The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 06, 1997
Filed:
Sep. 24, 1996
Karlene J Zuk, Hathorne, MA (US);
Osram Sylvania Inc., Danvers, MA (US);
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.