Ion exchangeable Li-containing glass compositions for 3-D forming
According to one embodiment, a glass article may include SiO 2 , Al 2 O 3 , Li 2 O and Na 2 O. The glass article may have a softening point less than or equal to about 810° C. The glass article may also have a high temperature CTE less than or equal to about 27×10 −6 /° C. The glass article may also be ion exchangeable such that the glass has a compressive stress greater than or equal to about 600 MPa and a depth of layer greater than or equal to about 25 μm after ion exchange in a salt bath comprising KNO 3 at a temperature in a range from about 390° C. to about 450° C. for less than or equal to approximately 15 hours.
1. A glass article comprising:
from about 65 mol.% to about 71 mol.% SiO 2 ;
from about 7 mol.% to about 12 mol.% Al 2 O 3 ;
from about 1 mol.% to about 9 mol.% Li 2 O;
from about 6 mol.% to about 16 mol.% Na 2 O;
from greater than 0 mol.% to about 5 mol.% K 2 O;
from about 0.8 mol.% to about 10 mol.% of a divalent oxide, the divalent oxide comprising both MgO and ZnO; and
less than about 0.5 mol. % B 2 O 3 , wherein a sum of a concentration of Al 2 O 3 (mol.%), and a concentration of the divalent oxide (mol.%) is greater than about 10 mol %, the glass article having:
a softening point less than or equal to about 810° C.;
a high temperature coefficient of thermal expansion less than or equal to about 27×10 −6 /° C.; and
a compressive stress greater than or equal to about 600 MPa and a depth of layer greater than or equal to about 35 μm after ion exchange in a salt bath comprising KNO 3 in a temperature range from about 390° C. to about 450° C. for less than or equal to approximately 15 hours.
2. The glass article of claim 1 , the glass article has L, a*, b*, color coordinates of L from about 0 to about 5.0, a* from about −2.0 to about 2.0, and b* from about 0 to about −5.0.
3. The glass article of claim 1 , wherein the glass article has an opacity greater than or equal to about 80% over a range of wavelengths from about 350 nm to about 750 nm.
4. The glass article of claim 1 , wherein the glass article further comprises from about 0.5 mol.% to about 2.0 mol.% ZrO 2 .
5. The glass article of claim 4 , wherein the glass article comprises from about 0 mol.% to about 3 mol.% P 2 O 5 .
6. The glass article of claim 1 , wherein the glass article is substantially free of ZrO 2 .
7. The glass article of claim 6 , wherein the glass article comprises from about 65.8 mol.% to about 71 mol.% SiO 2 .
8. The glass article of claim 1 comprising from about 2 mol.% to about 4 mol % MgO.
9. The glass article of claim 1 comprising from about 2 mol.% to about 4 mol % ZnO.
10. The glass article of claim 1 comprising:
from about 2 mol.% to about 4 mol % MgO; and
from about 2 mol.% to about 4 mol % ZnO.