White, opaque, β-spodumene/rutile glass-ceramic articles and methods for making the same
Crystallizable glasses, glass-ceramics, IXable glass-ceramics, and IX glass-ceramics are disclosed. The glass-ceramics exhibit β-spodumene ss as the predominant crystalline phase. These glasses and glass-ceramics, in mole %, include: 62-75 SiO 2 ; 10.5-17 Al 2 O 3 ; 5-13 Li 2 O; 0-4 ZnO; 0-8 MgO; 2-5 TiO 2 ; 0-4 B 2 O 3 ; 0-5 Na 2 O; 0-4 K 2 O; 0-2 ZrO 2 ; 0-7 P 2 O 5 ; 0-0.3 Fe 2 O 3 ; 0-2 MnOx; and 0.05-0.2 SnO 2 . Additionally, these glasses and glass-ceramics exhibit the following criteria: a. a ratio: [ Li 2 O + Na 2 O + K 2 O + MgO + ZnO ] [ Al 2 O 3 + B 2 O 3 ] between 0.7 to 1.5; b. a ratio : [ TiO 2 + SnO 2 ] [ SiO 2 + B 2 O 3 ] greater than 0.04. Furthermore, the glass-ceramics exhibit an opacity ≧about 85% over the wavelength range of 400-700 nm for an about 0.8 mm thickness and colors an observer angle of 10° and a CIE illuminant F02 determined with specular reflectance included of a* between −3 and +3, b* between −6 and +6, and L* between 88 and 97.
1. An IX, β-spodumene glass-ceramic comprising:
a. a nominal composition, in mole percent (mole %), comprising:
i. 62-75 SiO 2 ;
ii. 10.5-17 Al 2 O 3 ;
iii. 5-13 Li 2 O;
iv. 0-4 ZnO;
v. 0-8 MgO;
vi. 2-5 TiO 2 ;
vii. 0-4 B 2 O 3 ;
viii. 0-5 Na 2 O;
ix. 0-4 K 2 O;
x. 0-2 ZrO 2 ;
xi. 0-7 P 2 O 5
xii. 0-0.3 Fe 2 O 3 ;
xiii. 0-2 MnOx; and
xiv. 0.05-0.20 SnO 2 ;
b. a ratio:
[
Li
2
O
+
Na
2
O
+
K
2
O
+
MgO
+
ZnO
]
[
Al
2
O
3
+
B
2
O
3
]
between 0.7 to 1.5;
c. a ratio:
[
TiO
2
+
SnO
2
]
[
SiO
2
+
B
2
O
3
]
greater than about 0.04;
d. one or more β-spodumene solid solutions comprising at least about 70 wt % of the crystalline phases of the glass-ceramic;
e. at least one Ti-containing crystalline phase comprising:
i. about 2.5-8 wt % of the crystalline phases of the glass-ceramic,
ii. a morphology exhibiting a length ≧about 20 nm, and
iii. rutile;
f. an opacity comprising ≧about 85% over the wavelength range of 400-700 nm for an about 0.8 mm thickness;
g. a depth of layer (DOL) ≧about 2% of an overall thickness of an article of the IX, β-spodumene glass-ceramic and a compressive stress (σ s ) in at least a portion of a surface of the article of at least about 300 MPa; and
h. optionally, one or more crystalline phase comprising:
i. up to about 10 wt % of the crystalline phases of the glass-ceramic and
ii. a spinel structure,
wherein the at least one Ti-containing crystalline phase further comprises any one of anatase, a magnesium titanate, and an aluminum titanate; or further comprising mixtures of rutile and two or more of anatase, a magnesium titanate, and an aluminum titanate.
2. The IX, β-spodumene glass-ceramic according to claim 1 , further comprising cordierite or mixtures of rutile, cordierite, and one or more of anatase, a magnesium titanate, and an aluminum titanate.
3. The IX, β-spodumene glass-ceramic according to claim 1 , wherein the at least one Ti-containing crystalline phase comprises rutile comprising about 2-6 wt % of the crystalline phases of the glass-ceramic.
4. The IX, β-spodumene glass-ceramic according to claim 1 , wherein the one or more β-spodumene solid solutions comprise at least about 75 wt % of the crystalline phases of the glass-ceramic.
5. The IX, β-spodumene glass-ceramic according to claim 1 , wherein the optional one or more crystalline phase comprises:
about 1-10 wt % of the crystalline phases of the glass-ceramic and
a Zn-containing spinel structure.
