High strength glass-ceramics having petalite and lithium silicate structures

Patent metadata

Field	Value
Publication number	US-9809488-B2
Application number	US-201715424062-A
Country	US
Kind code	B2
Filing date	Feb 3, 2017
Priority date	Oct 8, 2014
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

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.

First claim

The invention claimed is:

1. A glass-ceramic article comprising:
a petalite crystalline phase; and
a lithium silicate crystalline phase,
wherein the petalite crystalline phase and the lithium silicate crystalline phase have higher weight percentages than other crystalline phases present in the glass-ceramic article, and
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.

2. The glass-ceramic article of claim 1 , wherein the petalite crystalline phase comprises 20 to 70 wt % of the glass-ceramic article and the lithium silicate crystalline phase comprises 20 to 60 wt % of the glass ceramic article.

3. The glass-ceramic article of claim 2 , wherein the petalite crystalline phase comprises 45 to 70 wt % of the glass-ceramic article and the lithium silicate crystalline phase comprises 20 to 50 wt % of the glass ceramic article.

4. The glass-ceramic article of claim 2 , wherein the petalite crystalline phase comprises 40 to 60 wt % of the glass-ceramic article and the lithium silicate crystalline phase comprises 20 to 50 wt % of the glass ceramic article.

5. The glass-ceramic article of claim 1 , wherein the lithium silicate crystalline phase is a lithium disilicate crystalline phase or a lithium metasilicate crystalline phase.

6. The glass-ceramic article of claim 1 , wherein the article has a transmittance of at least 90% for light in a wavelength range from 400 nm to 1,000 nm at a thickness of 1 mm.

7. The glass-ceramic article of claim 1 , wherein the glass-ceramic article has a composition comprising, in wt %:
SiO 2 : 55-80%;
Al 2 O 3 : 2-20%;
Li 2 O: 5-20%;
B 2 O 3 : 0-10%;
Na 2 O: 0-5%;
ZnO: 0-10%;
P 2 O 5 : 0.5-6%; and
ZrO 2 : 0.2-15%.

8. The glass-ceramic article of claim 7 , wherein the glass-ceramic article has a composition further comprising, in wt %:
K 2 O: 0-4%;
MgO: 0-8%;
TiO 2 : 0-5%;
CeO 2 : 0-0.4%; and
SnO 2 : 0.05-0.5%.

9. The glass-ceramic article of claim 7 , wherein the glass-ceramic article has a composition comprising, in wt %:
SiO 2 : 69-80%;
Al 2 O 3 : 6-9%;
Li 2 O: 10-14%;
B 2 O 3 : 0-12%;
P 2 O 5 : 1.5-2.5%; and
ZrO 2 : 2-4%.

10. The glass-ceramic article of claim 7 , wherein the glass-ceramic article has a composition comprising, in wt %:
SiO 2 : 69-80%;
Al 2 O 3 : 6-9%;
Li 2 O: 10-14%;
Na 2 O: 1-2%;
K 2 O: 1-2%;
B 2 O 3 : 0-12%;
P 2 O 5 : 1.5-2.5%; and
ZrO 2 : 2-4%.

11. The glass-ceramic article of claim 7 , wherein the glass-ceramic article has a composition comprising, in wt %:
SiO 2 : 65-80%;
Al 2 O 3 : 5-16%;
Li 2 O: 8-15%;
Na 2 O: 0-3%;
K 2 O: 0-3%;
B 2 O 3 : 0-6%;
ZnO: 0-2%;
P 2 O 5 : 0.5-4%; and
ZrO 2 : 0.2-6%.

12. The glass-ceramic article of claim 7 , wherein the glass-ceramic article has a composition comprising, in wt %:
SiO 2 : 60-80%;
Al 2 O 3 : 5-20%;
Li 2 O: 5-20%;
Na 2 O: 0-3%;
K 2 O: 0-3%;
B 2 O 3 : 0-6%;
ZnO: 0-4%;
P 2 O 5 : 0.5-4%; and
ZrO 2 : 0.2-8%.

13. The glass-ceramic article of claim 7 , wherein a sum of the weight percentage of P 2 O 5 and ZrO 2 is greater than 3.

14. The glass-ceramic article of claim 1 , wherein the glass-ceramic article has a fracture toughness of 1 MPa·m 1/2 or greater.

15. The glass-ceramic article of claim 1 , wherein the glass-ceramic article has a Vickers hardness of about 600 kgf/mm 2 or greater.

16. The glass-ceramic article of claim 1 , wherein the glass-ceramic article has a surface compressive stress in a range from about 100 MPa to about 500 MPa.

