Patent ID: 8312739
Filing Date: 2012-11-20
Classification: C03C,Y10T

Abstract:
1. A method of strengthening a glass, the method comprising: creating a compressive stress in an outer region of the glass, the region extending from a surface of the glass to a depth-of-layer, the compressive stress being sufficient to arrest flaws within the glass and to arrest flaws at the surface introduced by contact forces at the surface, and wherein the compressive stress is created by: a. providing a glass, the glass having a plurality of a first metal ions within the outer region, wherein the first metal ion is Na b. ion exchanging a first portion of the plurality of the first metal ions in the glass with a plurality of a second metal ions in a first salt bath, the first salt bath comprising up to 7.5 wt % of at least one salt containing the first metal ion, wherein the second metal ion is K c. ion exchanging a second portion of the plurality of the first metal ions in the glass with a plurality of the second metal ions in a second salt bath, wherein the second salt bath has a second concentration of the first metal ion that is less than the first concentration.