A revised interpretation of the mechanisms governing low friction tribolayer formation in alloyed-TMD self-lubricating coatings

Alloyed-transition metal dichalcogenide coatings are potential industrial dry lubricants for sliding in diverse environments. It is well established that these solid lubricant coatings show low friction properties due to the formation of a low shear-strength interface (tribolayer) during sliding. The mechanism governing the formation of these easy-shear tribolayers is analysed in this work. Mo-Se-C coatings were deposited using DC magnetron sputtering and were tribologically tested in two different sliding setups. Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM) were performed on the as-deposited coatings as well as the wear scars. This work unfolds the misconceptions behind the mechanisms / routes for the formation of the low friction interface and shows that its formation occurs both outside the coating (in the contact zone) and inside the top part of the coating (at the contact interface).

Automated summary

This study analyzed the mechanism behind the low friction properties of alloyed-transition metal dichalcogenide coatings, revealing that the formation of the low friction interface occurs both in the contact zone outside the coating and at the contact interface inside the top part of the coating.