Cobalt-Chromium (Co-Cr) alloys possess outstanding corrosion resistance and wear resistance because of passive film of a few nanometers' thickness on their surfaces. In this study, we have clarified the damage accumulation mechanism of Co-Cr alloys under the simultaneous reaction of corrosion and wear in sodium chloride solution. A corrosion wear characteristic of these alloys was evaluated by static polarization test under simultaneous wear damage. Wear was applied using a reciprocating rotational pin-on-flat abrasion machine. The pin material in all tests was polyethylene. Applied loads were 9.8 N. The disk rotation sliding rates were 10, 1.0, and 0.1 mm/s. The results show the current density increases significantly early only when the sliding rate is 10 mm/s. This is thought to occur because the wear on the passive film affects the corrosion reaction. The results also show that the current density drops (recovers) over time and approaches the Control. Therefore, if you assume the prolonged use of implants, the sliding rate in early use greatly affects the corrosion reaction.
