Glass-based articles with improved stress profiles

Abstract

Glass-based articles are manufactured by a unique ion exchange process that results in glass-based articles having improved stress profiles with higher stress values at moderate depths. A medium of the ion exchange process includes ions of two or more alkali metals of two or more alkali metal oxides in a base composition of a glass-based substrate in a ratio such that ions of each alkali metal are in chemical equilibrium with each of the respective alkali metals of the alkali metal oxides in the base glass composition.

1 - 21 . (canceled) 
     
     
         22 . A method of manufacturing a glass-based article comprising:
 exposing a glass-based substrate that contains two alkali metal oxides in a base composition, the glass-based substrate having opposing first and second surfaces defining a substrate thickness (t), to an ion exchange treatment to form the glass-based article, the ion exchange treatment including a medium comprising:
 first metal ions that are different from the two alkali metals of the alkali metal oxides in the base composition; and 
 ions of the two alkali metals of the two alkali metal oxides in the base composition in a ratio such that ions of each alkali metal are in chemical equilibrium with each of the respective alkali metals of the alkali metal oxides in the base composition. 
   
     
     
         23 . The method of  claim 22 , further comprising additional strengthening treatments selected from the group consisting of: ion exchange, thermal annealing, and combinations thereof. 
     
     
         24 . A method of manufacturing a glass-based article comprising:
 exposing a glass-based substrate that contains two alkali metal oxides in a base composition, the glass-based substrate having opposing first and second surfaces defining a substrate thickness (t), to a first ion exchange treatment to form a doped glass-based substrate, the first ion exchange treatment including a first medium comprising:
 first metal ions that are different from the two alkali metals of the alkali metal oxides in the base composition; and 
 ions of the two alkali metals of the two alkali metal oxides in the base composition in a ratio such that ions of each alkali metal are in chemical equilibrium with each of the respective alkali metals of the alkali metal oxides in the base composition; 
   thereafter exposing the doped glass-based substrate to a second ion exchange treatment including a second medium comprising second metal ions to form the glass-based article.   
     
     
         25 . The method of  claim 24 , wherein the second medium comprises:
 the ions of the two alkali metals of the two alkali metal oxides in the base composition in a ratio such that ions of each alkali metal oxide are in chemical equilibrium with each of the respective alkali metals of the alkali metal oxides in the base composition;   wherein the second metal ions are different from the two alkali metals in the base composition; and   wherein at a depth of three times a depth of layer (DOL) with respect to the second metal ions, a concentration of each of the two alkali metals is within 10% of a respective concentration of each of the two alkali metal oxides in the base composition.   
     
     
         26 . The method of  claim 24 , wherein the second medium comprises:
 the ions of the two alkali metals of the two alkali metal oxides in the base composition in a ratio such that ions of each alkali metal oxide are not in chemical equilibrium with each of the respective alkali metals of the alkali metal oxides in the base composition;   wherein the second metal ions are different from two alkali metals of the two alkali metal oxides in the base composition; and   wherein at a depth of three times a depth of layer (DOL) with respect to the second metal ions, a concentration of each of the two alkali metals is more than 10% different from a respective concentration of each of the two alkali metal oxides in the base composition.   
     
     
         27 . The method of  claim 24 , further comprising additional strengthening treatments selected from the group consisting of: ion exchange, thermal annealing, and combinations thereof. 
     
     
         28 . The method of  claim 22 , wherein at a depth of about three times a depth of layer (DOL) with respect to the first metal ions, a concentration of each of the two alkali metal oxides is within 10% of a respective concentration of each of the two alkali metal oxides in the base composition. 
     
     
         29 . The method of  claim 22 , wherein a surface concentration of each of the two alkali metal oxides is non-zero at one or both of the first and second surfaces. 
     
     
         30 . The method of  claim 22 , wherein the first metal ions have a first non-zero concentration that varies from the first surface to a depth of layer (DOL) with respect to the first metal ions, and at the first surface, the surface concentration of each of the two alkali metal oxides are ±5% of the respective concentration of each of the two alkali metal oxides in the base composition. 
     
     
         31 . The method of  claim 22 , wherein the base composition comprises 1 mol % or less of oxides of the first metal ions. 
     
     
         32 . The method of  claim 22 , wherein t is in the range of from 50 micrometers to 5 millimeters. 
     
     
         33 . The method of  claim 24 , wherein at a depth of about three times a depth of layer (DOL) with respect to the first metal ions, a concentration of each of the two alkali metal oxides is within 10% of a respective concentration of each of the two alkali metal oxides in the base composition. 
     
     
         34 . The method of  claim 24 , wherein in the doped glass-based substrate, the first metal ions have a first non-zero concentration that varies from the first surface to a depth of layer (DOL) with respect to the first metal ions, and at the first surface, the surface concentration of each of the two alkali metal oxides are ±5% of the respective concentration of each of the two alkali metal oxides in the base composition. 
     
     
         35 . The method of  claim 24 , wherein the base composition comprises 1 mol % or less of oxides of the first metal ions.