Lithium silicate glass ceramics and precursors thereof are described, which comprise copper and are characterized by very good mechanical and optical properties and can be used in particular as restorative materials in dentistry.

Lithium silicate glass ceramics and precursors thereof are described, which contain tin and are characterized by very good mechanical and optical properties and can be used in particular as restorative materials in dentistry.

The present disclosure relates to fusion formable highly crystalline glass-ceramic articles whose composition lies within the SiO.sub.2—R.sub.2O.sub.3—Li.sub.2O/Na.sub.2O—TiO.sub.2 system and which contain a silicate crystalline phase comprised of lithium aluminosilicate (β-spodumene and/or β-quartz solid solution) lithium metasilicate and/or lithium disilicate. Additionally, these silicate-crystal containing glass-ceramics can exhibit varying Na.sub.2O to Li.sub.2O molar ratio extending from the surface to the bulk of the glass article, particularly a decreasing Li.sub.2O concentration and an increasing Na.sub.2O concentration from surface to bulk. According to a second embodiment, disclosed herein is a method for forming a silicate crystalline phase-containing glass ceramic.

Optically transparent glass ceramic materials comprising a glass phase containing and a crystalline tungsten bronze phase comprising nanoparticles and having the formula M.sub.xWO.sub.3, where M includes at least one H, Li, Na, K, Rb, Cs, Ca, Sr, Ba, Zn, Cu, Ag, Sn, Cd, In, Tl, Pb, Bi, Th, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, and U, and where 0<x<1. Aluminosilicate and zinc-bismuth-borate glasses comprising at least one of Sm.sub.2O.sub.3, Pr.sub.2O.sub.3, and Er.sub.2O.sub.3 are also provided.

The present invention relates to a glass ceramic having a lithium aluminosilicate composition and including a crystal and a residual glass, in which the residual glass has a composition including, in terms of mol % based on oxides: 25% to 70% of SiO.sub.2; 3% to 35% of Al.sub.2O.sub.3; 0.1% to 20% of Li.sub.2O; 0.1% to 20% of Na.sub.2O; 0% to 10% of K.sub.2O; and 1% to 15% of ZrO.sub.2, and a parameter V is −600 or more and 720 or less, the parameter V being calculated based on the following formula: V=49.589×[SiO.sub.2]+61.806×[Al.sub.2O.sub.3]+45.456×[P.sub.2O.sub.5]+41.151×[MgO]+110.26×[CaO]+50.263×[SrO]+55.693×[Li.sub.2O]+3.598×[Na.sub.2O]+9.503×[K.sub.2O]+6.83×[TiO.sub.2]−2.885×[ZrO.sub.2]−3746.99.

A glass ceramic contains the following components by wt %: 60 to 80% of SiO.sub.2; 4 to 20% of Al.sub.2O.sub.3; 0 to 15% of Li.sub.2O; more than 0 but less than or equal to 12% of Na.sub.2O; 0 to 5% of K.sub.2O; more than 0 but less than or equal to 5% of ZrO.sub.2; 0 to 5% of P.sub.2O.sub.5; and 0 to 10% of TiO.sub.2. A crystalline phase contains at least one of R.sub.2SiO.sub.3, R.sub.2Si.sub.2O.sub.5, R.sub.2TiO.sub.3, R.sub.4Ti.sub.5O.sub.12, R.sub.3PO.sub.3, RAlSi.sub.2O.sub.6, RAlSiO.sub.4O.sub.10, R.sub.2Al.sub.2Si.sub.2O.sub.8, R.sub.4Al.sub.4Si.sub.5O.sub.18, quartz and quartz solid solution. With a liquidus temperature below 1,450° C., a thermal conductivity above 2 w/m.Math.k, and a Vickers hardness above 600 kgf/mm2, the glass ceramic is applicable to portable electronic devices and optical devices.

A cover glass is provided that includes a silica based glass ceramic with a thickness between 0.4 mm and 0.85 mm. The glass ceramic has a transmittance of more than 80% from 380 nm to 780 nm and a stress attribute selected from: an overall compressive stress (CS) of at least 250 MPa and at most 1500 MPa, a compressive stress at a depth of 30 μm (CS30) from one of the two faces of at least 160 MPa and at most 525 MPa, a depth of the compression layer (DoCL) of at least 0.2 times the thickness and less than 0.5 times the thickness, and any combinations thereof. The glass ceramic has at least one silica based crystal phase having in a near-surface layer a unit cell volume of at least 1% by volume larger than that of a core where the crystal phase has minimum stresses.

A magnetizable glass ceramic composition including: a continuous first glass phase including SiO.sub.2, B.sub.2O.sub.3, P.sub.2O.sub.5, and R.sub.2O; a discontinuous second glass phase including at least one of SiO.sub.2, B.sub.2O.sub.3, P.sub.2O.sub.5, R.sub.2O, or mixtures thereof; and a discrete magnetizable crystalline phase dispersed in the discontinuous second glass phase, where R.sub.2O is selected from at least one of K.sub.2O, Li.sub.2O, Na.sub.2O, or mixtures thereof. Also disclosed are a method of making and a method of using the magnetizable glass ceramic composition.

A coated glass or glass ceramic substrate includes a substrate with a surface area and a coating on that surface area. The coating includes a glass matrix and IR-reflecting pigments. The IR-reflecting pigments have a TSR value of at least 20%, as determined according to ASTM G 173. The coating, at a wavelength of 1500 nm, exhibits a remission of at least 35%, as measured according to ISO 13468.

Embodiments of a transparent glass-based material comprising a glass phase and a second phase that is different from and is dispersed in the glass phase are provided. The second phase may comprise a crystalline or a nanocrystalline phase, a fiber, and/or glass particles. In some embodiments, the second phase is crystalline. In one or more embodiments, the glass-based material has a transmittance of at least about 88% over a visible spectrum ranging from about 400 nm to about 700 nm and a fracture toughness of at least about 0.9 MPa.Math.m.sup.1/2, and wherein a surface of the glass-based material, when scratched with a Knoop diamond at a load of at least 5 N to form a scratch having a width w, is free of chips having a size of greater than 3 w.