Chemically strengthenable lithium aluminosilicate glasses with inherent damage resistance

摘要

A group of glass compositions in the Li₂O—Al₂O₃—SiO₂—B₂O₃ family that can be chemically strengthened in single or multiple ion exchange baths containing at least one of NaNO₃ and KNO₃ for a short time (2-4 hours) to develop a deep depth of layer (DOL). In some instances, the DOL is at least 70 μm; in others, at least 100 μm. The ion exchanged glasses have a high damage resistance (indentation fracture toughness ranging form greater than 10 kgf to greater than 50 kgf) that is better than or at least comparable to that of sodium aluminosilicate glasses.