Glasses with low excess modifier content
A glass composition includes: from 55.0 mol % to 70.0 mol % SiO 2 ; from 12.0 mol % to 20.0 mol % Al 2 O 3 ; from 5.0 mol % to 15.0 mol % Li 2 O; and from 4.0 mol % to 15.0 mol % Na 2 O. The glass composition has the following relationships −8.00 mol %≤R 2 O+RO−Al 2 O 3 −B 2 O 3 −P 2 O 5 ≤−1.75 mol %, 9.00≤(SiO 2 +Al 2 O 3 +Li 2 O)/Na 2 O, and (Li 2 O+Al 2 O 3 +P 2 O 5 )/(Na 2 O+B 2 O 3 )≤3.50. The glass composition may be used in a glass article or a consumer electronic product.
1. A glass article comprising:
a first surface;
a second surface opposite the first surface, wherein a thickness (t) of the glass article is measured as a distance between the first surface and the second surface; and
a compressive stress layer extending from at least one of the first surface and the second surface into the thickness (t) of the glass article, wherein
a central tension of the glass article is greater than or equal to 60 MPa,
the compressive stress layer has a depth of compression that is from greater than or equal to 0.15t to less than or equal to 0.25t, and
the glass article is formed from a glass comprising:
from greater than or equal to 55.0 mol % to less than or equal to 70.0 mol % SiO 2 ;
from greater than or equal to 12.0 mol % to less than or equal to 20.0 mol % Al 2 O 3 ;
from greater than or equal to 5.0 mol % to less than or equal to 15.0 mol % Li 2 O; and
from greater than or equal to 4.0 mol % to less than or equal to 10.0 mol % Na 2 O,
wherein:
−8.00 mol %≤R 2 O+RO −Al 2 O 3 −B 2 O 3 −P 2 O 5 ≤−1.75 mol %,
9.00≤(SiO 2 +Al 2 O 3 +Li 2 O)/Na 2 O,
1.50≤(Li 2 O+Al 2 O 3 +P 2 O 5 )/(Na 2 O+B 2 O 3 )≤3.50, and
RO is the sum of divalent cation oxides and R 2 O is the sum of alkali metal oxides.
2. The glass article of claim 1 , wherein the central tension of the glass article is greater than or equal to 80 MPa.
3. The glass article of claim 1 , wherein the central tension of the glass article is greater than or equal to 90 MPa.
4. The glass article of claim 1 , wherein the compressive stress layer has a depth of compression that is from greater than or equal to 0.18t to less than or equal to 0.22t.
5. The glass article of claim 1 , wherein the glass article has a liquidus viscosity from greater than or equal to 20 kP to less than 1000 kP.
6. A consumer electronic product, comprising:
a housing comprising a front surface, a back surface and side surfaces;
electrical components at least partially within the housing, the electrical components comprising at least a controller, a memory, and a display, the display at or adjacent the front surface of the housing; and
a cover substrate disposed over the display,
wherein at least a portion of at least one of the housing and the cover substrate comprises the glass article of claim 1 .
7. A glass article comprising:
a first surface;
a second surface opposite the first surface, wherein a thickness (t) of the glass article is measured as a distance between the first surface and the second surface; and
a compressive stress layer extending from at least one of the first surface and the second surface into the thickness (t) of the glass article, wherein
a central tension of the glass article is greater than or equal to 60 MPa,
the compressive stress layer has a depth of compression that is from greater than or equal to 0.15t to less than or equal to 0.25t, and
the glass article has a composition at a center depth of the glass article comprising:
from greater than or equal to 55.0 mol % to less than or equal to 70.0 mol % SiO 2 ;
from greater than or equal to 12.0 mol % to less than or equal to 20.0 mol % Al 2 O 3 ;
from greater than or equal to 5.0 mol % to less than or equal to 15.0 mol % Li 2 O; and
from greater than or equal to 4.0 mol % to less than or equal to 10.0 mol % Na 2 O,
wherein:
−8.00 mol %≤R 2 O+RO−Al 2 O 3 −B 2 O 3 −P 2 O 5 ≤−1.75 mol %,
9.00≤(SiO 2 +Al 2 O 3 +Li 2 O)/Na 2 O,
1.50≤(Li 2 O+Al 2 O 3 +P 2 O 5 )/(Na 2 O+B 2 O 3 )≤3.50, and
RO is the sum of divalent cation oxides and R 2 O is the sum of alkali metal oxides.