Influence of Minor Addition of In on Corrosion Resistance of Cu-Based Bulk Metallic Glasses in 3.5% NaCl Solution

The corrosion resistances of bulk metallic glasses (BMGs) Cu55−xZr37Ti8Inx (x=0∼5, at%) and Cu61−xZr34Ti5Inx (x=0∼3, at%) were investigated in 3.5 wt% NaCl aqueous solution. The electrochemical potentiodynamic polarization curves demonstrate that the addition of indium to copper-based BMGs can significantly enhance the corrosion potential and reduce the corrosion current density, i.e. greatly improves the corrosion resistance. And the value of Icorr for copper-based BMGs added with indium is lower than those without indium addition, by roughly one order of magnitude. The moderate replacement of copper by indium improves the corrosion resistance further. While the excessive addition of indium reduces the corrosion resistance, resulting from the lack of Zr-rich protective surface film.