Method of increasing IOX processability on glass articles with multiple thicknesses
A method of producing glass-based articles having sections of different thicknesses is provided, where a maximum central tension in a thinner section is less than that of a thicker section. The method includes reducing the thickness of a region of a glass-based article that includes a compressive stress layer extending from a surface to a depth of compression to form a glass-based article with multiple thickness regions, and then ion exchanging the glass-based article to form a stress profile in the thinner region that has a maximum central tension that is less than a maximum central tension of a stress profile of the thicker region. The glass articles produced by the method are also provided.
1. A method of manufacturing a glass-based article comprising:
exposing a glass-based substrate to a first molten bath comprising alkali metal ions to ion-exchange the glass-based substrate and form the glass-based article comprising a compressive stress layer extending from the surface to the depth of compression
reducing the thickness of a portion of the glass-based article containing the compressive stress layer extending from the surface to the depth of compression and a having a first thickness t 1 to form a glass-based article containing a region with a second thickness t 2 ;
exposing the glass-based article containing the region with the second thickness t 2 to a second molten bath comprising alkali metal ions to ion-exchange the glass-based article containing the region with the second thickness t 2 to form a first stress profile of a region having the first thickness t 1 comprising a first central tension region comprising a first maximum central tension (CT 1 ) and a second stress profile of the region with the second thickness t 2 comprising a second central tension region comprising a second maximum central tension (CT 2 ), wherein CT 2 is less than CT 1 ;
wherein t 2 is less than t 1 , and wherein the region with the second thickness t 2 is off-set from all edges of the glass-based article.
2. The method of claim 1 , wherein the glass-based substrate is a lithium-containing aluminosilicate and at least one of the first and second molten bath comprises ions of potassium and sodium.
3. The method of claim 1 , wherein reducing the thickness comprises at least one of machining and polishing.
4. The method of claim 1 , wherein reducing the thickness comprises acid etching.
5. The method of claim 1 , wherein the region having the first thickness t 1 comprises a first compressive stress (CS 1 ) and the region with the second thickness t 2 comprises a second compressive stress (CS 2 ), wherein CS 2 is less than CS 1 .
6. The method of claim 1 , wherein the region having the first thickness t 1 comprises a first depth of compression (DOC 1 ) and the region with the second thickness t 2 comprises a second depth of compression (DOC 2 ), wherein DOC 2 is less than DOC 1 .
7. The method of claim 1 , wherein the glass-based article comprises a soda-lime silicate, an alkali-aluminosilicate, an alkali-containing borosilicate, an alkali-containing aluminoborosilicate, or an alkali-containing phosphosilicate.
8. The method of claim 1 , wherein the glass-based article comprises a lithium-containing aluminosilicate.
9. The method of claim 1 , wherein t 2 is at least 100 microns less than t 1 .
10. The method of claim 1 , wherein the second molten bath further comprises one or more metals selected from the group consisting of: silver, copper, zinc, titanium, rubidium, and cesium.
11. The method of claim 1 , wherein the region having the second thickness t 2 comprises a surface compressive stress.
12. The method of claim 11 , wherein the region having the first thickness t 1 comprises a first surface compressive stress (CS 1 ) and CS 1 is 450 MPa or more.
13. The method of claim 1 , wherein the region having the second thickness t 2 comprises a second surface compressive stress (CS 2 ) and CS 2 is 450 MPa or more.