Co-sputtered Mo:S:C:Ti:B based coating for tribological applications

Composite structured hardened-solid soft lubricant films were deposited onto D2 tool steels by co-sputtering from MoS2, C, Ti, and TiB2 targets using closed-field unbalanced magnetron sputtering process (CFUBMS). The wear and friction properties of Mo:S:C:Ti:B based coating were investigated for tribological applications. The coated specimens were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. Reciprocating multi-pass sliding wear tests were carried out to compare their friction and wear properties. Hardness of the films was measured with microindentation. The friction coefficient of the Mo:S:C:Ti:B films may be as low as 0.042, depending on the level of the applied load and number of cycles. There is no significant change in the track depth under all applied loads. All coating wear track depths were measured to be 0.35 ± 0.05 μm. These results clearly indicate that the co-sputtered Mo:S:C:Ti:B based coatings possess the high load carrying capacity. It was noticed that transfer layers were not developed on the pin surfaces after 8000 cycles under 10 N load as well as at all applied loads.