Tribocorrosion behavior of NiTi alloy as orthopedic implants in Ringer's simulated body fluid

The tribocorrosion behavior of a biomedical NiTi alloy in Ringer's simulated body fluid was investigated through friction experimentation, electrochemical testing and abrasion mapping. The effects of applied load and particle concentration were considered. Due to the wear accelerated corrosion, the corrosion potential of the NiTi alloy shifted negatively and the corrosion current density increased by an order of magnitude, compared to the static electrochemical corrosion. The applied load effect on the wear rates of the NiTi alloy was higher than that of the particle concentration. The wear rates were decreased with the applied load increased, whereas the wear rates were decreased with the increase of abrasive particle concentrations. When the applied load was 1.5 N, the particle concentration was 0.03 g cm(-3), while the lowest wear rate of 9.47 X 10(-5) mm(3)/Nm was acquired under the corrosion-wear conditions. The SEM wear morphology showed that the two-body abrasive wear is the main wear mechanism. The waste map of the NiTi alloy was constructed, demonstrating that the applied load highly affected the material loss. And the material loss of the NiTi alloy belonged to the medium loss under most service situations in this paper. The low material loss region was located within the map at both low applied load and high particle concentration. The wear contribution on the material loss exceeded the corrosion contribution, signifying the wear responsibility for the material loss. Consequently, the corrosion-wear regime was mechanical abrasion dominant with corrosion in the paper.