Abstract: For providing glasses and glass-ceramics having properties suitable for use as a substrate of an information storage medium of next generation such as one for the perpendicular magnetic recording system without employing arsenic and antimony components which adversely affect human beings and the environment, there are provided glass-ceramics comprising SiO2, Li2O and Al2O3 on oxide basis, comprising lithium disilicate as a crystal phase, and comprising one or more elements selected from the group consisting of Sn, Ce, Mn, W, Ta, Bi, Nb, S, Cl and F.

Abstract: In all of an in-plane magnetic recording system and a perpendicular magnetic recording system, there is provided a crystallized glass for a disk substrate for information recording medium, etc., which has satisfactory surface properties capable of sufficiently adapting with a lamp loading system for high-density recording, has high strength such that it is able to withstand high-speed rotation and impact, has heat expansion properties and heat resistance in agreement with respective drive members, has a low melting temperature, has excellent productivity and is reduced in the elution amount of an alkali from the raw material, namely excellent in chemical durability. The crystallized glass of the invention is a crystallized glass containing an SiO2 component and an Li2O component; further containing at least one member selected from an SrO component and a BaO component in a total content of more than 3.

Abstract: Materials and methods for making low bulk density proppant capable of providing permeability at subterranean pressures. The low bulk density proppant is made from kaolin clay and at least one of calcined diatomaceous earth and burned kaolin clay.

Abstract: The amorphous and/or partially crystalline glass solders are particularly suitable for high-temperature applications, e.g. in fuel cells or sensors in the exhaust gas stream of internal combustion engines. The glass solder is characterized by a linear coefficient of thermal expansion in the temperature range from 20° C. to 300° C. of 8.0×10?6 K?1 to 11.0×10?6 K?1 and a hemisphere temperature of 820° C. to 1100° C. and is suitable for laser bonding.

Abstract: A ceramic component is provided, including a ceramic body containing silicon carbide, and an oxide layer provided on the ceramic body, the oxide layer being formed by oxidizing the ceramic body in the presence of alumina having a submicron particle size.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: The invention relates glass ceramic articles suitable for use as electronic device housing or enclosures which comprise a glass-ceramic material. Particularly, a glass-ceramic article housing/enclosure comprising a glass-ceramic material exhibiting both radio and microwave frequency transparency, as defined by a loss tangent of less than 0.5 and at a frequency range of between 15 MHz to 3.0 GHz, a fracture toughness of greater than 1.5 MPa·m1/2, an equibiaxial flexural strength (ROR strength) of greater than 100 MPa, a Knoop hardness of at least 400 kg/mm2, a thermal conductivity of less than 4 W/m° C. and a porosity of less than 0.1%.

Abstract: A crystalline glass with a characteristic of precipitating crystals from the surface of the crystalline glass to the interior thereof when it is being heated at a temperature higher than the softening point is used in the invention. A plurality of small crystalline glass masses 12 are accumulated and leveled in a fireproof mold coated with a mold release agent, and two crystalline glass plates 14A and 14B cut in an S shape are placed on the accumulated surface of the small crystalline glass masses 12 with the cut faces tightly bonded. A heat treatment is then performed to obtain a crystallized glass article having patterns. The crystalline glass plate can be cut into any shape to tightly bond the cut faces, and therefore the obtained crystallized glass articles have different patterns like natural-marble-like patterns, human figure patterns, animal patterns, etc. The invention also discloses a method of producing crystallized articles having patterns.

Abstract: The invention relates to a glass ceramic armour material consisting (in % by weight in relation to oxide base) of 5-33 SiO2, 20-50 Al2O3, 5-40 MgO, 0-15 B2O3, 0.1-30 Y2O3, Ln2O3, As2O3, Nb2O3 and/or Sc2O3 and 0-10 P2O5. The inventive armour material can also be reinforced with inorganic reinforcing fibres in a quantity of 5-65% by weight, preferably consisting of C, SiC, Si3N4, Al2O3, ZrO2 or Sialon. Said armour material is characterised in that it exhibits a high elasticity modulus and is producible from green glass without to fear a premature crystallisation.

