Glasses with modified young's modulus profile
Glass-based articles that include a reduced Young's modulus layer extending from a surface of the glass-based article to a depth of layer and an optional compressive stress layer extending from a surface of the glass-based article to a depth of compression are formed by exposing glass-based substrates to water vapor containing environments. The methods of forming the glass-based articles may include elevated pressures and/or multiple exposures to water vapor containing environments. The glass-based articles may be utilized in foldable or flexible electronic devices.
1. A glass-based article, comprising:
a reduced Young's modulus layer extending from a surface of the glass-based article to a depth of layer;
a hydrogen-containing layer extending from the surface of the glass-based article to a hydrogen depth of layer, wherein a hydrogen concentration of the hydrogen-containing layer decreases from a maximum hydrogen concentration to the hydrogen depth of layer; and
a compressive stress layer from hydrogen species extending from a surface of the glass-based article to a depth of compression,
wherein:
the compressive stress layer comprises a compressive stress greater than or equal to 10 MPa, and the reduced Young's modulus layer comprises a Young's modulus at a depth of 500 nm from the surface that is less than a bulk Young's modulus of a glass having a composition equivalent to the composition at the center of the glass-based article; and
the center of the glass-based article comprises greater than or equal to 10 mol % and less than or equal to 23 mol % K 2 O and greater than or equal to 2 mol % and less than or equal to 15 mol % P 2 O 5 .
2. The glass-based article of claim 1 , wherein the center of the glass-based article comprises greater than or equal to 55 mol % SiO 2 .
3. The glass-based article of claim 1 , wherein the bulk Young's modulus of a glass having a composition equivalent to the composition at the center of the glass-based article is less than or equal to 60 GPa.
4. The glass-based article of claim 1 , wherein the depth of compression is greater than or equal to 5 μm.
5. The glass-based article of claim 1 , wherein the depth of compression is greater than or equal to 20 μm.
6. The glass-based article of claim 1 , wherein the compressive layer comprises a compressive stress of greater than or equal to 100 MPa.
7. The glass-based article of claim 1 , wherein the Young's modulus at a depth of 500 nm from the surface is less than or equal to 95% of the bulk Young's modulus of a glass having a composition equivalent to the composition at the center of the glass-based article.
8. The glass-based article of claim 1 , wherein the Young's modulus at a depth of 500 nm from the surface is less than or equal to 90% of the bulk Young's modulus of a glass having a composition equivalent to the composition at the center of the glass-based article.
9. The glass-based article of claim 1 , wherein the glass-based article has a thickness of less than or equal to 200 μm.
10. The glass-based article of claim 1 , wherein the center of the glass-based article comprises:
greater than or equal to 55 mol % to less than or equal to 70 mol % SiO 2 ;
greater than or equal to 3 mol % to less than or equal to 17 mol % Al 2 O 3 ;
greater than or equal to 2 mol % to less than or equal to 10 mol % P 2 O 5 ; and
greater than or equal to 10 mol % to less than or equal to 20 mol % K 2 O.
11. The glass-based article of claim 1 , wherein the center of the glass-based article comprises:
greater than or equal to 0 mol % to less than or equal to 15 mol % B 2 O 3 ;
greater than or equal to 0 mol % to less than or equal to 10 mol % Na 2 O;
greater than or equal to 0 mol % to less than or equal to 5 mol % ZnO; and
greater than or equal to 0 mol % to less than or equal to 0.5 mol % SnO 2 .
12. The glass-based article of claim 1 , wherein the center of the glass-based article comprises:
greater than or equal to 0 mol % to less than or equal to 4 mol % Li 2 O; and
greater than or equal to 0 mol % to less than or equal to 5 mol % MgO.
13. The glass-based article of claim 1 , wherein the glass-based article is substantially free of Li 2 O and Na 2 O.
14. The glass-based article of claim 1 , wherein the glass-based article has a stress intensity of less than or equal to 0.4 MPa √m for a bend radius of 3.3 mm, flaw depth of 500 nm, and geometry factor of 0.73.
15. The glass-based article of claim 1 , comprising greater than or equal to 10 mol % and less than or equal to 15 mol % K 2 O.
16. The glass-based article of claim 1 , comprising greater than or equal to 2 mol % and less than or equal to 10 mol % P 2 O 5 .
17. A glass-based article, comprising:
a reduced Young's modulus layer extending from a surface of the glass-based article to a depth of layer;
a hydrogen-containing layer extending from the surface of the glass-based article to a hydrogen depth of layer, wherein a hydrogen concentration of the hydrogen-containing layer decreases from a maximum hydrogen concentration to the hydrogen depth of layer; and
a compressive stress layer from hydrogen species extending from a surface of the glass-based article to a depth of compression,
wherein:
the compressive stress layer comprises a compressive stress greater than or equal to 100 MPa; and
the center of the glass-based article comprises greater than or equal to 5 mol % and less than or equal to 23 mol % K 2 O and greater than or equal to 2 mol % and less than or equal to 15 mol % P 2 O 5 .
18. The glass-based article of claim 17 , wherein the reduced Young's modulus layer comprises a Young's modulus at a depth of 500 nm from the surface that is less than a bulk Young's modulus of a glass having a composition equivalent to the composition at the center of the glass-based article.
19. The glass-based article of claim 17 , comprising greater than or equal to 5 mol % and less than or equal to 15 mol % K 2 O.
20. The glass-based article of claim 17 , comprising greater than or equal to 2 mol % and less than or equal to 10 mol % P 2 O 5 .