Low crystallinity glass-ceramics

Patent metadata

Field	Value
Publication number	US-9878940-B2
Application number	US-201514623674-A
Country	US
Kind code	B2
Filing date	Feb 17, 2015
Priority date	Feb 21, 2014
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

Embodiments of the present disclosure pertain to crystallizable glasses and glass-ceramics that exhibit a black color and are opaque. In one or more embodiments, the crystallizable glasses and glass-ceramics include a precursor glass composition that exhibits a liquidus viscosity of greater than about 20 kPa*s. The glass-ceramics exhibit less than about 20 wt % of one or more crystalline phases, which can include a plurality of crystallites in the Fe 2 O 3 —TiO 2 —MgO system and an area fraction of less than about 15%. Exemplary compositions used in the crystallizable glasses and glass-ceramics include, in mol %, SiO 2 in the range from about 50 to about 76, Al 2 O 3 in the range from about 4 to about 25, P 2 O 5 +B 2 O 3 in the range from about 0 to about 14, R 2 O in the range from about 2 to about 20, one or more nucleating agents in the range from about 0 to about 5, and RO in the range from about 0 to about 20.

First claim

What is claimed is:

1. A glass-ceramic comprising:
greater than 0 wt % and less than about 20 wt % of one or more crystalline phases,
wherein at least one crystalline phase comprises a plurality of crystallites in the Fe 2 O 3 —TiO 2 —MgO system, the glass-ceramic is formed from a precursor glass exhibiting a liquidus viscosity of greater than about 20 kPa*s, and the crystallites comprise at least one of:
MgO in an amount in the range from about 5 mol % to about 50 mol %,
Fe 2 O 3 in an amount in the range from about 15 mol % to about 65 mol %, and
TiO 2 in an amount in the range from about 25 mol % to about 45 mol %.

2. The glass-ceramic of claim 1 , wherein the crystallites comprise MgO in an amount in the range from about 5 mol % to about 50 mol %.

3. The glass-ceramic of claim 1 , wherein the crystallites comprise Fe 2 O 3 in an amount in the range from about 15 mol % to about 65 mol %.

4. The glass-ceramic of claim 1 , wherein the crystallites comprise TiO 2 in an amount in the range from about 25 mol % to about 45 mol %.

5. The glass-ceramic of claim 1 , wherein the glass-ceramic comprises a color presented in CIELAB color space coordinates for CIE illuminant D65 determined from reflectance spectra measurements using a spectrophotometer with SCE of the following ranges:
L*=from about 14 to about 30;
a*=from about −1 to about +3; and
b*=from about −7 to about +3.

6. The glass-ceramic of claim 1 , wherein the plurality of crystallites form an area fraction of about 15% or less.

7. The glass-ceramic of claim 1 , wherein the crystallites comprise at least one of magnetite, pseudobrookite, and ∈-Fe 2 O 3 .

8. A glass-ceramic comprising:
greater than 0 wt % and less than about 20 wt % of one or more crystalline phases,
wherein at least one crystalline phase comprises a plurality of crystallites in the Fe 2 O 3 —TiO 2 —MgO system, the glass-ceramic is formed from a precursor glass exhibiting a liquidus viscosity of greater than about 20 kPa*s, and the one or more crystalline phases comprises a solid solution of MgO, TiO 2 , and Fe 2 O 3 .

9. The glass-ceramic of claim 8 , further comprising TiO 2 , wherein the ratio of TiO 2 :Fe 2 O 3 is in the range from about 0.1 to about 3.

10. The glass-ceramic of claim 8 , further comprising TiO 2 , wherein the ratio of TiO 2 :Fe 2 O 3 is greater than about 2.

11. The glass-ceramic of claim 1 , wherein the glass-ceramic is formed from a pre-cursor glass exhibiting a liquidus viscosity of about 50 kPa*s or greater.

12. The glass-ceramic of claim 1 , wherein the one or more crystalline phases comprises one or more ∈-Fe 2 O 3 crystallites.

