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 are compatible with conventional rolling and float processes, are transparent or translucent, and have high mechanical strength and fracture resistance. Further, the compositions are able to be chemically tempered to even higher strength glass ceramics that are useful as large substrates in multiple applications.
1. A glass-ceramic article comprising, in wt %:
wt %
SiO 2 (wt %)
65-80
Al 2 O 3 (wt %)
5-16
B 2 O 3 (wt %)
0-6
Li 2 O (wt %)
8-15
Na 2 O (wt %)
Greater than 0,
to 5
K 2 O (wt %)
0-3
ZnO (wt %)
0-2
ZrO 2 (wt %)
1-15
P 2 O 5 (wt %)
Greater than 0,
to 6
wherein the glass-ceramic article comprises 20 wt % to 70 wt % of a petalite crystalline phase.
2. The glass-ceramic article of claim 1 , further comprising a lithium silicate crystalline phase, wherein the article is transparent and has a transmittance of at least 85% for light in a wavelength range from 400 nm to 1,000 nm at a thickness of 1 mm.
3. The glass-ceramic article of claim 2 , wherein the lithium silicate crystalline phase comprises 20 to 60 wt % of the glass ceramic article.
4. The glass-ceramic article of claim 3 , wherein the lithium silicate crystalline phase is a lithium disilicate crystalline phase or a lithium metasilicate crystalline phase.
5. The glass-ceramic article of claim 1 , wherein the glass-ceramic article has a fracture toughness of 1 MPa·m 1/2 or greater.
6. The glass-ceramic article of claim 1 , wherein the glass-ceramic article has a fracture toughness of 1.2 MPa·m 1/2 or greater.
7. The glass-ceramic article of claim 6 , wherein the glass-ceramic article has a Vickers hardness of 600 kgf/mm 2 or greater.
8. The glass-ceramic article of claim 7 , wherein the glass-ceramic article has a ring-on-ring strength of at least 300 MPa.
9. A method of forming a glass-ceramic article, the method comprises:
forming a glass composition comprising, in wt %:
wt %
SiO 2 (wt %)
65-80
Al 2 O 3 (wt %)
5-16
B 2 O 3 (wt %)
0-6
Li 2 O (wt %)
8-15
Na 2 O (wt %)
Greater than 0,
to 5
K 2 O (wt %)
0-3
ZnO (wt %)
0-2
ZrO 2 (wt %)
1-15
P 2 O 5 (wt %)
Greater than 0,
to 6;
and
ceramming the glass composition to form a glass-ceramic article comprising a lithium silicate crystalline phase and 20 wt % to 70 wt % of a petalite crystalline phase,
wherein the article is transparent and has a transmittance of at least 85% for light in a wavelength range from 400 nm to 1,000 nm at a thickness of 1 mm.
10. The method of claim 9 , wherein the glass-ceramic article has a fracture toughness of 1 MPa·m 1/2 or greater.
11. The method of claim 9 , wherein the glass-ceramic article has a fracture toughness of 1.2 MPa·m 1/2 or greater.
12. A glass-ceramic article comprising, in wt %:
wt %
SiO 2 (wt %)
65-80
Al 2 O 3 (wt %)
7-10
B 2 O 3 (wt %)
0-6
Li 2 O (wt %)
10-20
Na 2 O (wt %)
Greater than 0,
to 5
K 2 O (wt %)
0-3
ZnO (wt %)
0-2
ZrO 2 (wt %)
3-15
P 2 O 5 (wt %)
0 to 6
wherein the glass-ceramic article comprises 20 wt % to 70 wt % of a petalite crystalline phase.
13. The glass-ceramic article of claim 12 , further comprising a lithium silicate crystalline phase, wherein the article is transparent and has a transmittance of at least 85% for light in a wavelength range from 400 nm to 1,000 nm at a thickness of 1 mm.
14. The glass-ceramic article of claim 13 , wherein the lithium silicate crystalline phase comprises 20 to 60 wt % of the glass ceramic article.
15. The glass-ceramic article of claim 14 , wherein the lithium silicate crystalline phase is a lithium disilicate crystalline phase or a lithium metasilicate crystalline phase.
16. The glass-ceramic article of claim 12 , wherein the glass-ceramic article has a fracture toughness of 1 MPa·m 1/2 or greater.
17. The glass-ceramic article of claim 12 , wherein the glass-ceramic article has a fracture toughness of 1.2 MPa·m 1/2 or greater.
18. The glass-ceramic article of claim 17 , wherein the glass-ceramic article has a Vickers hardness of 600 kgf/mm 2 or greater.
19. The glass-ceramic article of claim 18 , wherein the glass-ceramic article has a ring-on-ring strength of at least 300 MPa.
20. A method of forming a glass-ceramic article, the method comprises:
forming a glass composition comprising, in wt %:
wt %
SiO 2 (wt %)
65-80
Al 2 O 3 (wt %)
7-10
B 2 O 3 (wt %)
0-6
Li 2 O (wt %)
10-20
Na 2 O (wt %)
Greater than 0,
to 5
K 2 O (wt %)
0-3
ZnO (wt %)
0-2
ZrO 2 (wt %)
3-15
P 2 O 5 (wt %)
0 to 6;
and
ceramming the glass composition to form a glass-ceramic article comprising a lithium silicate crystalline phase and 20 wt % to 70 wt % of a petalite crystalline phase,
wherein the article is transparent and has a transmittance of at least 85% for light in a wavelength range from 400 nm to 1,000 nm at a thickness of 1 mm.
21. The method of claim 20 , wherein the glass-ceramic article has a fracture toughness of 1 MPa·m 1/2 or greater.
22. The method of claim 20 , wherein the glass-ceramic article has a fracture toughness of 1.2 MPa·m 1/2 or greater.