Glass-ceramic compositions and laminated glass articles incorporating the same
According to one embodiment, a glass-ceramic composition may include from about 60 mol. % to about 75 mol. % SiO 2 ; from about 5 mol. % to about 10 mol. % AI 2 O 3 ; from about 2 mol. % to about 20 mol. % alkali oxide R 2 O, the alkali oxide R 2 O including Li 2 O and Na 2 O; and from 0 mol. % to about 5 mol. % alkaline earth oxide RO, the alkaline earth oxide RO including MgO. A ratio of Al 2 O 3 (mol. %)) to the sum of (R 2 O (mol. %)+RO (mol. %)) may be less than 1 in the glass-ceramic composition. A major crystalline phase of the glass-ceramic composition may be Li 2 Si 2 O 5 . A liquidus viscosity of the glass-ceramic composition may be greater than 35 kP. The glass-ceramic composition may be used to form the glass clad layer(s) of a laminated glass article.
1. A glass-ceramic composition comprising:
from about 60 mol. % to about 75 mol. % SiO 2 ;
from about 5 mol. % to about 10 mol. % Al 2 O 3 ;
from about 2 mol. % to about 20 mol. % alkali oxide R 2 O, the alkali oxide R 2 O comprising Li 2 O and Na 2 O, wherein the alkali oxide R 2 O comprises from about 1 mol. % to about 10 mol. % Li 2 O;
from 0 mol. % to about 5 mol. % alkaline earth oxide RO, the alkaline earth oxide RO comprising MgO;
a ratio of Al 2 O 3 (mol. %)/(R 2 O (mol. %)+RO (mol. %)) of less than 1;
a major crystalline phase of Li 2 Si 2 O 5 ; and
a liquidus viscosity of greater than 35 kP.
2. The glass-ceramic composition of claim 1 , wherein the alkali oxide R 2 O comprises from about 1 mol. % to about 10 mol. % Na 2 O.
3. The glass-ceramic composition of claim 1 , wherein the alkaline earth oxide RO comprises greater than 0 mol. % and up to about 5 mol. % MgO.
4. The glass-ceramic composition of claim 1 , further comprising from greater than zero mol. % to about 4 mol. % of a nucleating agent selected from the group consisting of TiO 2 , ZrO 2 , P 2 O 5 , and combinations thereof.
5. The glass-ceramic composition of claim 4 , comprising from about 1 mol. % to about 4 mol. % TiO 2 .
6. The glass-ceramic composition of claim 4 , comprising ZrO 2 in an amount up to about 4 mol. %.
7. The glass-ceramic composition of claim 4 , wherein a ratio of (SiO 2 (mol. %)+Al 2 O 3 (mol. %)+Li 2 O (mol. %)+K 2 O (mol. %)+Na 2 O (mol. %))/(TiO 2 (mol. %)+P 2 O 5 (mol. %)+ZrO 2 (mol. %)) is greater than 26.
8. The glass-ceramic composition of claim 7 , wherein the ratio of (SiO 2 (mol. %)+Al 2 O 3 (mol. %)+Li 2 O (mol. %)+K 2 O (mol. %)+Na 2 O (mol. %))/(TiO 2 (mol. %)+P 2 O 5 (mol. %)+ZrO 2 (mol. %)) is less than 31.
9. The glass-ceramic composition of claim 1 , wherein a ratio of SiO 2 (mol. %) to Al 2 O 3 (mol. %) is greater than 7.
10. The glass-ceramic composition of claim 1 , wherein a ratio of (Li 2 O (mol. %)+2*SiO 2 (mol. %))/Al 2 O 3 (mol. %) is greater than 13.
11. The glass-ceramic composition of claim 1 , wherein a ratio of (R 2 O (mol. %)+2*SiO 2 (mol. %))/Al 2 O 3 (mol. %) is greater than 8.5.
12. The glass-ceramic composition of claim 1 , further comprising K 2 O in an amount up to about 10 mol. %.
13. The glass-ceramic composition of claim 1 , wherein the liquidus viscosity is greater than or equal to about 100 kP.
14. The glass-ceramic composition of claim 1 , wherein the glass-ceramic composition has a pre-ceramming CTE PC of greater than or equal to about 65×10 −7 /° C. and less than or equal to about 110×10 −7 /° C.
15. The glass-ceramic composition of claim 1 , wherein the glass-ceramic composition has a post-ceramming CTE AC of greater than or equal to 20×10 −7 /° C. and less than or equal to about 70×10 −7 /° C.