Evaluation of microstructure and corrosion behaviour of a titanium alloy in simulated biological fluids

Abstract

In this paper, the corrosion behaviour in Ringer-Brown solution of Ti-6AL-7Nb alloy indifferent microstructure conditions obtained after different thermal and plastic deformation treatments is discussed. Microscopic evaluation after the exposure of titanium and Ti-6Al-7Nb alloys in Ringer-Brown solution showed that the thermal-mechanical treatments produced favorable changes of the microstructure. Electrochemical behaviour in Ringer-Brown solution of titanium and its alloys revealed the following: self-passivation, very large passive potential range, low passive current densities; pitting corrosion appeared on three alloys but at very high values of the pitting parameters, without the possibility to appear this type of corrosion on implants, even in very long service conditions; corrosion rates lower than of base metal, all studied materials being "very stable"; very low toxicity.