Chemical Durability Improvement and Static Fatigue of Glasses

摘要

The following research results were obtained: (1) The rate of corrosion of silica glass by hot alkaline solution was reduced when a small amount of calcium is added to the solution. This inhibitor effect was caused by the deposition of calcium on the glass surface and a protective film formation. Similar but less drastic effect was observed for other alkaline earth elements. When heavy alkaline earth elements such as strontium, barium are contained in the alkaline solution, severe, mechanically damaging surface flow developed; (2) Mechanical strength of high silica glass was measured in various solvents. The strength varied while the dynamic fatigue susceptibility did not; (3) Surface of silica glass was made hydrophobic by chemical reactions. The resulting glasses showed very little tendency of dynamic fatigue. ; (4) Dissolution rate of silica glass was found to increase under hydrostratic pressure; (5) The strength increase commonly observed for abraded glass immersed in water (crack blunting) was attributed to dissolution-precipitation mechanism rather than to simple dissolution; and (6) Dynamic fatigue susceptibility of sodium silicate glasses was found to increase with increasing water content in glass.