A study on corrosion characterization of plasma oxidized 65/35 brass with various frequencies

In order to enhance the corrosion resistance, the brasses were exposed to pulsed DC oxygen plasma with various frequencies. The corrosion behavior of plasma oxidized brasses (POBs) with various pulse frequencies was investigated by electrochemical methods (potentiodynamic polarization test, electrochemical impedance spectroscopy) and surface analyses (X-ray diffraction, scanning electron microscopy). Particular attention was paid to the effects of pulse frequency on the corrosion properties of POBs. From the results of electrochemical test, it was found that the oxidized brass under the condition of 1.5 Torr oxygen pressure and 20 kHz frequency was effective in improving corrosion resistance. This was attributed to the protective oxidized layer (ZnO).