Corning Incorporated
GLASS AND GLASS CERAMIC COMPOSITE AND METHOD

Abstract:

A glass glass-ceramic composite comprises a substrate comprising an alkali-containing glass bulk, the bulk comprising Al.sub.2O.sub.3 and SiO.sub.2 and alkali, and a glass-ceramic surface layer, the surface layer comprising an alkali-depleted glass ceramic comprising Al.sub.2O.sub.3 and SiO.sub.2 with at least 5% crystalline phase by volume, wherein the alkali-depleted glass ceramic surface layer comprises a mol % Al.sub.2O.sub.3 of at least 51%. A method of preparing the composite is also disclosed.