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US 10,472,271 B2Granted
Glass with modified surface layer
AssigneeCorning Incorporated
InventorsIndrajit Dutta, Nicholas James Smith
Life of this patent
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Abstract
Embodiments of a glass substrate including an alkali-containing bulk and an alkali-depleted surface layer, including a substantially homogenous composition are disclosed. In some embodiments, the alkali-depleted surface layer includes about 0.5 atomic % alkali or less. The alkali-depleted surface layer may be substantially free of hydrogen and/or crystallites. Methods for forming a glass substrate with a modified surface layer are also provided.
Claims17
A glass substrate comprising:
- an alkali-containing bulk having an aluminosilicate composition comprising from about 7 mol % to about 26 mol % Al2O3 and at least 8 mol % Na2O;
- and
- an alkali-depleted surface layer,
- wherein the alkali-depleted surface layer is amorphous and comprises a substantially homogenous composition,
- wherein the alkali-depleted layer comprises a thickness in the range from about 10 nm to about 3000 nm, and
- further wherein the alkali-depleted surface layer comprises about 0.5 atomic % alkali or less.
3 more elements
A glass substrate comprising:
- a thickness t;
- an alkali-containing bulk having a bulk refractive index and an aluminosilicate composition comprising from about 7 mol % to about 26 mol % Al2O3 and at least 8 mol % Na2O;
- and
- an alkali-depleted surface layer comprising a thickness in the range from about 10 nm to about 3000 nm,
- wherein the alkali-depleted surface layer comprises a layer refractive index that is less than the bulk refractive index, and
- further wherein the alkali-depleted surface layer comprises about 0.5 atomic % alkali or less.
3 more elements
A method of forming a glass substrate with a modified surface layer comprising:
- providing a glass substrate comprising a concentration of alkali, a glass transition temperature (Tg) and a surface layer, the glass substrate further comprising an aluminosilicate composition comprising from about 7 mol % to about 26 mol % Al2O3 and at least 8 mol % Na2O;
- reducing the concentration of alkali in the surface layer,
- wherein the reducing comprises contacting a surface of the glass substrate with an electrode and subjecting the glass substrate to a thermal poling,
- wherein the electrode comprises an anode in contact with an anodic surface of the glass substrate and a cathode in contact with the cathodic surface of the glass substrate,
- wherein the thermal poling comprises applying voltage to the glass substrate such that the anode is positively-biased relative to the glass substrate to induce alkali depletion at the anodic surface of the glass,
- wherein the anode is a non-porous film comprising an oxidation-resistant conductive film or a noble metal, and the cathode is a graphite film,
- wherein the surface layer with reduced concentration of alkali comprises a substantially homogenous composition, and
- further wherein the surface layer with reduced concentration of alkali comprises about 0.5 atomic % alkali or less and a thickness in the range from about 10 nm to about 3000 nm.
5 more elements
Dependencies are inferred from the claim text.