Glass-based articles including a metal oxide concentration gradient

A glass-based article comprising:

• a first surface and a second surface opposing the first surface defining a thickness (t);
• a concentration of an ion-exchanged metal oxide that is both non-zero and varies along a thickness range from about 0⋅t to at least about 0.3⋅t, wherein the concentration of the ion-exchanged metal oxide comprising sodium (Na) reaches a minimum concentration at 0.5⋅t;
• a lithium aluminosilicate composition comprising from 6 mol % to 10 mol % Li2O and from 1 mol % to 3 mol % Na2O, wherein the molar concentration of Na2O at a center point of the glass-based article is less than about 45% of the total alkali metal oxide molar concentration of the glass-based article;
• and
• a warp of less than about 200 μm relative to a flat plane in the absence of post-ion exchange processing.

A glass-based article comprising:

• a first surface and a second surface opposing the first surface defining a thickness (t);
• a lithium aluminosilicate composition comprising:
• from 6 mol % to 10 mol % Li2O and from 1 mol % to 3 mol % Na2O, wherein a molar ratio of Li2O to alkali metal oxide content (R2O) is in a range of greater than or equal to 0.4 to less than or equal to 1 at the center point of the glass-based article;
• a concentration of an ion-exchanged metal oxide comprising sodium (Na) that is both non-zero and varies along a thickness range from about 0⋅t to at least about 0.3⋅t , reaches a minimum concentration at 0.5⋅t;
• a compressive stress spike depth of layer (DOLspike), wherein DOL spike/t is in the range from about 0.006 to about 0.014;
• and
• a warp of less than about 200 μm relative to a flat plane in the absence of post-ion exchange processing.

A glass-based article comprising:

• a first surface and a second surface opposing the first surface defining a thickness (t);
• a lithium aluminosilicate composition comprising:
• from 6 mol % to 10 mol % Li2O and from 1 mol % to 3 mol % Na2O, wherein a molar ratio of Li2O to alkali metal oxide content (R2O) is in a range of greater than or equal to 0.4 to less than or equal to 1 at the center point of the glass-based article;
• stress profile comprising:
• an inner region under a central tension CT;
• at least one compressive stress layer under a compressive stress CS, the compressive stress layer extending from a surface of the glass-based article to a depth of compression DOC, wherein DOC ≥0.1·t when t<0.5 mm and DOC ≥50 μm when t≥0.5 mm, and being adjacent to the inner region;
• a concentration of an ion-exchanged metal oxide comprising sodium (Na) that is both non-zero and varies along a thickness range from about 0·t to at least about 0.3⋅t, reaches a minimum concentration at 0.5⋅t;
• and
• a warp of less than about 200μm relative to a flat plane in the absence of post-ion exchange processing;
• wherein the glass-based article exhibits a transmittance of 88% or greater over a wavelength in the range of from about 380 nm to about 780 nm;
• and has at least a 60% survivability rate when subjected to an inverted ball drop test with a 4.2 g stainless steel ball having a diameter of 10 mm from a height of 100 cm onto a 30 grit sandpaper positioned above the surface of the glass so there is a 100 μm air gap between the sandpaper and the surface of the glass, wherein the survivability rate is based on testing at least 5 samples.