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.

The proceedings of STAIF-2007 feature a broad spectrum of topics on. These topics span the range from basic research to the most recent technology advances and hardware development and testing. The proceedings will be of particular interest to program managers, practicing engineers, academicians, graduate students, system designers, and researchers interested in the fields of space technology and space science.

PS304, a plasma spray deposited solid lubricant coating developed for high temperature sliding contacts was deposited on nine different substrate metals, heat treated at 650C in either air or argon and subsequently tested for strength using a commercially available pull-off adhesion test. Some samples were examined metallographically to help elucidate and explain the results. As deposited coatings exhibit pull-off strengths typically between 16 and 20 MPa with failure occuring (cohesively) within the coating. Heat treatment in argon at 650 C results in a slight increase in coating (cohesive) strength of about 30 percent to 21 to 27 MPa. Heat treatment in air at 650 C results in a dramatic increase in strength to over 30 MPa, exceeding the strength of the epoxy used in the pull test. Cross section metallographic analyses show that no microstructural coating changes occur following the argon heat treatments, however, exposure to air at 650C gives rise to the formation of a second chromium-rich phase precipitate within the PS304 NiCr constituent which provides a strengthening effect and a slight (approximately 5 percent) coating thickness increase. Subsequent heat treatments do not result in any further coating changes. Based upon these studies, PS304 is a suitable coating for use on a wide variety of high temperature substrates and must be heat treated following deposition to enhance strength and ensure dimensional stability. DellaCorte, Christopher Glenn Research Center NASA/TM-2002-211483, NAS 1.15:211483, E-13251

The performance and durability of advanced, high temperature foil air bearings are evaluated under a wide range (10-50 kPa) of loads at temperatures from 25 to 650 deg C. The bearings are made from uncoated nickel based superalloy foils. The foil surface experiences sliding contact with the shaft during initial start/stop operation. To reduce friction and wear, the solid lubricant coating, PS 304, is applied to the shaft by plasma spraying. PS304 is a NiCr based Cr2O3 coating with silver and barium fluoride/calcium fluoride solid lubricant additions. The results show that the bearings provide lives well in excess of 30,000 cycles under all of the conditions tested. Several bearings exhibited lives in excess of 100,000 cycles. Wear is a linear function of the bearing load. The excellent performance measured in this study suggests that these bearings and the PS 304 coating are well suited for advanced high temperature, oil-free turbomachinery applications.

High Temperature Coatings, Second Edition, demonstrates how to counteract the thermal effects of rapid corrosion and degradation of exposed materials and equipment that can occur under high operating temperatures. This is the first true practical guide on the use of thermally protective coatings for high-temperature applications, including the latest developments in materials used for protective coatings. It covers the make-up and behavior of such materials under thermal stress and the methods used for applying them to specific types of substrates, as well as invaluable advice on inspection and repair of existing thermal coatings. With his long experience in the aerospace gas turbine industry, the author has compiled the very latest in coating materials and coating technologies, as well as hard-to-find guidance on maintaining and repairing thermal coatings, including appropriate inspection protocols. The book is supplemented with the latest reference information and additional support to help readers find more application- and industry-type coatings specifications and uses. - Offers an overview of the underlying fundamental concepts of thermally-protective coatings, including thermodynamics, energy kinetics, crystallography and equilibrium phases - Covers essential chemistry and physics of underlying substrates, including steels, nickel-iron alloys, nickel-cobalt alloys and titanium alloys - Provides detailed guidance on a wide variety of coating types, including those used against high temperature corrosion and oxidative degradation and thermal barrier coatings