Ion exchangeable glasses having high fracture toughness
In embodiments, a glass includes from 45 mol % to 70 mol % SiO 2 ; from 11.5 mol % to 25 mol % Al 2 O 3 ; from 2 mol % to 20 mol % Li 2 O; from greater than 0 mol % to 10 mol % Na 2 O; from 9 mol % to 19 mol % MgO; from 4 mol % ZrO 2 ; and from 0 mol % to 0.5 mol % TiO 2 . In other embodiments, a glass includes from 45 mol % to 70 mol % SiO 2 ; from 4 mol % to 25 mol % Al 2 O 3 ; from 5 mol % to 20 mol % Li 2 O; from 0.1 mol % to 10 mol % Na 2 O; from 6 mol % to 25 mol % MgO; from 0.1 mol % to 4 mol % ZrO 2 ; from 0.1 mol % to 5 mol % K 2 O; and from 0.05 mol % to 0.5 mol % SnO 2 .
1. A glass, comprising:
greater than or equal to 45 mol % to less than or equal to 70 mol % SiO 2 ;
greater than or equal to 4 mol % to less than or equal to 25 mol % Al 2 O 3 ;
greater than or equal to 5 mol % to less than or equal to 20 mol % Li 2 O;
greater than or equal to 0.1 mol % to less than or equal to 10 mol % Na 2 O;
greater than or equal to 13 mol % to less than or equal to 25 mol % MgO;
greater than or equal to 0.1 mol % to less than or equal to 4 mol % ZrO 2 ;
greater than or equal to 0.1 mol % to less than or equal to 5 mol % K 2 O; and
greater than or equal to 0.05 mol % to less than or equal to 0.5 mol % SnO 2 ,
wherein the glass has a K IC fracture toughness greater than or equal to 0.83 MPa·m 0.5 and a Young's modulus greater than or equal to 86 GPa, and
wherein (Li 2 O+Na 2 O+MgO)/Al 2 O 3 is greater than or equal to 1.68 and less than or equal to 2.5, where each component concentration is in mol %.
2. The glass of claim 1 , comprising:
greater than or equal to 51 mol % to less than or equal to 65 mol % SiO 2 .
3. The glass of claim 1 , comprising:
greater than or equal to 12.0 mol % to less than or equal to 19 mol % Al 2 O 3 .
4. The glass of claim 1 , comprising:
greater than or equal to 6 mol % to less than or equal to 12 mol % Li 2 O.
5. The glass of claim 1 , comprising:
greater than 0.25 mol % to less than or equal to 6 mol % Na 2 O.
6. The glass of claim 1 , comprising:
greater than or equal to 14 mol % to less than or equal to 19 mol % MgO.
7. The glass of claim 1 , comprising:
greater than 0.25 mol % to less than or equal to 2 mol % ZrO 2 .
8. The glass of claim 1 , comprising:
greater than or equal to 0 mol % to less than or equal to 10 mol % B 2 O 3 .
9. The glass of claim 1 , comprising:
greater than or equal to 0 mol % to less than or equal to 4 mol % P 2 O 5 .
10. The glass of claim 1 , comprising:
greater than or equal to 0 mol % to less than or equal to 3 mol % CaO.
11. D) A glass-based article, comprising:
a compressive stress layer extending from a surface of the glass-based article to a depth of compression;
a central tension region; and
a composition at a center of the glass-based article comprising:
greater than or equal to 45 mol % to less than or equal to 70 mol % SiO 2 ;
greater than or equal to 4 mol % to less than or equal to 25 mol % Al 2 O 3 ;
greater than or equal to 5 mol % to less than or equal to 20 mol % Li 2 O;
greater than or equal to 0.1 mol % to less than or equal to 10 mol % Na 2 O;
greater than or equal to 13 mol % to less than or equal to 25 mol % MgO;
greater than or equal to 0.1 mol % to less than or equal to 4 mol % ZrO 2 ;
greater than or equal to 0.1 mol % to less than or equal to 5 mol % K 2 O; and
greater than or equal to 0.05 mol % to less than or equal to 0.5 mol % SnO 2 ,
wherein the glass has a K IC fracture toughness greater than or equal to 0.83 MPa·m 0.5 and a Young's modulus greater than or equal to 86 GPa, and
wherein (Li 2 O+Na 2 O+MgO)/Al 2 O 3 is greater than or equal to 1.68 and less than or equal to 2.5, where each component concentration is in mol %.
12. The glass-based article of claim 11 , wherein the compressive stress layer comprises a compressive stress greater than or equal to 400 MPa to less than or equal to 2000 MPa.
13. The glass-based article of claim 11 , wherein the central tension region comprises a maximum central tension greater than or equal to 30 MPa to less than or equal to 300 MPa.
14. The glass-based article of claim 11 , wherein the depth of compression is greater than or equal to 0.15t to less than or equal to 0.25t, where tis the thickness of the glass-based article.
15. The glass-based article of claim 11 , wherein the compressive stress layer comprises a compressive stress spike extending from the surface of the glass-based article to a depth of compressive stress spike, and the depth of compressive stress spike is greater than or equal to 3 μm to less than or equal to 10 μm.
16. The glass-based article of claim 11 , wherein the glass-based article has a thickness t greater than or equal to 0.2 mm to less than or equal to 2 mm.
17. The glass-based article of claim 11 , wherein a glass having the same composition and microstructure as the composition at the center of the glass-based article has a K IC fracture toughness greater than or equal to 0.8 MPa·m 0.5 to less than or equal to 1.0 MPa·m 0.5 .
18. The glass-based article of claim 11 , wherein a glass having the same composition and microstructure as the composition at the center of the glass-based article has a Young's modulus greater than or equal to 80 GPa to less than or equal to 100 GPa.