Abstract: The present invention relates to preparing an improved lithium silicate glass ceramic for the manufacture of blocks for dental appliance fabrication using a CAD/CAM process. The lithium silicate material has a chemical composition that is different from those reported in the prior art including 8 to 10% of germanium dioxide in the final composition. The softening points are close to the crystallization final temperature of 830° C. indicating that the samples will support the temperature process without shape deformation. The resulting material has improved castability and higher density.

Abstract: The invention is directed to transparent glass-ceramic materials for use in transparent armor systems. Applications include armor systems for ground vehicles and aircraft as well as personal protective equipment. The glass-ceramic materials according to the invention exhibit a ballistic limit vs. areal density line slope of 1.0 or greater, preferably 1.1 or greater and more preferably 1.2 or greater. The crystalline phase of the glass ceramic materials may include ?-quartz, spinel, spinel solid solutions, mullite and phases known in the art to be transparent.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: Provided is a zirconia-mullite refractory raw material which is less likely to undergo alternation and microstructural degradation under high-temperature conditions, and low in thermal expansion rate, so as to have thermal shock resistance and corrosion resistance. The zirconia-mullite refractory raw material comprises crystalline zirconia and mullite as primary components, with the remainder being corundum and/or a matrix glass, wherein the crystalline zirconia includes a eutectic zirconia crystal having a grain size of 1.0 ?m or less, and has a maximum grain size of 30 ?m or less, and the matrix glass is contained in an amount of 5 mass % or less. The zirconia-mullite refractory raw material has a chemical composition comprising 30 to 55 mass % of ZrO2, 30 to 55 mass % of Al2O3 and 10 to 25 mass % of SiO2, wherein each of the chemical components falls within a primary phase region of ZrO2 in an Al2O3—ZrO2—SiO2 system phase diagram.

Abstract: The present invention provides a method of making a decorated multilayer glass structure using a single firing step that includes that use of a crystallizing glass enamel composition that contains ingredients to ensure the complete burnout of the organic portion of the composition upon firing and bending of a mated pair of glass sheets. A benefit of the composition is that when applied to one sheet of a mated pair of glass sheets, it burns out completely during firing and bending of the pair. The presence of high levels of oxidizers in the composition ensures a supply of oxygen to enable combustion of the organic vehicle while firing the glass sheets and prior to the sintering of the enamel composition to only one glass sheet in a mated pair of decorated or colored glass sheets.

Abstract: The invention relates to synthetic hybrid rock compositions, articles of manufacture and related processes employing mineral waste starting materials such as mine tailings, mine development rock, ash, slag, quarry fines, and slimes, to produce valuable articles of manufacture and products, which are characterized by superior physical and structural characteristics, including low porosity, low absorption, increased strength and durability, and retained plasticity. The resulting materials are compositionally and chemically distinct from conventional synthetic rock materials as demonstrated by scanning electron microprobe analysis, and are useful in a wide variety of applications, particularly with respect to commercial and residential construction.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: Spherical and rod-shaped proppants and anti-flowback agents made from sillimanite minerals possess high strength and high conductivity. The sillimanite minerals may be selected from the group consisting of kyanite, sillimanite, and andalusite and may be used alone or in combination with other materials, such as bauxite, kaolin, meta-kaolin, pure or technical grade alumina (about 98%-99.9% alumina by weight), alumina-containing slag, zirconia, silica, iron, alkali elements (such as calcium, magnesium, and sodium), and virtually any other mineral containing alumina. The starting material may optionally be milled to achieve better compacity and crush resistance in the final proppant or anti-flowback agent. A fracturing fluid may comprise the rods or spheres alone, or in combination with each other or other proppants or anti-flowback agents of different shapes.

Abstract: A ceramic component is provided, including a ceramic body containing silicon carbide, and an oxide layer provided on the ceramic body, the oxide layer being formed by oxidizing the ceramic body in the presence of alumina having a submicron particle size.

