Method of making translucent alumina articles
 A method of making a translucent alumina article is described. The method comprises the following steps: PA0 Step 1 - An alumina powder and a sintering aid are mixed in a liquid for a period sufficient to form a homogeneous slurry. PA0 Step 2 - The homogeneous slurry from Step 1 is dried remove the liquid to form a dried powder. PA0 Step 3 - The dried powder is shaped to form a compacted green body. PA0 Step 4 - The compacted green body from Step 3 is heated at a temperature equal to or less than 500.degree. C. and for a period sufficient to form a compacted green body having a density of at least 30% of theoretical density. PA0 Step 5 - The compacted green body having a density of at least 30% of theoretical density from Step 4 is heated at a temperature from about 800.degree. C. to about 1300.degree. C. in an oxygen containing atmosphere for a period sufficient to impart green strength to said compacted green body to form a prefired compacted green body. PA0 Step 6 - The prefired compacted green body from Step 5 is sintered at a temperature from about 1700.degree. C., to about 2000.degree. C. in an nitrogen/hydrogen atmosphere consisting essentially of nitrogen and hydrogen for a period sufficient to form a translucent polycrystalline alumina article, the hydrogen being equal to or greater than about one volume percent of said nitrogen/hydrogen atmosphere and having a dew point in the range of minus 15.degree. C. to about minus 110.degree. C. 
GTE Laboratories Incorporated
Y C C
Y10S C04B C04B
additional inventional inventional
George C. William H.
Wei Rhodes