Forming of Large Thin Walled Fused Silica Shapes by Gelcasting

Gelcasting was used to form large and thin walled shapes of fused silica. Large square crucibles of 720x720x420 with a thickness of 14mm for polycrystalline silicon melting and fused silica radoms of up to 500mm in diameter and 1000mm in height with a thickness of 10 to 12 mm have been formed and sintered with excellent homogeneity. Process parameters have been discussed such as dispersion of the ceramic particles in the casting slurry and design of the casting moulds. Simultaneous vibration treatment was applied during the casting process for more homogeneous structure of the formed bodies for some of the casting shapes.