Abstract: An opalescent glass-ceramic product, especially for use as a dental material or as an additive to or component of dental material, including SiO2, Al2O3, P2O5, Na2O, K2O, CaO and Me(IV))O2. In order to obtain improved opalescence with improved transparency, in addition to fluorescence, thermal expansion and a combustion temperature adapted to other materials, the opalescent ceramic product is completely or substantially devoid of ZrO2 and TiO2, such that the Me(II)O content in the glass ceramic is less than approximately 4 wt % and the Me(IV)O2 content amounts to approximately 0.5-3 wt %. The invention also relates to a method for the production of the opalescent glass-ceramic product.

Abstract: A method for reshaping a glass body having a Tg and Tx by placing a glass body preform in a mold comprising a cavity having a void volume in the range of 70 to 130 percent of the volume of the glass body preform. The glass body preform is then heated at a temperature between (Tg) and (Tx+50 degrees Celsius) while applying pressure to the glass body preform to form a reshaped glass body.

Abstract: A glass forming apparatus and a glass forming method of high economical merit and high production efficiency are provided. More specifically, the glass forming apparatus has dies, in which at least one die is divided into a heat exchange unit and a press unit, and in the glass forming apparatus and glass forming method, the plane precision is improved in the contact dividing surfaces of the heat exchange unit and the press unit. A glass forming apparatus includes a die having a press surface for pressing a glass material, in which the die has a plurality of dies, and at least one die is divided into a heat exchange unit and a press unit. Preferably, the surface precision of at least one part of each dividing surface in contact with the heat exchange unit and the press unit has a flatness (PV) of 500 ?m or less, and the plane precision of at least one part of the dividing surface has a surface roughness (Ra) of 100 ?m or less.

Abstract: The present invention relates to glass-ceramic materials, processes for making the same and articles comprising the same. The glass-ceramic material has a composition, by weight of the total composition, comprising 55-68% SiO2; 18-24% Al2O3; 3.3-4.1% Li2O; 1.5-4.0% ZnO; 1.5-5.0% MgO; 2-5% TiO2; 0-2% ZrO2; 0-5% B2O3; 0-8% P2O5; 0-2% Na2O, 0-2% K2O; and at least one component resulting from an effective amount of at least one fining agent; wherein: the total of B2O3 and P2O5 is at least 1.5% by weight, the total of MgO and ZnO is at least about 3.5% by weight, the total of Na2O and K2O is less than about 3.0% by weight, the total of P2O5, B2O3, Na2O and K2O is less than about 11% by weight, the weight ratio of the sum total of Na2O+K2O to the sum total of P2O5+B2O3 ( Na 2 ? O + K 2 ? O B 2 ? O 3 + P 2 ? O 5 ) is less than about 0.

Abstract: Ceramics comprising (i) at least one of Nb2O5 or Ta2O5 and (ii) at least two of (a) Al2O3, (b) Y2O3, or (c) at least one of ZrO2 or HfO2. Embodiments of ceramics according to the present invention can be made, formed as, or converted into optical waveguides, glass beads, articles (e.g., plates), fibers, particles (e.g., abrasive particles), and thin coatings.

Abstract: The method produces a glass-ceramic article substantially in the form of a plate with improved high temperature difference resistance or strength. The glass-ceramic article contains keatite mixed crystals (KMK) or high quartz mixed crystals (HQMK) as well as the keatite mixed crystals (KMK). The method includes heating a glass-ceramic in a high quartz mixed crystal state to form the keatite mixed crystals with a heating rate of 20 K/min to 150 K/min, preferably more than 15 K/min, especially preferably more than 20 K/min. These high heating rates increase the temperature difference resistance.

Abstract: Methods for making glasses and glass-ceramics comprising Al2O3 and SiO2. Glasses made according to the present invention can be made, formed as, or converted into glass beads, articles (e.g., plates), fibers, particles, and thin coatings. Some embodiments of glass-ceramic particles made according to the present invention can be are particularly useful as abrasive particles.

Abstract: This invention relates to glass-ceramic materials in the BaO—La2O3—SiO2 system, which are suitable for processing via a powder route, and which, after heat-treatment have a combination of high thermal expansion and excellent refractoriness. The precursor glass powders of the present invention have compositions on a weight percent basis of 10–55% BaO, 3–50% La2O3, 25–48% SiO2 and optionally up to 30% in total of other compatible metal oxides. The powders are substantially free from alkali metal oxides and from boron oxide such that the refractoriness of the glass-ceramic materials is not compromised. The materials may be advantageously employed at high temperatures in direct combination with other materials of high expansion or may be used to join or hermetically seal components made of other materials having similarly high expansion.

