Effect of pulse current density on microstructure and wear property of Ni-TiN nanocoatings deposited via pulse electrodeposition

Abstract TiN nanoparticles were utilized as reinforced phase to co-deposit with Ni ions for preparing Ni-TiN nanocoatings (NCs) in this research. The influence of pulse current density on microstructure, relative texture coefficient, microhardness and wear properties of Ni-TiN NCs was also examined. The results illustrate that the moderate nucleation quantity and the finest Ni embryos with average size of 141.6 nm were found in the coatings prepared at a pulse current density of 60 mA/cm2. The thicknesses of Ni-TiN NCs deposited at 20, 60 and 100 mA/cm2 were 50.7, 62.8, and 78.3 μm, respectively. The Ni-TiN NC fabricated at 60 mA/cm2 emerged the smoothest and the most compact surface morphology of all Ni-TiN coatings with Ra value of 29.57 nm. The XRD peaks of nickel in Ni-TiN NC deposited at 20 mA/cm2 has high intensity and are sharp, while XRD peaks of nickel in the NCs obtained at 60 and 100 mA/cm2 has lower intensity and are broader. XRD also illustrates that Ni and TiN phases were the main components of three Ni-TiN NCs. Microhardness value of the Ni-TiN NC deposited at 20 mA/cm2 is only 693.2 HV, which is the lowest value deposited among all three Ni-TiN NCs. However, the coating prepared at 60 mA/cm2 presents the highest microhardness value of 922.1 HV among these NCs. In addition, this coating exhibits a few slight scratches with few small pits, illustrating the best wear resistance.