Ion exchangeable, opaque gahnite-spinel glass ceramics with high hardness and modulus

Patent metadata

Field	Value
Publication number	US-12024461-B2
Application number	US-202217837467-A
Country	US
Kind code	B2
Filing date	Jun 10, 2022
Priority date	Nov 30, 2018
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

An opaque gahnite-spinel glass ceramic is provided. The glass ceramic includes a first crystal phase including (Mg x Zn 1-x )Al 2 O 4 where x is less than 1 and a second crystal phase includes at least one of tetragonal ZrO 2 , MgTa 2 O 6 , mullite, and cordierite. The glass ceramic has a Young's modulus greater than or equal to 90 GPa, and has a hardness greater than or equal to 7.5 GPa. The glass ceramic may be ion exchanged. Methods for producing the glass ceramic are also provided.

First claim

What is claimed is:

1. A method, comprising:
ceramming a precursor glass to form a glass ceramic that is opaque in the visible range,
wherein the glass ceramic comprises:
a first crystal phase including (Mg x Zn 1-x )Al 2 O 4 where x is less than 1; and
a second crystal phase consists of tetragonal ZrO 2 and one or more of MgTa 2 O 6 , mullite, and cordierite;
wherein the glass-ceramic has a Young's modulus greater than or equal to 90 GPa, and has a hardness greater than or equal to 7.5 GPa.

2. The method of claim 1 , further comprising forming nuclei in the precursor glass prior to the ceramming.

3. The method of claim 1 , wherein the ceramming comprises heat treating the precursor glass at a temperature of at least 750° C. for a time period of at least 30 minutes.

4. The method of claim 1 , wherein the ceramming comprises irradiating the precursor glass with a laser to form the glass ceramic.

5. The method of claim 1 , further comprising ion exchanging the glass ceramic.

6. A method, comprising:
ceramming a precursor glass to form a glass ceramic that is opaque in the visible range,
wherein the glass ceramic comprises:
a first crystal phase including (Mg x Zn 1-x )Al 2 O 4 where x is less than 1; and
a second crystal phase including tetragonal ZrO 2 and at least one of MgTa 2 O 6 , mullite, and cordierite;
wherein the glass-ceramic has a Young's modulus greater than or equal to 90 GPa, and has a hardness greater than or equal to 7.5 GPa.

7. The method of claim 6 , further comprising forming nuclei in the precursor glass prior to the ceramming.

8. The method of claim 6 , wherein the ceramming comprises heat treating the precursor glass at a temperature of at least 750° C. for a time period of at least 30 minutes.

9. The method of claim 6 , wherein the ceramming comprises irradiating the precursor glass with a laser to form the glass ceramic.

10. The method of claim 6 , further comprising ion exchanging the glass ceramic.

11. The method of claim 6 , wherein the second crystal phase includes MgTa 2 O 6 .

12. The method of claim 6 , wherein the second crystal phase includes mullite.

13. The method of claim 6 , wherein the second crystal phase includes cordierite.

14. A method, comprising:
ceramming a precursor glass to form a glass ceramic that is opaque in the visible range,
wherein the glass ceramic comprises:
a first crystal phase including (Mg x Zn 1-x )Al 2 O 4 where x is less than 1; and
a second crystal phase consists of mullite and cordierite;
wherein the glass-ceramic has a Young's modulus greater than or equal to 90 GPa, and has a hardness greater than or equal to 7.5 GPa.

15. The method of claim 14 , further comprising forming nuclei in the precursor glass prior to the ceramming.

16. The method of claim 14 , wherein the ceramming comprises heat treating the precursor glass at a temperature of at least 750° C. for a time period of at least 30 minutes.

17. The method of claim 14 , wherein the ceramming comprises irradiating the precursor glass with a laser to form the glass ceramic.

18. The method of claim 14 , further comprising ion exchanging the glass ceramic.

Assignees

• Corning Inc

Inventors

• Beall George Halsey
• Andrews Mitchell Alexandra Lai Ching Kao
• Smith Charlene Marie

Classifications

• C03C10/0036 Primary

  containing SiO2, Al2O3 and a divalent metal oxide as main constituents · CPC title

• C03C10/0045 Primary

  containing SiO2, Al2O3 and MgO as main constituents · CPC title

• C03B23/0305

  Press-bending accelerated by applying mechanical forces, e.g. inertia, weights or local forces · CPC title

• C03C2203/10

  Melting processes · CPC title

• C03C23/0025

  by a laser beam · CPC title