Abstract: The invention provides an antimicrobial phosphate glass composition including, in weight percent based on oxide: greater than 45 to 90 of P2O5, 0 to 60 of B2O3, 0 to 40 of SiO2, 0 to 20 weight percent of Al2O3, 0 to 30 of SO3, 0 to 0.1 of Li2O, 0 to 0.1 of Na2O, 0 to 0.1 of K2O, 0 to 40 of CaO, 0 to 40 of MgO, 0 to 15 of SrO, 0 to 40 of BaO, 0 to 40 of ZnO, 0 to 5 of Ag2O, 0 to 15 of CuO, 0 to 10 of Cr2O3, 0 to 10 of I—, 0 to 10 of TeO2, 0 to 10 of GeO2, 0 to 10 of TiO2, 0 to 10 of ZrO2, 0 to 10 of La2O3, 0 to 5 of Nb2O3, 0 to 5 of CeO2, 0 to 5 of Fe2O3, 0 to 5 of WO3, 0 to 5 of Bi2O3, and 0 to 5 of MoO3.

Abstract: The invention is directed to highly crystalline, frit-sintered glass-ceramic materials and seals made using them that are suitable for solid oxide fuel cell applications. The seals have a coefficient of thermal expansion in the range of 70-130×10?7° C., preferably 85-115×10?7° C. The glass-ceramic materials have a crystalline component and a glass component, the crystalline component being >50% of the glass-ceramic and the glass component being <50%. In one preferred embodiment the crystalline component is >75%. Regarding the crystalline component only, >50% of the crystals in the crystalline component of the glass-ceramic has a structure selected from the structural groups represented by walstromite, cyclowollastonite, ?-(Ca,Sr)SiO3, kalsilite, kaliophilite and wollastonite (the primary crystalline phase) and the remaining <50% of the crystalline component is at least one secondary crystalline phase.

Abstract: A synthetic microsphere having a low alkali metal oxide content and methods of forming the microsphere and its components are provided. The synthetic microsphere is substantially chemically inert and thus a suitable replacement for natural cenospheres, particularly in caustic environments such as cementitious mixtures. The synthetic microsphere can be made from an agglomerate precursor that includes an aluminosilicate material, such as fly ash, a blowing agent such as sugar, carbon black, and silicon carbide, and a binding agent. The synthetic microsphere is produced when the precursor is fired at a pre-determined temperature profile so as to form either solid or hollow synthetic microspheres depending on the processing conditions and/or components used.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: A dielectric ceramic composition comprises as a main component, Cu oxide, Si oxide and one selected from the group consisting of Zn oxide alone and a combination of Mg oxide and Zn oxide, as a subcomponent, a glass component including B oxide and at least one selected from the group consisting of Si oxide, Ba oxide, Ca oxide, Sr oxide, Li oxide and Zn oxide, and having a glass softening point is 750° C. or less, wherein a content of said glass component is 1.5 to 15 wt % with respect to 100 wt % of said main component. According to the present invention, a dielectric ceramic composition can be provided which is available to be sintered at low temperature (for example, 950° C. or lower) while comparatively decreasing contents of a glass component, which shows good properties (specific permittivity, loss Q value and insulation resistance), and which is available to perform cofiring different materials.

Abstract: A crystalline glass with a characteristic of precipitating crystals from the surface of the crystalline glass to the interior thereof when it is being heated at a temperature higher than the softening point is used in the invention. A plurality of small crystalline glass masses 12 are accumulated and leveled in a fireproof mold coated with a mold release agent, and two crystalline glass plates 14A and 14B cut in an S shape are placed on the accumulated surface of the small crystalline glass masses 12 with the cut faces tightly bonded. A heat treatment is then performed to obtain a crystallized glass article having patterns. The crystalline glass plate can be cut into any shape to tightly bond the cut faces, and therefore the obtained crystallized glass articles have different patterns like natural-marble-like patterns, human figure patterns, animal patterns, etc. The invention also discloses a method of producing crystallized articles having patterns.

Abstract: A ceramic body, a ceramic catalyst body, a ceramic catalyst body and related manufacturing methods are disclosed wherein a cordierite porous base material has a surface, formed with acicular particles made of a component different from that of cordierite porous base material, which has an increased specific surface area with high resistance to a sintering effect. The ceramic body is manufactured by preparing a slurry containing an acicular particle source material, preparing a porous base material, applying the slurry onto a surface of the porous base material and firing the porous base material, whose surface is coated with the slurry, to cause acicular particles to develop on the surface of the porous base material. A part of or a whole of surfaces of the acicular particles is coated with a constituent element different from that of the acicular particles.

