Surface hardened biocompatible metallic medical implants

A surface hardened metallic medical implant, the implant having a metallic alloy body with a surface, the body comprising:

• a metallic alloy, and less than about 2 wt. % of a metal solute that is more oxidizable than metallic components of the metallic alloy body, a substantial proportion of the metal solute at a depth of less than about 200 microns beneath the surface of the implant body being oxidized to strengthen and harden the surface of the implant to a hardness of about 40 Rockwell C, the solute being oxidized by a process comprising internally oxidizing solute near the surface of the implant body while maintaining a metallic luster on the surface of the implant.

A surface hardened metallic medical implant, the implant comprising:

• a surface hardened cobalt-chromium-molybdenum implant body with surface hardness greater than about 40 Rockwell C, the alloy comprising a hardened surface produced by a process comprising:
• (1) selecting a cobalt-chromium-molybdenum alloy containing from about 1 to about 2 wt. % tantalum, the tantalum being more internally oxidizable than other elements of the cobalt-chromium-molybdenum alloy implant body;
• (2) hardening the surface of the implant body by internal oxidation of a substantial proportion of the tantalum at the surface of the implant while maintaining a metallic luster on the surface of the implant.

A surface hardened metallic medical implant, the implant having a metallic alloy body with a surface, the body comprising:

• a cobalt-chromium-molybdenum alloy, and from about 1 to about 2 wt. % of tantalum as a metal solute, a substantial proportion of the tantalum at a depth of less than about 200 microns beneath surfaces of the implant body being oxidized to strengthen and harden the surface to a hardness of about 40 Rockwell C, the tantalum solute being oxidized by a process comprising internally oxidizing said solute near the surface of the implant body.