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. 07, 1999
Filed:
Feb. 06, 1997
Waltraud M Kriven, Champaign, IL (US);
Dong-Hau Kuo, Urbana, IL (US);
The Board of Trustees of the University of Illinois, Urbana, IL (US);
Abstract
The invention comprises a multilayer high-strength, high-toughness, flaw-tolerant oxide ceramic composite having a metal phosphate later, a first yttria stabilized zirconia layer, a yttria stabilized zirconia-alumina layer and a second yttria stabilized zirconia layer; and a method for producing the same. The metal phosphate are selected from the group consisting of monazites, xenotimes, calcium phosphate, aluminum phosphate, zirconium phosphate and substituted zirconnium phosphate wherein Zr.sup.4+ is partially replaced by divalent metal ions. The ceramic composition of the invention may be further strengthened by the incorporation of selected particulates, whiskers or fibers, or mixture of the same, into the yttria stabilized zirconia layers, the yttria stabilized zirconia-alumina layers and the metal phosphate layers. A multilayer ceramic of the invention comprising a YPO.sub.4 layer, a first yttria stabilized zirconia layer, a 30 vol % yttria stabilized zirconia-70 vol % alumina layer and a second yttria stabilized zirconia layer was found to have a 4-point flexural strength of 358, 392 MPa and an apparent work-of-fracture in the range of 8.2, 10 kJ/m.sup.2.