Dry lubricant

About: Dry lubricant is a research topic. Over the lifetime, 2187 publications have been published within this topic receiving 43905 citations. The topic is also known as: solid lubricant.

Hollow nanoparticles of WS2 as potential solid-state lubricants

Abstract: Solid lubricants fill a special niche in reducing wear in situations where the use of liquid lubricants is either impractical or inadequate, such as in vacuum, space technology or automotive transport. Metal dichalcogenides MX2 (where M is, for instance, Mo or W and X is S or Se) are widely used as solid lubricants. These materials are characterized by a layered structure with weak (van der Waals) inter-layer forces that allow easy, low-strength shearing1,2. Within the past few years, hollow nanoparticles (HNs) of MX2 with structures similar to those of nested carbon fullerenes and nanotubes have been synthesized3,4. Here we show that these materials can act as effective solid lubricants: HN-WS2 outperforms the solid lubricants 2H-MoS2 and 2H-WS2 in every respect (friction, wear and lifetime of the lubricant) under varied test conditions. We attribute the outstanding performance of HN-WS2 to its chemical inertness and the hollow cage structure, which imparts elasticity and allows the particles to roll rather than to slide.

Thin films of fullerene-like MoS2 nanoparticles with ultra-low friction and wear

Abstract: The tribological properties of solid lubricants such as graphite and the metal dichalcogenides MX2 (where M is molybdenum or tungsten and X is sulphur or selenium) are of technological interest for reducing wear in circumstances where liquid lubricants are impractical, such as in space technology, ultra-high vacuum or automotive transport. These materials are characterized by weak interatomic interactions (van der Waals forces) between their layered structures, allowing easy, low-strength shearing. Although these materials exhibit excellent friction and wear resistance and extended lifetime in vacuum, their tribological properties remain poor in the presence of humidity or oxygen, thereby limiting their technological applications in the Earth's atmosphere. But using MX2 in the form of isolated inorganic fullerene-like hollow nanoparticles similar to carbon fullerenes and nanotubes can improve its performance. Here we show that thin films of hollow MoS2 nanoparticles, deposited by a localized high-pressure arc discharge method, exhibit ultra-low friction (an order of magnitude lower than for sputtered MoS2 thin films) and wear in nitrogen and 45% humidity. We attribute this 'dry' behaviour in humid environments to the presence of curved S-Mo-S planes that prevent oxidation and preserve the layered structure.

Lubricant Additives: Chemistry and Applications

Abstract: Deposit Control Additives: Oxidation Inhibitors Antioxidants, J. Dong and C.A. Migdal Zinc Dithiophosphates, R.A. McDonald Ashless Phosphorus-Containing Lubricating Oil Additives, W.D. Phillips Detergents, S.Q. A. Rizvi Dispersants, S.Q. A. Rizvi Film-Forming Additives Selection and Application of Solid Lubricants as Friction Modifiers, G. Mariani Organic Friction Modifiers, D. Kenbeck and T.F. Bunemann Antiwear Additives and Extreme-Pressure Additives Ashless Antiwear and Extreme-Pressure Additives, L.O. Farng Sulfur Carriers, T. Rossrucker and A. Fessenbecker Viscosity Control Additives: Viscosity Modifiers Olefin Copolymer Viscosity Modifiers, M.J. Covitch Polymethacrylate Viscosity Modifi ers and Pour Point Depressants, B.G. Kinker Pour Point Depressants, J. Souchik Miscellaneous Additives Tackifiers and Antimisting Additives, V.J. Levin, R.J. Stepan, and A.I. Leonov Seal Swell Additives, R.E. Zielinski and C.M. A. Chilson Antimicrobial Additives for Metalworking Lubricants, W.R. Schwingel and A.C. Eachus Surfactants in Lubrication, G. Biresaw Corrosion Inhibitors and Rust Preventatives, M.T. Costello Additives for Bioderived and Biodegradable Lubricants, M. Miller Applications Additives for Crankcase Lubricant Applications, E.A. Bardasz and G.D. Lamb Additives for Industrial Lubricant Applications, L.R. Rudnick Formulation Components for Incidental Food-Contact Lubricants, S. Lawate Lubricants for the Disk Drive Industry, T.E. Karis Additives for Grease Applications, R. Silverstein and L.R. Rudnick Trends Long-Term Trends in Industrial Lubricant Additives, F.L. Lee and J.W. Harris Long-Term Additive Trends in Aerospace Applications, C.E. Snyder, L.J. Gschwender, and S.K. Sharma Eco Requirements for Lubricant Additives, T. Habereder, D. Moore, and M. Lang Methods and Resources Testing Methods for Additive Lubricant Performance, L.R. Rudnick Lubricant Industry-Related Terms and Acronyms, L.R. Rudnick Internet Resources for Additive/Lubricant Industry, L.R. Rudnick Index

Ionic liquids as advanced lubricant fluids.

Abstract: Ionic liquids (ILs) are finding technological applications as chemical reaction media and engineering fluids. Some emerging fields are those of lubrication, surface engineering and nanotechnology. ILs are thermally stable, non-flammable highly polar fluids with negligible volatility, these characteristics make them ideal candidates for new lubricants under severe conditions, were conventional oils and greases or solid lubricants fail. Such conditions include ultra-high vacuum and extreme temperatures. Other very promising areas which depend on the interaction between IL molecules and material surfaces are the use of ILs in the lubrication of microelectromechanic and nanoelectromechanic systems (MEMS and NEMS), the friction and wear reduction of reactive light alloys and the modification of nanophases.

Aluminum Metal-Matrix Composites for Automotive Applications: Tribological Considerations

Abstract: Aluminum alloys possess a number of mechanical and physical properties that make them attractive for automotive applications, but they exhibit extremely poor resistance to seizure and galling. Reinforcement of aluminum alloys with solid lubricants, hard ceramic particles, short fibers and whiskers results in advanced metal-matrix composites (MMC) with precise balances of mechanical, physical and tribological characteristics. Advanced manufacturing technologies such as squeeze infiltration of molten alloys into fiber performs can be employed to produce near net-shape components. Brake rotors, pistons, connecting rods and integrally cast MMC engine blocks are some of the successful applications of Al MMCs in automotive industry. This paper gives an overview of the tribological behavior of Al MMCs reinforced with hard particles, short fibers, and solid lubricants, and the technologies for producing automotive parts from these novel materials.