Enhancing the Anticorrosion Performance of the Electrodeposited Ni Layer by the Ultrasonic Potential Activation Method and the Application

Abstract In MEMS area, the micro electrodeposition method can be used to fabricate the micro metal devices. However, due to the corrosion effect, the electrodeposited layer may detach from the substrate. In order to handle this problem, the novel ultrasonic potential activation method was proposed to enhance the corrosion resistance of the layer. The electrodeposition experiments were applied. The crystallite size of the electrodeposited layer was measured by the X‐ray diffraction (XRD) method. The surface morphology and the atom contents of the layer were examined by the SEM and the EDS methods. The Tafel plots and the electrochemical impedance spectroscopy (EIS) tests were determined by the electrochemical workstation. The corrosion performance of the electrodeposited layer was verified by immersing the layer into the 10% HCl and 10% HNO 3 solution. The experimental results show that the value of the corrosion current of the layer can be reduced from 6.81 × 10 −4 A/cm 2 to 2.97 × 10 −4 A/cm 2 and the value of the R ct can be improved from 3.8 Ω cm −2 to 11.2 Ω cm −2 with the ultrasonic potential activation. In order to verify the anticorrosion effects, the high aspect ratio micro columns were fabricated through the ultrasonic potential activation method. The results show that the micro columns do not fall off after the corrosion experiments. This work may contribute to improve the corrosion resistance of the micro metal devices.