High strength glass-ceramics having petalite and lithium silicate structures
In embodiments, a precursor glass composition comprises from about 55 wt. % to about 80 wt. % SiO 2 ; from about 2 wt. % to about 20 wt. % Al 2 O 3 ; from about 5 wt. % to about 20 wt. % Li 2 O; greater than 0 wt % to about 3 wt. % Na 2 O; a non-zero amount of P 2 O 5 less than or equal to 4 wt. %; and from about 0.2 wt. % to about 15 wt. % ZrO 2 . In embodiments, ZrO 2 (wt. %)+P 2 O 5 (wt. %) is greater than 3. When the precursor glass composition is converted to a glass-ceramic article, the glass-ceramic article may include grains having a longest dimension of less than 100 nm.
1. A glass-ceramic article comprising:
from about 55 wt. % to about 80 wt. % SiO 2 ;
greater than 6 wt. % to 10 wt. % Al 2 O 3 ;
greater than 12 wt. % to about 20 wt. % Li 2 O;
1 wt % to about 3 wt. % Na 2 O;
a non-zero amount of P 2 O 5 less than or equal to 5 wt. %; and
from about 0.2 wt. % to about 15 wt. % ZrO 2 , wherein:
ZrO 2 (wt. %)+P 2 O 5 (wt. %) is greater than 3;
the glass-ceramic article has an average transmittance greater than 85% over the wavelength range from 400 nm to 1000 nm for a glass-ceramic article thickness of 1 mm; and
the glass-ceramic article comprises grains and the grains have a longest dimension of less than 100 nm.
2. The glass-ceramic article of claim 1 comprising a phase assemblage comprising:
a petalite crystalline phase; and
one or more lithium silicate crystalline phases.
3. The glass-ceramic article of claim 2 , wherein the phase assemblage comprises from about 20 wt. % to about 70 wt. % of the petalite crystalline phase.
4. The glass-ceramic article of claim 2 , wherein the phase assemblage comprises from about 20 wt. % to about 60 wt. % of the one or more lithium silicate crystalline phase.
5. The glass-ceramic article of claim 4 , wherein the one or more lithium silicate crystalline phase comprises a lithium disilicate phase and a lithium metasilicate phase.
6. The glass-ceramic article of claim 1 comprising a surface compressive stress from about 100 MPa to about 500 MPa.
7. The glass-ceramic article of claim 1 comprising a central tension of at least 10 MPa.
8. The glass-ceramic article of claim 1 comprising a depth of compressive layer of 30 μm or greater.
9. The glass-ceramic article of claim 1 comprising from about 70 wt. % to about 75 wt. % SiO 2 .
10. The glass-ceramic article of claim 1 comprising greater than 6 wt. % to about 9 wt. % Al 2 O 3 .
11. The glass-ceramic article of claim 1 comprising from about 1.5 wt. % to about 4 wt. % P 2 O 5 .
12. The glass-ceramic article of claim 1 comprising from about 0.5 wt. % to about 8 wt. % ZrO 2 .
13. The glass-ceramic article of claim 1 wherein ZrO 2 (wt. %)+P 2 O 5 (wt. %) is greater than 4.
14. The glass-ceramic article of claim 1 comprising a thickness of from about 0.8 mm to about 10 mm.
15. The glass-ceramic article of claim 1 comprising a thickness of less than or equal to 6 mm.
16. A glass-ceramic article comprising:
from about 55 wt. % to about 80 wt. % SiO 2 ;
from about 2 wt. % to 10 wt. % Al 2 O 3 ;
greater than 10 wt. % to about 20 wt. % Li 2 O;
greater than 0 wt % to about 3 wt. % Na 2 O;
a non-zero amount of P 2 O 5 less than or equal to 4 wt. %; and
from about 0.2 wt. % to about 15 wt. % ZrO 2 , wherein:
ZrO 2 (wt. %)+P 2 O 5 (wt. %) is greater than 3;
the glass-ceramic article comprises a petalite crystalline phase; and
the glass-ceramic article has an average transmittance greater than 85% over the wavelength range from 400 nm to 1000 nm for a glass-ceramic article thickness of 1 mm.
17. The glass-ceramic article of claim 16 comprising from about 1.5 wt. % to about 4 wt. % P 2 O 5 .
18. The glass-ceramic article of claim 16 comprising from about 0.5 wt. % to about 8 wt. % ZrO 2 .