摘要:
A moving bed filtration process for the production of sphere based crystals is disclosed. Sphere based crystals having an opal-like structure or an inverse opal-like structure can be produced in accordance with the invention.
摘要:
Acicular bodies of a metal compound are produced by slowly precipitating an organic salt of the metal from a solution of an ester of a dicarboxylic acid having 1-5 carbon atoms and firing the precipitate in an oxidizing atmosphere. These acicular bodies have a cross-sectional dimension less than about 20 nullm and are useful for providing reinforcement of a larger ceramic body. Acicular bodies of rare-earth metal oxides also are useful in reinforcing x-ray scintillator bodies without diminishing their luminescent capacity.
摘要:
A ceramic article resulting from a chemical interaction between a particulate ceramic material and a ceramic matrix material is described. The ceramic matrix results from at least partial chemical transformation of a precursor material. A chemical bond between the ceramic matrix and the particulate ceramic material is developed during manufacture. The configuration of the ceramic article is developed through use of a rapid prototyping process. A ceramic article comprising different compositions in two or more regions of the article is described. A manufacturing process comprising the steps employed to produce such a ceramic article is also described. The ceramic article described herein is particularly suited for use as a mold for metal casting. The manufacturing process disclosed herein enables production of such a mold within a matter of hours, rather than days, as required by prior art casting technologies.
摘要:
Doped, pyrogenically prepared oxides of metals and/or non-metals which are doped with one or more doping components in an amount of 0.00001 to 20 wt. %. The doping component may be a metal and/or non-metal or an oxide and/or a salt of a metal and/or a non-metal. The BET surface area of the doped oxide may be between 5 and 600 m2/g. The doped pyrogenically prepared oxides of metals and/or non-metals are prepared by adding an aerosol which contains an aqueous solution of a metal and/or non-metal to the gas mixture during the flame hydrolysis of vaporizable compounds of metals and/or non-metals.
摘要:
Ceramic mass and thermal transfer media suitable for use in thermal regenerative oxidizers made using a mixture of a ball clay, talc and optionally a dolomitic limestone have enhanced resistance to environments containing halogens and hydrogen halides. The media preferably comprises less than 0.25% by weight of alkali metal, expressed as the oxide, and has a cordierite: silica phase ratio of less than 1.2:1, as determined by X-ray diffraction.
摘要:
The present invention provides amorphous inorganic particles as a dental material comprising silica and inorganic oxide(s) other than silica and having high x-ray impermeability. The inorganic particles as a dental material comprise silica with the content in the range from 70 to 98 weight % and oxide(s) of one or more elements selected from the group consisting of Zr, Ti, La, Ba, Sr, Hf, Y, Zn, AL, and B, wherein 5 to 70 weight % of the silica is originated from an acidic silicic acid solution and 30 to 95 weight % of the silica is originated from a sol of silica. This inorganic particles as a dental material have average particle diameter in the range from 1 to 10 nullm, specific surface area in the range from 50 to 350 m2/g, pore volume in the range from 0.05 to 0.5 ml/g, amorphous crystallinity as observed by x-ray diffraction, and the refractive index in the range from 1.47 to 1.60.
摘要:
A method of making a permeable fiber-reinforced ceramic body comprising mixing an organic particulate with silica fiber, alumina fiber, alumina borosilicate fiber, a dispersant, and water to produce a slurry of fibrous ceramic material. The slurry is then placed within a mold and vaccuum pressure is applied thereto to substantially remove the water to form a fibrous ceramic body. The fibrous ceramic body is then dried and sintered to a temperature sufficient to bond the ceramic material together to form a porous ceramic article. Simultaneously, the fibrous ceramic body is heated to a temperature sufficient to generally burn off the organic particulate to create voids interconnecting the pores to form a permeable fiber reinforced porous ceramic article.
摘要:
Ceramics comprising filler crystal particles having an average particle diameter of not smaller than 2.5 nullm and a matrix crystal phase present on the grain boundaries of the filler crystal particles, the filler crystal particles being Al2O3 and the matrix crystal phase being diopside-type oxide crystals precipitated from the crystallized glass. The ceramics has a dielectric loss tangent at 60 to 77 GHz of not higher than 50null10null4, and can be effectively used as an insulating substrate in a wiring board for transmitting high-frequency signals.
摘要:
The present invention relates to a very high performance refractory article especially resistant to corrosion, and to a new process for the manufacture of such an article. In particular, the invention relates to an article made of crystalline silica having high density and capable of withstanding the corrosive atmosphere of a glassmaking furnace, notably an oxy-fuel fired furnace. This article includes at least 50% by weight of crystalline silica, not more than 1% by weight of residual quartz and not more than 0.4% by weight of titanium oxide, having an apparent density greater than or equal to 1.88 and a flux factor less than or equal to 0.75.
摘要:
A process is provided for forming a low k fluorine and carbon-containing silicon oxide dielectric material by reacting with an oxidizing agent one or more silanes including one or more organofluoro silanes characterized by the absence of aliphatic CnullH bonds. In one embodiment, the process is carried out using a mild oxidizing agent. Also provided is a low dielectric constant fluorine and carbon-containing silicon oxide dielectric material for use in an integrated circuit structure containing silicon atoms bonded to oxygen atoms, silicon atoms bonded to carbon atoms, and carbon atoms bonded to fluorine atoms, where the dielectric material is characterized by the absence of aliphatic CnullH bonds and where the dielectric material has a ratio of carbon atoms to silicon atoms of C:Si greater than about 1:3.