LAUSR

Abstract Ni-B4C-TiC nanocomposite coating was successfully developed on AZ80 magnesium alloy by electrocodeposition technique using square wave form of pulse current. The duty cycle and the current density were varied and the frequency of the pulse current was fixed at 10 Hz. 0 g/L, 0.5 g/L and 1 g/L of Boron carbide and Titanium carbide nanoparticles were added to the Watt's nickel bath. The surface morphology of the coatings has been studied using SEM and XRD. The microhardness and wear resistance of the composite coatings have been analysed with Vickers microhardness tester and pin on disc tribometer. The nanocomposite coatings obtained with a current density of 2 A/dm2, duty cycle of 30%, 0.5 g/L of B4C and 1 g/L of TiC  nanoparticles exhibited the highest hardness of 656 Hv and the lowest specific wear rate of 1.26E−8 mm3/Nm as compared to the uncoated substrate which had a hardness of 119.27 Hv. From the results, it is inferred that excellent grain refinement of nickel and orientation of nanoparticles brought about by the pulse current has played a significant role in the improvement of the coating properties.