Abstract: A transparent sintered yttrium aluminum garnet ceramic material formed from a solid-state reaction of a mixture of yttrium oxide powder and aluminum oxide powder during sintering. The ceramic material preferably has an in-line transmission of greater than 75% so it may used to fabricate arc tubes for high intensity discharge lamps used in automotive headlamps.

Abstract: A transparent sintered yttrium aluminum garnet ceramic material formed from a solid-state reaction of a mixture of yttrium oxide powder and aluminum oxide powder during sintering. The ceramic material preferably has an in-line transmission of greater than 75% so it may used to fabricate arc tubes for high intensity discharge lamps used in automotive headlamps.

Abstract: 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.

Abstract: A method of manufacturing a transparent sintered ceramic material, comprising the steps of combining amounts of yttrium oxide powder with aluminum oxide powder, forming the mixture into a desired shape, and sintering the oxide powder mixture. Combining the amounts of yttrium oxide powder with aluminum oxide powder forms an oxide powder mixture. The yttrium oxide powder has a particle surface area of about 9 m2 per gram to about 36 m2 per gram and the aluminum oxide powder has a particle surface area of about 3 m2 per gram to about 30 m2 per gram. Sintering the oxide powder mixture forms yttrium aluminum garnet ceramic.

Abstract: A composition for making a transparent sintered yttrium aluminum garnet ceramic material wherein the composition includes an amount of yttrium oxide powder and aluminum oxide powder. The yttrium oxide powder has a particle surface area of about 18 m2 per gram and the aluminum oxide powder has a surface area of about 10 m2 per gram. The mixture is doped with a Si containing compound and Mg-containing compound, and formed into a desired shape. The mixture in the formed shape is converted to yttrium aluminum garnet during a sintering schedule to form a transparent ceramic material having an in-line transmission of at least 50%.