Abstract: Disclosed is a sintered ceramic body having a composition comprising (i) Si.sub.3 N.sub.4, (ii) a combination of an oxide of an element of the group IIIa of the Periodic Table having an ionic radius smaller than 0.97 .ANG. and an oxide of other element of the group IIIa of the Periodic Table, having an ionic radius larger than 0.97.degree. and (iii) an oxide or nitride of at least one of the following: (1) at least one element of group IIa of the Periodic Table; (2) Al; (3) Ti; (4) Cr; (5) Ga; (6) Zr; and (7) Si. This sintered silicon nitride body shows a high oxidation resistance when it is used for a long time at high temperatures, and the sintered body is excellent in the creep characteristics and flexural strength at high temperatures.

Abstract: Dental materials using calcium phosphate glass-ceramics and having the color tone with high approximation to that of natural teeth. In those dental materials, calcium phosphate composite, nickel oxide and one or more other type of compounds selected from oxides of iron, manganese, cerium, titanium and tungsten, are contained as coloring component. Also, if necessary, Al.sub.2 O.sub.3 and/or SiO.sub.2 is contained as a color assisting agent in that composite. The calcium phosphate glass-ceramic according to this invention consists of the same components as that of natural teeth. Besides, it is possible to adjust the color tone delicately to match with the color tone of each individual`s teeth. Moreover, the coloring components are incorporated in crystals of calcium phosphate. Consequently, they cause no elution during use and are therefore ideal as dental material.

Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is at least either of magnesium and zinc and where k and x are numerals in the ranges of 1.00 to 1.04 and of 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of lithium oxide, silicon dioxide, and, possibly, at least one of barium oxide, calcium oxide, and strontium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dilectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (typically from 1050.degree. to 1200.degree. C.

Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is one or more of magnesium, zinc, strontium, and calcium, and where k, and x are numerals in the ranges of 1.00 to 1.04, and 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of boron oxide, silicon dioxide, and, possibly, at least one of barium oxide, magnesium oxide, zinc oxide, strontium oxide, and calcium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided from are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere.

Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is one or more of magnesium, zinc, strontium, and calcium, and where k, and x are numerals in the ranges of 1.00 to 1.04, and 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of boron oxide and at least one of barium oxide, magnesium oxide, zinc oxide, strontium oxide, and calcium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (typically from 1050.degree. to 1200.

Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x-y M.sub.x L.sub.y O.sub.k TiO.sub.2, where M is at least either of mag-nesium and zinc, L is at least either of strontium and calcium, k, x and y are numerals in the ranges of 1.00 to 1.04, 0.002 to 0.049, and 0.001 to 0.048, respectively, and x+y is a value in the range of 0.02 to 0.05. To this major ingredient is added a minor proportion of a mixture of lithium oxide, silicon dioxide, and, possibly, at least one of barium oxide, calcium oxide, and strontium oxide.

Abstract: A liquid transfer ball formed from sintered zirconium oxide particles which exhibits utility as the ball element of a ball pen writing instrument to transfer ink from an ink reservoir to a writing surface such as paper. The ball exhibits a porosity of less than 8% by volume and is immune to corrosive action of inks.

Abstract: A refractory fiber composition and method for making refractory fiber from the composition. The refractory fiber composition includes kaolin clay as a source of alumina and silica to which is added zircon.

Abstract: A sealing composition suitable for sealing alumina packages for integrated circuits at a temperature below about 450.degree. C. for a short time of about 10 minutes. The composition is a mixture of 50-80 wt % vitreous solder glass powder of PbO-B.sub.2 O.sub.3 system having a deformation point of 350.degree. C. or less, 1-35 wt % zinc material powder and 1-35 wt % zircon powder. The zircon powder is of a synthetic zircon artificially prepared to eliminate radioactive impurities such as uranium and/or thorium.

Abstract: A process for the preparation of silicon nitride powders, which are suitable for the manufacture of high quality structural ceramics is described. The synthesis process is based on the reduction of silicon dioxide by carbon in a nitrogen stream at elevated temperatures to form alpha silicon nitride. Silicon nitride powders of various morphologies are obtained by this technique by varying either the type of reactants used or the process conditions. Structural ceramics with densities exceeding 99% of theoretical and having satisfactory mechanical strength and oxidation resistance were sintered from powders synthesized by the method of this invention.

Abstract: A glass glazing is provided with a coating of a colored enamel composition along one or more edges. The enamel composition includes a vitreous matrix pigment and from 2 to 5% by weight of powdered tin dioxide which preferably is an additive during a comminution step. The vitreous matrix which represents at least 75% by weight of the enamel composition includes the following constituentsSiO: 25-33 (% by weight)PbO: 47-65B.sub.2 O.sub.3 : 3-7Na.sub.2 O: 1-4K.sub.2 O: 0-2Li.sub.2 O: 0-0.8ZnO: 0.2-0.5and provides a molar ratio of SiO.sub.2 to PbO between 1.6 and 2.7. The total content of the alkaline oxide are less than 5% by weight.The linear thermal expansion coefficient of the vitreous matrix is less than the glazing to be coated.

