Effect of normal force on tribocorrosion behavior of commercially pure titanium in biomedical applications

摘要

Tribocorrosion is the interplay between chemical, electrochemical and mechanical processes that leads to a degradation of passivating materials in a corrosive environment. The tribocorrosion behavior of commercially pure titanium (cp Ti) was monitored and evaluated by electrochemical and friction measurements. Tribometers were used to impose different loading forces in a pin-on-disc mode. Electrochemical measurements such as open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) were applied to in situ characterize the corrosion behavior of cp Ti before, during and after continuous unidirectional sliding in a phosphate buffered saline (PBS) solution. Scanning electron spectroscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and profilometry were performed to analyze the surface morphology/chemical composition and the total wear volume at the end of sliding tests. The experimental results showed that the applied normal force affects the corrosion-wear degradation of cp Ti. Both of the material loss due to mechanical wear and the material loss due to corrosion of active material in the sliding track enlarge with the increase of normal force, but the former still dominates in the whole studied range.