Back to results
US 9,802,853 B2Granted
Fictive temperature in damage-resistant glass having improved mechanical characteristics
AssigneeCorning Incorporated
InventorsRichard Orr Maschmeyer, John Christopher Thomas, Kevin Lee Wasson
Life of this patent
Estimating the term…
Abstract
A strengthened glass sheet product as well as process and an apparatus for making the product. The process comprises cooling the glass sheet by non-contact thermal conduction for sufficiently long to fix a surface compression and central tension of the sheet. The process results in thermally strengthened glass sheets having improved breakage properties.
Claims31
A thermally strengthened glass sheet:
- the glass sheet having a thickness, expressed in millimeters, of t, a length, expressed in millimeters, of l, and a width, expressed in millimeters, of w, t being less than l and less than w;
- the glass sheet having a first major surface and a second major surface separated by the thickness t, the first major surface of the sheet being flat to 100 μm total indicator run-out (TIR) along any 50 mm or less profile of the first major surface
- the glass sheet comprising a glass having a softening temperature, expressed in units of ° C., of Tsoft and an annealing temperature, expressed in units of ° C., of Tanneal, and a surface fictive temperature measured on the first major surface of the glass sheet represented by Tfs, when expressed in units of ° C.;
- the glass sheet having a non-dimensional surface fictive temperature parameter θs given by (Tfs−Tanneal)/(Tsoft−Tanneal),
- wherein the parameter θs is in the range of from 0.50 to 0.9.
2 more elements
A thermally strengthened glass sheet:
- the glass sheet having a thickness, expressed in millimeters, of t, a length, expressed in millimeters, of l, and a width, expressed in millimeters, of w, t being less than l and less than w;
- the glass sheet having a first major surface and a second major surface separated by the thickness t, the first major surface of the sheet being flat to 100 μm total indicator run-out (TIR) along any 50 mm or less profile of the first major surface
- the glass sheet comprising a glass having a softening temperature, expressed in units of ° C., of Tsoft and an annealing temperature, expressed in units of ° C., of Tanneal, and a surface fictive temperature measured on the first major surface of the glass sheet represented by Tfs, when expressed in units of ° C.;
- the glass sheet having a non-dimensional surface fictive temperature parameter θs given by (Tfs−Tanneal)/(Tsoft−Tanneal),
- wherein the parameter θs is in the range of from 0.50 to 0.9;
- and
- wherein the glass has a low temperature linear CTE, expressed in 1/° C., of αSCTE a high temperature linear CTE, expressed in 1/° C., of αLCTE, an elastic modulus, expressed in GPa, of E, and a strain temperature, expressed in units of ° C., of Tstrain;
- the first major surface of the glass sheet having a thermally induced surface compressive stress of less than 600 MPa and greater than
- P
- 1
-
- (
- h
- )
- *
- t
- (
- P
- 2
-
- (
- h
- )
- +
- t
- )
- ·
- E
- ·
- [
- T
- strain
- ·
- α
- CTE
- s
- +
- α
- CTE
- L
- ·
- (
- T
- soft
- -
- T
- strain
- )
- ]
- ;
- in units of MPa;
- wherein P1 is given by
- 910.2
- -
- 259.2
- ·
- exp
-
- (
- -
- h
- 0.143
- )
- ;
- P2 is given by
- 2.53
- +
- 23.65
- (
- 1
- +
- (
- h
- 0.00738
- )
- 1.58
- )
- ;
- and h is greater than or equal to 0.020 cal/s·cm2·° C.
76 more elements
A thermally strengthened glass sheet:
- the glass sheet having a thickness, expressed in millimeters, of t, a length, expressed in millimeters, of l, and a width, expressed in millimeters, of w, t being less than l and less than w;
- the glass sheet having a first major surface and a second major surface separated by the thickness t, the first major surface of the sheet being flat to 100 total indicator run-out (TIR) along any 50 mm or less profile of the first major surface
- the glass sheet comprising a glass having a softening temperature, expressed in units of ° C., of Tsoft and an annealing temperature, expressed in units of ° C., of Tanneal, and a surface fictive temperature measured on the first major surface of the glass sheet represented by Tfs, when expressed in units of ° C.;
- the glass sheet having a non-dimensional surface fictive temperature parameter θs given by (Tfs−Tanneal)/(Tsoft−Tanneal),
- wherein the parameter Os is in the range of from 0.50 to 0.9;
- and
- wherein the glass has a low temperature linear CTE, expressed in 1/° C., of αSCTE, a high temperature linear CTE, expressed in 1/° C., of αLCTE, an elastic modulus, expressed in GPa, of E, and a strain temperature, expressed in units of ° C., of Tstrain;
- the glass sheet having a thermally induced central tension of less than 300 MPa and greater than
- P
- 1
-
- CT
-
- (
- h
- CT
- )
- *
- t
- 2
-
- (
- P
- 2
-
- CT
-
- (
- h
- CT
- )
- +
- t
- )
- ·
- E
- ·
- [
- T
- strain
- ·
- α
- CTE
- s
- +
- α
- CTE
- L
- ·
- (
- T
- soft
- -
- T
- strain
- )
- ]
- ;
- in units of MPa;
- wherein P1CT is given by
- 910.2
- -
- 259.2
- ·
- exp
-
- (
- -
- h
- CT
- 0.143
- )
- ;
- P2CT is given by
- 2.53
- +
- 23.65
- (
- 1
- +
- (
- h
- CT
- 0.00738
- )
- 1.58
- )
- ;
- and hCT is greater than or equal to 0.020 cal/s·cm2·° C.
86 more elements
Dependencies are inferred from the claim text.