Modern Self-Lubricating Coatings for Automotive, Aviation and Spacecraft Industry

Abstract:

A series of nanocomposite, self-lubricating coatings designed for dry friction at different temperatures based on amorphous carbon or amorphous MoS₂ or amorphous MoO₃ matrix was deposited by magnetron sputtering onto high-speed (HS) steel or Ti6Al4V alloy substrates and characterized with use of LM, SEM, TEM and HRTEM microscopy as well as with use of several other techniques. The nanocomposite nc-MeC/a-C(:H) carbon-based coatings (where Me=Cr or Ti or W) were composed of different nanocrystalline phases of a given transition metal of a size of several nanometers embedded in an amorphous hydrogenated or hydrogen-free carbon matrix. The nanocomposite MoS₂(Ti,W) coatings were composed of Ti_α or W_α or TiS₂ nanocrystallites of 3 nm ÷ 10 nm diam. embedded in a semi-crystalline MoS₂ matrix with MoS₂ clusters of 3 nm÷8 nm diam. The magnetron sputtered MoO₃ based coatings after deposition were composed of Ag nanocrystallites of 50 nm÷100 nm diam. embedded in an amorphous fractal-type matrix composed of MoO₃ clusters of different size from very small to relatively great ones (not exceeding, however, 400 nm diam.). These amorphous clusters after 3 hours annealing in the ambient atmosphere under normal pressure at 300 °C transform into nanocrystalline MoO₃ ones or after same annealing at 450 °C into crystalline silver molybdate Ag₂MoO₄ ones. The coatings preserve their resistance to wear and their low friction coefficient to approximately 250 °C in case of carbon-based coatings or to 350 °C in case of MoS₂-based ones or to 550 °C in case of MoO₃-based coatings. Several mechanical and tribological chracteristics of the coatings are given in the paper as well.

• Periodical: Materials Science Forum (Volume 782)
• Pages: 31-38
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.782.31
• Online since: April 2014
• Authors: Bogdan Wendler, Tomasz Moskalewicz, Marcin Kot, Slawomir Zimowski, Aleksandra Czyrska-Filemonowicz, Wojciech Pawlak, Adam Rylski, Katarzyna Wlodarczyk-Kowalska, Piotr Nolbrzak, Marcin Makowska
• Keywords: Carbon-Based Coatings, Friction Coefficient (FC), Magnetron Sputtering, Microstructure, MoO₃-based Coatings, MoS₂-based Coatings, Nanocomposite Coatings, Nanohardness, Nanostructure, Resistance to Corrosion, Resistance to Wear, Self-Lubrication

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