Electrochemical behavior of biocompatible alloys

Abstract

The electrochemical behavior of Ti6Al4V and Ti22Nb alloys was studied in a 0.15 M (0.9 %) physiological sodium chloride solution at room temperature (22 ± 1) °C. The experimental samples of the Ti6Al4V alloy were in different states of the thermomechanical treatment: as-received and hot rolled. The samples of Ti22Nb were studied in the as-cast, heat-treated and aged stages. The microstructural features of the Ti6Al4V alloy in three different states influenced not only the passivation but also the rate of corrosion that was (0.12, 0.07 and 0.10) mm per year for the equiaxed ( + ), acicular in the transformed grains and coarse lamellar ( + ) phases, respectively. The as-cast TiNb sample with a dendritic microstructure and very fine martensite showed the lowest corrosion rate of 0.26 mm per year unlike the specimens after the heat treatment and aging with the rate of 0.34 mm and 0.33 mm per year, respectively.