Glasses and glass ceramics including a metal oxide concentration gradient
A glass-based article may include from about 45 mol. % to about 80 mol. % SiO 2 ; from about 0 mol. % to about 10 mol. % Na 2 O; less than about 5 mol. % K 2 O; a non-zero amount of Al 2 O; and an amorphous phase and a crystalline phase. The article may further in include a stress profile comprising a surface compressive stress (CS) and a maximum central tension (CT). A ratio of Li 2 O (mol. %) to R 2 O (mol. %) in the article is from about 0.5 to about 1, where R 2 O is the sum of Li 2 O, Na 2 O, and K 2 O in the article. CT may be greater than or equal to about 50 MPa and less than about 100 MPa. CS may be greater than 2.0·CT. A depth of compression (DOC) of the stress profile may be greater than or equal to 0.14·t and less than or equal to 0.25·t, where t is the thickness of the article.
1. A glass-based article comprising:
greater than or equal to 45 mol. % and less than or equal to about 80 mol. % SiO 2 ;
greater than or equal to 0 mol. % and less than or equal to 10 mol. % Na 2 O;
less than 5 mol. % K 2 O;
a non-zero amount of Al 2 O 3 ;
a first surface and a second surface opposing the first surface thereby defining a thickness (t) of the glass-based article; and
a stress profile comprising a surface compressive stress (CS) and a maximum central tension (CT), wherein:
the glass-based article is a glass-ceramic comprising an amorphous phase and a crystalline phase;
a ratio of Li 2 O (mol. %) to R 2 O (mol. %) in the glass-based article is greater than or equal to 0.5 and less than or equal to 1, where R 2 O is the sum of Li 2 O, Na 2 O, and K 2 O in the glass-based article;
CT is greater than or equal to about 50 MPa and less than about 100 MPa;
CS is greater than 2.0·CT; and
a depth of compression (DOC) of the stress profile is greater than or equal to 0.14·t and less than or equal to 0.25·t.
2. The glass-based article of claim 1 , wherein CS is greater than or equal to 150 MPa.
3. The glass-based article of claim 1 , wherein CS is greater than or equal to 200 MPa.
4. The glass-based article of claim 1 , wherein CS is greater than 2.5·CT.
5. The glass-based article of claim 1 , wherein the glass-based article is strengthened by an ion exchange process resulting in the stress profile.
6. A glass-based article comprising:
greater than or equal to 45 mol. % and less than or equal to about 80 mol. % SiO 2 ;
greater than or equal to 0 mol. % and less than or equal to 10 mol. % Na 2 O;
less than 5 mol. % K 2 O;
a non-zero amount of Al 2 O 3 ; and
a stress profile comprising a surface compressive stress (CS) and a maximum central tension (CT), wherein:
the glass-based article is a glass-ceramic comprising an amorphous phase and a crystalline phase;
a ratio of Li 2 O (mol. %) to R 2 O (mol. %) in the glass-based article is greater than or equal to 0.5 and less than or equal to 1, where R 2 O is the sum of Li 2 O, Na 2 O, and K 2 O in the glass-based article;
the glass-based article is strengthened by an ion exchange process resulting in the stress profile;
CT is greater than or equal to about 100 MPa; and
a ratio of the maximum central tension to the surface compressive stress (CT:CS) is from about 0.05 to about 1.
7. The glass-based article of claim 6 , wherein CS is greater than or equal to 150 MPa.
8. The glass-based article of claim 6 , wherein CT:CS is from about 0.2 to about 0.5.
9. The glass-based article of claim 6 , wherein:
the glass-based article comprises a first surface and a second surface opposing the first surface thereby defining a thickness (t) of the glass-based article; and
a depth of compression (DOC) of the stress profile is greater than or equal to 0.12·t.
10. The glass-based article of claim 6 , wherein:
the glass-based article comprises a first surface and a second surface opposing the first surface thereby defining a thickness (t) of the glass-based article;
CT is less than about 250 MPa;
CS is greater than 2.0·CT; and
a depth of compression (DOC) of the stress profile is greater than or equal to 0.14·t and less than or equal to 0.25·t.
11. The glass-based article of claim 10 , wherein CS is greater than 200 MPa.
12. The glass-based article of claim 10 , wherein CS is greater than 2.5·CT.
13. A glass-based article comprising:
greater than or equal to 45 mol. % and less than or equal to about 80 mol. % SiO 2 ;
greater than or equal to 0 mol. % and less than or equal to 10 mol. % Na 2 O;
less than 5 mol. % K 2 O;
a non-zero amount of Li 2 O;
a non-zero amount of Al 2 O 3 ;
a first surface and a second surface opposing the first surface thereby defining a thickness (t) of the glass-based article; and
a stress profile comprising a maximum central tension (CT) and a surface compressive stress (CS) extending to a depth of compression (DOC), wherein:
the glass-based article is a glass-ceramic comprising an amorphous phase and a crystalline phase;
a ratio of Li 2 O (mol. %) to R 2 O (mol. %) in the glass-based article is greater than or equal to 0.5 and less than or equal to 1, where R 2 O is the sum of Li 2 O, Na 2 O, and K 2 O in the glass-based article;
the glass-based article is strengthened by an ion exchange process resulting in the stress profile;
CT is greater than or equal to 75 MPa and less than or equal to 250 MPa;
CS is greater than 1.5·CT; and
DOC is greater than or equal to 0.14·t and less than or equal to 0.25·t.
14. The glass-based article of claim 13 , wherein CS is greater than 2.5·CT.
15. The glass-based article of claim 13 , wherein a ratio of CT:CS is from about 0.05 to about 1.0.
16. The glass-based article of claim 13 , wherein a ratio of CT:CS is from about 0.2 to about 0.5.
17. The glass-based article of claim 13 , wherein the ratio of CT:CS is from about 0.3 to about 0.5.