Magnesium aluminosilicate glasses with high fracture toughness

Abstract

A glass composition includes: Si 2 O, greater than 0 mol % to less than or equal to 24 mol % Al 2 O 3 , B 2 O 3 , K 2 O, greater than or equal to 10 mol % to less than or equal to 38 mol % MgO, Na 2 O, and Li 2 O. The glass composition may have a fracture toughness of greater than or equal 0.80 MPa√m and a Young's modulus of greater than or equal to 80 GPa to less than or equal to 120 GPa. The glass composition is chemically strengthenable. The glass composition may be used in a glass article or a consumer electronic product.

What is claimed is: 
     
         1 . A composition, comprising:
 greater than or equal to 52.0 mol % to less than or equal to 59.0 mol % SiO 2 ;   greater than or equal to 10.0 mol % to less than or equal to 19.0 mol % Al 2 O 3 ;   greater than or equal to 3.0 mol % to less than or equal to 8.5 mol % B 2 O 3 ;   greater than or equal to 7.0 mol % Li 2 O; and   less than or equal to 9.0 mol % Na 2 O.   greater than or equal to 0 mol % to less than or equal to 15.80 mol % CaO; and   greater than or equal to 9.80 mol % to less than or equal to 37.40 mol % MgO.   
     
     
         2 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to 14.0 mol % to less than or equal to 19.0 mol % Al 2 O 3 .   
     
     
         3 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to 7.0 mol % to less than or equal to about 9 mol % Li 2 O.   
     
     
         4 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to about 0.2 mol % to less than or equal to about 0.5 mol % K 2 O.   
     
     
         5 . The composition of  claim 1 , wherein the composition comprises:
 less than or equal to 3.5 mol % Na 2 O.   
     
     
         6 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to 8.0 mol % Li 2 O.   
     
     
         7 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to 8.0 mol % Li 2 O;   less than or equal to 3.5 mol % Na 2 O; and   greater than or equal to 0.2 mol % K 2 O.   
     
     
         8 . The composition of  claim 7 , wherein the composition comprises:
 greater than or equal to about 0.2 mol % to less than or equal to about 0.5 mol % K 2 O.   
     
     
         9 . The composition of  claim 7 , wherein the composition comprises:
 greater than or equal to 13.0 mol % to less than or equal to 19.0 mol % MgO; and   greater than or equal to 0.1 mol % to less than or equal to 3.5 mol % CaO.   
     
     
         10 . The composition of  claim 7 , wherein the composition comprises:
 greater than or equal to 0.5 mol % to less than or equal to 2.5 mol % CaO.   
     
     
         11 . The composition of  claim 7 , wherein the composition is substantially free of P 2 O 5 . 
     
     
         12 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to 10.5 mol % to less than or equal to 15.0 mol % MgO.   
     
     
         13 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to 13.0 mol % to less than or equal to 37.40 mol % MgO.   
     
     
         14 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to 0.1 mol % to less than or equal to 3.5 mol % CaO.   
     
     
         15 . The composition of  claim 1 , wherein the composition comprises:
 greater than or equal to 0.5 mol % to less than or equal to 2.5 mol % CaO.   
     
     
         16 . The composition 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 or equal to 27.0 mol % to 40.0 mol %. 
     
     
         17 . The composition of  claim 1 , wherein the composition has a liquidus viscosity of less than 100 Poise. 
     
     
         18 . The composition of  claim 1 , wherein the composition has a fracture toughness of greater than or equal 0.80 MPa√m. 
     
     
         19 . The composition of  claim 1 , wherein the composition has a Young's modulus of greater than or equal to 80 GPa to less than or equal to 120 GPa. 
     
     
         20 . The composition of  claim 1 , wherein the composition has a hardness of greater than or equal to 6.5 GPa to less than or equal to 9.2 GPa.