Tribological Performance and Coating Characteristics of Sputter-Deposited Ti-Doped MoS₂ in Rolling and Sliding Contact

Abstract

In this work, the tribological behavior of Ti-containing MoS₂ film is studied under sliding and rolling contacts. Ti-MoS₂ films deposited on AISI 52100 and M50 specimens contain ∼16 at% Ti are slightly substoichiometric in sulfur and have an amorphous structure. Experiments show that the friction and wear performance of Ti-MoS₂ films is influenced by humidity and temperature.

For the first time, the rolling contact performance of Ti-MoS₂ films was evaluated using a thrust bearing tribometer and ball-on-rod tribometers at ∼1 GPa Hertzian contact stress. Rolling contact measurements performed in humid air indicate that the useful life of Ti-MoS₂ as a solid lubricant depends upon the amount of coating material retained in the contacts. Results of the rolling contact experiments performed in a vacuum indicate that Ti-MoS₂ film on balls may function extremely well as a solid lubricant for ball bearings operating in vacuum.

KEY WORDS:

• Solid Lubricant
• MoS₂
• Rolling Contact
• Bearings

ACKNOWLEDGEMENT

We acknowledge Richard Fowler for providing assistance in the Ti-MoS₂ deposition. The authors wish to thank the UNT Center for Advanced Research and Technology (CART) for the FIB/TEM analyses, and the Nanovea Company for the nanoindentation measurements.

Funding

This research was funded by The Timken Company.