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AssigneeCorning Incorporated
InventorsAdam James Ellison, Benjamin Zain Hanson, Rostislav Vatchev Roussev
Estimating the term…
Ion exchangeable glass compositions that develop concentration profiles and stress profiles that have higher magnitudes of concentration and compressive stress profiles than those provided by the error function (erfc)-shaped compressive stress profile for similar surface concentrations of stress-inducing components such as K+ or K2O and stresses. The advantaged stress profile is the result of a glass composition that is low in K2O (or potassium) in the base glass prior to ion exchange. A glass comprising lower amounts of K+ or K2O has a stronger dependence of diffusivity on concentration, leading to a non-erfc-shaped concentration profile. Several glass compositions that contain low amounts of K+ or K2O exhibit this beneficial effect, whereas other glasses containing higher amounts of K+ or K2O do not exhibit this effect.
An alkali aluminosilicate glass having a layer under a compressive stress CS(d) that varies as a function of depth d from the surface to a depth of layer DOL, wherein CS(d)>CSerfc(d) at 0<d≦DOL, where CSerfc(d) is a compressive stress at depth d determined from an error function erfc.
An ion exchanged glass comprising a first alkali metal cation and a second alkali metal cation, wherein the first alkali metal cation is larger than the second alkali metal cation, and wherein the compressive stress σ(d) at a depth d is given by the equation σ(d)=(BE/1-v)(Cavg−C(d), where B is the lattice dilation coefficient, E is Young's modulus, v is the Poisson ratio, C(d) is the concentration of the larger ion, and Cavg is the average concentration.
A method of ion exchanging a glass, the method comprising:
Dependencies are inferred from the claim text.