In Situ Crystallization of Lithium Disilicate Glass
Effect of pressure on crystal growth rate
Crystallization of a Li2O · 2SiO2 (LS2) glass subjected to a uniform hydrostatic pressure of 4.5 and 6 GPa was investigated up to a temperature of 750 °C. The density of the compressed glass is ∼2% greater at 4.5 GPa than 1 atm and, depending on the processing temperature, up to 10% greater at 6 GPa. Crystal growth rates investigated as a function of temperature and pressure show that lithium disilicate crystal growth is an order of magnitude slower at 4.5 GPa than 1 atm resulting in a shift of +45 °C (±10 °C) in the growth rate curve at high pressure compared to 1 atm conditions. At 6 GPa lithium disilicate crystallization is suppressed entirely, while a new high pressure lithium metasilicate crystallizes at temperatures 95 °C (±10 °C) higher than those reported for lithium disilicate crystallization at 1 atm. The observed decrease in crystal growth rate with increasing pressure for the lithium disilicate glass up to 750 °C is attributed to an increase in viscosity with pressure associated with fundamental changes in glass structure accommodating densification.
T. Fuss et al., "In Situ Crystallization of Lithium Disilicate Glass," Journal of Non-Crystalline Solids, Elsevier, Jul 2006.
The definitive version is available at http://dx.doi.org/10.1016/j.jnoncrysol.2006.03.005
Materials Science and Engineering
Keywords and Phrases
Crystallization; Crystal Growth; Silicates; Pressure Effects
Article - Journal
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