Method for making strengthened glass

Abstract

There is a method for making. The method includes providing an untreated alkali aluminosilicate glass having an annealing point temperature that is at least about 580° C. The method also includes providing a mixed potassium and sodium salt bath having greater than about 50 mole % potassium salt and less than about 50 mole % sodium salt. The method also includes immersing the untreated glass in the mixed salt bath and maintaining the mixed salt bath with the immersed untreated glass within a temperature range from about 450° C. to less than the annealing point temperature of the untreated glass for a period greater than about 2 hours to produce a strengthened glass. The produced strengthened glass has a surface compression of at least about 100,000 psi and a compression case depth of at least about 600 microns.

Dependencies are inferred from the claim text.