Abstract: Apatite glass ceramic which contains at least one glass phase and at least one apatite phase and is characterized in that at least one of the apatite phases is a phosphate- and fluorine-free siliceous oxyapatite phase.

Abstract: The method of supporting and transporting hot flat glass on a gas bed for ceramicizing includes arranging a number of spaced-apart porous or perforated planar segments to form a base with a gas-permeable support surface so that slits, which are narrower than the planar segments, are formed between them, forcing gas through the porous or perforated planar segments and conducting the gas away through the slits between them so as to form the gas bed with no static pressure zones and with a parabolic pressure distribution and producing a predetermined temperature profile for ceramicizing through which the hot flat glass is transported on the gas bed without deformation and without any contact between it and the base. The resulting glass ceramic has smoother surfaces without pits or deformations.

Abstract: A silica glass member for semiconductor in which each concentration of Fe, Cu, Cr and Ni is 5 ppb or less and the concentration of an OH group is 30 ppm or less and which has a viscosity of 1013.0 poise or more at 1200° C. is provided as a silica glass member for semiconductor having high heat-resistance and higher purity.

Abstract: The support plate for transporting products during thermal treatment at firing temperatures is a nonporous keatite glass ceramic supporting member without a glassy surface layer. It has a nubby structure on an underside thereof and preferably C-shaped rounded edges. A method of making the keatite glass ceramic supporting member is described.

Abstract: Disclosed is a substantially transparent glass-ceramic ceramic, and a method for making a glass-ceramic, exhibiting an aluminogallate spinel crystal phase and having a glass-ceramic composition that lies within the SiO2—Al2O3—ZnO—K2O—Ga2O3—Na2O system and particularly consisting essentially, in weight percent on an oxide basis, of 25-50% SiO2, 15-45% ZnO, 0-26% Al2O3, 0-25% K2O, 0-10% Na2O, 0-32% Ga2O3, a K2O+Na2O amount of greater than 10%, a Al2O3+Ga2O3 of greater than 10%, the glass ceramic microstructure containing a crystal phase comprising at least 15%, by weight, of hexagonal ZnO crystals. Another aspect disclosed is optical element selected from the group consisting of an optical fiber, a gain or laser medium, and an amplifier component, a saturable absorber, with the element comprising a transparent glass-ceramic of the same composition and containing a crystallinity of at least about 15% by weight of hexagonal ZnO crystals.

Abstract: A display panel is provided that has a multilayer structure made of a colored glass layer having a desired shape and optical characteristics and a non-colored glass layer having high transparency, as well as high productivity. The display panel has a non-colored glass layer and a colored glass layer contacting the non-colored glass layer. A multilayer structure is formed that includes a colored paste layer and a non-colored paste layer. In the colored paste layer, crystallization glass powder that is crystallized at the temperature TA and coloring agent are diffused. In the non-colored paste layer, glass powder whose softening point is the temperature TB that is higher than the temperature TA. The multilayer structure is heated to the temperature TC that is higher than the temperature TB and is lower than the softening point of the crystallization glass powder after the crystallization to be burned, so that the non-colored glass layer and the colored glass layer are formed simultaneously.

Abstract: A composition for a glass-ceramic material that contains a crystallinity of at least about 30% by weight of forsterite components at a liquidus temperature of about 1525° C. or below. The glass-ceramic has a composition, in weight percent on an oxide basis, consisting essentially of about: 40-60% SiO2; 10-25% Al2O3; 18-30% MgO; 3-10% Na2O; 0-10% K2O; >5-15% TiO2. The invention further comprises a method for achieving high crystalline yield at such a low liquidus with increased solubility of high levels of chromium ions. The glass-ceramics can be used in drawing optical fibers and as gain media in amplifier and laser devices for near infrared wavelengths.

Abstract: The present invention relates to a glass substrate of which the outer periphery portion is unprocessed. The present invention also relates to a manufacturing method for a glass substrate of which the outer periphery portion is unprocessed, characterized in that a first lapping process, a second lapping process, a polishing process and a washing process are carried out after a press molding process is carried out so as to compress glass between an upper mold and a lower mold without regulating the edge surface of the outer periphery portion of the glass and, then, a crystallization process or an annealing process is carried out.