Abstract: A translucent piezoelectric glass ceramic is disclosed. The glass ceramic is prepared from a precursor glass by a ceraming process, using a temperature gradient to effect the precipitation of non-ferroelectric piezo-active crystallites from the precursor glass with a preferred direction of orientation and having an average crystal size of less than 1 micrometer. Alternatively, a translucent piezoelectric glass ceramic comprising ferroelectric crystallites may be prepared by poling. In this case the crystal size is controlled to be smaller than 90 nanometers but preferably larger than 10 nanometers.

Abstract: The present invention provides an inorganic composition for use in information recording medium disc substrate and such, having an excellent surface property capable of sufficiently corresponding with a ramp load system for high density recording, a high degree of tolerability to high speed rotation, and high productivity at a low melting point. Specifically, this invention provides an inorganic composition containing one crystalline phase selected from the group consisting of ?-quartz (?-SiO2), lithium disilicate (Li2Si2O5) and lithium monosilicate (Li2SiO3), or that contain at least a crystalline phase of lithium monosilicate (Li2SiO3), in which a mean particle diameter of a particle showing a crystalline phase contained in the inorganic composition is 1 ?m or less, a ring flexural strength is 300 MPa or more, and a surface roughness (an arithmetic mean roughness) thereof after a polishing process is 10 ? or less.

Abstract: The process of making the glass-ceramic includes ceramicizing a starting glass at a heating or cooling rate during the ceramicization of at least 10 K/min, so that the glass-ceramic contains at least 50% by volume of ferroelectric crystallites with a maximum diameter of from 20 to 100 nm and not more than 10% by volume of nonferroelectric crystallitesis. The glass ceramic produced by the process contains no pores or not more than 0.01% by volume of the pores and a value of e?·V2max of the glass-ceramic is at least 20 (MV/cm)2, wherein e? is the dielectric constant at 1 kHz and Vmax is the breakdown voltage per unit thickness. The ferroelectric crystallites preferably have a perovskite structure and are composed of substantially pure or doped BaTiO3 and/or BaTi2O5.

Abstract: The invention is directed to highly crystalline, frit-sintered glass-ceramic materials and seals made using them that are suitable for solid oxide fuel cell applications. The seals have a coefficient of thermal expansion in the range of 70-130×10?7° C., preferably 85-115×10?7° C. The glass-ceramic materials have a crystalline component and a glass component, the crystalline component being >50% of the glass-ceramic and the glass component being <50%. In one preferred embodiment the crystalline component is >75%. Regarding the crystalline component only, >50% of the crystals in the crystalline component of the glass-ceramic has a structure selected from the structural groups represented by walstromite, cyclowollastonite, ?-(Ca,Sr)SiO3, kalsilite, kaliophilite and wollastonite (the primary crystalline phase) and the remaining <50% of the crystalline component is at least one secondary crystalline phase.

Abstract: The invention is directed to highly crystalline, frit-sintered glass-ceramic materials and seals made using them that are suitable for solid oxide fuel cell applications. The seals have a coefficient of thermal expansion in the range of 70-130×10?7° C., preferably 85-115×10?7° C. The glass-ceramic materials have a crystalline component and a glass component, the crystalline component being>50% of the glass-ceramic and the glass component being<50%. In one preferred embodiment the crystalline component is >75%. Regarding the crystalline component only,>50% of the crystals in the crystalline component of the glass-ceramic has a structure selected from the structural groups represented by walstromite, cyclowollastonite, ?-(Ca,Sr)SiO3, kalsilite, kaliophilite and wollastonite (the primary crystalline phase) and the remaining <50% of the crystalline component is at least one secondary crystalline phase.

