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:
Mar. 21, 1989
Filed:
Apr. 23, 1987
Applicant:
Inventors:
Sheldon Lieberman, Burlington, MA (US);
Elizabeth Trickett, Framingham, MA (US);
Sophia R Su, Weston, MA (US);
Assignee:
GTE Laboratories Incorporated, Waltham, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C04B / ;
U.S. Cl.
CPC ...
264 65 ; 501 12 ; 501 97 ;
Abstract
A process for making a homogeneous yttria-alumina doped silicon nitride article is described. A uniform coating of yttria and alumina is applied to the surface of silicon nitride particles by a chemical application of the hydroxides of yttrium and aluminum followed by drying and a subsequent conversion of the hydroxides to the corresponding oxides. The resulting powder is formed into an article and pressureless sintered to a density greater than 99% of theoretical.