Study of Electrolyte and Voltage on Electrochemical Machining of Intermetallic Compound Ni-50%Ti

Effect of applied voltage and electrolyte composition on electrochemical machining (ECM) of intermetallic compound Nitinol is studied. Oxide film breakdown of Nitinol is firstly defined with the use of cyclic polarization test. Anodic dissolution of Nitinol alloy (50%Ni-50%Ti) in three different solutions basically consist of NaCl is carried out in a potentiostat machine. Machining voltage varied from 2 volts to about 30V (potentials higher than Etranspassive). Machining rate (produced current density), current vs.time curve characterization and final surface finish was of interest for study. It seems that Multi Attribute Decision Making can be used for selection of suitable electrolyte and voltage of ECM. Comparing parameters, the best electrolyte and applied voltage wasof 300 gr/Lit NaCl + 2.4 gr/Lit NaF and 22 to 26 volts. Roughness exsiting over the surface is related to Nitinol microstructure.