Corrosion behaviour of sintered Ti-Ni-Cu-Nb in 0.9% NaCl environment

The uniform and localized corrosion behaviour of sintered Ti-Ni containing niobium and copper additions were studied using potentiodynamic and cyclic polarization measurements in 0.9% sodium chloride. Results indicated that copper and niobium addition did not have significant effects on the uniform corrosion characteristics, but significantly improved the pitting corrosion resistance. Both copper and niobium additions significantly increased the re-passivation potentials, while copper was observed to reduce the pitting hysteresis loop area. Alloys containing 15% copper and 2% niobium additions depicted the most improved pitting corrosion resistance, and increased the re-passivation value from -315.60 mV to a high re-passivation potential of 840.68 mV.