Method of surface preparation of NiTi by electropolishing

The electropolishing process of NiTi was performed on raw samples. Besides that, the effect ofelectro polishing bath and also the operation condition of the process on the quality of surfaceand electro polishing rate were established. Anodic polarizations of NiTi up to wereperformed in various H2SO4 and HCl concentrations in methanolic solutions. The passivity couldbe overcome in methanolic solution with concentration of more than molL-1 of H2SO4. Thedissolution kinetics were studied in dependence of the polarization potential, the H2SO4 and HClconcentration and temperature effect. Studies on the influence of the temperature on the electropolishing process show that the higher the temperature is, the higher the electro polishing rate.The best result was obtained with molL-1 methanolic H2SO4 acid and molL-1 at 298 whichcan yield an electropolish current of 0.011 A/cm-2 at potential of V. Finally, the surface, aswell as current efficiency, showed an optimum under these conditions.

Keywords:

Electro polishing , NiTi , Methanolic H2SO4 and HCl