Abstract: The invention relates to a method for producing UV polarizers, according to which spheroid particles situated near the surface of the glass are incorporated into the support material (primarily standard float glass) in a novel arrangement. According to the method for producing UV polarizers, after the introduction of metal ions (e.g., silver ions) into the glass surface, a large size distribution of particles is achieved by multiple alternation of a heat treatment for separating out spherical metal particles, followed by the renewed introduction of metal ions and a subsequent heat treatment. A deformation of the glass produces spheroid particles of various sizes and different semi-axis relationships. The particles are characterized by their large size distribution and are deformed differently in relation to their spheroid shape. In this way UV polarizers are produced which have a wide absorption range since the absorption bands having different maximum positions overlap.

Abstract: The invention relates to the production of decorative facing materials using a glass-pelletizer and refractory filler. The inventive method for a continuous production of decorative facing slabs consists in loading of basic materials into casting-moulds which are placed on an open heat-insulated palette, and in thermal treatment in a furnace at a temperature ranging from 900° C. to 950° C. After the thermal treatment, the palette with the moulds is taken out and conditioned at an ambient temperature during 80-90 sec accompanied by cooling the surface of the slabs to a temperature ranging from 600° C. to 634° C. Afterwards, the slabs are placed in a heat-insulated closed space having a thermal resistance of walls which makes it possible to cool the surface of the slab to a temperature ranging from 100° C. to 140° C. with an average cooling rate ranging from 0.016 to 0.020 degrees/sec.

Abstract: The present invention relates to novel mineral glasses which are cerammable and which have a composition, expressed in percentages by weight of oxides, consisting essentially of: SiO2 65-70; Al2O3 18-20.5; Li2O 2.5-3.8; MgO 0.55-1.5; ZnO 1.2-2.8; BaO 0-1.4; SrO 0-1.4; with BaO+SrO 0.4-1.4; with MgO+BaO+SrO 1.1-2.3; Na2O 0-<1; K2O 0-<1; with Na2O+K2O 0-<1; 1 with ⁢   ⁢ 2.8 ⁢   ⁢ Li 2 ⁢ O + 1.2 ⁢ ZnO 5.2 ⁢   ⁢ MgO > 1.

Abstract: A crucible used in the growth of polycrystal silicon by a cast method comprises a crucible body for, when solid material silicon is melted, containing the melted material silicon, and a material holder provided on the crucible body, for holding further material silicon on the material silicon loaded into the crucible body.

Abstract: A process for the preparation of crystalline silica powder from amorphous silica powder is disclosed. The water and hydroxyl content in the crystalline powder is much lower than that in the amorphous silica powder. The process involves heating the amorphous silica powder in the presence of a noble metal without the need for adding an impurity, such as an alkali crystallization promoter. Preferably, the amorphous silica powder is sol-gel derived, and a high purity silica glass product can therefore be made having a water content of less than 0.1 ppm.

Abstract: A process for modifying the surface of a quartz glass crucible and a modified quartz glass crucible produced by the process, where the crucible has a transparent coated layer containing a crystallization accelerator on the surface. The process includes coating a mixed solution containing a metal salt and a partial hydrolyzate of alkoxysilane oligomer on the surface of the crucible and heating to obtain a quartz glass crucible having a transparent coated layer. The crystallization promoter contains a metal oxide or a metal carbonate dispersed in a silica matrix.

Abstract: The present invention relates to: a glass-ceramic which is opaque which has a low, or zero thermal expansion coefficient, which contains a solid solution of &bgr;-quartz as crystalline phase, which has a specific composition; and, to a process for obtaining said glass-ceramic.

Abstract: Glass-ceramic consisting of: SiO3: 30-70%; Al2O3: 8-45%; M2O: 8-30%; MO: 0-30%; B2O3: 0-15%: P2O5: 0-15%; Zr2O: 0-12%; TiO2: 0-12%, wherein: M is chosen in the group consisting, of: Li, Na, K or mixture thereof; M′ is chosen in the group consisting of: Be, Mg, Ca, Ba, Sr, Zn, Pb or mixture thereof are described.

Abstract: A method for making a glass ceramic, optoelectronic material such as a clad optical fiber or other component for use in an optoelectronic device. The method comprises preparing a glass composition batch to yield a precursor glass for a nanocrystalline glass-ceramic that is doped with at least one kind of optically active ion, such as a transition metal or lanthanide element; melting the batch; forming a glass cane; surrounding the cane with a chemically inert cladding material shaped in the form of a tube; drawing a glass fiber from the combined precursor-glass “cane-in-tube” at a temperature slightly above the liquidus of the precursor glass composition, and heat treating at least a portion of the drawn clad glass fiber under conditions to develop nanocrystals within the core composition and thereby forming a glass ceramic.

