Lithium disilicate glass-ceramic compositions and methods thereof

Abstract

A glass-ceramic composition as defined herein. The glass-ceramic composition includes a first crystalline phase comprising lithium disilicate. The glass-ceramic composition can include up to 10 wt % CaO, up to 5 wt % Na2O, up to 10 wt % B2O3, and greater than 0.5 wt % ZrO2. The glass-ceramic composition can also include from 50 to 75 wt % SiO2, from 1 to 5 wt % Al2O3, from 1 to 8 wt % P2O5, and from 5 to 20 wt % Li2O. In aspects, the glass-ceramic composition can include a second crystalline phase including wollastonite, apatite, cristobalite, β-quartz, lithiophosphate, or a combination thereof. Also disclosed are methods of making and using the disclosed compositions.

What is claimed is: 
     
         1 . A glass-ceramic article, comprising:
 a first crystalline phase comprising lithium disilicate;   a second crystalline phase selected from a group consisting of: wollastonite, apatite, cristobalite, β-quartz, lithiophosphate, or a combination thereof; and   a glass-ceramic composition comprising, based on a 100 wt % total of the glass-ceramic composition:
 50 to 75 wt % SiO 2 , 
 1 to 5 wt % Al 2 O 3 , 
 1 to 8 wt % P 2 O 5 , 
 up to 10 wt % CaO, 
 5 to 20 wt % Li 2 O, 
 up to 5 wt % Na 2 O, 
 greater than 0.5 wt % ZrO 2 , and 
 up to 10 wt % B 2 O 3 . 
   
     
     
         2 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition comprises, based on a 100 wt % total of the glass-ceramic composition:
 50 to 60 wt % SiO 2 ,   1 to 3 wt % Al 2 O 3 ,   2 to 6 wt % P 2 O 3 ,   4 to 8 wt % CaO,   7.5 to 12.5 wt % Li 2 O,   0.5 to 2 wt % Na 2 O, and   1 to 8 wt % ZrO 2 .   
     
     
         3 . The glass-ceramic article of  claim 1 , further comprising a compressive stress layer on at least one surface of the glass-ceramic article. 
     
     
         4 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition comprises, based on a 100 wt % total of the glass-ceramic composition, further comprising at least one of:
 2 to 10 wt % CaO;   0.5 to 5 wt % Na 2 O;   0.1 to 10 wt % B 2 O 3 ; or   combinations thereof.   
     
     
         5 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition comprises, based on a 100 wt % total of the glass-ceramic composition, 2 to 10 wt % CaO. 
     
     
         6 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition comprises, based on a 100 wt % total of the glass-ceramic composition, 0.5 to 5 wt % Na 2 O. 
     
     
         7 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition comprises, 0.1 to 10 wt % B 2 O 3  based on a 100 wt % total of the glass-ceramic composition: 
     
     
         8 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition further comprises from 0.1 to 1.0 wt % F − , based on a 100 wt % total of the glass-ceramic composition. 
     
     
         9 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition has a fracture toughness greater than 1.5 MPa·m 1/2 . 
     
     
         10 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition has a fracture toughness of from 1.4 to 2.0 MPa·m 1/2 . 
     
     
         11 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition has a flexural strength greater than 300 MPa. 
     
     
         12 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition has a strength of from 200 MPa to 500 MPa. 
     
     
         13 . The glass-ceramic article of  claim 1 , wherein the glass-ceramic composition further comprises a crystallinity of greater than 80% by volume. 
     
     
         14 . A method of making the glass-ceramic article of  claim 1 , the method comprising:
 ceramming a precursor glass mixture comprising, based on a 100 wt % total of the precursor glass mixture:
 50 to 75 wt % SiO 2 , 
 1 to 5 wt % Al 2 O 3 , 
 1 to 8 wt % P 2 O 5 , 
 up to 10 wt % CaO, 
 5 to 20 wt % Li 2 O, 
 up to 5 wt % Na 2 O, 
 greater than 0.5 wt % ZrO 2 , and 
 up to 10 wt % B 2 O 3 , by heating the precursor glass mixture at 650° C. to 750° C. for from 0.5 hours to 10 hours and then heating at 750° C. to 850° C. for 0.5 hours to 20 hours; and 
   ion exchanging the resulting glass-ceramic composition to create at least one compressive stress layer on at least one surface of the glass-ceramic composition to increase mechanical strength,   wherein the glass-ceramic article further comprises a second crystalline phase selected from a group consisting of: wollastonite, apatite, cristobalite, β-quartz, lithiophosphate, or a combination thereof.   
     
     
         15 . The method of  claim 14 , wherein the precursor glass mixture comprises, based on a 100 wt % total of the precursor glass mixture:
 50 to 60 wt % SiO 2 ,   1 to 3 wt % Al 2 O 3 ,   2 to 6 wt % P 2 O 3 ,   4 to 8 wt % CaO,   7.5 to 12.5 wt % Li 2 O,   0.5 to 2 wt % Na 2 O,   1 to 8 wt % ZrO 2 , and   0.1 to 10 wt % B 2 O 3 .   
     
     
         16 . The method of  claim 14 , wherein the glass-ceramic composition further comprises a crystallinity of greater than 80% by volume. 
     
     
         17 . The method of  claim 14 , wherein the glass-ceramic composition comprises, based on a 100 wt % total of the glass-ceramic composition, further comprising at least one of:
 2 to 10 wt % CaO;   0.5 to 5 wt % Na 2 O;   0.1 to 10 wt % B 2 O 3 ; or   combinations thereof.   
     
     
         18 . The method of  claim 14 , wherein the precursor glass mixture comprises, based on a 100 wt % total of the precursor glass mixture, 2 to 10 wt % CaO. 
     
     
         19 . The method of  claim 14 , wherein the precursor glass mixture comprises, based on a 100 wt % total of the precursor glass mixture, 0.5 to 5 wt % Na 2 O. 
     
     
         20 . The method of  claim 14 , wherein the precursor glass mixture further comprises a source of 0.1 to 10 wt % B 2 O 3 , based on a 100 wt % total of the precursor glass mixture.