Effect of Ti on microstructure, mechanical properties and corrosion resistance of Zr-Ta-Ti alloys processed by spark plasma sintering

The microstructure, mechanical properties and corrosion resistance of Zr-30%Ta and Zr-25%Ta-5%Ti alloy prepared by spark plasma sintering (SPS) technology were investigated. The experimental results showed that the Zr-Ta-Ti alloys made by the SPS processing have a low level of porosity with the relative density of 96%-98%. The analyses of XRD and TEM revealed that the Zr-30Ta alloy consists of alpha+beta phase, and the Zr-25Ta-5Ti alloy belongs to the near beta type alloy containing a small amount of alpha and omega phases. With the addition of Ti, the elastic modulus of the alloys was decreased from (99.5 +/- 7.2) GPa for Zr-30Ta alloy to (73.6 +/- 6.3) GPa for Zr-25Ta-5Ti alloy. Furthermore, it is shown that, in comparison to CP-Ti and Ti-6Al-4V alloy, the Zr-Ta-Ti alloy produced in this work offers an improved corrosion resistance due to the more stable ZrO(2)and Ta(2)O(5)generated in the passivation film on the surface of the alloys. This study demonstrates that Zr-Ta-Ti alloys are a promising candidate of novel metallic biomaterials.