Electrochemical reaction mechanism of nitinol in the amidosulphonic acid- formamide system

Cyclic voltammetry and polarization curves were used for a study of the electrochemical reaction mechanism of the NiTi alloy in the amidosulphonic acid-formamide system. The anodic polarization curves and the Tafel curves were obtained. The dynamical parameters of the NiTi alloy are: a�F5.6399,b�F0.7229,i₀�F1.5784×10^-8 A/cm²,nβ�F0.08. The results of cyclic voltammetry show that the NiTi alloy dissolves in the solution as an intermetallic instead of titanium and nickel separately, the anodic reaction of the NiTi alloy in the system belongs to an inreversible process, the anodic peak on the CV curve corresponds with an one step seven electrons oxidation process, and the anodic reaction is:  NiTi - 7e → Ti4⁺ + Ni3⁺. For Ni3⁺ is very instable in the acid solution, then a reduction process happens: Ni3⁺ + e → Ni2⁺.