In Situ Crystallization of Lithium Disilicate Glass

Alternative Title

Effect of pressure on crystal growth rate

Abstract

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.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Crystallization; Crystal Growth; Silicates; Pressure Effects

International Standard Serial Number (ISSN)

0022-3093; 1873-4812

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2006 Elsevier, All rights reserved.

Publication Date

01 Jul 2006

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