摘要:
A polycrystallinc body comprising aluminum oxide, magnesium oxide, hafnium oxide, and yttrium oxide in which alumina grains have an average size of at least lOµm and wherein the yttrium oxide is present in an amount of at least 6 ppm of the weight of the ceramic body, and the magnesium and hafnium oxides are present at a molar ratio of about 0.5: 1 to about 3: 1.
摘要:
A polycrystalline alumina body includes aluminum oxide, magnesium oxide, zirconium oxide, and lutetium oxide. The lutetium oxide is present in an amount of at least 10 ppm of the weight of the ceramic body, and the magnesium and zirconium oxides are present at a molar ratio of from 0.5:1 to 3:1.
摘要:
A polycrystalline alumina transparent ceramic is provided. The optical axis of whole or parts crystal grain in the polycrystalline alumina transparent ceramic arrange along the same orientation and thus the polycrystalline alumina transparent ceramic has a certain property of optimized orientation.
摘要:
An arc tube in a high intensity discharge lamp comprises an arc body comprising a single-phase first ceramic material has a first elemental composition, and the arc body has a sealed chamber. At least two legs are attached to the arc body, and at least one of the legs has a single-phase second ceramic material having a second elemental composition that is different from the first elemental composition. An electrode is positioned within a respective leg, each electrode has a tip positioned within the chamber and the tips of the electrodes are spaced apart forming an arc region there between.
摘要:
The present invention relates to a method of manufacturing a transparent polycrystalline aluminum oxynitride. Aluminum oxynitride manufactured by prior art methods has a great number of porosities therein and thus has low transparency. The present invention is directed to solving such a problem. In the method of manufacturing aluminum oxynitride of the present invention, a sintering additive added to a source powder includes less than 0.5wt.% MgO. Further, the source powder is presintered at 1550 °C to 1750 °C so that a relative density becomes 95% or more and is then resintered at 1900 °C or more so that a relative density higher than that of presintering can be accomplished. According to the present invention, a cubic-phased polycrystalline aluminum oxynitride ceramic can be obtained, wherein porosities therein are nearly eliminated and its substantial transparency becomes 95% or more.
摘要:
A first inorganic powder molded body 1A and a second inorganic powder molded body 1B are obtained. Each of the bodies contains an inorganic powder, an organic dispersion medium having a reactive functional group and a gelling agent and is solidified by chemical reaction of the organic dispersion medium and the gelling agent. Slurry 5A containing a powder component and an organic dispersion medium is applied to a joint surface 4A of the first inorganic powder molded body 1A. The inorganic powder molded bodies 1A and 1B are allowed to abut on each other while interposing the slurry 5A therebetween, and integrated together into a joined body. A sintered body is obtained by sintering the joined body.
摘要:
A method for preparing a polycrystalline transparent alumina sintered article, which comprises admixing an alumina having a purity of 99.9 % or higher with MgO in the range of 0.002 to 0.010 wt % and La2O3 in the range of 0.005 to 0.020 wt % in a manner such that the sum of MgO and La2O3 is 0.030 wt % or less and the relationship: 0.2
摘要翻译:一种多晶透明氧化铝烧结体的制造方法,其特征在于,将纯度为99.9%以上的氧化铝与0.002〜0.010重量%的MgO和0.005〜0.020重量%的La2O3以0.005〜0.020重量%的比例混合, MgO和La 2 O 3的总和为0.030重量%以下,并且满足关系:0.2 <= MgO / La 2 O 3 <= 0.5,在900〜1200℃下煅烧所得混合物,对煅烧产物进行滑移浇铸, 产物进行螯合处理,并在1650〜1900℃的还原气氛中将螯合物保持1小时以上,从而在常压下进行烧成。 通过该方法制备的多晶透明氧化铝烧结体在用于高压放电块的发光壳体中的烧结助剂的种类和用量方面进行了优化。
摘要:
A method for forming single element arc tubes is provided. The method includes the use of the lost foam process in combination with ceramic forming processes. First, a polymeric material (20) is formed to define the internal dimensions. The outer dimensions are established with an external mold (40), followed by filling the mold with a suspension (60) that hardens. The outer mold is removed and the part is debindered to melt and remove the inner foam shape, followed by sintering to form a substantially transparent ceramic arc tube (70).
摘要:
An apparatus (10) for the development of transparent alumina ceramics using microwave energy at the frequency between 0.915 and 2.45 GHz inclusive in hydrogen atmosphere at ambient pressure comprises an enclosed, insulated chamber (14) to retain a workpiece (12) for the application of microwave energy. The chamber comprises a TE 103 single mode or a multimode microwave cavity into which is mounted a quartz tube (18). An insulation material (20), transparent to microwave energy, is positioned within the quartz tube. A port (28) for the introduction of hydrogen penetrates the cavity so that the microwave sintering of the workpiece is performed in an ultra-pure hydrogen atmosphere. The workpiece is preferably mounted on a refractory ceramic such as alumina tube for the microwave sintering process. A method, preferably using the apparatus, develops transparent alumina ceramics and single crystal sapphire.
摘要:
A method for forming single element arc tubes is provided. The method includes the use of the lost foam process in combination with ceramic forming processes. First, a polymeric material (20) is formed to define the internal dimensions. The outer dimensions are established with an external mold (40), followed by filling the mold with a suspension (60) that hardens. The outer mold is removed and the part is debindered to melt and remove the inner foam shape, followed by sintering to form a substantially transparent ceramic arc tube (70).