Glasses having high fracture toughness
A glass composition includes: 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; 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 %. The glass composition may be 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. The glass composition is chemically strengthenable. The glass composition may be used in a glass article or a consumer electronic product.
1 . A glass article, comprising:
greater than or equal to 50 mol % and less than or equal to 69 mol % SiO 2 ;
greater than or equal to 14 mol % and less than or equal to 25 mol % Al 2 O 3 ;
greater than 8 mol % and less than or equal to 18 mol % Li 2 O, and
greater than 0 mol % and less than or equal to 2 mol % Y 2 O 3 ;
wherein the glass 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.
2 . The glass article of claim 1 , further comprising greater than 0 mol % and less than or equal to 17.5 mol % MgO.
3 . The glass article of claim 1 , further comprising greater than 0 mol % and less than or equal to 4 mol % CaO.
4 . The glass article of claim 1 , further comprising greater than 0 mol % and less than or equal to 2 mol % TiO 2 .
5 . The glass article of claim 1 , further comprising greater than 0 mol % and less than or equal to 2.5 mol % ZrO 2 .
6 . The glass article of claim 1 , further comprising greater than 0 mol % and less than or equal to 1 mol % SrO.
7 . The glass article of claim 1 , comprising greater than or equal to 0.5 mol % and less than or equal to 1.5 mol % Y 2 O 3 .
8 . The glass article of claim 1 , further comprising greater than 0 mol % and less than 1 mol % K 2 O.
9 . The glass article of claim 1 , further comprising greater than or equal to 0.5 mol % and less than or equal to 8 mol % Na 2 O.
10 . The glass article of claim 1 , wherein (Li 2 O+Na 2 O+MgO)/Al 2 O 3 is from 0.9 to less than 1.3.
11 . 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 greater than 23 mol % to less than 50 mol %.
12 . The glass article of claim 1 , further comprising greater than 0 mol % and less than or equal to 8 mol % B 2 O 3 .
13 . The glass article of claim 1 , wherein the glass is fusion formable.
14 . 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 %.
15 . 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 1 .