Electropolishing parameters of NiTi alloy
(1.General Research Institute for Nonferrous Metals, Beijing 100088, China2.State Key Laboratory for Fabrication and Processing of Nonferrous Metals, Beijing 100088, China)
Abstract: Electropolishing has been used in NiTi alloy in several fields for its special characteristics, but its essential details and electropolishing mechanism have not been reported yet as a demand from business competition, which, to a great degree, restricts the application and extension of the electropolishing technology. The effect of processing parameters on nitinol electropolishing was explored. Besides the electrolyte, other factors that influence the electropolishing are temperature, current density, time, spacing between anode and cathode, electrolyte stirring, etc. Studies on the effect of the temperature on the electropolishing process show that the higher the temperature is, the bigger the electropolishing rate is, following the near Gauss law. The relationship between the temperature and the surface roughness follows a near parabolic law, and the relationship between the temperature and the surface reflectivity follows a near sigmoidal law. The relationship between the electropolishing voltage and the current density follows a near cubic law, while that between the electropolishing rate and current density follows a near linear law. The relationship between the electropolishing rate and the time follows a near sigmoidal law. The practical spacing between anode and cathode is confirmed by the Hall bath experiment.
Key words: NiTi alloy; nitinol; electropolishing; processing parameters