Low temperature moldable sheet forming glass compositions
The embodiments described herein relate to low temperature moldable sheet forming glass compositions and glass articles formed from the same. In various embodiments, the glass composition comprises from about 60 mol. % to about 67 mol. % SiO 2 , from about 6 mol. % to about 11 mol. % B 2 O 3 , from about 4.5 mol. % to about 11 mol. % Li 2 O, Al 2 O 3 , Na 2 O, and K 2 O. The glass composition also includes greater than about 2 mol. % RO, where RO are divalent metal oxides, and R 2 O from about 14 mol. % to about 20 mol. %, where R 2 O are alkali metal oxides. The glass composition also has a glass transition temperature T g of less than about 500 C, a softening point of less than about 650 C, and a coefficient of thermal expansion (CTE) of less than about 85×10 −7 K −1 .
1. A glass composition comprising:
from about 60 mol. % to about 67 mol. % SiO 2 ;
from about 6 mol. % to about 11 mol. % B 2 O 3 ;
from about 4.5 mol. % to about 11 mol. % Li 2 O;
Al 2 O 3 ;
Na 2 O;
K 2 O;
greater than about 2 mol. % RO, where RO are divalent metal oxides;
from about 14 mol. % to about 20 mol. % R 2 O, where R 2 O are alkali metal oxides,
wherein the glass composition has a glass transition temperature T g of less than about 500° C. and an average coefficient of thermal expansion (CTE) of less than about 85×10 −7 K −1 , and
wherein the glass composition has a softening point of less than about 650° C.
2. The glass composition of claim 1 , wherein the glass composition has a softening point of less than about 600° C.
3. The glass composition of claim 1 , wherein the glass composition has a liquidus viscosity of greater than about 90 kP.
4. The glass composition of claim 1 , wherein Al 2 O 3 is present in an amount of from about 2.5 mol. % to about 7.5 mol. %.
5. The glass composition of claim 1 , wherein Na 2 O is present in an amount of from about 5 mol. % to about 9.4 mol. %.
6. The glass composition of claim 1 , wherein K 2 O is present in an amount of from about 1 mol. % to about 5 mol. %.
7. The glass composition of claim 1 , wherein R 2 O (mol. %)>Al 2 O 3 (mol. %).
8. The glass composition of claim 1 , wherein 20 mol. %<[R 2 O+RO] (mol. %)<28 mol. %.