Tribocorrosion Behaviour of Ti–6Al–4V Alloy in Biomedical Implants: Effects of Applied Load and Surface Roughness on Material Degradation

Abstract

Tribocorrosion covers the science of surface transformations resulting from the interaction of mechanical loading and chemical reactions that occur between elements of a tribosystem exposed to corrosive environments. Implant materials are subjected to relative movements, which can cause wear damage, together with corrosive attack of the body fluids. Ti–6Al–4V alloy has been widely used for this purpose due to its superior biocompatibility and excellent corrosion resistance and good mechanical properties. The purpose of this work is to evaluate the tribocorrosion of Ti–6Al–4V alloy under different load and surface conditions. The tribocorrosion tests of Ti–6Al–4V alloy were performed using pin on disc tests at phosphate buffer saline solution (PBS), under various loading (0.5–25) N and surfaces roughness (240, 320, 400, 600) μm grits. Surface morphology, chemical composition and tribocorrosion resistance studied by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and Tafel potential polarization. The result indicate, by increasing contact load, the smoother surface (600 μm grit) give lower average tribocorrosion current density as compared with surface (320, 240, 400) μm grits suggesting that the damage is more pronounced on the smooth surface.