Accession Number : ADA118837

Title :   Chemical Durability Improvement and Static Fatigue of Glasses.

Descriptive Note : Final technical rept. 1 Apr 78-31 Mar 82,


Personal Author(s) : Tomozawa,Minoru

PDF Url : ADA118837

Report Date : Aug 1982

Pagination or Media Count : 21

Abstract : 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.

Descriptors :   *Glass, *Static tests, *Fatigue(Mechanics), *Strain rate, Surface energy, Creep strength, Strength(Mechanics), Stress corrosion, Mechanical properties, Chemical reactions, Inhibitors, Alkaline earth compounds, Silicates, Sorption, Precipitation, Moisture content, Deposition

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE