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:
May. 03, 1994
Filed:
Mar. 15, 1993
H Ravindranath Shetty, Warsaw, IN (US);
Walter H Ottersberg, Warsaw, IN (US);
Zimmer, Inc., Warsaw, IN (US);
Abstract
A method of surface hardening cobalt-chromium based orthopedic implant devices, and a cobalt-chromium orthopedic implant device prepared by the disclosed method. An orthopedic implant device made of a cobalt-chromium or cobalt-chromium-molybdenum alloy, such as ASTM F-75 or ASTM F-799 is exposed to molecular nitrogen gas or ionized nitrogen at a process temperature and for a process time duration sufficient to enhance surface hardness and wear resistance properties, without the formation of a measurable nitrogen layer that tends to increase surface roughness and brittleness and diminish wear resistance properties. The process temperature is in the range of 500.degree. F. to 2400.degree. F., preferably about 1400.degree. F., and the process time duration at the preferred process temperature is approximately 48 hours. The hardened surface of the cobalt-chromium-molybdenum implant occurs primarily due to nitride formation and solid solution hardening of the cobalt-chromium-molybdenum with nitrogen and oxygen, by dissolution.