Liquidus temperatures (TL) were measured for the following float glass-type composition region (in mass%): 72·7 to 74·0 SiO2, 13·1 to 14·2 Na2O, 7·95 to 8·95 CaO, 2·97 to 3·97 MgO, 0·10 to 0·45 Al2O3, and 0·03 to 0·10 K2O. Glasses also contained constant minor fractions of Fe2O3 (0·71) and TiO2 (0·01). Fractions of silica, wollastonite, and devitrite were determined in glasses quenched from 900°C. Partial specific values for TL were evaluated for silica and wollastonite phase-fields. The measured TL values were compared with values estimated using various models available in the literature. The differences between predicted and measured TL for the float glass composition region can be attributed to several causes, the most prominent being the neglecting of differences in the slopes of liquidus surfaces within different primary phase-fields. Inaccurate estimates can also be expected when a model is applied to a glass with a smaller or a larger number of key components. Finally, erroneous estimates occur when the model is extrapolated beyond the composition region covered by data to which model equations were fitted, or when a model that covers a large composition region is applied to a smaller subregion where the TL -composition relationship has a significant lack of fit.
Revised: January 17, 2007 |
Published: June 1, 2006
Citation
Hrma P.R., D.E. Smith, J. Matyas, J.D. Yeager, J.V. Jones, and E.N. Boulos. 2006.Effect of float glass composition on liquidus temperature and devitrification behaviour.Glass Technology - European Journal of Glass Science and Technology Part A 47, no. 3:78-90.PNNL-SA-52267.