Assessment and effect of reinforcement of multi-walled carbon nanotubes in Ni-Al2O3 and Ni-SiC nanocomposite coatings using pulse reverse electrodeposition technique

Abstract

The nanocomposite coating provides a higher degree of corrosion resistance, microhardness, wear resistance and significantly improves the tribological qualities of the base metal. This research work is aimed at investigating the effect of the proportion of multi walled carbon nanotubes (MWCNT) mixed with Ni-Al 2 O 3 and Ni-SiC nanocomposite coatings on a mild steel AISI 1018 specimen against its tribological characteristics through experimental investigation. The pulse reverse electro deposition technique is deployed for coating formulation with optimized coating parameters. The proportions of carbon nanotubes vary in three different ratios ranging from 1:1 to 2 :1. Tribological characteristics (microhardness and surface morphology) are assessed using a Vickers microhardness testing machine and a scanning electron microscope (SEM). Nine different coating combinations are considered in this study and their tribological attributes are compared with the un-coated sample. From the results, it can be observed that the samples coated with Al 2 O 3 nanoparticles reinforced with carbon nanotubes (CNTs) possess excellent magnitudes of micro-hardness in comparison with the uncoated and SiC-CNT coated samples with an enhancement factor of 2.88 and 1.37, respectively. Moreover, the variation of the CNT proportion in the coating blend has the tleast significant effect and therefore, addition of CNT particles beyond the blend ratio of 1:1 may be avoided to reduce the coating cost of samples significantly. Also, SEM images clearly reveal a uniform coating distribution owing to the application of optimized coating parameters.