THE INFLUENCE OF ELECTROCHEMICAL POTENTIALS ON THE FRICTION AND WEAR OF IRON AND IRON-OXIDES IN AQUEOUS SYSTEMS

This paper examines the influence of electrochemical potentials on the friction and wear of iron/iron and iron oxide/alumina oxide rubbing c ontacts, lubricated with aqueous fluids. The chemical nature of surfac e films on metals under electrode potential control has been investiga ted using simultaneous voltammetry, impedance spectroscopy and Fourier transform infrared (FTIR) microspectroscopy. This approach has enable d the friction and wear behavior of rubbing contacts with well-defined and controlled surface compositions to be investigated as a function of electrode potential. It has been shown that electrochemical potenti als influence friction coefficient in two separate ways, i.e., by modi fying the effective intersurface normal force via electrochemical doub le layer effects and by controlling the surface chemistry and then the shear strengths of the films present on the rubbing surfaces.