Corrosion monitoring of NiTi alloy with small-amplitude potential intermodulation technique

The effects of thermal cycling on corrosion resistivity of Nickel-titanium shape memory alloy are studied. The corrosion properties of material has been studied with small-amplitude potential intermodulation technique at various temperatures from 0°C to 70°C. The corrosion properties has been determined from the system responses to a potential distortion to two sinusoidal waves. The Tafel slopes and corrosion rate at each temperature have been compared with the results of Linear Polarization Resistance (LPR), Electrochemical Impedance Spectroscopy (EIS) techniques. System response time for each technique and deviation from steady state conditions has been compared with obtained polarization resistance (Rp) values from EIS method. Differential Scanning Calorimetry (DSC) is used to determine the forward and reverse martensitic transformation temperatures. DSC graph shows martensitic phase at room temperature and temperature regime for experimental (from 0°C to 70°C).