A Study of the Tribological Properties of Sputter-deposited MoSX/Cr Coatings

In this investigation, MoSx/Cr coatings were deposited by direct-current magnetron sputter onto Ck45 (AISI 1045) plain carbon steel substrates. The MoSx/Cr ratio in the coatings was controlled by sputtering the composite targets. The chemical characterization was performed using EDX (energy dispersive X-ray analysis); the structural characterization was accomplished by X-ray diffraction (XRD) studies. The mechanical properties of coatings were analyzed by nanoindentation experiments. The tribological behavior of the coatings was investigated using the pin on disc test at room temperature. MoSx/Cr coatings with Cr atomic percentage of 13% was found to possess the optimum wear resistance and durability. The MoSx/Cr coatings showed a maximum hardness of 12.5 GPa at a dopant content of 13 at.% Cr. Moreover, the films exhibited a steady state friction coefficient from 0.15 to 0.19 and the main wear mechanisms of the MoSx/Cr coating in air were abrasive, adhesive, and oxidation.