Sustainable reinforcement: Mechanical and tribological performance of gel-cast fused silica composites

The present study investigates the mechanical performance of gel-cast fused silica composites doped with bio-waste-derived natural silica. Natural silica was extracted from rice husk, and ceramic composites were fabricated using gel casting. The tribological performance of the composites was evaluated in terms of wear rate and coefficient of friction, and mechanical performance was assessed in terms of hardness and compressive strength. Results revealed that silica doping at 10 wt% significantly enhanced wear resistance and increased the hardness from 486 HV to 569 HV and compressive strength from 0.79 GPa to 2.17 GPa. However, at 15 wt% doping, wear resistance deteriorated due to structural inconsistencies, reducing hardness to 535 HV and compressive strength to 1.43 GPa. Further insights were gained through Fourier transform Infrared spectroscopy (FTIR) analysis, which confirmed silica presence with characteristic absorption peaks at 805 cm⁻¹ and 1100 cm⁻¹. Additionally, ANOVA and regression analysis established that material composition and applied load were the most influential factors, accounting for 97.57 % of wear rate variation. This study provides a foundational benchmark for optimizing silica-doped ceramics in wear-resistant applications.