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:
Jul. 13, 1999
Filed:
Apr. 22, 1997
Jin-Joo Park, Itami, JP;
Yasushi Mochida, Itami, JP;
Akira Kuibira, Itami, JP;
Osamu Komura, Itami, JP;
Akira Yamaguchi, Itami, JP;
Abstract
A silicon nitride ceramic sliding material comprising silicon nitride crystal grains and a grain boundary phase and having a porosity of 2 to 10% and a maximum pore size of 20 to 100 .mu.m. The silicon nitride ceramic sliding material preferably has a textural structure wherein the proportion of the total area of silicon nitride crystal grains of 0.1 to 10 .mu.m.sup.2 in area to the total area of all the silicon nitride crystal grains present in an arbitrary two-dimensional cross section is 30 to 90% and the proportion of the number of silicon nitride crystal grains of 2 to 10 in aspect ratio to the number of all the silicon nitride crystal grains present in that cross section is at least 20%. The material is produced by mixing a silicon nitride powder with a sintering aid powder, molding the resulting mixture, then heat-treating the resulting molded body in a nitrogen-containing atmosphere under reduced pressure at 1,000 to 1,500.degree. C., and then sintering it in a nonoxidizing atmosphere under ordinary pressure or under pressure, at 1,550 to 1,800.degree. C.