Assessment on the microhardness and corrosion resistance characteristics of Ni-SiC and Ni-MWCNT coatings by pulse reverse electrodeposition technique

Abstract

The characteristics of Silicon carbide (SiC) and multi-walled carbon nanotube (MWCNT) nano composite coatings by a Pulse Reverse Electrodeposition (PRE) method is investigated in detail to enhance the microhardness (MH) and corrosion resistance characteristics of AISI 304 stainless steel substrate. The electrodeposition nature, dissolution behavior, surface characteristics are assessed by Scanning Electron Microscopy (SEM) with energy dispersive x-ray (EDX), x-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Microhardness (MH) Test and Electrochemical studies. The coatings are prepared in the watts type bath using pulse reverse electrodepositions (PRE) method of varying the electrolyte deposition parameters in different combinations. Present results clearly reveal that, there is a drastic improvement in the magnitude of microhardness of coated specimens, silicon carbide (SiC) and multi-walled carbon nanotube (MWCNT) composite coatings yield a maximum hike of 91.6% and 168% respectively. Furthermore, the Nyquist and impedance plots clearly depict that, multi-walled carbon nanotube (MWCNT) exhibits higher corrosion resistance characteristics.