DCMS Mo-Se-C solid lubricant coatings – Synthesis, structural, mechanical and tribological property investigation

Comparative Study of DC and RF Sputtered MoSe2 Coatings Containing Carbon—An Approach to Optimize Stoichiometry, Microstructure, Crystallinity and Hardness

“…The deposition rate with bias was always lower due to enhanced Ar + ion bombardment resulting in higher material removal from the growing coating along with higher density and compactness. DC sputtered Mo-Se-C coatings also show higher deposition rates than our recent work [37], due to confocal sputtering resulting in continuous arrival of sputtered species on the substrates. In previous work the arrival was intermittent as the substrates were passing in front of the targets one by one.…”

“…DC power supply provides higher deposition rates at lower costs when compared to RF sputtering. On the other hand, we noticed in our previous study that DC sputtering was hindered by plasma instabilities at the MoSe 2 target, which was attributed to charge accumulation on the surface of the target [37]. Thus, RF sputtering of MoSe 2 might improve stability of the deposition.…”

“…Two different target-power supply combinations (RF and DC) were used to identify the main deposition parameters, and to further compare the properties of the coatings achieved by both methods. Previously, our research group deposited Mo-Se-C coatings by RF sputtering of a composite target [20,25,38], and DC sputtering of 2 separate targets [37]; the latter study showed much improved properties when compared to other reports on TMD-C systems. Also, better control of the coating properties could be achieved while working with separate targets as it grants freedom to vary the applied power to the targets.…”

“…Besides, the literature reports many incongruencies regarding the microstructure; sometimes TMD nanoparticles/crystals are present in TMD-C coatings, while, in other cases the coatings are amorphous. In our previous studies, we observed that carbon-based MoSe 2 nanocomposite coatings performed better in a humid atmosphere, exhibiting higher stoichiometry compared to other TMDs [20,37]. The low hardness of Mo-Se-C coatings is still an issue as a combination of lower hardness and higher Se/Mo ratio results in higher wear of the coatings.…”

“…The low hardness of Mo-Se-C coatings is still an issue as a combination of lower hardness and higher Se/Mo ratio results in higher wear of the coatings. The application of substrate bias can improve the hardness but has an adverse effect on the stoichiometry [37].…”