Glass-ceramic articles with increased resistance to fracture and methods for making the same
A glass-ceramic article having one or more crystalline phases; a residual glass phase; a compressive stress layer extending from a first surface to a depth of compression (DOC); a maximum central tension greater than 70 MPa; a stored tensile energy greater than 22 J/m 2 ; a fracture toughness greater than 1.0 MPa√m; and a haze less than 0.2.
1 . A glass-ceramic article, comprising:
a residual glass phase that is less than or equal to 50 wt % of the glass-ceramic article;
a composition of the glass-ceramic article, based on 100 mol % of the glass-ceramic article, comprising:
greater than or equal to 1.7 mol % ZrO 2 ;
from 60 mol % to 72 mol % SiO 2 ;
from 0 mol % to 6 mol % Al 2 O 3 ;
from 24 mol % to 32 mol % Li 2 O;
from 0 mol % to 2 mol % B 2 O 3 ;
from 0 mol % to 2 mol % Na 2 O; and
from 0 mol % to 2 mol % K 2 O,
wherein the glass-ceramic article comprises a molar ratio Li 2 O (mol %)/R 2 O (mol %) from greater than or equal to 0.85 to less than or equal to 1.00, where R 2 O is a total amount of Li 2 O, Na 2 O, and K 2 O;
a first surface of the glass-ceramic article; and
a compressive stress layer extending from the first surface of the glass-ceramic article to a depth of compression,
wherein the glass-ceramic article has a maximum central tension greater than 90 MPa.
2 . The glass-ceramic article of claim 1 , further comprising a stored tensile energy greater than 22 J/m 2 .
3 . The glass-ceramic article of claim 2 , wherein the stored tensile energy is no more than 100 J/m 2 .
4 . The glass-ceramic article of claim 3 , wherein the depth of compression is at least 0.05 mm and no more than 0.6 mm.
5 . The glass-ceramic article of claim 4 , further comprising a thickness of the glass-ceramic article, wherein the thickness is at least 0.2 mm and no more than 4 mm.
6 . The glass-ceramic article of claim 5 , wherein the ZrO 2 is greater than or equal to 1.7 mol % and less than or equal to 4.5 mol % ZrO 2 .
7 . The glass-ceramic article of claim 6 , wherein the molar ratio Li 2 O (mol %)/R 2 O (mol %) is from greater than or equal to 0.95 to less than or equal to 0.99.
8 . The glass-ceramic article of claim 7 , further comprising P 2 O 5 from 0.7 mol % to 2.2 mol %.
9 . The glass-ceramic article of claim 1 , further comprising a haze less than 0.2.
10 . The glass-ceramic article of claim 9 , further comprising a fracture toughness greater than 1.0 MPa√m.
11 . The glass-ceramic article of claim 1 , wherein the haze is less than 0.18.
12 . The glass-ceramic article of claim 1 , further comprising average transmittance of the glass-ceramic article at or exceeding 85% per mm over a wavelength range from 450 nm to 600 nm, including surface reflection losses of light.
13 . The glass-ceramic article of claim 1 , wherein the composition comprises from 65 mol % to 72 mol % SiO 2 .
14 . A glass-ceramic article, comprising:
a residual glass phase that is less than or equal to 50 wt % of the glass-ceramic article;
a composition of the glass-ceramic article, based on 100 mol % of the glass-ceramic article, comprising:
greater than or equal to 1.7 mol % ZrO 2 ;
from 60 mol % to 72 mol % SiO 2 ;
from 0 mol % to 6 mol % Al 2 O 3 ;
from 24 mol % to 32 mol % Li 2 O;
from 0 mol % to 2 mol % B 2 O 3 ;
from 0 mol % to 2 mol % Na 2 O; and
from 0 mol % to 2 mol % K 2 O,
wherein the glass-ceramic article comprises a molar ratio Li 2 O (mol %)/R 2 O (mol %) from greater than or equal to 0.85 to less than or equal to 1.00, where R 2 O is a total amount of Li 2 O, Na 2 O, and K 2 O;
a first surface of the glass-ceramic article;
a compressive stress layer extending from the first surface of the glass-ceramic article to a depth of compression; and
a stored tensile energy greater than 22 J/m 2 .
15 . The glass-ceramic article of claim 14 , wherein the stored tensile energy is no more than 100 J/m 2 .
16 . The glass-ceramic article of claim 14 , further comprising a haze less than 0.2.
17 . A glass-ceramic article, comprising:
a residual glass phase that is less than or equal to 50 wt % of the glass-ceramic article;
a composition of the glass-ceramic article, based on 100 mol % of the glass-ceramic article, comprising:
greater than or equal to 1.7 mol % ZrO 2 ;
from 60 mol % to 72 mol % SiO 2 ;
from 0 mol % to 6 mol % Al 2 O 3 ;
from 24 mol % to 32 mol % Li 2 O;
from 0 mol % to 2 mol % B 2 O 3 ;
from 0 mol % to 2 mol % Na 2 O; and
from 0 mol % to 2 mol % K 2 O,
wherein the glass-ceramic article comprises a molar ratio Li 2 O (mol %)/R 2 O (mol %) from greater than or equal to 0.85 to less than or equal to 1.00, where R 2 O is a total amount of Li 2 O, Na 2 O, and K 2 O;
a first surface of the glass-ceramic article;
optical retardance at room temperature of less than 40 nm per mm of thickness measured using a grey-field polariscope GFP-1400 photoelastic stress measurement system.
18 . The glass-ceramic article of claim 17 , further comprising a first surface of the glass-ceramic article, and a compressive stress layer extending from the first surface of the glass-ceramic article to a depth of compression, wherein the depth of compression is at least 0.05 mm and no more than 0.6 mm.
19 . The glass-ceramic article of claim 18 , further comprising a thickness of the glass-ceramic article, wherein the thickness is at least 0.2 mm and no more than 4 mm.
20 . The glass-ceramic article of claim 19 , further comprising a stored tensile energy greater than 22 J/m 2 ; and a haze less than 0.2.