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:
Nov. 08, 1994
Filed:
Dec. 23, 1992
Applicant:
Inventors:
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C04B / ;
U.S. Cl.
CPC ...
501 97 ; 501 96 ; 501 98 ; 501154 ; 423344 ; 264 63 ; 264 65 ; 264299 ; 264D / ;
Abstract
Si.sub.3 N.sub.4 -based sintered compositions containing MgO and optionally other sintering additives, which after sintering, has a flexural strength level at room temperatures of .gtoreq.800 MPa, measured by the four-point bending method, and a Weibull modulus of >15, is produced by mixing MgO, any additional sintering additives and Si.sub.3 N.sub.4 powder to form a mixture, calcining the mixture in an oxygen-free atmosphere to obtain a pre-synthesis mixture, and adding the pre-synthesis mixture to uncalcined Si.sub.3 N.sub.4 powder which is then sintered.