Strength of optical glass under conditions of axial compression

Abstract

Glass and pyrocerams can be effectively used in structures operating under high external pressure, as well as in other products of new technology subjected to compression.In some cases it is indispensable to use transparent materials with good optical properties, but so far only insufficient data are available on the structural strength of optical glass and pyrocerams under compression [1][2][3][4], and this limits the possibilities of designing highly stressed structural elements.The object of the present work was to investigate the structural strength of different kinds of optical glass under axial compression, with a view to the effect of the chemical composition, the shape of the cross section, and the conditions of support of the specimens, as well as the length of their storage after their production.We studied optical glass types LK5, K8, TK3, TKII4 belonging to the group of crown glasses (containing lead oxide PbO < 3%), and FI, FI01, TFI01, TFI0 belonging to the group of flint glasses (containing lead oxide PbO > 3%).Information on the chemical composition, specific weight, and some optical properties of the investigated types of glass is presented in Table I.Light crown glass (glass LK5) belongs to the five-component system R~0--B2Os--AI~O3--SiO2--F. Crown glass K8 belongs to the system K20-Na~O-B~Os--Si02 containing a small amount (10-12%) of oxides of bivalent metals PbO, BaO, ZnO, CaO, MgO. Heavy crown glass (TK3, TKII4) is based on the ternary system BaO--B2Os--SiO~.The basis of the second group of glass, flint glass (FI, FI01) and heavy flint glass (TFI01, TFI0), is the system K2(>-PbO-SiO2.Flint glass contains up to 22% lead oxide, heavy flint glass 1.5-2 times more.