High strength glass-ceramics having petalite and lithium silicate structures
Glass and glass ceramic compositions having a combination of lithium silicate and petalite crystalline phases along with methods of making the glass and glass ceramic compositions are described. The compositions include Li 2 O, SiO 2 , and Al 2 O 3 . Ion-exchanged glass-ceramic articles made from the glass and glass ceramic compositions have a surface compressive stress in a range from about 100 MPa to about 500 MPa.
1. An ion-exchanged glass-ceramic article comprising Li 2 O, SiO 2 , and Al 2 O 3 , wherein:
the ion-exchanged glass-ceramic article consists of:
a petalite crystalline phase;
a lithium silicate crystalline phase consisting of lithium disilicate and, optionally, lithium metasilicate; and
a residual glass phase; and
the ion-exchanged glass-ceramic article has a surface compressive stress in a range from about 100 MPa to about 500 MPa.
2. The ion-exchanged glass-ceramic article of claim 1 , wherein the ion-exchanged glass-ceramic article has a depth of layer of at least about 100 μm.
3. The ion-exchanged glass-ceramic article of claim 1 , wherein the ion-exchanged glass-ceramic article has a central tension of at least 10 MPa.
4. The ion-exchanged glass-ceramic article of claim 1 , wherein the petalite crystalline phase is present in the ion-exchanged glass ceramic article in an amount of from 20 to 70 wt %.
5. The ion-exchanged glass ceramic article of claim 1 , wherein the lithium silicate crystalline phase is present in the ion-exchanged glass ceramic article in an amount of from 20 to 60 wt %.
6. The ion-exchanged glass ceramic article of claim 1 , wherein the ion-exchanged glass-ceramic article comprises:
from about 55 to about 80 wt % SiO 2 ;
from about 5 to about 20 wt % Li 2 O;
from about 2 to about 20 wt % Al 2 O 3 ;
from greater than 0 to about 10 wt % ZrO 2 ; and
from about 0.5 to about 15 wt % P 2 O 5 .
7. The ion-exchanged glass ceramic article of claim 1 , wherein the ion-exchanged glass ceramic article comprises an average transmittance of about 85% or greater of light in a wavelength range from 400 nm to 1,000 nm at a thickness of 1 mm.
8. The ion-exchanged glass ceramic article of claim 1 , wherein the ion-exchanged glass ceramic article comprises a fracture toughness of 1.0 MPa·m 1/2 or greater, as measured in accordance with ASTM C1421-10.
9. An ion-exchanged glass-ceramic article comprising Li 2 O, SiO 2 , and Al 2 O 3 , wherein:
the ion-exchanged glass-ceramic article consists of:
a petalite crystalline phase;
a lithium silicate crystalline phase present in an amount of 20 to 60 wt % of the glass-ceramic article, wherein the lithium silicate crystalline phase consists of lithium disilicate and, optionally, lithium metasilicate; and
a residual glass phase; and
the ion-exchanged glass-ceramic article has a surface compressive stress of about 100 MPa or greater.
10. The ion-exchanged glass-ceramic article of claim 9 , wherein the surface compressive stress is about 200 MPa or greater.
11. The ion-exchanged glass-ceramic article of claim 9 , wherein the surface compressive stress is from about 100 MPa to about 500 MPa.
12. The ion-exchanged glass-ceramic article of claim 9 , wherein the ion-exchanged glass-ceramic article has a depth of layer of at least about 100 μm.
13. The ion-exchanged glass-ceramic article of claim 9 , wherein the ion-exchanged glass-ceramic article has a central tension of at least about 10 MPa.
14. The ion-exchanged glass-ceramic article of claim 9 , wherein the petalite crystalline phase is present in the ion-exchanged glass ceramic article in an amount of from 20 to 70 wt %.
15. The ion-exchanged glass ceramic article of claim 9 , wherein the ion-exchanged glass-ceramic article comprises:
from about 55 to about 80 wt % SiO 2 ;
from about 5 to about 20 wt % Li 2 O;
from about 2 to about 20 wt % Al 2 O 3 ;
from greater than 0 to about 10 wt % ZrO 2 ; and
from about 0.5 to about 15 wt % P 2 O 5 .
16. The ion-exchanged glass ceramic article of claim 9 , wherein the ion-exchanged glass ceramic article comprises an average transmittance of about 85% or greater of light in a wavelength range from 400 nm to 1,000 nm at a thickness of 1 mm.
17. The ion-exchanged glass ceramic article of claim 9 , wherein the ion-exchanged glass ceramic article comprises a Vickers hardness of 775 kgf/mm 2 or greater.
18. The ion-exchanged glass ceramic article of claim 9 , wherein the ion-exchanged glass ceramic article comprises a fracture toughness of 1.0 MPa·m 1/2 or greater, as measured in accordance with ASTM C1421-10.
19. An ion-exchanged glass-ceramic article comprising Li 2 O, SiO 2 , and Al 2 O 3 , wherein:
the ion-exchanged glass-ceramic article comprises:
a petalite crystalline phase; and
a lithium silicate crystalline phase;
the ion-exchanged glass-ceramic article comprises grains having a longest dimension of 100 nm or less as measured by a scanning electron microscope; and
the ion-exchanged glass-ceramic article has a surface compressive stress in a range from about 100 MPa to about 500 MPa.