High strength glass-ceramics having lithium disilicate and beta-spodumene structures

Patent metadata

Field	Value
Publication number	US-10196301-B2
Application number	US-201715615186-A
Country	US
Kind code	B2
Filing date	Jun 6, 2017
Priority date	Sep 6, 2013
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

Glass and glass ceramic compositions having a combination of lithium disilicate and β-spodumene 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 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 comprising:
30-65 wt % of a lithium disilicate first crystalline phase; and
20-60 wt % of a β-spodumene second crystalline phase; and
further comprising about 2.4-12 wt % B 2 O 3 .

2. The glass ceramic of claim 1 , comprising:
40-55 wt % of a lithium disilicate first crystalline phase; and
25-45 wt % of a β-spodumene second crystalline phase.

3. The glass ceramic of claim 1 , wherein the residual glass phase comprises less than 25 wt %.

4. The glass ceramic of claim 1 , wherein the glass ceramic has a composition comprising, in wt %:
SiO 2 : 68-82%;
Al 2 O 3 : 5-12.5%;
2.4-10% B 2 O 3 ;
Li 2 O: 8-15%;
Na 2 O: >0-5%;
K 2 O: 0-5%;
(Na 2 O+K 2 O): >0-5%;
P 2 O 5 : >0-4%;
ZrO 2 : 0-10%; and
TiO 2 : 0-4%.

5. The glass ceramic of claim 4 , wherein the glass ceramic has a composition comprising, in wt %:
SiO 2 : 70-80%;
Al 2 O 3 : 6-9%;
2.4-9% B 2 O 3 ;
Li 2 O: 10-13%;
Na 2 O: >0-2.5%;
K 2 O: 0-3%;
(Na 2 O+K 2 O): 1-3%;
P 2 O 5 : 1-3%;
ZrO 2 : 0-5%; and
TiO 2 : 0-4%.

6. The glass ceramic of claim 1 , wherein the glass ceramic has a coefficient of thermal expansion greater than 5 ppm/° C.

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

8. The glass ceramic of claim 1 , wherein the glass ceramic has a Vickers indentation crack initiation load of about 15 kgf or greater.

9. The glass ceramic of claim 1 , wherein the glass-ceramic comprises a color presented in CIELAB color space coordinates determined from reflectance spectra measurements using a spectrophotometer, with illuminant D65 and specular reflectance excluded, of the following ranges:
a*=from about −1 to about +3;
b*=from about −7 to about +3; and
L*>85.

10. The glass ceramic of claim 1 , wherein the glass ceramic is formed from a base glass having a liquidus viscosity greater than 1000 P.

11. The glass ceramic of claim 4 , wherein the glass ceramic comprises, in wt %:
TiO 2 : >0-3%, and
ZrO 2 : >0-4.

12. The glass ceramic of claim 4 , wherein the glass ceramic further comprises a coloring component.

13. The glass ceramic of claim 12 , wherein the coloring component comprises V 2 O 5 , Cr 2 O 3 , TiO 2 , MnO 2 , NiO, ZnO, CuO, NiO, Co 3 O 4 , and combinations thereof.

14. The glass ceramic of claim 13 , wherein the total wt % of coloring component is from >0 to about 4 wt %.

15. A method of forming a glass of claim 1 , wherein the method comprises:
a. forming a glass composition,
b. ceramming the glass composition.

Assignees

• Corning Inc

Inventors

• Beall George Halsey
• Fu Qiang
• Moore Lisa Anne
• Pinckney Linda Ruth
• Smith Charlene Marie

Classifications

• C03C3/093

  containing zinc or zirconium · CPC title

• C03C3/097 Primary

  containing phosphorus, niobium or tantalum · CPC title

• C03C10/0054

  containing PbO, SnO2, B2O3 · CPC title

• C03C21/002

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title