Published online by Cambridge University Press: 28 February 2011
The densification of sol-gel processed silica was studied by comparing calculated and measured viscosities between 700 and 850°C. Linear shrinkage was measured in a dilatometer. From shrinkage data, relative bulk densities were determined. The densities were used in a model for viscous sintering to calculate viscosities. Beam-bending viscosimetry was used to determine viscosities directly. The deflection rate of a centrally loaded beam was measured. Both the calculated and measured viscosities had the same time dependence. The temperature dependence was also determined.