Influence of pre-heat treatment on glass structure and chemical strengthening of aluminosilicate glass

We consider a commercial aluminosilicate glass as an example case to obtain an understanding of the correlations between heat treatment and characteristics of chemical strengthening. Different heat treatments are performed prior to an ionic exchange process, and their effects on the chemical strengthening are investigated. It is verified that pre-heating treatment is influential, increasing the generated compressive stress by ∼10%, whereas depth of the compressive layer is observed to be remained identical regardless of heat treatment. These behaviors are able to be connected with structural evolutions observed through a Raman analysis, revealing that 4- and 3-membered ring structures are increased with proper heat-treatment. This indicates that the glass structure tends to be densified on a medium range scale by forming a smaller ring structure, which influences the stuffing effect of chemical strengthening. The stress profile of aluminosilicate glasses can be additionally engineered via heat-treatment conducted before the ionic exchange process.