The strength of fused silica

Abstract

Silica fibres and flame polished rods having strengths around 600 Kg/mm$^2$ were prepared and the preparation conditions studied. The effects on fibre strengths of atmospheric and temperature changes, and of variations in rate of stressing and previous heat treatment, were extensively investigated. From the results obtained a comprehensive qualitative picture of the strength of silica has been deduced; it is found to be strongly dependent on the testing conditions and to extend over the range 280 to 1500 Kg/mm$^2$.