Abstract: A process for making a homogeneous melt for producing mineral wool insulation. This insulating material is made from waste products namely, bottom ash, cement kiln dust, slag, and waste from mineral wool production. These materials, along with a binder, are homogenized into a mixture. Thereafter, the process includes briquetting the mixture into agglomerated pieces. The agglomerates are then melted in a cupola furnace and the molten agglomerate is discharged into a receiver. Hot combustion gases are then passed into the melt or molten agglomerate to chemically homogenize the melt and heat the melt to a preselected temperature. Thereafter, the melt is converted into fibers using conventional practices.

Abstract: This invention relates to ceramic high dielectric composition with BaTiO.sub.3 as host component; and by containing 1-5 weight part of CaTiO.sub.3 and 2-3 weight parts of Ta.sub.2 O.sub.5 to 100 weight parts of the BaTiO.sub.3, a composition having dielectric constant of 3000 or above, a small voltage dependency, a large bending strength and good high frequency characteristic is provided; and it has a good characteristic when used as thin film type dielectric body like laminated ceramic capacitor.

Abstract: Glass fibers having the following constituents in the ranges of proportions indicated: SiO.sub.2, 57-70 wt. %; Al.sub.2 O.sub.3, 2-7 wt. %; CaO, 5-10 wt. %; MgO, 0-4 wt. %; B.sub.2 O.sub.3, 0-4.5 wt. %; and F, 0.5-4 wt. %; and wherein B.sub.2 O.sub.3 and F are present in amounts according to the relationship:3.ltoreq.B.sub.2 O.sub.3 +1.5 F.ltoreq.6.5and wherein the fibers also contain the alkali oxides Na.sub.2 O and K.sub.2 O, in amounts according to the relationship:16 wt. %<Na.sub.2 O+K.sub.2 O<20 wt. %.The glass fibers are used advantageously in thermal and/or acoustic insulation.

Abstract: A ceramic heater of the present invention comprises a sintered heating element bonded to a supporting substrate or a sintered element alone. A sintered body comprises the heating element is mainly composed of silicon nitride with such sintering agents as yttrium oxide to be superior in strength, thermal shock resistance and thermal resistance. The sintered body also includes 10-80 mol % of titanium carbide, titanium nitride or a mixture thereof which are electrically conductive ceramics so that the specific electrical resistance can be controlled.A method for producing a ceramic heater of the present invention consists of the first process in which a powdery mixture is prepared by mixing powders which are made to have structures of a solid solution by previous calcination of silicon nitride and a sintering agent and powders of conductive ceramics which comprise either or both of titanium carbide and titanium nitride, and the second process in which such powdery mixture is formed and sintered by heating.

Abstract: A selenium-base chalcogenide glass for use as optical fibers suitable for transmitting with low loss infrared rays, particularly that of 10.6 .mu.m in wavelength, is provided. The infrared optical fibers with low transmission loss, which is suitable for practical use, are obtained by incorporating 2 to 100 ppm of at least one of Al Ga, and In into a selenium-base chalcogenide glass, thereby to reduce the absorption due to the vibration of Ge--O bond formed by the contamination with oxygen. The infrared optical fibers made of such a glass material show a transmission loss of 3-4 dB/m which is less than 1/2.5 of the loss (10 dB/m) of a reference glass.

Abstract: SiO.sub.2 /MeO metallic silicates, wherein Me is lead or an alkaline earth metal, have a molar ratio of SiO.sub.2 to MeO of greater than 2, and same are well suited as pigments, fillers, and especially as glass-formers.

Abstract: A silicon nitride powder having an enhanced sintering activity is prepared by heating a mixture of a nitrogen-containing silane compound and a sintering aid in a non-oxidizing atmosphere.

Abstract: A fiber-free refractory coating composition consisting essentially of an aluminosilicate mineral selected from the group consisting of kyanite, andalusite, and sillimanite; alumina; colloidal silica; and water. This mixture is characterized by good adhesion to substrate material, and excellent resistance to thermal shock and chemical attack through a wide range of firing temperatures up to 3000.degree. F.

Abstract: A ceramic composition capable of sintering at a sufficiently low temperature to enable the use of a low cost base metal as the electrode material in the fabrication of capacitors. The major ingredient of the composition is expressed as Ba.sub.k-x M.sub.x O.sub.k TiO.sub.2, where M is at least either of magnesium and zinc and where k and x are numerals in the ranges of 1.00 to 1.04 and of 0.02 to 0.05, respectively. To this major ingredient is added a minor proportion of a mixture of lithium oxide, silicon dioxide, and, possibly, at least one of barium oxide, calcium oxide, and strontium oxide. For the fabrication of coherently bonded bodies of this composition, as for use as the dielectric bodies of capacitors, the moldings of the mixture of the major ingredient and additive in finely divided form are sintered in a reductive or neutral atmosphere and then reheated at a lower temperature in an oxidative atmosphere. The sintering temperature can be so low (typically from 1050.degree. to 1200.degree. C.