In vitro evaluation of a γ-TiAl intermetallic for potential endoprothesic applications

In vitro properties of a new γ-based TiAl intermetallic have been evaluated in the as-received state and after carrying out surface modifications by oxidation under two different heat treatments, namely 700 °C, 24 h and 1000 °C, 1 h. Cathodic stripping voltammetry was used to determine the concentration of Ti and Al elements released into a solution simulating the body fluids (Ringerʹs solution) after six months immersion. Electrochemical techniques were used to measure the corrosion resistance and the susceptibility to pitting corrosion. The results confirmed that the best material is the TiAl intermetallic pre-oxidised at 700 °C, since it produces a much lower concentration of Al and Ti ions and also exhibits the lowest passive current densities. The latter are one order of magnitude lower than those of the as-received intermetallic alloy and after pre-oxidation at 1000 °C and two orders of magnitude lower than that obtained from a conventional Ti6Al4V currently used as biomaterial.