Fretting and galvanic corrosion behaviors and mechanisms of Co-Cr-Mo and Ti-6Al-4V alloys

The objective of the present work was to characterize the galvanic corrosio n behavior of Co-Cr-Mo and Ti-6Al-4V alloys using fretting, corrosion and e lectrochemical techniques under corrosion and corrosive fretting conditions . Results showed that they are not susceptible to galvanic corrosion when C o-Cr-Mo and Ti-6Al-4V are simultaneously used in an assembled part in the p ure corrosion condition, but the fretting surfaces will become more vulnera ble to galvanic corrosion. Acceleration of anodic dissolution of the frette d area is dominated by the "large cathode effect". Ti-6Al-4V acts as a cath ode with respect to the non-contact area of the Co-Cr-Mo alloy. For frettin g pairs composed of the same alloy, galvanic corrosion can also take place on the non-contact area which will act as the "large-area" cathode. The fre tting corrosion mechanism of two biomaterials has been proposed based upon observations of the topography of the fretted scars as well as other corros ion information. (C) 2001 Elsevier Science B.V. All rights reserved.