Lithia-alumina-silica containing glass compositions and glasses suitable for chemical tempering and articles made using the chemically tempered glass

Abstract

A glass composition for chemical tempering includes oxides in wt % ranges of: SiO 2 60 to 75; Al 2 O 3 18 to 28; Li 2 O 3 to 9; Na 2 O 0 to 3; K 2 O 0 to 0.5; CaO 0 to 3; MgO 0 to 3; ZrO 2 0 to 3; where MgO+CaO is 0 to 6 wt %; Al 2 O 3 +ZrO 2 is 18 to 28 wt %, and Na 2 O+K 2 O is 0.05 to 3.00 wt %. The glass has a log 10 viscosity temperature in the temperature range of 1328° F. (720° C.) to 1499° F. (815° C.); a liquidus temperature in the temperature range of 2437° F. (1336° C.) to 2575° F. (1413° C.), and a log 7.6 softening point temperature in the temperature range of 1544° F. (840° C.) to 1724° F. (940° C.). The chemically tempered glass has, among other properties, an abraded modulus of rupture of 72 to 78 KPSI, and a modulus of rupture of 76 to 112 KPSI.

1 - 51 . (canceled) 
     
     
         52 . A method of chemically strengthening a glass piece, comprising the steps of:
 providing a glass piece having a predetermined shape and thickness and a composition according to claim  1 , wherein the glass piece has at least one of the following properties: (a) a log 10 viscosity temperature of at least 1280° F. (694° C.) and (b) a liquidus temperature of at least 2350° F. (1288° C.);   submerging the glass piece in a molten sodium nitrate bath heated to a temperature of greater than 300° F. for at least 8 hours to provide the glass piece with a case depth in the range of 7 to 16.5 mils, and   removing the glass piece from the bath.   
     
     
         53 . A method of chemically strengthening a glass piece, comprising the steps of:
 providing a glass piece having a predetermined shape and thickness and a composition comprising:   
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Ingredient 
                   Percent by weight 
                 
                     
                     
                 
                     
                   SiO 2   
                   60 to 75; 
                 
                     
                   Al 2 O 3   
                   18 to 28; 
                 
                     
                   Li 2 O 
                   3 to 9; 
                 
                     
                   Na 2 O 
                   0 to 3; 
                 
                     
                   K 2 O 
                   0 to 0.5; 
                 
                     
                   CaO 
                   0 to 3; 
                 
                     
                   MgO 
                   0 to 3; 
                 
                     
                   SO 3   
                   0 to 0.20; 
                 
                     
                   Total iron expressed as Fe 2 O 3   
                   0 to 1.25; 
                 
                     
                   ZrO 2   
                   0 to 3; 
                 
                     
                   Total tin expressed as SnO 2   
                   0 to 0.70; 
                 
                     
                   TiO 2   
                   0 to 5; 
                 
                     
                   P 2 O 5   
                   0 to 1.75; 
                 
                     
                   ZnO 
                   0 to 1.25; and 
                 
                     
                   B 2 O 3   
                   0 to 1.75; 
                 
                     
                     
                 
             
                
                
                
               
               
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
         
           where CaO+MgO is 0 to 6 wt %, Al 2 O 3 +Zr0 2  is 18 to 28 wt %, and Na 2 O+K 2 0 is 0.05 to 3.00 wt %, wherein the glass piece has a log 10 viscosity temperature of at least 1413° F. (767° C.) and a liquidus temperature of at least 2435° F. (1335° C.); 
         
         submerging the glass piece in a molten sodium nitrate bath heated to a temperature of greater than 300° F. for at least 8 hours to provide the glass piece with a case depth in the range of 7 to 16.5 mils, and 
         removing the glass piece from the bath. 
       
     
     
         54 . The method according to  claim 52 , wherein the glass piece is a shaped glass piece. 
     
     
         55 . The method according to  claim 53 , wherein the glass piece is a shaped glass piece. 
     
     
         56 . The method according to  claim 52 , wherein the glass piece has at least one of the following properties:
 glass within the tensile stress zone of the glass piece has a higher concentration of lithium than glass in the compression zone of the glass piece;   the glass piece has a case depth in the range of 7 to 16.5 mils (0.17 to 0.419 millimeters);   center tension in the glass piece is in the range of 5,700 to 14,900 pounds per square inch (39 to 103 mega Pascal (“mPa”));   the glass has a CTA in the range of 632 to 1,390 pounds per inch (113 to 248 kilograms per centimeter);   the glass piece has a modulus of rupture in the range of 76,000 to 120,000 pounds per square inch (524 to 827 mPa);   the glass piece has an abraded modulus of rupture in the range of 67,000 to 89,000 pounds per square inch (462 to 614 mPa);   the glass piece has a HV (Vicker's hardness) 1000 in the range of 586 to 614 kilograms force per square millimeters; and   the glass piece has an HK (Knoop's hardness) 1000 in the range of 503 to 529 kilograms force per square millimeters.   ped glass piece.   
     
     
         57 . The method according to  claim 53 , wherein the glass piece has at least one of the following properties:
 glass within the tensile stress zone of the glass piece has a higher concentration of lithium than glass in the compression zone of the glass piece;   the glass piece has a case depth in the range of 7 to 16.5 mils (0.17 to 0.419 millimeters);   center tension in the glass piece is in the range of 5,700 to 14,900 pounds per square inch (39 to 103 mega Pascal (“mPa”));   the glass has a CTA in the range of 632 to 1,390 pounds per inch (113 to 248 kilograms per centimeter);   the glass piece has a modulus of rupture in the range of 76,000 to 120,000 pounds per square inch (524 to 827 mPa);   the glass piece has an abraded modulus of rupture in the range of 67,000 to 89,000 pounds per square inch (462 to 614 mPa);   the glass piece has a HV (Vicker's hardness) 1000 in the range of 586 to 614 kilograms force per square millimeters; and   the glass piece has an HK (Knoop's hardness) 1000 in the range of 503 to 529 kilograms force per square millimeters.