Tribological behavior of Ni-based composite coatings produced by cold spray

The current experiment examined the friction and wear characteristics of Ni-based composite coatings developed by cold spray route. In the developed coatings, fixed concentration of MoS 2 (10 wt. %) and varying concentrations of Ag (5, 10, and 15 wt. %) were incorporated to evaluate the lubricating potential of reinforcing elements. The specimens were slid in various working regimes of loads (6, 11, 16, & 21 N) and at a fixed sliding speed of 0.3 m/s under room temperature (RT). According to the investigation, all participating composite coatings have revealed a lower coefficient of friction (COF) and wear rate as the testing load increased from 6 to 16 N, beyond which a reverse trend was recorded till 21 N. However, composite coating with 10 wt. % Ag has shown excellent tribological properties in terms of the lowest COF (0.29) as well as wear rate (4.0 × 10 −5 mm 3 /Nm) at 16 N and 0.3 m/s. The superior tribological characteristics of the aforesaid coating have been explained and well connected to the synergistic effect of solid lubricants (Ag and MoS 2 ) as well as the optimal weight percent of Ag in the creation of tribo layer on the wear track.