High Performance Space Lubrication of MoS₂ with Tantalum

Abstract

Molybdenum disulfide coatings have been employed as lubricants for spacecraft since the 1950s but continue to face major engineering challenges including performance in both terrestrial air and deep space vacuum environments and service lifetimes on the order of decades without maintenance. Co‐deposition of MoS2 with additive compounds provide enhancements in some circumstances but a lubricant which can perform in all space‐facing environments with long lifetimes remains an ongoing problem. Herein, it is demonstrated the multi‐environment adaptable performance of a novel MoS2 + tantalum lubricant coating, which excels as a lubricant in both terrestrial and space environments while the benchmark space‐qualified commercial MoS2 lubricants do not. It is noted that the 10% tantalum additive exhibits preferential oxidation in air to preserve the lubricating ability of MoS2 while forming phases of TaS2, which aid in the exceptional lubrication of MoS2 in ultra‐high vacuum. Additionally, completely different tribofilms of small particles and compact sheets are noted for air and vacuum environments, respectively, which allows for adaptable lubricating mechanisms from a single coating depending on the environment. This novel coating sets the benchmark as the first demonstrated instance of a fully versatile space lubricant which offers high‐performance in both terrestrial and deep space environments.

Core–Shell Engineering Boosted Active Hydrogen Generation in Cu2–xS/MoS2 Quantum Dots for Efficient Electrocatalytic Nitrate Reduction to Ammonia

“…Moreover, Raman spectroscopy is another useful piece of evidence to demonstrate the synthesis of MoS 2 . As shown in Figure 1f, the two small peaks are observed at 375 and 399 cm −1 , 42 which correspond to the characteristic E 1 2g and A 1g vibration modes of MoS 2 , respectively. The experiment proved that MoS 2 was successfully combined with the catalyst.…”

Recent advances in the mechanics of 2D materials

“…It has been well known that the interlayer shear resistance is low in most 2D materials, which is due to weak vdW interactions between atomically smooth crystal planes [185,186]. For this reason, many of their bulk counterparts, such as graphite and MoS 2 , have been used in applications as solid/dry lubricants [186,187]. This also leads to easy interlayer slip in 2D layered systems when subjected to stretching or bending, and in turn, the interlayer slip lowers the overall in-plane and bending stiffness.…”

Controlled Growing of Graphdiyne Film for Friction Reduction and Antiwear

“…The current international community is increasingly concerned about the energy crisis, and improving energy efficiency becomes an effective way to address this issue. , Seeking innovative ways to reduce friction and wear which have been confirmed as a key source of primary energy consumption is becoming a consensus in both science and the engineering fields. , Toward this target, ultralow friction and/or near-zero friction are proposed and implemented by fabricating materials or tuning contact forms between friction interfaces. , Among all tribological technologies, ultralow friction between solid surfaces is crucial, because solid lubrication can avoid adverse environmental impact of wasted lubricating oil and is applicable to wide ranges of working conditions such as high temperature and high vacuum. − Recent studies have reached an agreement that fine control over the structure and interface behavior of friction pairs is of great significance to reduce friction, and synthesizing materials with designed structure to realize ultralow friction is attracting more and more research attention.…”