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Stress in Leached Phase‐Separated Glass
Author(s) -
SCHERER GEORGE W.,
DREXHAGE MARTIN G.
Publication year - 1985
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1985.tb10168.x
Subject(s) - residual stress , leaching (pedology) , phase (matter) , materials science , ion , ion exchange , alkali metal , microstructure , diffusion , analytical chemistry (journal) , mineralogy , composite material , chemistry , thermodynamics , chromatography , environmental science , physics , organic chemistry , soil science , soil water
When a phase‐separated glass is leached, stresses develop because of release of thermal stresses, creation of surface area, ion exchange, and hydration. Analyses are presented for the thermal stresses, including the portion that develops on cooling from the heat‐treatment temperature to the setting temperature of the less viscous phase. During leaching, the interfacial energy of the residual phase increases, so that phase tends to contract. A more important effect is the contraction caused by removal of alkali and B 2 O 3 from the residual phase during leaching. The extent of removal of B 2 O 2 decreases with heat‐treatment time, t H , because the scale of the microstructure increases as t 1/3 H . The change in residual B 2 O 2 content with t H is shown to be consistent with diffusion‐controlled ion exchange. The dependence of stress on t H in partially leached glasses, measured by Drexhage and Gupta, results principally from the change in extent of ion exchange; the reduction in surface area with increasing t H also has a significant effect on the stresses.