Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation of a hydrodynamic air film. This solid lubrication is typically accomplished by coating the non-moving foil surface with a thin, soft polymeric film. The following paper introduces a systems approach in which the solid lubrication is provided by a combination of self lubricating shaft coatings coupled with various wear resistant and lubricating foil coatings. The use of multiple materials, each providing different functions is modeled after oil-lubricated hydrodynamic sleeve bearing technology which utilizes various coatings and surface treatments in conjunction with oil lubricants to achieve optimum performance. In this study, room temperature load capacity tests are performed on journal foil air bearings operating at 14,000 rpm. Different shaft and foil coating technologies such as plasma sprayed composites, ceramic, polymer and inorganic lubricant coatings are evaluated as foil bearing lubricants. The results indicate that bearing performance is improved through the individual use of the lubricants and treatments tested. Further, combining several solid lubricants together yielded synergistically better results than any material alone. DellaCorte, Christopher and Zaldana, Antonio R. and Radil, Kevin C. Glenn Research Center NASA/TM-2002-211482, NAS 1.15:211482, E-13250, ARL-TR-2867

Insightful working knowledge of friction, lubrication, and wear in machines Applications of tribology are widespread in industries ranging from aerospace, marine and automotive to power, process, petrochemical and construction. With world-renowned expert co-authors from academia and industry, Applied Tribology: Lubrication and Bearing Design, 3rd Edition provides a balance of application and theory with numerous illustrative examples. The book provides clear and up-to-date presentation of working principles of lubrication, friction and wear in vital mechanical components, such as bearings, seals and gears. The third edition has expanded coverage of friction and wear and contact mechanics with updated topics based on new developments in the field. Key features: Includes practical applications, homework problems and state-of-the-art references. Provides presentation of design procedure. Supplies clear and up-to-date information based on the authors’ widely referenced books and over 500 archival papers in this field. Applied Tribology: Lubrication and Bearing Design, 3rd Edition provides a valuable and authoritative resource for mechanical engineering professionals working in a wide range of industries with machinery including turbines, compressors, motors, electrical appliances and electronic components. Senior and graduate students in mechanical engineering will also find it a useful text and reference.

Whether an airplane or a space shuttle, a flying machine requires advanced materials to provide a strong, lightweight body and a powerful engine that functions at high temperature. The Aerospace Materials Handbook examines these materials, covering traditional superalloys as well as more recently developed light alloys. Capturing state-of-the-art d

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An understanding of friction and wear behavior of materials is crucial in order to improve their performance and durability. New research is providing the opportunity to solve common problems relating to the development of materials, surface modification, coatings, and processing methods across industries. Processing Techniques and Tribological Behavior of Composite Materials provides relevant theoretical frameworks and the latest empirical research findings on the strategic role of composite tribology in a variety of settings. This book is intended for students, researchers, academicians, and professionals working in industries where wear reduction and performance enhancement of machines and machine elements is essential to success.