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:
Sep. 17, 1996
Filed:
Sep. 26, 1995
Cornelia Boberski, Liederbach, DE;
Hartmut Kruner, Eppstein/Taunus, DE;
Gunter Riedel, Kelkheim/Taunus, DE;
Rainer Hamminger, Mannheim, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
A shaped part of sintered silicon nitride has high mechanical strength and comprises at least 87% by weight of silicon nitride and up to 13% by weight of an additive combination of Al.sub.2 O.sub.3 and Y.sub.2 O.sub.3. The Y.sub.2 O.sub.3 /Al.sub.2 O.sub.3 weight ratio is in the range of from 1.1 to 3.4. It can additionally contain HfO.sub.2 and/or ZrO.sub.2 in amounts of up to 1.0% by weight. The shaped part has a density of 98% of the theoretical maximum density, a mechanical strength of .gtoreq.850 MPa at room temperature and a mechanical strength of .gtoreq.800 MPa at a temperature of 800.degree. C. Its fracture toughness K.sub.IC is in the range .gtoreq.8 MPa.multidot..sqroot.m.