New Approach to Increase CNT Contents in Electrodeposited Ni-CNT Composite Thin Films by Modified Current Conditions

In this paper, an electrodeposition method for nickel (Ni)-multiwalled carbon nanotubes (MWCNTs) composite thin films is presented. The composite film is deposited using an electrolyte in which MWCNTs are randomly dispersed. Two kinds of MWCNTs annealed at 1200 °C and 2600 °C were used for the electrodeposition using pulse or sine waveforms. An electrodeposition condition using CNT annealed at 1200 °C and sine waveform with maximum current 0.2 A and frequency 5.0 Hz results in a maximum CNT weight fraction of 5.4% in the composite film. The electrodeposited film with the maximum CNT content shows a microindentation hardness of 17.0 GPa, which is approximately 1.45 times greater than that of a pure Ni film. Moreover, mechanical strengthening is found in the composite films due to the addition of CNTs. This result shows that the electrodeposition for the Ni-MWCNT composite thin film with modified current condition would be applicable to microsystem, which requires micromechanical components with high mechanical strength.