Glasses and glass-ceramics with high E-moduli
AssigneeSchott Glas
InventorsBurkhard Speit, Silke Wolff, Peter Brix, Monika Gierke
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Abstract
High E-moduli glasses and glass-ceramics are disclosed based on the SiO2—B2O3—RO—R2O—ZrO2—TiO2—Nb2O5—La2O3 system. The chemically pre-stressable glasses are lithium-poor or lithium-free. The glass-ceramics contain from 2 to 9 percent by weight lithium and the predominant crystalline phase is lithium titanate. These glasses and glass-ceramics particularly have a high specific E-modulus.
Claims19
A high E-modulus glass comprising
- SiO2 17 to 34% by weight, B2O3 1 to 8% by weight, Al2O3 0 to 8% by weight, Li2O 0 to <2% by weight, Na2O 0.5 to 10% by weight, MgO 10 to 20% by weight, CaO 4 to 12% by weight, TiO2 14.5 to 25% by weight, ZrO2 1 to 8% by weight, Nb2O5 0.5 to 4.5% by weight, La2O3 5.5 to 15% by weight, Ce2O3 0 to 8% by weight,
- and at least one refining agent, as needed, in an amount suitable for refining, with the proviso that ≦16% by weight of a sum of said La2O3 and said Ce2O3 is present.
A chemically pre-stressed glass made by chemically pre-stressing a high E-modulus glass, said high E-modulus glass comprising
- SiO2 17 to 34% by weight, B2O3 1 to 8% by weight, Al2O3 0 to 8% by weight, Li2O 0 to <2% by weight, Na2O 0.5 to 10% by weight, MgO 10 to 20% by weight, CaO 4 to 12% by weight, TiO2 14.5 to 25% by weight, ZrO2 1 to 8% by weight, Nb2O5 0.5 to 4.5% by weight, La2O3 5.5 to 15% by weight, Ce2O3 0 to 8% by weight,
- and at least one refining agent, as needed, in an amount suitable for refining, with the proviso that ≦16% by weight of a sum of said La2O3 and said Ce2O3 is present,
- and said chemically pre-stressed glass having an elasticity modulus E between 100×103 N/mm2 and 120×103 N/mm2, a specific elasticity modulus E/ρ of from 30×105 N cm/g to 36×105 N cm/g and a thermal expansion coefficient α20/300 between 8.0×10−6/K and 11.0×10−6/K.
A high E-modulus glass-ceramic made from a base glass comprising
- SiO2 17 to 34% by weight, B2O3 1 to 8% by weight, Al2O3 0 to 8% by weight, Li2O 2 to 10% by weight, Na2O 0.5 to 10% by weight, MgO 10 to 20% by weight, CaO 4 to 12% by weight, TiO2 14.5 to 25% by weight, ZrO2 1 to 8% by weight, Nb2O5 0.5 to 4.5% by weight, La2O3 5.5 to 15% by weight, Ce2O3 0 to 8% by weight,
- and at least one refining agent, as needed, in an amount suitable for refining, with the proviso that ≦16% by weight of a sum of said La2O3 and said Ce2O3 is present.
Dependencies are inferred from the claim text.