Case hardened orthopedic implant

Abstract

A cobalt chrome or austenitic stainless steel alloy orthopedic prosthetic implant. The implant comprises a core and a hardened surface layer. The surface layer is carburized in a process that prevents the formation of carbides on the surface layer.

1 - 20 . (canceled)  
     
     
         21 . A method for case hardening a surface layer of a component consisting essentially of a cobalt chrome alloy, comprising the steps of: 
 activating the surface layer of the component by applying a layer of iron thereto; and    carburizing the activated surface layer of the component at a temperature and for a time insufficient for carbides to form on the surface layer.    
     
     
         22 . A method for case hardening a surface layer of a component consisting essentially of a cobalt chrome alloy, comprising the steps of: 
 activating the surface layer of the component by exposing the surface layer to a gaseous hydrogen halide mixture; and    carburizing the activated surface layer of the component at a temperature and for a time insufficient for carbides to form on the surface layer.