Fabrication and corrosion behavior of Ti-based bulk metallic glass composites containing carbon nanotubes

This study explored the feasibility of preparing Ti₅₀Cu ₂₈Ni₁₅Sn₇ bulk metallic glass composite with powder metallurgy. With high energy ball milling of a pure Ti, Cu, Ni, Sn and carbon nanotube (CNT) powder mixture, the CNT/Ti₅₀Cu ₂₈Ni₁₅Sn₇ metallic glass composite powders can be formed with mechanical alloying (MA) after 8 h milling. The bulk metallic glass composite was successfully prepared by vacuum hot pressing the as-milled CNT/Ti₅₀Cu₂₈Ni₁₅Sn₇ metallic glass composite powders. The corrosion behavior of the Ti₅₀Cu ₂₈Ni₁₅Sn₇ bulk metallic glass as well as composites modified by the addition of CNT was investigated by electrochemical measurements. Electrochemical characterization was performed in Hanks' solution at 37 °C with physiologically relevant dissolved oxygen content. The results of potentiodynamic polarization measurements revealed that the Ti-based bulk metallic glass composites examined showed spontaneous passivity by anodic polarization with a passive current density of about 10^-5 A/cm ². The higher corrosion resistance of the Ti-based bulk metallic glass composites was attributed to stable and protective passive films enriched with titanium containing certain amounts of additional elements.