Investigation of Key Factors on Manufacture of Fused Silica Parts by Gel-Casting Method

In this research according to unique properties of fused silica and Its numerous applications fused silica parts with 77% by weight solid loading formed by gel casting. Rheological behavior of the slurry and sintering conditions were optimized. Sample sintered at optimum conditions has bulk density of 1.71 g/cm3, open porosity of 18.13%, water absorption of 10.60%, linear shrinkage after firing of 3.5%, closed porosity of 1.09% and relative density of 78.80%. Its thermal expansion coefficient in range of room temperature to 1000 ◦C has been measured 0.4432×10-6 1/ 􀁄C. Results showed that With increasing temperature and time In addition to the increased vscous flow, Crystallization also extend. Finally sintered at high temperature and short time for an instance with the lowest overall high crystallinity and density, were found suitable