Tribocorrosion Behaviour of Biomedical Porous Ti–20Nb–5Ag Alloy in Simulated Body Fluid

Abstract

Porous Ti–20Nb–5Ag (wt.%) alloy was developed using powder metallurgy (PM) route with the porosity of 43% after sintering in a high vacuum atmosphere. The microstructure of the porous alloy revealed various micro, macro and interconnected pores with an average pore size of about 114 µm. Tribocorrosion behaviour of the porous alloy was examined in simulated body fluid under the various applied load of 1–10 N using DC electrochemical corrosion technique and kinetic parameters (corrosion potential, corrosion current density and breakdown potentials). After tribocorrosion test, the OCP values decreased from 0.17 to − 0.49 VSCE as applied load was increased. The potentiodynamic polarization results revealed that the corrosion potential decreased, while corrosion current density increased under higher applied loads. Active–passive transition plots showed metastable passivity due to severe fluctuations of passive current density. After tribocorrosion, the surface morphology was analysed using SEM, and it exhibited the severity of wear tracks at higher applied loads. The results indicated that the developed porous Ti–20Nb–5Ag alloys exhibit better tribocorrosion properties in simulated body fluid. Through observations of SEM images of the worn surfaces, the visible scratches and deep grooves were observed along the sliding direction, indicating a predominant abrasive mechanism.