Abstract: An internally nucleated, toughened cordierite glass-ceramic is disclosed. The cordierite glass-ceramic has good oxidation resistance and fracture toughness and coefficient of thermal expansion rivaling that of silicon nitride. The glass-ceramic may be cast as a liquid. Annealing produces a material of high crystallinity combining high hardness, high Young's modulus, good thermal stability, high strength, low density and good dielectric properties. The glass-ceramic comprises interlocking crystalline phases dominated by cordierite and a second phase having an elongated or acicular structure. A third phase may comprise a crystalline ceramic that promotes acicularity of the second phase. The third phase is preferably capable of twinning.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: A glass ceramic composition is used for a multilayer ceramic substrate 2 including glass ceramic layers 3 laminated, the multilayer ceramic substrate 2 being used for a multilayer ceramic module 1. The glass ceramic composition includes a first ceramic powder mainly composed of forsterite, a second ceramic powder mainly composed of at least one component selected from CaTiO3, SrTiO3 and TiO2, and a borosilicate glass powder containing Li2O, MgO, B2O3, SiO2, ZnO and Al2O3. The glass ceramic composition contains 3 percent by weight or more of the borosilicate glass powder and further contains at least one additive selected from the group consisting of CaO, BaO and SrO.

Abstract: A glass ceramic composition for glass ceramic layers laminated in multilayer ceramic substrate included in multilayer ceramic module is provided. The glass ceramic composition contains a first ceramic powder mainly composed of forsterite, a second ceramic powder mainly composed of at least one material selected from CaTiO3, SrTiO3 and TiO2, and a borosilicate glass powder containing Li2O, MgO, B2O3, SiO2, ZnO and possibly Al2O3. The content of the borosilicate glass powder is about 3 percent by weight or more. The borosilicate glass powder further contains at least one additive selected from the group consisting of CaO, BaO and SrO.

Abstract: The invention is directed to highly crystalline, frit-sintered glass-ceramic compositions having a coefficient of thermal expansion in the range of 85-115×10?7° C. The primary crystal phases of the glass-ceramics of the invention possess a cyclosilicate structure. The glass-ceramic of the invention are useful as metal-to-metal, metal-to-ceramic and ceramic-to-ceramic sealing agents, and also as high-performance coating for metals and ceramics. In their broadest composition the glass-ceramic contain, in weight percent, 30-55% SiO2, 5-40% CaO, 0-50% BaO, 0.1-10% Al2O3, and 0-40% SrO, wherein the sum of CaO+BaO+SrO is in the range of 35-65 wt. %. Optionally, the glass-ceramic compositions may contain at least one from the group of >0-15 wt. % MgO and >0-10 wt. % ZnO. Also optionally, the glass ceramic compositions may contain >0-10 wt. % of at least one transition metal or rare earth metal oxide.

Abstract: A glass-ceramic is provided having a thermal expansion coefficient in a range of 3-6 ppm/° C., a dielectric constant that is less than 5 and a Quality factor Q of at least 400. The glass-ceramic consists essentially of SiO2 in a range of 45-58 wt %, Al2O3 in a range of 10-18 wt % and MgO in a range of 10-25 wt %. A method of making the glass-ceramic is also provided. Further, an electronic package is also provided, including a base member and a glass-ceramic substrate bonded to the base member.

Abstract: The invention is directed to highly crystalline, frit-sintered glass-ceramic compositions having a coefficient of thermal expansion in the range of 85-115×10?7° C. The primary crystal phases of the glass-ceramics of the invention possess a cyclosilicate structure. The glass-ceramic of the invention are useful as metal-to-metal, metal-to-ceramic and ceramic-to-ceramic sealing agents, and also as high-performance coating for metals and ceramics.

Abstract: A glass-ceramic composition contains first ceramic particles principally containing forsterite; second ceramic particles principally containing at least one selected from the group consisting of calcium titanate, strontium titanate, and titanium oxide; and borosilicate glass particles containing about 3% to 15% lithium oxide, about 20% to 50% magnesium oxide, about 15% to 30% boron oxide, about 10% to 45% silicon oxide, about 6% to 20% zinc oxide, 0% to about 15% aluminum oxide, and at least one additive selected from the group consisting of calcium oxide, barium oxide, and strontium oxide on a weight basis. The content of the borosilicate glass particles is about 3% or more; the lower limit of the content of the additive is about 2%; and the upper limit of the additive content is about 15%, about 25%, or about 25% when the additive is calcium oxide, barium oxide, or strontium oxide, respectively, on a weight basis.

