Glasses having high fracture toughness

1. A glass article, comprising:

50 mol % to 69 mol % SiO 2 ;

12.5 mol % to 25 mol % Al 2 O 3 ;

0 mol % to 8 mol % B 2 O 3 ;

0.5 mol % to 4 mol % CaO;

greater than 0 mol % to 17.5 mol % MgO;

0.5 mol % to 8 mol % Na 2 O;

0 mol % to 2.5 mol % La 2 O 3 ; and

greater than 8 mol % to 18 mol % Li 2 O;

wherein:

(Li 2 O+Na 2 O+MgO)/Al 2 O 3 is from 0.9 to less than 1.3; and

Al 2 O 3 +MgO+Li 2 O+ZrO 2 +La 2 O 3 +Y 2 O 3 is from greater than 23 mol % to less than 50 mol %.

2. The glass article of claim 1 , comprising greater than 8 mol % to 16 mol % Li 2 O.

3. The glass article of claim 1 , further comprising K 2 O.

4. The glass article of claim 1 , comprising 0 mol % to 2 mol % TiO 2 .

5. The glass article of claim 1 , comprising 0 mol % to 2.5 mol % ZrO 2 .

6. The glass article of claim 1 , comprising 0 mol % to 1 mol % SrO.

7. The glass article of claim 1 , comprising greater than 0 mol % to 12 mol % MgO.

8. The glass article of claim 1 , comprising greater than 0.5 mol % to 17.5 mol % MgO.

9. The glass article of claim 1 , comprising 14 mol % to 24 mol % Al 2 O 3 .

10. The glass article of claim 1 , comprising 0.5 mol % to 8 mol % B 2 O 3 .

11. The glass article of claim 1 , comprising 0 mol % to 2 mol % Y 2 O 3 .

12. The glass article of claim 1 , wherein the glass article is substantially free of P 2 O 5 .

13. The glass article of claim 1 , wherein (Li 2 O+Na 2 O+MgO)/Al 2 O 3 is from 0.9 to 1.0.

14. The glass article of claim 1 , wherein Al 2 O 3 +MgO+Li 2 O+ZrO 2 +La 2 O 3 +Y 2 O 3 is from 25 mol % to 46 mol %.

15. The glass article of claim 1 , wherein 5.631+0.148·Al 2 O 3 +0.142·B 2 O 3 −0.062·CaO−0.188·K 2 O+0.030·MgO−0.099·Na 2 O−0.043·Li 2 O−0.188·P 2 O 5 +0.020·ZnO−0.062·SrO+0.200·ZrO 2 ≥6.5, wherein the value of each component is in mol %.

16. A consumer electronic product, comprising:

a housing having a front surface, a back surface and side surfaces;

electrical components provided at least partially within the housing, the electrical components including at least a controller, a memory, and a display, the display being provided at or adjacent the front surface of the housing; and

a cover glass disposed over the display,

wherein at least one of a portion of the housing or a portion of the cover glass comprises the glass article of claim 15 .

17. The glass article of claim 1 , wherein the glass article is characterized by at least one of the following:

a K 1C value measured by a chevron short bar method of at least 0.75; and

a K 1C value measured by a double torsion method of at least 0.8.

18. The glass article of claim 1 , wherein the glass is fusion formable.

19. A glass article, comprising:

50 mol % to 69 mol % SiO 2 ;

12.5 mol % to 25 mol % Al 2 O 3 ;

0 mol % to 8 mol % B 2 O 3 ;

greater than 0 mol % to 4 mol % CaO;

greater than 0 mol % to 17.5 mol % MgO;

0.5 mol % to 8 mol % Na 2 O;

K 2 O;

0 mol % to 2.5 mol % La 2 O 3 ; and

greater than 8 mol % to 18 mol % Li 2 O;

wherein:

(Li 2 O+Na 2 O+MgO)/Al 2 O 3 is from 0.9 to less than 1.3; and

Al 2 O 3 +MgO+Li 2 O+ZrO 2 +La 2 O 3 +Y 2 O 3 is from greater than 23 mol % to less than 50 mol %.

20. The glass article of claim 19 , comprising greater than 8 mol % to 16 mol % Li 2 O.

21. The glass article of claim 19 , comprising 0 mol % to 2 mol % TiO 2 .

22. The glass article of claim 19 , comprising 0 mol % to 2.5 mol % ZrO 2 .

23. The glass article of claim 19 , comprising 0 mol % to 1 mol % SrO.

24. The glass article of claim 19 , comprising greater than 0 mol % to 12 mol % MgO.

25. The glass article of claim 19 , comprising greater than 0.5 mol % to 17.5 mol % MgO.

26. The glass article of claim 19 , comprising 14 mol % to 24 mol % Al 2 O 3 .

27. The glass article of claim 19 , comprising 0.5 mol % to 8 mol % B 2 O 3 .

28. The glass article of claim 19 , comprising 0 mol % to 2 mol % Y 2 O 3 .

29. The glass article of claim 19 , wherein the glass article is substantially free of P 2 O 5 .

30. The glass article of claim 19 , wherein (Li 2 O+Na 2 O+MgO)/Al 2 O 3 is from 0.9 to 1.0.

31. The glass article of claim 19 , wherein Al 2 O 3 +MgO+Li 2 O+ZrO 2 +La 2 O 3 +Y 2 O 3 is from 25 mol % to 46 mol %.

32. The glass article of claim 19 , The glass article of claims 1 , wherein 5.631 +0.148·Al 2 O 3 +0.142·B 2 O 3 −0.062·CaO−0.188·K 2 O+0.030·MgO−0.099·Na 2 O −0.043·Li 2 O −0.188·P 2 O 5 +0.020·ZnO−0.062·SrO+0.200·ZrO 2 ≥6.5, wherein the value of each component is in mol %.

33. The glass article of claim 19 , wherein the glass article is characterized by at least one of the following:

a K 1C value measured by a chevron short bar method of at least 0.75; and

a K 1C value measured by a double torsion method of at least 0.8.

34. A glass article, comprising:

a composition at a center of the glass article comprising:

50 mol % to 69 mol % SiO 2 ;

12.5 mol % to 25 mol % Al 2 O 3 ;

0 mol % to 8 mol % B 2 O 3 ;

greater than 0 mol % to 4 mol % CaO;

greater than 0 mol % to 17.5 mol % MgO;

0.5 mol % to 8 mol % Na 2 O;

0 mol % to 2.5 mol % La 2 O 3 ; and

greater than 8 mol % to 18 mol % Li 2 O;

wherein:

(Li 2 O+Na 2 O+MgO)/Al 2 O 3 is from 0.9 to less than 1.3;

Al 2 O 3 +MgO+Li 2 O+ZrO 2 +La 2 O 3 +Y 2 O 3 is from greater than 23 mol % to less than 50 mol %; and

the composition at the center of the glass article comprises:

0.5 mol % to 4 mol % CaO; or

K 2 O,

a compressive stress region extending from a surface of the glass article to a depth of compression.

35. The glass article of claim 34 , wherein the glass article comprises a compressive stress of at least 400 MPa.

36. The glass article of claim 34 , wherein the depth of compression is at least 20% of a thickness of the glass article.

37. The glass article of claim 34 , wherein the glass article comprises a maximum central tension of less than 85 MPa.