Experimental Studies on Wear and Corrosion Resistance of Pulse electrodeposited Ni-TiO2 Nanocomposite Coatings on AISI 304 Stainless Steel


 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 L_27 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 / cm2 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 were then heat treated for an hour at 400°C in a closed furnace and quenched in SAE 40 grade oil. Test results of post heat-treated sample produced maximum microhardness of 446.45 Hv, reduced surface roughness of 0.292 µm, superior wear rate of 3.20E-07 mm3/Nm and corrosion protection efficiency of 94.52 % of NiTiO2 coating at low frequency, along with enhanced wear and corrosion resistance as compared with the as-coated sample.