densification behavior of fused silica: effects of particle size, compaction pressure, sintering temperature/time, and boron oxide addition

This study systematically investigates the optimization of processing parameters for 400-mesh chinese fused silica ceramics, focusing on milling, blending, and sintering strategies to achieve high-density components. twenty-hour attrition milling with zirconia balls (40:1 ball-to-powder ratio) produces a homogeneous powder with an average particle size of ~ 5 µm, enhancing sinterability compared to unmilled powder. excessive milling, however, reduces green density due to increased interparticle friction. a 70:30 blend of milled/unmilled powder provides an optimal balance between enhanced diffusion kinetics (from milled powder) and improved particle packing (from unmilled powder). this blend achieves 94% theoretical density after sintering at 1250 °c for 5 hours, while reducing milling energy by 30%. prolonged sintering (> 5 h) promotes cristobalite formation, grain growth, and density reduction, underscoring the importance of precise thermal control.   b₂o₃ additions (0.5–3 wt.%) hinder densification by promoting premature crystallization and disrupting diffusion pathways, making it unsuitable as a sintering aid. sem analysis confirms that the 70/30 blend yields uniform grains (1.5 ± 0.3 µm) with minimal porosity (< 6%), outperforming both fully milled and unmilled powders. these findings provide a practical framework for industrial production, emphasizing cost-effective blending and optimized sintering protocols to achieve high-performance fused silica ceramics.