Abstract: A polycrystalline 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.

Abstract: A polycrystalline 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.

Abstract: A polycrystalline body comprising aluminum oxide, magnesium oxide, hafnium oxide, and yttrium oxide in which alumina grains have an average size of at least 10 ?m 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.

Abstract: Discharge tubes for a lamp include a body portion with a first end, a second end, and a tubular member defining an interior area. The tubular member extends along an elongated axis between the first end and the second end. The discharge tube further includes a first end portion provided at the first end of the body portion. The first end portion includes a first tubular extension having a first through passage in communication with the interior area. The first end portion further includes a first transition section connected between the first tubular extension and the body portion.

Abstract: Discharge tubes for a lamp include a body portion with a first end, a second end, and a tubular member defining an interior area. The tubular member extends along an elongated axis between the first end and the second end. The discharge tube further includes a first end portion provided at the first end of the body portion. The first end portion includes a first tubular extension having a first through passage in communication with the interior area. The first end portion further includes a first transition section connected between the first tubular extension and the body portion.

Abstract: A foil interface suited to interconnection of an electrode (18, 20) with an outer connector (24, 26) of a lamp includes a first electrically conductive connector (18, 20, 24, 26) includes a shank portion (46) and terminating in a shelf (48). A region (60) of progressively decreasing thickness is intermediate the shank portion and the shelf. An electrically conductive foil connector (28, 30) is mounted to the shelf adjacent a first end (70) of the foil connector.

Abstract: Discharge tubes for a lamp include a body portion with a first end, a second end, and a tubular member defining an interior area. The tubular member extends along an elongated axis between the first end and the second end. The discharge tube further includes a first end portion provided at the first end of the body portion. The first end portion includes a first tubular extension having a first through passage in communication with the interior area. The first end portion further includes a first transition section connected between the first tubular extension and the body portion.

Abstract: Discharge tubes for a lamp include a body portion with a first end, a second end, and a tubular member defining an interior area. The tubular member extends along an elongated axis between the first end and the second end. The discharge tube includes a first end portion provided at the first end of the body portion. The first end portion includes a first tapered portion that is tapered in a direction extending substantially perpendicular from the elongated axis. The first tapered portion includes an interior surface facing the interior area. The tapered portion spans between a maximum extent in the direction of the elongated axis and a minimum extent in the direction of the elongated axis.

Abstract: Discharge tubes for a lamp include a body portion with a first end, a second end, and a tubular member defining an interior area. The tubular member extends along an elongated axis between the first end and the second end. The discharge tube further includes a first end portion provided at the first end of the body portion. The first end portion includes a first tubular extension having a first through passage in communication with the interior area. The first end portion further includes a first transition section connected between the first tubular extension and the body portion.

Abstract: Discharge tubes for a lamp include a body portion with a first end, a second end, and a tubular member defining an interior area. The tubular member extends along an elongated axis between the first end and the second end. The discharge tube includes a first end portion provided at the first end of the body portion. The first end portion includes a first tapered portion that is tapered in a direction extending substantially perpendicular from the elongated axis. The first tapered portion includes an interior surface facing the interior area. The tapered portion spans between a maximum extent in the direction of the elongated axis and a minimum extent in the direction of the elongated axis.

Abstract: 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).

Abstract: An arc discharge lamp comprising an arc tube including a starting aid is provided. The starting aid comprises at least one prealloyed powder bound to the surface of the arc tube.

Abstract: An arc discharge lamp comprising an arc tube including a starting aid is described. The starting aid comprises at least one metal cermet coating applied to the surface of the arc tube, or a metal layer including refractory glass disposed over said cermet coating or said metal layer.

Abstract: An arc discharge lamp comprising an arc tube comprising a starting aid is provided. The starting aid comprises a coating on the surface of the arc tube. The coating is comprised of metal oxide, nitride, carbide, silicide, and mixtures thereof.

Abstract: An improved method of applying a particulate material to a substrate, includes the steps of: removing impurities from a surface of the substrate; forming a coating composition having a bonding material and at least one particulate material; applying the coating composition to the substrate surface; and creating a diffusion bond between the substrate, bonding material and particulate material for generating a continuous interface between the substrate surface and particulate material such that the change in mechanical properties between the substrate and particulate material occurs in a direction normal to the plane of the substrate surface, thereby minimizing residual strain and coefficient of thermal expansion mismatch between the substrate and particulate material, the surfaces of individual particles of said particulate material being chemically wetted by the bonding material. The particulate material and the bonding material comprise a layer on the substrate surface.