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:
Aug. 03, 1999
Filed:
Feb. 19, 1998
Remco van Weeren, Oldwick, NJ (US);
Jeffrey A Goldacker, Findlay, OH (US);
Philip J Whalen, Sparta, NJ (US);
Other;
Abstract
A ceramic body having a surface region containing tetragonal zirconia is sintered to at least 95% theoretical density at a temperature below about 1550 .degree. C. The surface region is then heat treated to reverse local stresses therein. Low temperature degradation in tetragonal zirconia, and materials containing tetragonal zirconia, is significantly inhibited. The heat treated ceramic is especially suited for use in structural components such as valves, engine housings, pistons (chambers) and the like which, during operation, are frequently exposed to temperatures ranging from room temperature to 500.degree. C. for prolonged periods of time.