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 3w.

Glass compositions include one or more of silica (SiO.sub.2), magnesia (MgO) and alumina (Al.sub.2O.sub.3) as essential components and may optionally include sodium oxide (Na.sub.2O), potassium oxide (K.sub.2O), zirconia (ZrO.sub.2), titania (TiO.sub.2), zinc oxide (ZnO), manganese oxide (MnO.sub.2), hafnium oxide (HfO.sub.2) and other components. The glasses may be characterized by low density at room temperature.

Reinforced crystallized glass characterized including crystallized glass as a base material, the crystallized glass containing, as expressed in terms of mol % on an oxide basis, 30.0% to 70.0% of an SiO.sub.2 component, 8.0% to 25.0% of an Al.sub.2O.sub.3 component, 2.0% to 25.0% of an Na.sub.2O component, 1.0% to 6.0% of an Li.sub.2O component, 0 % to 25.0% of an MgO component, 0% to 30.0% of a ZnO component, and 0% to 10.0% of a TiO.sub.2 component, in which a surface of the reinforced crystallized glass is formed with a compressive stress layer, and a depth (DOLzero) of the compressive stress layer is 60 μm or more.

A glass-ceramic comprising, in weight percent on an oxide basis, of 50 to 70% SiO.sub.2, 0 to 20% Al.sub.2O.sub.3, 12 to 23% MgO, 0 to 4% Li.sub.2O, 0 to 10% Na.sub.2O, 0 to 10% K.sub.2O, 0 to 5% ZrO.sub.2, and 2 to 12% F, wherein the predominant crystalline phase of said glass-ceramic is a trisilicic mica, a tetrasilicic mica, or a mica solid solution between trisilicic and tetrasilicic, and wherein the total of Na.sub.2O+Li.sub.2O is at least 2 wt. %; wherein the glass-ceramic can be ion-exchanged.

A sintered machinable glass-ceramic is provided. The machinable glass-ceramic is formed by mixing phyllosilicate material having a sheet structure, with a glass fit and firing the mixture at relatively low temperatures to sinter the phyllosilicate, while maintaining the sheet-like morphology of the phyllosilicate and its associated cleaving properties. The sintered machinable glass-ceramic can be machined with conventional metal working tools and includes the electrical properties of the phyllosilicate. Producing the sintered machinable glass-ceramic does not require the relatively high-temperature bulk nucleation and crystallization needed to form sheet phyllosilicate phases in situ.

A production apparatus making continuously curved crystalline glass as a cover or container includes a melting device, a drainage device, a molding device, and a crystallizing device. The melting device melts glass raw material to form a glass melt. The drainage device drains the glass melt to the molding device. The molding device includes a rotating table and a plurality of molding molds thereon. Each molding mold can be moved toward or away from the drainage device by the rotating table. Each molding mold has a molding cavity. At least one part of the molding cavity includes a plane, and at least one part of the molding cavity includes a curved surface to extrude the glass melt with such different surface forms. The crystallizing device crystallizes the curved glass member to achieve the curved crystallized glass member. A method for manufacturing such glass is also provided.

A glass ceramic sintered body having a small dielectric loss in a high frequency band of 10 GHz or higher and a wiring substrate using the same are provided. The glass ceramic sintered body contains crystallized glass, an alumina filler, and silica. The content of the crystallized glass is 45 mass % to 85 mass %, the content of the alumina filler is 14.8 mass % to 50.1 mass % in terms of Al.sub.2O.sub.3, and the content of silica is 0.2 mass % to 4.9 mass % in terms of SiO.sub.2.

Provided are black crystallized glass that is safe and easy to produce, and reinforced crystallized glass of the black crystallized glass. Crystallized glass and reinforced crystallized glass containing, by wt % in terms of oxide, 40.0% to 70.0% of a SiO.sub.2 component, 11.0% to 25.0% of an Al.sub.2O.sub.3 component, 5.0% to 19.0% of a Na.sub.2O component, 0% to 9.0% of a K.sub.2O component, 1.0% to 18.0% of one or more components selected from a MgO component and a ZnO component, 0% to 3.0% of a CaO component, 1.0% to 3.5% of a TiO.sub.2 component, and 1.0% to 6.5% of a Fe.sub.2O.sub.3 component, and not containing a CoO component and a Co.sub.3O.sub.4 component.

Compounds, compositions, articles, devices, and methods for the manufacture of light guide plates and back light units including such light guide plates made from glass. In some embodiments, light guide plates (LGPs) are provided that have similar or superior optical properties to light guide plates made from PMMA and that have exceptional mechanical properties such as rigidity, CTE and dimensional stability in high moisture conditions as compared to PMMA light guide plates.

A crystallized glass contains: from 58 to 70% of SiO.sub.2, from 15 to 30% of Al.sub.2O.sub.3, from 2 to 10% of Li.sub.2O, from 0 to 10% of Na.sub.2O, from 0 to 10% of K.sub.2O, from 0 to 15% of Na.sub.2O+K.sub.2O, from 0 to 15% of MgO+CaO+SiO+BaO+ZnO, from 0.1 to 6% of SnO.sub.2, from 0.5 to 6% of ZrO.sub.2, from 0 to 4% of TiO.sub.2, and from 0 to 6% of P.sub.2O.sub.5 in mass %, in which the crystallized glass has a degree of crystallinity of 1 to 95%, and an average visible light transmittance of 50% or greater at a thickness of 0.8 mm and a wavelength of 380 to 780 nm, and a compression stress layer is formed on a surface.