Strengthened glass

Abstract

Chemically strengthened glass and a method for making utilizing differential chemistry are provided. The method includes providing a substrate having a glass chemical structure. Host alkali ions are situated in the chemical structure. The substrate has a treatment-rich volume and a treatment-poor volume located as opposed to each other in the substrate. The method also includes providing an exchange medium characterized by including a composition associated with an ion exchange rate of invading alkali ions having an average ionic radius that is larger than an average ionic radius of the host alkali ions. The method also includes providing a modified exchange medium including a modified composition associated with a modified ion exchange rate of the invading alkali ions. The method also includes applying the exchange mediums and conducting ion exchange to produce the strengthened substrate.

1 - 17 . (canceled) 
     
     
         18 . An article of manufacture, the article comprising:
 a chemically strengthened substrate characterized by having a glass chemical structure including alkali ions situated in the glass chemical structure
 wherein the substrate has dimensional volumes including
 a treatment-rich volume including a rich surface of the substrate, 
 a treatment-poor volume including a poor surface of the substrate and characterized by having a variation from the treatment-rich volume in at least one of a chemical composition and a chemical structure, and 
 a bulk volume, within the substrate, adjacent at least one of the treatment-rich volume and the treatment-poor volume, 
 wherein a concentration of metal in at least one of the treatment-poor volume and the treatment-rich volume is ≧ about 0.4 mole % higher than a concentration of the metal in the bulk volume, 
 wherein a concentration of the metal is higher in the treatment-poor volume than a concentration of the metal in the treatment-rich volume, and 
 wherein a concentration of alkali ions in a diffusion depth of at least one of the treatment-rich volume and the treatment-poor volume is ≦ about 0.5 mole % higher than a concentration of the alkali ions in the bulk volume. 
 
   
     
     
         19 . The article of  claim 18 , wherein at least one of the treatment-rich volume and the treatment-poor volume has a diffusion depth of about 5 to 150 μm. 
     
     
         20 . The article of  claim 18 , wherein the chemically strengthened glass substrate comprises greater than 50 mole % SiO 2 . 
     
     
         21 . The article of  claim 18 , wherein the chemically strengthened glass substrate comprises about 1 to 25 total mole % of Li 2 O+Na 2 O+K 2 O in the diffusion depth, wherein the diffusion depth is about 5 to 150 μm. 
     
     
         22 . An article of manufacture, the article comprising:
 a chemically strengthened substrate made by a process including
 providing a substrate characterized by having
 a glass chemical structure comprising host alkali ions having an average ionic radius situated in the glass chemical structure, and 
 wherein the substrate has dimensional volumes including a treatment-rich volume and a treatment-poor volume located as opposed to each other in the substrate, 
 
 providing an exchange medium including a composition including invading alkali ions having an average ionic radius that is larger than the average ionic radius of the host alkali ions
 wherein the composition is associated with an ion exchange rate of the invading alkali ions, 
 
 providing a modified exchange medium including a modified composition including invading alkali ions
 wherein the modified composition is associated with a modified ion exchange rate of the invading alkali ions and 
 wherein the modified ion exchange rate is slower than the ion exchange rate, 
 
 applying the modified exchange medium to a surface of the treatment-rich volume; 
 applying the exchange medium to a surface of the treatment-poor volume; and 
 conducting ion exchange while applying at least one of the exchange medium and the modified exchange medium to produce the strengthened substrate.