Sintered polycrystalline terbium aluminum garnet and use thereof in magneto-optical devices
    2.
    发明授权
    Sintered polycrystalline terbium aluminum garnet and use thereof in magneto-optical devices 失效
    烧结多晶铽铝石榴石及其在磁光装置中的应用

    公开(公告)号:US07592281B2

    公开(公告)日:2009-09-22

    申请号:US12210549

    申请日:2008-09-15

    IPC分类号: C04B35/50

    摘要: A composition is provided that includes a plurality of calcined particles of terbium aluminum oxide having a mean particle domain size of between 30 and 600 nanometers. A translucent article having a surface includes polycrystalline terbium aluminum garnet having a mean grain size from 1 to 10 microns and light scattering inclusions of aluminum-rich oxide and/or terbium-rich oxide that are present at less than 2 surface area percent of the surface. A process for forming such an article involves sintering the above provided composition at a temperature between 1500° C. and 1700° C. to yield a sintered article. The article has improved translucency and even transparency as sintering is performed under vacuum at a temperature between 1610° C. and 1680° C. Hot isostatic pressing alone or in combination with article polishing also improves article translucency.

    摘要翻译: 提供了一种组合物,其包括多个平均粒子域尺寸在30和600纳米之间的氧化铽的煅烧颗粒。 具有表面的半透明制品包括平均粒度为1至10微米的多晶铽铝石榴石和富含Al的氧化物和/或富含铽的氧化物的光散射夹杂物,其表面积小于2的表面积百分比 。 形成这种制品的方法包括在1500℃和1700℃之间的温度下烧结上述所提供的组合物,得到烧结制品。 该制品具有改善的半透明度和均匀的透明度,因为在1610℃和1680℃之间的温度下在真空下进行烧结。单独的热等静压或与制品抛光相结合也可改善制品半透明度。

    Transparent yttria ceramics and method for producing same

    公开(公告)号:US4166831A

    公开(公告)日:1979-09-04

    申请号:US884942

    申请日:1978-03-09

    IPC分类号: C04B35/505 H01J5/04 C04B35/50

    CPC分类号: C04B35/505 H01J5/04

    摘要: An article of manufacture is provided comprising a substantially transparent high density polycrystalline yttria-base body consisting essentially of yttria and from about 0.01 to 5 wt. % alumina.A method for preparing the transparent yttria doped with alumina is also provided comprising admixing alumina or a precursor thereof with yttria or a precursor thereof, drying the admixed powders, calcining the admixed powders and pressing the calcined powders into a desired shape and thereafter sintering the shaped powder for about 1/4 to six hours at a temperature above the eutectic temperature at a sufficiently low oxygen atmosphere to prevent oxidative contaminants.

    Niobium-ceramic feedthrough assembly and ductility-preserving sealing
process
    5.
    发明授权
    Niobium-ceramic feedthrough assembly and ductility-preserving sealing process 失效
    铌陶瓷馈通组件和延性保温密封工艺

    公开(公告)号:US5057048A

    公开(公告)日:1991-10-15

    申请号:US425072

    申请日:1989-10-23

    IPC分类号: H01J9/32 H01J61/36

    CPC分类号: H01J9/326 H01J61/368

    摘要: A process for sealing of niobium-ceramic through-wall assemblies for ceramic or metal vessels for high temperature and high pressure or vacuum applications, for example an electrical feedthrough and sealable fill opening in an alumina arc tube for a high intensity discharge (HID) lamp. The process produces a fritless hermetic seal while maintaining the ductility of the niobium components. The niobium-ceramic through-wall assembly includes an axially bored alumina or yttria sealing means having a ductile niobium throughpiece close fitted to and extending through the bore. The throughpiece is preferably essentially pure niobium, but may contain up to about 2% zirconium. The assembly is fired at about 1400.degree.-2000.degree. C. in a pure oxygen- and hydrogen-free (

    摘要翻译: 用于高温高压或真空应用的用于陶瓷或金属容器的铌 - 陶瓷通孔组件的密封方法,例如用于高强度放电(HID)灯的氧化铝弧管中的电馈通和可密封的填充开口 。 该工艺产生无油封密封,同时保持铌组分的延展性。 铌 - 陶瓷通孔组件包括轴向无孔氧化铝或氧化钇密封装置,其具有紧密地装配并延伸穿过孔的延性铌通孔。 通孔优选基本上是纯铌,但可含有高达约2%的锆。 该组件在约1400°-2000℃下以纯无氧和无氢(各自为<5ppm)惰性,优选流动的大气或真空中燃烧足以在通气和通气之间形成气密密封的时间 密封方式。 然后将烧制的组件冷却至低于250℃,同时保持纯惰性气氛或真空。 铌穿透件的端部在烧制后保持足够的延展性以允许夹紧端部。

