Abstract
Abstract
Electrochemical mechanical polishing technology was studied in this research in order to investigate the effects of electrochemical parameters such as the electrolyte, pH values, and operating potential on the metal removal rate of polishing AISI 316L stainless steel (SS316L).
The dynamic polarization curve method was employed to evaluate the effects of the compositions of electrolyte (phosphoric acid and H2O2) and electrochemical parameters (pH values, H2O2 concentration, and operating potential) on the metal removal rate of SS316L.
The results showed that SS316L, in the lower-pH-value electrolyte solution, will have a shorter passive region and higher current densities of both passive and trans-passive regions. The concentration of hydrogen ions was higher at lower pH values, resulting in damage of the passive film. The H2O2 additive will also release hydrogen ions which will accelerate the reaction. Thus, the passive region was severely shortened. However, the H2O2 will also release OH− ions. Therefore, the pH value of the electrolyte will increase slightly, and the current density in the trans-passive region decrease slightly.
The electrochemical reactions were strong (higher metallic dissolution rate) at pH 2 solution. Therefore, the metal removal rate was higher. An appropriate amount of H2O2 additive (6 vol %) may also improve the electrochemical reactions and increase the polishing efficiency.