Corning Incorporated
TOUGH GLASS COMPOSITE AND METHOD

Abstract:

Embodiments of a glass substrate including an alkali-containing bulk and an alkali-depleted surface layer, including a substantially homogenous composition with at least 51 mol % Al.sub.2O.sub.3 are disclosed. In some embodiments, the alkali-depleted surface layer includes about 0.5 atomic % alkali or less. The alkali-depleted surface layer can be substantially free of hydrogen and/or crystallites. Methods for forming a glass substrate with a modified surface layer are also provided.