Experimental studies on wear and corrosion resistance of pulse electrodeposited Ni-TiO2 nanocomposite coatings on AISI 304 stainless steel

Abstract

Nickel-nano titanium oxide (Ni-TiO2) composite coatings were developed on stainless steel 304 substrate using pulsed electro-deposition technique. Experiments were carried out employing L27 orthogonal array, taking current density, frequency, and duty cycle as prime parameters. Coating characterization was done using FESEM with EDAX and XRD. Applying the Response Surface Methodology optimization method, the optimized values of the parameters were identified as duty cycle, frequency and current density with values of 24%, 10 Hz and 0.6 A cm-2 respectively. Vickers micro-hardness, surface roughness, wear resistance and corrosion resistance were measured initially for the as-coated sample. The sample that yielded the optimum parameters was then heat treated for an hour at 400 °Cin a closed furnace and quenched in SAE 40 grade oil. Test results of post heattreated sample produced maximum micro-hardness of 446.45Hv, reduced surface roughness of 0.292 7mu;m, superior wear rate of 3.20E-07mm3N-1-m-1 and corrosion protection efficiency of 94.52% of Ni-TiO2 coating at low frequency, along with enhanced wear and corrosion resistance as compared with the as-coated sample.