Abstract: A method of making an HID lamp and an HID lamp that includes a ceramic envelope with a ceramic capillary, wherein the capillary has an electrode feed-through therein that is sealed inside the capillary by a frit seal that extends inside the capillary a first distance from a distal end of the capillary, and a ceramic heat sink around at least half an external diameter of the capillary, wherein the heat sink is separated from the envelope and from the distal end of the capillary and the heat sink is in thermally conductive contact with the capillary and has an external diameter at least 1.5 times the external diameter of the capillary. In one preferred embodiment, the heat sink does not overlap the frit seal.

Abstract: A method of making an HID lamp and an HID lamp that includes a ceramic envelope with a ceramic capillary, wherein the capillary has an electrode feed-through therein that is sealed inside the capillary by a frit seal that extends inside the capillary a first distance from a distal end of the capillary, and a ceramic heat sink around at least half an external diameter of the capillary, wherein the heat sink is separated from the envelope and from the distal end of the capillary and the heat sink is in thermally conductive contact with the capillary and has an external diameter at least 1.5 times the external diameter of the capillary. In one preferred embodiment, the heat sink does not overlap the frit seal.

Abstract: A method of forming hollow bodies of ceramic material suitable for use as the discharge vessels of high intensity discharge lamps includes forming a fugitive core of substantially pure graphite having a configuration matching the interior configuration of the hollow body. A flowable powder, including binders, of the ceramic material is formed and added to fill the annular space between a flexible elastomeric mold defining the outer contour and the fugitive core defining the inner contour. The ceramic powder is isostatically compressed in the mold about the core to form a sub-assembly. The sub-assembly is removed from the mold, heated at a rate and time and in a suitable atmosphere to volatilize the fugitive core, and subsequently the sub-assembly is sintered to form the hollow body.

Abstract: An arc robe for a discharge lamp comprises a hollow body containing an arc generating and sustaining medium. The body has oppositely disposed ends each containing an electrode sealed therein by a seal associated with the ends. At least one of the ends has a heat shield thereabout, the heat shield comprising a metal foil wrapped about the end and being fixed to the seal. The metal foil is preferably nickel having a thickness of from about 0.0254 mm to 0.127 mm.

Abstract: A sintered, translucent ceramic article comprises alpha alumina and up to 0.050 wgt. percent magnesia and between 0.001 to 0.100 wgt. percent lutetium oxide. In a preferred embodiment, the lutetium oxide is at 0.050 wgt. percent and in a second preferred embodiment half the lutetium oxide is replaced by yttrium oxide. A method of making a translucent ceramic article comprises the steps of: forming an aqueous slurry to yield one of the composition described above; adding nitric acid to adjust the pH to 4.6; adding an aqueous binder and plasticizer in the amount of 2.5 solids wgt. percent; spray-drying the slurry; forming an article by wet-bag isopressing; prefiring said article in air at about 1325.degree. C. for about 2 hours; and sintering said air-fired article in hydrogen for about 3 hours at 1800.degree. C.

Abstract: A sintered, translucent ceramic article comprises alpha alumina and up to 0.050 wgt. percent magnesia and between 0.001 to 0.100 wgt. percent lutetium oxide. In a preferred embodiment, the lutetium oxide is at 0.050 wgt. percent and in a second preferred embodiment half the lutetium oxide is replaced by yttrium oxide. A method of making a translucent ceramic article comprises the steps of: forming an aqueous slurry to yield one of the composition described above; adding nitric acid to adjust the pH to 4.6; adding an aqueous binder and plasticizer in the amount of 2.5 solids wgt. percent; spray-drying the slurry; forming an article by wet-bag isopressing; prefiring said article in air at about 1325.degree. C. for about 2 hours; and sintering said air-fired article in hydrogen for about 3 hours at 1800.degree. C.