Gyroid-Architected SiC via FFF: SEM/EDS/XRD Microstructural Verification and Vickers Microhardness

Additive manufacturing (AM) of technical ceramics enables the creation of architected, lightweight components with high functional performance. This work investigates the fabrication of silicon carbide (SiC) parts using Fused Filament Fabrication (FFF) with a gyroid infill from the triply periodic minimal surfaces (TPMS) family. The end-to-end workflow comprised filament handling, controlled extrusion, chemical and thermal debinding, and vacuum sintering at 2185 °C. Printed specimens were assessed for relative density, microstructure, and composition. Scanning electron microscopy (SEM) revealed well-consolidated interlayer interfaces, homogeneous particle packing, and minimal residual porosity; energy-dispersive spectroscopy (EDS) detected only Si and C, indicating efficient binder removal and chemical stability. X-ray diffraction (XRD) confirmed predominant β-SiC, with no significant secondary crystalline phases. Vickers hardness averaged 2212 HV (~22 GPa), consistent with dense SiC reported in the literature. The gyroid architecture enhanced gas transport during debinding/sintering, supporting defect-free densification and relative densities of over 99%, while preserving dimensional fidelity. These results validate the synergy between SiC and gyroid topology in extrusion-based AM, highlighting a viable route to lightweight, compositionally pure, and mechanically robust ceramics for aerospace, automotive, and defense applications.