Abstract: Provided is a crystallized glass spacer for a field emission display resistant to charging with application of an electric field and resistant to chipping or cracking thanks to high fracture toughness. An SiO2—TiO2-based glass is subjected to a reduction and crystallization heat treatment at 600-900° C. in a hydrogen atmosphere or in a mixed atmosphere of hydrogen and nitrogen, to obtain a crystallized glass spacer for FED consisting essentially of, in molar percentage, SiO2: 20-50%, TiO2: 25-45%, MgO+CaO+SrO+BaO+ZnO: 20-50%, B2O3+Al2O3: 0-10% and ZrO2: 0-10%, and containing as a principal crystal at least one crystal selected from BaXTi8O16-based crystals (X=0.8-1.5), Ba2TiSi2O8-based crystals and TiO2-based crystals.

Abstract: The invention is directed to highly crystalline, frit-sintered glass-ceramic materials and seals made using them that are suitable for solid oxide fuel cell applications. The seals have a coefficient of thermal expansion in the range of 70-130×10?7° C., preferably 85-115×10?7° C. The glass-ceramic materials have a crystalline component and a glass component, the crystalline component being >50% of the glass-ceramic and the glass component being <50%. In one preferred embodiment the crystalline component is >75%. Regarding the crystalline component only, >50% of the crystals in the crystalline component of the glass-ceramic has a structure selected from the structural groups represented by walstromite, cyclowollastonite, ?-(Ca,Sr)SiO3, kalsilite, kaliophilite and wollastonite (the primary crystalline phase) and the remaining <50% of the crystalline component is at least one secondary crystalline phase.

Abstract: An insulating ceramic composition forming insulating ceramic layers (3) stacked in a multilayer ceramic substrate (2) used in a monolithic ceramic electronic component, such as a multilayer ceramic module (1). The insulating ceramic composition contains a first ceramic powder mainly containing forsterite, a second ceramic powder mainly containing at least one compound selected from the group consisting of CaTiO3, SrTiO3, and TiO2, and a borosilicate glass powder. The borosilicate glass powder contains 3 to 15 percent by weight of lithium in terms of Li2O, 30 to 50 percent by weight of magnesium in terms of MgO, 15 to 30 percent by weight of boron in terms of B2O3, 10 to 35 percent by weight of silicon in terms of SiO2, 6 to 20 percent by weight of zinc in terms of ZnO, and 0 to 15 percent by weight of aluminum in terms of Al2O3. The insulating ceramic composition can be fired at a temperature of 1000° C.

Abstract: The present invention relates to: novel glass-ceramics of ?-quartz and/or of ?-spodumene; articles made from said novel glass-ceramics; and ithium alumino-silicate glasses, which are precursors of said novel glass-ceramics; methods of preparing said novel glass-ceramics and articles made from said novel glass-ceramics. The present invention relates to the use of SnO2 and of Br, as an agent for fining the glass-ceramic glass precursor.

Abstract: Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength.

Abstract: Nanoscale particles, particle coatings/particle arrays and corresponding consolidated materials are described based on an ability to vary the composition involving a wide range of metal and/or metalloid elements and corresponding compositions. In particular, metalloid oxides and metal-metalloid compositions are described in the form of improved nanoscale particles and coatings formed from the nanoscale particles. Compositions comprising rare earth metals and dopants/additives with rare earth metals are described. Complex compositions with a range of host compositions and dopants/additives can be formed using the approaches described herein. The particle coating can take the form of particle arrays that range from collections of disbursable primary particles to fused networks of primary particles forming channels that reflect the nanoscale of the primary particles. Suitable materials for optical applications are described along with some optical devices of interest.

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 bioactive glass having a composition substantially comprising 20 to 40 mol % of CaO, 40 to 60 mol % of SiO2, and 10 to 20 mol % of MgO is high in bioactivity and mechanical strength, and a sintered calcium phosphate glass using the bioactive glass as a sintering aid is excellent in biocompatibility and mechanical strength.

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: A dielectric ceramic obtained by firing a raw material comprising an alumina powder, a crystallizable glass powder mainly containing SiO2, CaO and MgO, and a noncrystallizable glass powder mainly containing SiO2, B2O3 and Na2O. After the firing, the dielectric ceramic contains an alumina crystal phase, a diopside crystal phase (Ca(Mg, Al)(Si, Al)2O6) and a magnesia-spinel crystal phase (MgAl2O4) and has a porosity of not higher than 2.2% when measured by a mercury penetration method.