17. The glass-ceramic article of claim 1 , further comprising a compressive stress layer having a depth of layer (DOL) of at least about 30 μm.

18. The glass-ceramic article of claim 1 , further comprising grains having a longest dimension of 500 nm or less.

19. The glass-ceramic article of claim 1 , further comprising grains having a longest dimension of 100 nm or less.

20. The glass-ceramic article of claim 1 , wherein the glass-ceramic article has a ring-on-ring strength of at least 300 MPa.

21. An electronic device comprising a cover wherein the cover comprises the glass-ceramic article of claim 1 .

22. A method of forming a glass-ceramic article, the method comprises:
forming a glass composition comprising, in wt %:
SiO 2 : 55-80%;
Al 2 O 3 : 2-20%;
Li 2 O: 5-20%;
B 2 O 3 : 0-10%;
Na 2 O: 0-5%;
ZnO: 0-10%;
P 2 O 5 : 0.5-6%; and
ZrO 2 : 0.2-15%; and

ceramming the glass composition to form a glass-ceramic article comprising a petalite crystalline phase and a lithium silicate crystalline phase,
wherein the petalite crystalline phase and the lithium silicate crystalline phase have higher weight percentages than other crystalline phases present in the glass-ceramic article, and
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.

23. The method of claim 22 , wherein the glass composition further comprises, in wt %:
K 2 O: 0-4%;
MgO: 0-8%;
TiO 2 : 0-5%;
CeO 2 : 0-0.4%; and
SnO 2 : 0.05-0.5%.

24. The method of claim 22 , wherein the glass composition comprises, in wt %:
SiO 2 : 69-80%;
Al 2 O 3 : 6-9%;
Li 2 O: 10-14%;
B 2 O 3 : 0-12%;
P 2 O 5 : 1.5-2.5%; and
ZrO 2 : 2-4%.

25. The method of claim 22 , wherein the glass composition comprises, in wt %:
SiO 2 : 69-80%;
Al 2 O 3 : 6-9%;
Li 2 O: 10-14%;
Na 2 O: 1-2%;
K 2 O: 1-2%;
B 2 O 3 : 0-12%;
P 2 O 5 : 1.5-2.5%; and
ZrO 2 : 2-4%.

26. The method of claim 22 , wherein the glass composition comprises, in wt %:
SiO 2 : 65-80%;
Al 2 O 3 : 5-16%;
Li 2 O: 8-15%;
Na 2 O: 0-3%;
K 2 O: 0-3%;
B 2 O 3 : 0-6%;
ZnO: 0-2%;
P 2 O 5 : 0.5-4%; and
ZrO 2 : 0.2-6%.

27. The method of claim 22 , wherein the glass composition comprises, in wt %:
SiO 2 : 60-80%;
Al 2 O 3 : 5-20%;
Li 2 O: 5-20%;
Na 2 O: 0-3%;
K 2 O: 0-3%;
B 2 O 3 : 0-6%;
ZnO: 0-4%;
P 2 O 5 : 0.5-4%; and
ZrO 2 : 0.2-8%.

28. The method of claim 22 , wherein a sum of the weight percentage of P 2 O 5 and ZrO 2 is greater than 3.

29. The method of claim 22 , further comprising ion-exchanging the glass-ceramic article to create a compressive stress layer having a depth of layer of at least 30 μm.

30. The method of claim 22 , wherein ceramming comprises the sequential steps of:
heating the glass composition to a glass pre-nucleation temperature;
maintaining the glass pre-nucleation temperature for a predetermined period of time;
heating the composition to a nucleation temperature;
maintaining the nucleation temperature for a predetermined period of time;
heating the composition to a crystallization temperature; and
maintaining the crystallization temperature for a predetermined period of time.

31. The method of claim 22 , wherein ceramming comprises the sequential steps of:
heating the composition to a nucleation temperature;
maintaining the nucleation temperature for a predetermined period of time;
heating the composition to a crystallization temperature; and
maintaining the crystallization temperature for a predetermined period of time.

32. The method of claim 22 , wherein the petalite crystalline phase comprises 20 to 70 wt % of the glass-ceramic article

Assignees

• Corning Inc

Inventors

• Beall George Halsey
• Fu Qiang
• Smith Charlene Marie

Classifications

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• C03B32/02

  Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)} · CPC title

• C03C4/02

  for coloured glass · CPC title

• C03C10/0027 Primary

  containing SiO2, Al2O3, Li2O as main constituents · CPC title

• C03C3/097

  containing phosphorus, niobium or tantalum · CPC title