摘要:
Compositions, articles and methods for making such articles are disclosed. The compositions, articles and methods include calcium aluminate materials having a low coefficient of thermal expansion.
摘要:
Rare-earth alloy is cast into a sheet (6) or the like by using a tundish (3, 13). The refractory material of the tundish used for casting does not necessitate preheating for improving the flowability of the melt (2). The refractory material used essentially consists of 70 wt % or more of Al2O3 and 30 wt % or less of SiO2, or 70 wt % or more of ZrO2 and 30 wt % or less of one or more of Y2O3, Ce2O3, CaO, MgO, Al2O3, TiO2 and SiO2. The refractory material has 1 g/cm3 or less of bulk density, has 0.5 kca/(mhnull C.) or less of thermal conductivity in the temperature range of from 1200 to 1400null C., and has 0.5 wt % or less of ratio of ignition weight-loss under the heating condition of 1400null C. for 1 hour.
摘要翻译:通过使用中间包(3,13)将稀土合金铸造成板(6)等。 用于铸造的中间包的耐火材料不需要预热以改善熔体(2)的流动性。 使用的耐火材料主要由70重量%以上的Al 2 O 3和30重量%以下的SiO 2,或70重量%以上的ZrO 2和30重量%以下的Y 2 O 3,Ce 2 O 3,CaO,MgO, Al2O3,TiO2和SiO2。 难熔材料的堆积密度为1g / cm 3以下,在1200〜1400℃的温度范围内具有0.5kcal /(mh℃)以下的导热性,并且在0.5〜 在1400℃的加热条件下点火重量损失比1小时。
摘要:
A creep-resistant and chemical-resistant ceramic refractory composition includes a mixed oxide of the general formula R3Al5O12 where R is at least one of Dy, Ho, Y, Er, Tm, Yb, and Lu, the mixed oxide having a garnet structure and comprising in solid solution at least one dopant of a transition metal element and a rare-earth element, which effects in the composition enhanced optical emission in at least one spectral range.
摘要:
A method of manufacturing a phosphate-bonded refractory product entirely during the mixing cycle by reacting phosphoric acid and alumina derived from one or more sources of finely divided reactive alumina, for example null-alumina and/or alumina hydroxide to form a proto aluminum orthophosphate gel or paste binder in the pan of a high-intensity mixer at ambient temperatures.
摘要:
A ceramic polycrystal and a method of manufacturing such a ceramic polycrystal having thermal stability enough to be used in an arc tube are provided. The ceramic polycrystal has crystalline particles. Each of crystalline particles has a crystalline structure selected from triclinc, monoclinic, rhombi, tetragonal, trigonal, and hexagonal systems, with an average grain size being not less than 5 nullm and a linear transmittance being not less than 8%.
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:
Ceramic oxide pre-forms comprising substantially continuous, alpha alumina fibers, and methods for making the same. The ceramic oxide pre-forms are useful, for example, as in making metal matrix composites reinforced with substantially continuous, alpha alumina fibers.
摘要:
A method of manufacturing oriented sintered ceramic product which enables to manufacture an oriented sintered product with an average crystal grain size of 20 nullm or less and a grain width 0.4 times or less of the grain size, or an oriented sintered product with an average crystal grain size of 20 nullm or more and a grain width 0.5 times or more of the grain size with no grain growth of plate-like seed crystals, the method comprising dispersing a non-ferromagnetic powder having a not-cubic crystal structure into a slurry, consolidating the slurry under a magnetic field and sintering the molding product.
摘要:
A ceramic article which consists essentially, by weight on the oxide basis, of 10-25% SiO2, 65-85% Al2O3, and 2-12% Li2O and comprises beta-eucryptite as a first phase having a negative component in thermal expansion and a melting point Tm1, and a second phase having a positive component in thermal expansion which is higher than the component in thermal expansion of the first phase and a melting point Tm2, wherein Tm2>Tm1, wherein the first phase is at most 50% by weight of the ceramic, and wherein the ceramic is characterized by microcracking. Tm2 is at least 1800null C. The ceramic article exhibits a near zero coefficient of thermal expansion from room temperature to 800null C., a high refractoriness, and a high resistance to thermal shock properties which make the inventive ceramic extremely desirable in high temperature applications, such as filters for diesel exhaust engines.