Abstract

Solid-gel hybrid lubricating systems are emerging as a promising candidate for next-generation space lubrication. Herein, three distinct WS2 films with tailored crystallinity, namely highly crystalline, nanocrystalline (NC-WS2), and amorphous, were deposited by magnetron sputtering. These WS2 films exhibited a comparable friction coefficient (COF) averaging 0.034, but their wear life reduced from 4.38 x 105 to 2.07 x 105 revolutions as crystallinity decreased. The WS2/MACs gel hybrid lubricants demonstrated exceptional performance enhancement, achieving a wear life exceeding 6.0 x 105 revolutions. Notably, the NC WS2/MACs gel system exhibited optimal tribological characteristics, delivering the lowest recorded COF of 0.047 +/- 0.002 and an ultralow wear rate of 2.70 x 10-8 mm3/N & sdot;m. Mechanisms reveal that onion-like nanostructures enhance oil penetration, while the gel network provides dual wear protection via debris encapsulation and tribo-induced in-situ graphitization. This work offers a viable technical solution for space lubrication, supporting the development of more durable spacecraft and expanding the boundaries of space exploration.

Keywords Plus: THIN-FILMS，FRICTION，WS2，VACUUM

Published in TRIBOLOGY INTERNATIONAL，Volume218；10.1016/j.triboint.2026.111699，JUN 2026