeleton that enhances particle necking. XRD analyses confirmed the presence of 3C-SiC as the dominant phase, while binder addition markedly enhanced densification and mechanical strength. Incorporating urea-formaldehyde resin achieved a compressive strength of 25.5 MPa after only 15 min of sintering at 1500 °Crepresenting a 4-fold improvement over binder-free samples. Furthermore, specific surface area measurements revealed that the resin-bonded samples achieved substantial microstructural densification (0.35 m2/g) by contributing to the reduction of accessible open pore networks. This work provides a potentially scalable and simplified atmospheric processing strategy for SiC production, showing that a fully atmospheric route combined with binder chemistry can yield improved mechanical performance in β-SiC ceramics at significantly reduced temperature and time.