Evaluation of mechanical and corrosion biocompatibility of TiTa alloys

As-received and heat-treated Ti40Ta and Ti50Ta alloys were evaluated to det ermine their corrosion as well as mechanical performances and compared to T i6A14V, a common material utilized for orthopedic (surgical) implants. Anod ic potentiodynamic tests performed in Plasmalyte(TM) showed that all sample s, except for the Ti50Ta specimen aged at 400 degreesC for 3 h gave a curve similar to that of Ti6A14V. Optical and TEM microscopy was performed to de termine as-received and heat-treated microstructures. As-received materials showed an alpha precipitate in an alpha+beta and martensite matrix. Sample s that were aged at 400 degreesC increased in the density and the length of the alpha precipitate. Vickers hardness measurements were performed to get an approximation of the tensile strengths. Aged Ti40Ta and Ti50Ta specimen s produced the highest tensile values when compared to the Ti6A14V material , representing a 31% and 56% increase for the 3 h samples and an 18% and 58 % increase for the 10 h samples. Of all the materials studied the Ti50Ta sp ecimen aged for 10 h exhibited the best biocompatibility showing excellent corrosion resistance combined with the highest tensile strength (1089 MPa a nd 58% harder/stronger than Ti6A14V). (C) 2001 Kluwer Academic Publishers.