Low viscosity glasses and methods and systems for manufacture
A glass article including any one or several of SiO 2 , Al 2 O 3 , B 2 O 3 , Li 2 O, SnO 2 and a fusion line. The glass article can also include a liquidus viscosity less than or equal to 100 kP. In some embodiments, the glass article includes, on an oxide basis, from 60 mol % to 74 mol % SiO 2 , from 7 mol % to 18 mol % Al 2 O 3 , from 3 mol % to 16 mol % B 2 O 3 , from 0 mol % to 6 mol % Na 2 O, from 0 mol % to 5 mol % P 2 O 5 , from 5 mol % to 11 mol % Li 2 O, less than or equal to 0.2 mol % SnO 2 .
1. A glass article having a fusion line and comprising on an oxide basis:
from greater than or equal to 60 mol % to less than or equal to 74 mol % SiO 2 ;
from greater than or equal to 7 mol % to less than or equal to 18 mol % Al 2 O 3 ;
from greater than or equal to 3 mol % to less than or equal to 16 mol % B 2 O 3 ;
from greater than or equal to 0 mol % to less than or equal to 5 mol % P 2 O 5 ;
from greater than or equal to 0 mol % to less than or equal to 0.2 mol % SnO 2 ;
from greater than or equal to 5 mol % to less than or equal to 11 mol % Li 2 O;
from greater than 0 mol % to less than or equal to 6 mol % Na 2 O; and
from greater than or equal to 0 mol % to less than 0.1 mol % K 2 O;
wherein the glass article has a strain point from greater than or equal to 515° C. to less than or equal to 625° C.
2. The glass article of claim 1 wherein P 2 O 5 is from greater than 0 mol % to less than or equal to 5 mol %.
3. The glass article of claim 1 further comprising a molar ratio of Al 2 O 3 :(R 2 O+RO) greater than or equal to 0.9, where R 2 O is a sum of alkali metal oxides in mol % and RO is a sum of divalent cation oxides in mol %.
4. The glass article of claim 1 , wherein the glass article has a liquidus viscosity of less than or equal to 300 kP.
5. The glass article of claim 1 , wherein the glass article has a liquidus viscosity of less than or equal to 100 kP.
6. The glass article of claim 1 , wherein the glass article has a liquidus viscosity of less than or equal to 50 kP.
7. The glass article of claim 1 , wherein the glass article has a liquidus viscosity of less than or equal to 25 kP.
8. The glass article of claim 1 , wherein the glass article has an annealing point from greater than or equal to 550° C. to less than or equal to 675° C.
9. The glass article of claim 1 , wherein the glass article has a softening point from greater than or equal to 825° C. to less than or equal to 950° C.
10. The glass article of claim 1 , wherein the glass article has an annealing point from greater than or equal to 550° C. to less than or equal to 675° C. and a softening point from greater than or equal to 825° C. to less than or equal to 950° C.
11. The glass article of claim 1 , wherein the glass article is strengthened by an ion exchange process, such that a compressive stress layer is formed on at least one surface of the glass article.
12. The glass article of claim 11 , wherein a depth of compression is greater than or equal to 0.15 t, where t is a thickness of the glass article.
13. The glass article of claim 11 , wherein a depth of compression (DOC) is from greater than or equal to 0.15 t to less than or equal to 0.25 t, where t is a thickness of the glass article.
14. The glass article of claim 11 , wherein the glass article has a central tension from greater than or equal to 30 MPa to less than or equal to 150 MPa.
15. The glass article of claim 11 , wherein the glass article is strengthened by an ion exchange process that adds potassium ions to the glass article and a potassium depth of layer (DOL) is from greater than or equal to 5 μm to less than or equal to 30 μm.
16. The glass article of claim 11 , wherein a compressive stress layer has a compressive stress at its surface from greater than or equal to 300 MPa to less than or equal to 950 MPa.
17. The glass article of claim 11 , wherein the glass article has a Knoop Scratch Lateral Cracking Threshold of greater than or equal to 5 N to less than or equal to 24 N.
18. The glass article of claim 11 , wherein the glass article has an Indentation Fracture Threshold of greater than or equal to 15 kgf.