Pulsed electrodeposition, mechanical properties and wear mechanism in Ni-W/SiC nanocomposite coatings used for automotive applications

Abstract In the present work, the dry sliding wear behaviour of electrodeposited Ni-W/SiC nanocomposite coatings after heat treatment was studied. For that purpose, Ni-14 (at%) W/SiC composite coatings with varying proportion of β-SiC particle content were deposited using pulsed current electrodeposition and subsequently heat-treated at 500 °C in vacuum. The coatings were analysed for its structure, surface topography, particle content in coating and inter-particle spacing. The mechanical properties of coatings were evaluated and correlated with SiC content in the respective coating. Sliding wear tests under dry condition were carried out (at room temperature) against WC-Co disc using pin-on-disc configuration. It has been observed that the mechanical properties of nanocomposite coatings follow the rule of mixtures (ROM). The wear rate of the nanocomposite system has demonstrated a linear relationship with the inter-particle spacing of SiC particles embedded in the Ni-W matrix. Specific wear rate and friction coefficient of nanocomposite coatings were rationalised through a mathematical model based on the inverse rule of mixtures (I-ROM).