Abstract: Provided is a substrate for information recording medium composed of such a crystallized glass as having high Young's modulus, strength and heat resistance, being excellent in surface smoothness, surface homogeneity and surface processability, as well as having a relatively low temperature of glass liquid phase and being capable of producing cheaply, and an information recording medium using this substrate.

Abstract: A method for the production of a glass substrate for magnetic recording mediums is herein provided and this method is characterized in that the final cleaning step is performed in two stages, in which scrubbing and dip-cleaning steps are carried out after the completion of the first cleaning stage and after the growth of needle-like projections comprising an alkali metal carbonate on the surface of the glass substrate. The method for the production of a glass substrate for magnetic recording mediums does not require the use of an expensive device having high resistance to acids. Moreover, in the glass substrate for magnetic recording mediums produced by the foregoing method, any growth of needle-like projections containing an alkali metal carbonate on the surface of the glass substrate is inhibited even during temporal storage of the substrate.

Abstract: In respect of a method for manufacturing a preform of an optical fiber, the method comprises the steps of forming a porous glass preform by accumulating glass particles, preparing a container made of a quartz glass, which is formed by heating the quartz glass with an electric furnace, providing a dehydration gas and an inert gas to the container, heating the container to which dehydration gas and inert gas is provided and dehydrating and sintering the porous glass preform by inserting the porous glass preform into the container, which is heated.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: The present invention provides a construction material for internal and external use in buildings and other architectural structures. The material is made from a glassy material that has been crystallized in the presence of crystalline seed particles. The construction material has higher mechanical strength and lower water absorption than conventional glass based construction materials. The invention also provides methods for producing these improved construction materials.

Abstract: A polished glass disk medium substrate suitable for use as a substrate for a hard disk, a hard disk containing the substrate and methods for making the substrate. The substrate containing glass forming raw materials may be formed so as to have a Young's modulus of 110 or higher.

Abstract: Disclosed is a substantially transparent glass-ceramic ceramic, and a method for making a glass-ceramic, exhibiting an aluminogallate spinel crystal phase and having a glass-ceramic composition that lies within the SiO2—Ga2O3—Al2O3—K2O—Na2O— system and particularly consisting essentially, in weight percent on an oxide basis, of 25-55% SiO2, 9-50% Ga2O3, 7-33% Al2O3, 0-20% K2O, 0-15% Na2O, 0-6 Li2O and 5-30% K2O+Na2O, the glass ceramic microstructure containing a crystal phase comprising at least 5%, by weight, of aluminogallate spinel crystals. Another aspect disclosed is optical element selected from the group consisting of an optical fiber, a gain or laser medium, and an amplifier component, a saturable absorber, with the element comprising a transparent glass-ceramic of the same composition and containing a crystallinity of at least about 5% by weight of aluminogallate spinel crystals.

Abstract: The invention relates to a method and a device for storing and transporting hot flat glass in a contactless manner during glass production, said storage and transportation being carried out on a gas bed which is constructed over a gas permeable bearing surface pertaining to a base (2). Pressurised gas is supplied to the base via a connection (5), said gas being guided through the gas permeable base and then re-evacuated. The aim of the invention is to obtain an optimum pressure distribution above the bearing surface, without any static pressure. In order to achieve this, the base (2) consists of a plurality of interspaced segments (21, 22 . . . 2n) respectively comprising a porous and/or perforated bearing surface (7a) as a gas outlet surface. Evacuation openings (61, 62 . . . 6n) are formed between said segments for evacuating the gas. The segments are preferably formed by bars (7) having a box profile.

Abstract: The present invention relates to a glass substrate of which the outer periphery portion is unprocessed. The present invention also relates to a manufacturing method for a glass substrate of which the outer periphery portion is unprocessed, characterized in that a first lapping process, a second lapping process, a polishing process and a washing process are carried out after a press molding process is carried out so as to compress glass between an upper mold and a lower mold without regulating the edge surface of the outer periphery portion of the glass and, then, a crystallization process or an annealing process is carried out.

