Improvement of tribocorrosion behavior on titanium alloy by carbide-derived carbon (CDC)

Abstract In total hip replacements (THRs), metal-on-metal (MoM) design used to be predominant in the market until 2009 when it has been shown that its wear products could cause several adverse local tissue reactions (ALTR). The leading cause of excessive MoM wear products is the tribocorrosive reaction, which is the synergism of tribology and corrosion. To mitigate this effect, inspired by the presence of tribolayer on retrieved hip implants, carbide-derived carbon (CDC) has been proposed to be a potential solution for the current problem. In this study, we successfully carburized Ti6Al4V alloy and fabricated CDC, which was characterized by X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). According to the results of tribocorrosion experiments, CDC specimens presented less potential drop, less wear volume loss and lower friction coefficient in 3.6 k- and 100 k-cycle experiments. The mechanism of CDC's protection was proposed to explain the current data. Meanwhile, CDC's biocompatibility was also examined by cell proliferation and direct observation of stained actins and nuclei in cells by confocal microscopy. Combined with all collected data, it has been concluded that CDC can provide excellent protection to titanium alloy substrate with similar biocompatibility to Ti6Al4V.