Enhancing irradiation tolerance and inducing superlubricity in MoS2/W multilayer film exposed to atomic oxygen
Xin Fan, Wenhao He, Z. L. Zhang, Beibei He, Yan‐Wen Lin, Qinsheng He, Liang‐Feng Huang, Siming Ren, Zhibin Lu, Jibin Pu, Qunji Xue
Abstract
Molybdenum disulfide (MoS2) is a ubiquitous lubricant for use in outer space. Here, we present a MoS2/W nano-multilayer film engineered through precise structural optimization by fine-tuning sputtering parameters. This architecture, featuring alternating metallic W layers and highly oriented MoS2 layers, restricts oxidation depth to less than 25 nm (2.7×1021 atoms·cm−2)—just one-23rd of that observed in composite structure—outperforming previously reported space lubricants. Intriguingly, the metal oxide nanoparticles formed during atomic oxygen irradiation further reduce friction, enabling robust superlubricity with a friction coefficient of ~0.008. Our approach, bolstered by theoretical calculations and experiments, elucidates that this achievement is facilitated by the dual strengthening of the nano-multilayer structure and the in-situ generation of high-concentration, small-sized oxide nanoparticles at the contact interface. These findings provide invaluable insights into the design of irradiation-resistant and durable lubricating materials for space applications. MoS2 is an attractive lubricant for space-based applications, yet suffers from degradation by atomic oxygen in low Earth orbit. Here, a MoS2/W multilayer film exhibits oxidation resistance and sustained super lubricity, offering a lubrication solution for aerospace applications.