Analytical investigations on gaseous corrosion of silicate glasses using scanning electron microscopy, energy dispersive x-ray and x-ray diffraction analyses

Prepared samples of K₂O-CaO-SiO₂ glasses with different compositions were subjected to gaseous corrosion of water vapour and SO₂ gas mixture in the presence and absence of ultraviolet light. Morphological and chemical composition changes were followed using scanning electron microscopy (SEM) combined with energy dispersive x-ray analysis (EDX). X-ray diffraction analysis was used for identifying the products of corrosion reactions on the glass surfaces. The results indicate the formation of surface crust layers of arcanite, gypsum and syngenite. Surface cracks were also observed. It was also observed that the quantity of corrosion products increased on samples exposed to ultraviolet light. This indicates that ultraviolet light might enhance the corrosion reaction mechanism and consequently increase the surface corrosion products.