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:
Dec. 12, 1989
Filed:
Nov. 13, 1987
Tseng-Ying Tien, Ann Arbor, MI (US);
Board of Regents Acting for and on Behalf of University of Michigan, Ann Arbor, MI (US);
Abstract
Novel partially stabilized zirconia ceramic compositions exhibiting improved toughness comprising: a major component consisting of ZrO.sub.2, a minor stabilizing component Y.sub.2 O.sub.3 and an effective amount of a toughening agent (e.g., Ta.sub.2 O.sub.5). The toughness of the tetragonal zirconia polycrystal (e.g., 96% ZrO.sub.2, 3 mole % Y.sub.2 O.sub.3) can be increased nearly three-fold by replacing 1% of the ZrO.sub.2 with Ta.sub.2 O.sub.5. Empirical equations based on ratios of fundamental lattice parameters (e.g. c/a) quantitatively relating to the stability/instability of tetragonal zirconia oxide are disclosed and used in a novel method for improving the toughness of the ceramic compositions.