Glass-ceramic articles having specified elastic modulus and fracture toughness
US11927722B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2023 |
| Grant date | Mar 12, 2024 |
| Priority date | — |
| Expiry date | Mar 13, 2043 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2217/734
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A transparent article is described herein that includes: a glass-ceramic substrate comprising first and second primary surfaces opposing one another and a crystallinity of at least 40% by weight; and an optical film structure disposed on the first primary surface. The optical film structure comprises a plurality of alternating high refractive index (RI) and low RI layers and a scratch-resistant layer. The article also exhibits an average photopic transmittance of greater than 80% and a maximum hardness of greater than 10 GPa, as measured by a Berkovich Hardness Test over an indentation depth range from about 100 nm to about 500 nm. The glass-ceramic substrate comprises an elastic modulus of greater than 85 GPa and a fracture toughness of greater than 0.8 MPa·√m. Further, the optical film structure exhibits a residual compressive stress of ≥700 MPa and an elastic modulus of ≥140 GPa.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.