Micro asperity-based fretting corrosion of CoCrMo, Ti-6Al-4V, and 316L SS: Assessment of an electrochemical and micro-mechanical model

Effects of potential, normal load, and cycles on volume abraded and fretting currents were investigated for CoCrMo, Ti-6Al-4 V, and 316 L SS in phosphate buffered saline. Tribocorroded regions were analyzed with microscopy and spectroscopy. Fretting currents were compared to values predicted using the Gilbert, 2020 model. Currents varied with alloy, potential and load as predicted. The charge released decreased over time due to an oxidizing wear track but was linearly related to volume removed. The average fretting corrosion currents during the first 100 cycles showed only a small fraction of the wear volume (5-16%) was the result of elec-trochemical processes for these alloys with the remainder being due to plastic deformation and metal wear particle generation. The highest currents occurred initially, and immediately fell to a steady amplitude of less than half of the initial current due to rapid oxide wear track filling.