13. The glass-ceramic of claim 12 , wherein the one or more crystalline phases comprises a solid solution of ∈-Fe 2 O 3 and MgTiO 3 .

14. A glass-ceramic comprising:
greater than 0 wt % and less than about 20 wt % of one or more crystalline phases, and
a compressive stress of at least about 200 MPa and a depth of layer of at least about 15 μm,
wherein at least one crystalline phase comprises a plurality of crystallites in the Fe 2 O 3 —TiO 7 —MgO system, and the glass-ceramic is formed from a precursor glass exhibiting a liquidus viscosity of greater than about 20 kPa*s.

15. The glass-ceramic of claim 14 , wherein the glass ceramic exhibits any one of
an average edge strength, as measured by 4-point bend of at least about 700 MPa, an average flexural strength, as measured by ring-on-ring testing, of about 2000 N or greater, and
an average flexural strength, as measured by abraded ring-on-ring testing, of about 1000 N or greater.

16. An opaque, black glass-ceramic comprising:
greater than 0 wt % and less than about 20 wt % of one or more crystalline phases;
a composition comprising, on an oxide basis, in mol %:
SiO 2 in the range from about 50 to about 76;
Al 2 O 3 in the range from about 4 to about 25;
P 2 O 5 +B 2 O 3 in the range from about 0 to about 14;
Fe 2 O 3 in the range from about 0.25 to about 5;
R 2 O in the range from about 2 to about 20, wherein R 2 O includes one or more of Li 2 O, Na 2 O, K 2 O, Rb 2 O, Cs 2 O, Cu 2 O, and Ag 2 O;
one or more nucleating agents in the range from about 0 to about 5;
RO in the range from about 0 to about 20, wherein RO includes one or more of MgO, CaO, SrO, BaO, and ZnO; and
at least one of the compositional relationships of:
R 2 O—Al 2 O 3 in the range from about −2 to about 3; and
R 2 O+RO—Al 2 O 3 in the range from about −2 to about 5,

wherein the crystalline phases comprise a plurality of crystallites in the Fe 2 O 3 —TiO 2 —MgO system and having an area fraction of about 10% or less, and
wherein the opaque, black glass-ceramic is formed from a precursor glass having a liquidus viscosity of greater than about 20 kPa*s.

17. The opaque, black glass-ceramic of claim 16 , wherein the one or more nucleating agents comprises TiO 2 .

18. The opaque, black glass-ceramic of claim 16 , wherein the composition comprises, on an oxide basis, in mol %:
SiO 2 in an amount in the range from about 58 to about 72;
Al 2 O 3 in an amount in the range from about 8 to about 20;
B 2 O 3 in an amount in the range from about 0 to about 12;
R 2 O in an amount in the range from about 2 to about 20;
RO in an amount in the range from about 0 to about 10;
SnO 2 in an amount in the range from about 0 to about 0.5;
TiO 2 in an amount in the range from about 0.25 to about 5;
Fe 2 O 3 in an amount in the range from about 0.25 to about 5; and
at least one of the compositional relationships of
R 2 O—Al 2 O 3 in the range from about −2 to about 3; and
R 2 O+RO—Al 2 O 3 in the range from about −2 to about 5.

19. An electronic device comprising the glass-ceramic of claim 1 .

20. A light emitting device comprising a display cover, wherein the display cover comprises the glass-ceramic of claim 1 .

21. An electronic device comprising the glass-ceramic of claim 16 .

22. A light emitting device comprising a display cover, wherein the display cover comprises the glass-ceramic of claim 16 .

Assignees

• Corning Inc

Inventors

• Baker David Eugene
• Dejneka Matthew John
• Dutta Indrajit
• Morena Robert Michael
• Smith Charlene Marie

Classifications

• C03C2204/04

  Opaque glass, glaze or enamel · CPC title

• C03C10/0018

  containing SiO2, Al2O3 and monovalent metal oxide as main constituents · CPC title

• C03C3/091

  containing aluminium · CPC title

• C03C4/02

  for coloured glass · CPC title

• C03C10/0081

  having a magnetic crystal phase · CPC title