The effect of Ti-addition on the corrosion behavior of the partially crystallized Ni-based bulk metallic glasses

Ni55Nb30Sn5Ti5Zr5 and Ni55Nb30Sn5Zr10 bulk metallic glasses with the partially crystallized structure were prepared by water-cooled copper-mold casting. The microstructures of the two alloys were investigated by means of XRD. The corrosion behavior of the alloys in 1 M NaCl and 1 M NaOH aqueous solution at room temperature was investigated by potentiodynamic polarization and immersion methods. The surface morphology after corrosion in 10% HCl solution was observed by SEM. Both Ni-based alloys exhibited spontaneous passive behavior in the selected electrolytes. The partially crystallized alloys had higher corrosion resistance in comparison with the fully amorphous alloy. Ti-addition to Ni55Nb30Sn5Zr10 alloy can improve the corrosion resistance due to the formation of Ti oxides.