Tribocorrosion behaviour of nanostructured titanium substrates processed by high-pressuretorsion

Abstract

Aseptic loosening induced by wear particles from artificial bearing materials is one of themain causes of malfunctioning in total hip replacements. With the increase in young andactive patients, complications in revision surgeries and immense health care costs, there isconsiderable interest in wear-resistant materials that can endure longer in the harsh andcorrosive body environment. Here, the tribological behaviour of nanostructured titaniumsubstrates processed by high-pressure torsion (HPT) is investigated and compared with thecoarse-grained samples. The high resolution transmission electron microscopy revealsthat a nanostructured sample has a grain size of 5–10 nm compared to that of ∼ 10 µm and ∼ 50 µm for untreated and annealed substrates, respectively. Dry and wet wear tests were performedusing a linear reciprocating ball-on-flat tribometer. Nanostructured samples show the bestdry wear resistance and the lowest wear rate in the electrolyte. There was significantlylower plastic deformation and no change in preferred orientation of nanostructured samplesattributable to the wear process. Electrochemical impedance spectroscopy (EIS) showslower corrosion resistance for nanostructured samples. However, under the action of bothwear and corrosion the nanostructured samples show superior performance and that makesthem an attractive candidate for applications in which wear and corrosion actsimultaneously.