The invention relates to glass articles suitable for use as electronic device housing/cover glass which comprise a glass ceramic material. Particularly, a cover glass comprising an ion-exchanged glass ceramic exhibiting the following attributes (1) optical transparency, as defined by greater than 90% transmission at 400-750 nm; (2) a fracture toughness of greater than 0.6 MPa.Math.m.sup.1/2; (3) a 4-point bend strength of greater than 350 MPa; (4) a Vickers hardness of at least 450 kgf/mm.sup.2 and a Vickers median/radial crack initiation threshold of at least 5 kgf; (5) a Young's Modulus ranging between about 50 to 100 GPa; (6) a thermal conductivity of less than 2.0 W/m C., and (7) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.

The present invention relates to a glass ceramic powder comprising i) a glass material formed from a glass mixture containing a lithium and oxygen containing compound selected from Li.sub.2O and/or Li.sub.2CO.sub.3, SiO.sub.2, K.sub.2O, La.sub.2O.sub.3, and ii) seed particles comprising Li.sub.2SiO.sub.3 crystals and/or Li.sub.2Si.sub.2O.sub.5 crystals. The present invention also relates to a method of manufacturing of said glass ceramic powder, a method for preparing compacted and sintered bodies from the glass ceramic powder and bodies obtainable by said method.

Provided is a method for quickly producing a dental prosthesis with a good accuracy. The method for producing a dental prosthesis including: a melting step of melting a material including no less than 60.0 mass % and no more than 80.0 mass % of SiO.sub.2, no less than 10.0 mass % and no more than 20.0 mass % of Li.sub.2O, and no less than 5.1 mass % and no more than 10.0 mass % of Al.sub.2O.sub.3; a glass blank production step of cooling to solidify the molten material to obtain a glass blank; a lithium disilicate blank production step of heating the glass blank to obtain a lithium disilicate blank whose main crystalline phase is lithium disilicate; and a processing step of processing the lithium disilicate by machining.

Glass and glass ceramic compositions having a combination of lithium disilicate and -spodumene crystalline phases along with methods of making the glass and glass ceramic compositions are described. The compositions are compatible with conventional rolling and float processes and have high mechanical strength and fracture resistance. Further, the compositions are able to be chemically tempered to even higher strength glass ceramics that are useful as large substrates in multiple applications.

A process for preparing glass-ceramic body including the steps of providing a basic glass body and subjecting the basic glass body to a thermal treatment whereby a crystalline phase embedded in a glass matrix is formed. The basic glass body is made of a composition comprising 65 to 72 wt-% SiO.sub.2, at least 10.1 wt-% Li.sub.2O and at least 10.1 wt-% Al.sub.2O.sub.3 based on the total weight of the composition, the proportion of Li.sub.2O to Al.sub.2O.sub.3 being from 1:1 to 1.5:1. The thermal treatment involves a nucleation step followed by several crystallization steps at different temperatures, whereby at least two different crystalline phases are formed.

Provided is lithium disilicate crystalline glass containing cristobalite crystal phase for high strength and aesthetic traits and its manufacturing process thereof. Exemplary embodiments of the present invention provide the high strength and aesthetic lithium disilicate crystalline glass, one kind of dental restoration materials, and its manufacturing method which induces the growth of the different crystal phase, cristobalite, from glass with lithium disilicate crystal.

Glass-ceramic containers and methods of making glass ceramic containers with high transparency and fracture toughness suitable for use as, for example a beverage or food container, such as for example, a baby bottle or personal hydration bottle. The glass ceramic containers may have an average wall thickness in the range of 1 mm to 2.5 mm and a fracture toughness of 1 MPa*m{circumflex over ()} or more.

The invention relates to glass-ceramics based on the lithium disilicate system which can be mechanically machined easily in an intermediate step of crystallization and, after complete crystallization, represent a very strong, highly-translucent and chemically-stable glass-ceramic. Likewise, the invention relates to a method for the production of these glass-ceramics. The glass-ceramics according to the invention are used as dental material.

The invention relates to glass articles suitable for use as electronic device housing/cover glass which comprise a glass ceramic material. Particularly, a cover glass comprising an ion-exchanged glass ceramic exhibiting the following attributes (1) optical transparency, as defined by greater than 90% transmission at 400-750 nm; (2) a fracture toughness of greater than 0.6 MPa.Math.m.sup.1/2; (3) a 4-point bend strength of greater than 350 MPa; (4) a Vickers hardness of at least 450 kgf/mm.sup.2 and a Vickers median/radial crack initiation threshold of at least 5 kgf; (5) a Young's Modulus ranging between about 50 to 100 GPa; (6) a thermal conductivity of less than 2.0 W/m C., and (7) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.