Solute segregation and its influence on the microstructure and electrochemical behavior of Ti-Nb-Zr alloys

The main aim of this work is to evaluate microstructure and electrochemical behavior of Ti-30Nb-xZr alloys using polarization techniques. Several alloys with different Zr contents were evaluated (from 2.5 to 15 wt.%). Samples were prepared by arc melting and cast in copper molds in a centrifugal casting machine. The as-cast samples showed a dendritic microstructure whose scale was found to depend on the Zr content. Martensite formation proved to be dependent on solute segregation. It was observed that the addition of Zr has no influence on corrosion potential. However, Zr addition affects the passive current density behavior. After polarization, the microstructures with passive film formed on their surfaces were analyzed by scanning electron microscopy. (C) 2008 Elsevier B.V. All rights reserved.