    Dense alumina with a primary recrystallized polycrystalline structure
and crystal orientation
    6.
    发明授权
    Dense alumina with a primary recrystallized polycrystalline structure and crystal orientation 失效
    具有一次再结晶多晶结构和晶体取向的密集氧化铝

    公开(公告)号:US4323545A

    公开(公告)日:1982-04-06

    申请号:US768062

    申请日:1977-02-14

    IPC分类号: C04B35/111 C01F7/02

    CPC分类号: C04B35/111 Y10S264/91

    摘要: The invention is directed to a transparent alumina material and a method of preparing this material.The material is characterized as a dense primary recrystallized polycrystalline structure having a degree of preferred crystal orientation. The material is transparent to visible and infrared light and quantitative values are given.The transparent alumina covered by this invention is made by means of hot forging and an annealing process for powders or dense compacts of high-purity alumina.

    摘要翻译: 本发明涉及一种透明氧化铝材料及其制备方法。 该材料的特征在于具有优选晶体取向程度的致密的一次再结晶多晶结构。 材料对可见光和红外光透明,并给出定量值。 本发明覆盖的透明氧化铝是通过热锻造和用于高纯度氧化铝的粉末或致密压块的退火工艺制成的。

    Electric gas ignitor utilizing a fiber ignition element
    7.
    发明授权
    Electric gas ignitor utilizing a fiber ignition element 失效
    电气点火器利用纤维点火元件

    公开(公告)号:US4206492A

    公开(公告)日:1980-06-03

    申请号:US658447

    申请日:1976-02-17

    IPC分类号: F02B75/02 H01C3/00

    CPC分类号: H01C3/00 F02B2075/027

    摘要: An electric gas ignitor is disclosed having a gas igniting fiber comprising a core of conductive refractory material and an outer, high strength, oxidation resistant coating. One aspect of the invention concerns a primary current path defined by at least a portion of the fiber core and comprising a material having a highly uniform resistance per unit length. A substantially uniform temperature distribution is thereby promoted on the fiber surface and the formation of localized "hot spots" is inhibited. The primary current path is preferably an anisotropic material having a preferred crystal orientation which uniformly conducts electricity along the fiber length.A second aspect of the invention is directed to the inclusion of a diffusion-barrier material between the fiber core and the oxidation-resistant coating to prevent diffusion of the core and coating, which changes the fiber operating temperature and decreases its operating life. The diffusion-barrier material is preferably refractory, closely packed, dense and, more perferably, is an anisotropic material having its preferred crystal orientation in a direction which inhibits the diffusion while forming the primary current path of the fiber.

    摘要翻译: 公开了一种具有包含导电耐火材料芯和外部高强度抗氧化涂层的气体点燃纤维的电气点火器。 本发明的一个方面涉及由光纤芯的至少一部分限定的初级电流路径,并且包括每单位长度具有高均匀电阻的材料。 从而在纤维表面上促进了基本均匀的温度分布,并且抑制了局部“热点”的形成。 初级电流路径优选为具有沿纤维长度均匀导电的优选晶体取向的各向异性材料。 本发明的第二方面涉及在纤维芯和抗氧化涂层之间包含扩散阻挡材料,以防止芯和涂层的扩散,这改变了纤维的工作温度并降低了其使用寿命。 扩散阻挡材料优选是耐火的,紧密堆积的,致密的,并且更优选的是在形成纤维的初级电流路径的同时抑制扩散的方向上具有其优选的晶体取向的各向异性材料。

    Method of sintering translucent alumina
    10.
    发明授权
    Method of sintering translucent alumina 失效
    烧结半透明氧化铝的方法

    公开(公告)号:US4762655A

    公开(公告)日:1988-08-09

    申请号:US802414

    申请日:1985-11-27

    IPC分类号: C04B35/111 C04B35/10

    CPC分类号: C04B35/111 Y10S264/91

    摘要: An improved process for producing a translucent polycrystalline alumina body comprising sintering a prefired compacted green body of alumina of predetermined shape is disclosed. The green body of alumina includes alumina doped with one or more sintering aids. The method of the present invention comprises sintering the prefired compacted green body of predetermined shape at a maximum sintering temperature in an atmosphere containing nitrogen and an amount of hydrogen greater than or equal to about 2.5 volume percent and less than 75 volume percent for a period of time sufficient to produce a translucent polycrystalline alumina body.

    摘要翻译: 公开了一种用于制造半透明多晶氧化铝体的改进方法,其包括烧结预制的压缩的预定形状的氧化铝生坯体。 氧化铝的生坯体包括掺有一种或多种烧结助剂的氧化铝。 本发明的方法包括在包含氮气和大于或等于约2.5体积%且小于75体积%的氢气的量的最大烧结温度下烧结预定形状的预制压实生坯,持续一段时间 足以产生半透明的多晶氧化铝体。