Glass with surface and central regions under compression
AssigneeCorning Incorporated
InventorsDana Craig Bookbinder, Timothy Michael Gross
Life of this patent
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Abstract
A glass article having an engineered stress profile. The central or core region of the glass is in compression and the surface or outer region of the glass is either under neutral stress or in compression. The outer surface region and the core region are separated by an intermediate region that is under tension. A flaw that penetrates the outer region in compression will propagate in the underlying tensile intermediate layer, but will not penetrate though the compressive core region of the glass. The compressive core region prevents flaws from penetrating through the thickness of the glass.
Claims60
A glass article, the glass article comprising:
- a. an outer region extending from the surface to a depth of layer, wherein the outer region is under neutral stress or a first compressive stress;
- b. a core region under a second compressive stress, the core region including a mid-point between the surface and a second surface opposite the surface of the glass article;
- and
- c. an intermediate region disposed between the surface and the core region, wherein the intermediate region is under a tensile stress.
A glass article, the glass article having a laminate structure, wherein the laminate structure comprises:
- an outer region extending from a surface of the glass article to a depth of layer, wherein the outer region is under neutral stress or a first compressive stress;
- a core region under a second compressive stress, the core region including a mid-point between the surface and a second surface opposite the surface of the glass article;
- and
- an intermediate region disposed between the outer region and the core region, wherein the intermediate region is under a tensile stress.
A glass article, the glass article comprising:
- an outer region extending from the surface to a depth of layer of at least 5 μm, wherein the outer region is under a first compressive stress of at least 500 MPa;
- a core region under a second compressive stress;
- and
- an intermediate region disposed between the surface and the core region, wherein the intermediate region is under a tensile stress.
A glass article, the glass article having a laminate structure, wherein the laminate structure comprises:
- an outer region extending from a surface of the glass article to a depth of layer, the outer region comprising a skin glass, the skin glass comprising a first alkali metal ion, wherein the outer region is under neutral stress or a first compressive stress;
- a core region comprising a core glass under a second compressive stress, the core glass comprising a second alkali metal ion;
- and
- an intermediate region disposed between the outer region and the core region, the intermediate region being under a tensile stress and comprising the core glass and a third alkali metal ion, wherein the first alkali metal ion is larger than the third alkali metal ion.
Dependencies are inferred from the claim text.