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B. S. Lunin, A. N. Kharlanov, S. E. Kozlov
Dehydration and
formation of KU-1 silica glass surface defects under annealing
Abstract
Formation of KU-1 silica glass surface
defects at annealing is considered. Based on experimental data obtained by
annealing of silica glass samples in temperature range 800-980°C, it is showed that internal stress forming due to dehydration of surface zone is main cause of
the surface defects. To determine the depth of this zone for different
annealing conditions a formula is suggested. It shows that the internal stress
is less than critical one and silica glass surface is not changed if annealing
temperature is 850°C or more due to fast relaxation rate. Under lower annealing
temperature the surface defects are formed in a few dozens of hours at
annealing.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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