24/06/2005 - Controller General of Patents, Designs, and Trade Marks

(21) Application No.1782 /DEL/1997 A (22) Date of filing of Application: 27/6/1997
(54) Title of the invention: “A METHOD OF MAKING AN APTICALLY
TRANSPARENT CERAMIC ARTICLE.”
(51) International Classification 7 : C04B 35/10,
H01J 61/30
(30) Priority Data:
(31) Document No.: NA
(32) Date: NA
(33) Name of convention country: NA
(66) Filed U/s 5(2): NIL
(61) Patent of addition to application No.: NA
(62) Filed on: NA
(63) Divisional to Application No.: NIL
(64) Filed on: NA
Total No Of Page: 12
(57) Abstract
(71) Name of the applicant:
OSRAM-SYLVANIA INC.,
Address of the Applicant:
100Endicott Street, Danvers, MA 01923,
United States of America
(72) Name of the Inventor:
GEORGE CHIATSING WEI
ARLENE HECKER
DAVID GOODMAN
A method of making an optically transparent ceramic article comprising the steps of:
-forming, by conventional method, an aqueous slurry of alumina powder comprising alumina,
magnesia, and zirconia, and yttria;
-add nitric acid, and aqueous binder and plasticizer, by conventional method.
-spray-dry the slurry by conventional method.
-forming an article by use of sintering to yield the following composition, based on the weight
percentage of about:
magnesia 0.020%
zirconia 0.018%
yttria 0.035%
alumina balance
18106