Abstract: Voltage is applied between electrodes (14a, 14b) under UV irradiation to perform a UV excitation poling, thereby producing microcrystal particles at a core unit (10a). Accordingly, second-order optical nonlinearity is developed at the core unit (10a) of an optical fiber (10). Under a high-temperature condition, a second-order optical nonlinearity can be imparted by a comparatively low-voltage UV excitation poling when a second-order optical nonlinearity decreases.

Abstract: The specification describes ceram-glass compositions useful for electro-optic devices. The compositions have active ferroelectric ingredients in a tellurium oxide host. Proper processing of the ceram-glass produces highly transparent material with desirable ferroelectric properties. The ceram-glass materials can be used for electro-optic devices in both bulk and thin film applications.

Abstract: This invention is directed to lithium disilicate (Li2Si2O5) based glass-ceramics comprising silica, lithium oxide, alumina, potassium oxide and phosphorus pentoxide. The glass-ceramics are useful in the fabrication of single and multi-unit dental restorations (e.g. anterior bridges) made by heat pressing into refractory investment molds produced using lost wax techniques. The glass-ceramics have good pressability, i.e., the ability to be formed into dental articles by heat-pressing using commercially available equipment. In accordance with one embodiment directed to the process of making the glass-ceramics, the compositions herein are melted at about 1200° to about 1600° C., thereafter quenched (e.g., water quenched or roller quenched) or cast into steel molds, or alternately, cooled to the crystallization temperature. The resulting glass is heat-treated to form a glass-ceramic via a one or two step heat-treatment cycle preferably in the temperature range of about 400° to about 1100° C.

Abstract: A method of producing a polarizing glass article that exhibits a broad band of high contrast polarizing properties in the infrared region of the radiation spectrum. The polarizing glass is phase-separated or exhibits photochromic properties based on silver, copper, or copper-cadmium halide crystals or a combination thereof, which are precipitated in the glass and having a size in the range of 200-5000 Å. The glass has a surface layer containing elongated silver, copper, or copper cadmium metal particles, or a mixture thereof. The method comprises subjecting the glass article to a time-temperature cycle in which the temperature is at least about 76° C. or greater above the glass softening point, in a step to thermally form and precipitate large halide crystals, and elongated metallic particles under a stress of not over about 3000 psi, preferably not over about 2675 psi.

Abstract: A glass-ceramic which is substantially and desirably totally transparent, and which contains a predominant, orthosilicate crystal phase whose composition lies within the ternary Mg2SiO4—Zn2SiO4—Li4SiO4 system. The glass-ceramic is formed from precursor glasses having the following compositions, in weight percent on an oxide basis: 35-72 SiO2, 0-20 Al2O3, 0-40 ZnO, 0-18 MgO, 1-15 Li2O, 0-18 K2O, 0-8 Na2O, 0-8 P2O5, with the condition that &Sgr;ZnO+MgO≧7. The glass-ceramic may be doped with up to 1 wt. % chromium, oxide to impart optical activity thereto.

Abstract: The present invention relates to glass ceramic material and its use as means for joining different types of material and as support. Said glass ceramic material comprising, on a weight percent basis, 10-35% MgO, 10-55% BaO and 25-50% SiO2 and is formed by the following steps: a) melting of glass raw material at a temperature in excess of 1450 ° C. and that the thereby formed melt is cooled rapidly to a temperature below 900° C. and thereafter to ambient temperature to form a precursor glass, b) milling of the precursor glass into a sinterable glass powder with an average particle size in the range of 1 micron to 100 microns, c) forming of the glass powder into a green body of suitable shape, with or without organic processing aids, and subjecting said green body to a thermal treatment comprising a heating stage of average heating rate not exceeding 100 ° C./minute between the temperatures of 750 ° C. and 900 ° C.

Abstract: High-strength sinterable lithium disilicate glass ceramics are described which can be further processed in particular by pressing in the viscous state to shaped dental products.

Abstract: A process is described for the preparation of shaped translucent lithium disilicate glass ceramic products which are characterized by high strength and good chemical stability and may be processed by pressing in the plastic state or milling to finished glass ceramic products which may be used in particular as dental restorations.

Abstract: A composite for a dental restoration is presented comprising ground, densified, embrittled glass fibers together with fillers and a polymeric matrix precursor composition. The ground, densified, embrittled glass fibers are obtained by grinding glass fibers which have been densified and embrittled by heating glass fibers at a temperature substantially below the softening point of the glass fibers, without significant fusion or melting together of the fibers. The composite is particularly useful as a direct filling material, in that it has the feel and workability of an amalgam.