6. The IX, β-spodumene glass-ceramic according to claim 1 , wherein the IX, β-spodumene glass-ceramic exhibits one or more of:
a. a fracture toughness of greater than about 0.8 MPa·m 1/2 ; or
b. MOR of greater than 40,000 psi; or
c. a dielectric constant determined over a frequency between about 15 MHz-3.0 GHz at about 25° C. of less than about 10; or
d. a loss tangent determined over a frequency between about 15 MHz-3.0 GHz at about 25° C. of less of less than 0.02; or
e. a depth of layer (DOL) ≧about 40 μm in at least a portion of a surface of an article of the IX, β-spodumene glass-ceramic having a 2 mm overall thickness; or
f. a compressive stress (σ s ) of at least about 500 MPa in at least a portion of a surface of an article of the IX, β-spodumene glass-ceramic having a 2 mm overall thickness; or
g. any combination of two or more of the preceding.
7. The IX, β-spodumene glass-ceramic according to claim 1 , wherein the glass-ceramic comprises a color presented in CIELAB color space coordinates for an observer angle of 10° and a CIE illuminant F02 determined from reflectance spectra measurements using a spectrophotometer with specular reflectance included comprising:
a. CIE a* between −3 and +3;
b. CIE b* between −6 and +6; and
c. CIE L* between 88 and 97.
8. The IX, β-spodumene glass-ceramic according to claim 1 , wherein the-β-spodumene solid solutions comprise a Li 2 O:Al 2 O 3 :SiO 2 ratio between about 1:1:4.5-1:1:8.
9. The IX, β-spodumene glass-ceramic according to claim 1 , wherein the Ti-containing crystalline phase comprises an acicular morphology.
10. A glass-ceramic comprising:
a. a composition, in mole %, comprising:
i. 62-75 SiO 2 ;
ii. 10.5-17 Al 2 O 3 ;
iii. 5-13 Li 2 O;
iv. 0-4 ZnO;
v. 0-8 MgO;
vi. 2-5 TiO 2 ;
vii. 0-4 B 2 O 3 ;
viii. 0-5 Na 2 O;
ix. 0-4 K 2 O;
x. 0-2 ZrO 2 ;
xi. 0-7 P 2 O 5
xii. 0-0.3 Fe 2 O 3 ;
xiii. 0-2 MnOx; and
xiv. 0.05-0.20 SnO 2 ;
b. a ratio:
[
Li
2
O
+
Na
2
O
+
K
2
O
+
MgO
+
ZnO
]
[
Al
2
O
3
+
B
2
O
3
]
between 0.7 to 1.5;
c. a ratio:
[
TiO
2
+
SnO
2
]
[
SiO
2
+
B
2
O
3
]
greater than about 0.04;
d. one or more β-spodumene solid solutions comprising at least about 70 wt % of the crystalline phases of the glass-ceramic;
e. at least one Ti-containing crystalline phase comprising:
i. about 2.5-8 wt % of the crystalline phases of the glass-ceramic,
ii. a morphology exhibiting a length≧about 20 nm, and
iii. rutile;
f. an opacity comprising≧about 85% over the wavelength range of 400-700 nm for an about 0.8 mm thickness; and
g. optionally, one or more crystalline phase comprising:
i. up to about 10 wt % of the crystalline phases of the glass-ceramic; and
ii. a spinel structure.
11. The glass-ceramic according to claim 10 wherein the at least one Ti-containing crystalline phase further comprises any one of anatase, a magnesium titanate, an aluminum titanate, or mixtures of rutile and two or more of anatase, a magnesium titanate, and an aluminum titanate.
12. The glass-ceramic according to claim 10 , further comprising cordierite or mixtures of rutile, cordierite, and one or more of anatase, a magnesium titanate, and an aluminum titanate.
13. The glass-ceramic according to claim 10 , wherein the at least one Ti-containing crystalline phase comprises rutile comprising about 2-6 wt % of the crystalline phases of the glass-ceramic.
14. The glass-ceramic according to claim 10 , wherein the one or more β-spodumene solid solutions comprises at least about 75 wt % of the crystalline phases of the glass-ceramic.
15. The glass-ceramic according to claim 10 , further comprising:
a. the optional one or more crystalline phase comprising:
i. about 1-10 wt % of the crystalline phases of the glass-ceramic and
ii. a Zn-containing spinel structure.
16. The glass-ceramic according to claim 10 , wherein the glass-ceramic comprises at least a portion of at least one of an electronic devices or a portable computing device.
17. The glass-ceramic according to claim 10 , wherein the glass-ceramic comprises a color presented in CIELAB color space coordinates for an observer angle of 10° and a CIE illuminant F02 determined from reflectance spectra measurements using a spectrophotometer with specular reflectance included comprising:
i. CIE a* between −3 and +3;
j. CIE b* between −6 and +6; and
k. CIE L* between 88 and 97.
18. The glass-ceramic according to claim 10 , wherein the Ti-containing crystalline phase comprises an acicular morphology.