This book draws upon the science of tribology to understand, predict and improve abrasive machining processes. Pulling together information on how abrasives work, the authors, who are renowned experts in abrasive technology, demonstrate how tribology can be applied as a tool to improve abrasive machining processes. Each of the main elements of the abrasive machining system are looked at, and the tribological factors that control the efficiency and quality of the processes are described. Since grinding is by far the most commonly employed abrasive machining process, it is dealt with in particular detail. Solutions are posed to many of the most commonly experienced industrial problems, such as poor accuracy, poor surface quality, rapid wheel wear, vibrations, work-piece burn and high process costs. This practical approach makes this book an essential tool for practicing engineers. Uses the science of tribology to improve understanding and of abrasive machining processes in order to increase performance, productivity and surface quality of final products. A comprehensive reference on how abrasives work, covering kinematics, heat transfer, thermal stresses, molecular dynamics, fluids and the tribology of lubricants. Authoritative and ground-breaking in its first edition, the 2nd edition includes 30 per cent new and updated material, including new topics such as CMP (Chemical Mechanical Polishing) and precision machining for micro-and nano-scale applications.

Tribology of Abrasive Machining Processes

In this paper we report the conjugation of an aromatic moiety (pyrene (P), fluorene (F), or naphthalene (N)) to pentapeptides GAGAS (1), GVPVP (2), VPGVG (3), VTEEI (4), VYGGG (5), and YGFGG (6) to...

Aromatic−Aromatic Interactions Induce the Self-Assembly of Pentapeptidic Derivatives in Water To Form Nanofibers and Supramolecular Hydrogels

A microvolume liquid handling system includes a microdispenser (16) employing a piezoelectric transducer (60) attached to a glass capillary (62), a positive displacement pump (12) for priming and aspirating transfer liquid into the microdispenser (16), controlling the pressure of the liquid system, and washing the microdispenser (16) between liquid transfers, and a pressure sensor (14) to measure the liquid system pressure and produce a corresponding electrical signal. The pressure signal is used to verify and quantify the microvolume of transfer liquid dispensed and is used to perform automated calibration and diagnostics on the microdispenser (16).

Microvolume liquid handling system

Biomechanical properties of high-toughness double network hydrogels.

Modern engine lubricant specifications include compositional constraints in terms of the permitted level of sulphated ash, phosphorus and sulphur (SAPS). This necessitates a reduction in the concentration of the additive zinc dialkyldithiophosphate (ZDDP) used in engine oils, and there is currently great interest in identifying anti-wear additives that contain low or zero SAPS to partially or wholly replace ZDDP.

This paper reviews the main chemical classes that are reported in the literature as potential low- or zero-SAPS anti-wear agents. There are many such possible additives, although none appears to be quite as versatile as ZDDP. Instead, combinations of anti-wear and extreme pressure additives are likely to be employed in the future. The literature reveals a strong imbalance in the amount and depth of research carried out on the various additive types, with a great deal of research on a few classes of additives and very little recent work on most others. Copyright © 2007 John Wiley & Sons, Ltd.

Low- and zero-sulphated ash, phosphorus and sulphur anti-wear additives for engine oils

Friction, wear, and lubrication of hydrogels as synthetic articular cartilage

In recent years, synthetic hydrogels have been studied not only as possible replacements for articular cartilage but also as platforms for growing cartilage in a damaged joint. In the present study, the tribological behaviour of synthesized poly (2- hydroxyethyl) methacrylate (polyHEMA) hydrogels was investigated in a four-factor, two-level designed experiment using a device developed for biotribology research. The contact geometry consisted of a 6mm diameter stainless steel ball on flat polyHEMA disks. The variables in the designed experiment were (a) applied load, (b) lubrication, (c) hydrogel cross-link density and (d) degree of hydrogel hydration. Linear oscillating sliding contact tests were conducted for 30 minutes for each test. The results showed several significant main effects and first-order interactions. Increasing the applied load from 6 to 20N increased average hydrogel wear by 125%. Increased cross-link density reduced wear by over 60%. And increased hydration resulted in an increase of 130% in wear. The coefficient of friction ranged from a low value of 0.02 to a high of 1.7 while linear wear varied by a factor of over 60. Interactions between (a) hydration and lubrication and (b) hydration and cross-linking on wear were highly significant. The single most important finding from this study was that, as expected, there was no correlation between friction - which is commonly reported in the literature on hydrogels- and wear. Most of the data fell into two groups, namely low wear-low friction and high wear-low friction. These results may be useful in the tribological design of hydrogels for both low wear and low friction.

Michael J. Furey

Papers

Friction, wear, and lubrication of hydrogels as synthetic articular cartilage

Friction, Wear, and Lubrication of Hydrogels as Synthetic Articular Cartilage

Tribological behavior of unidirectional graphite-epoxy and carbon-PEEK composites

The formation of polymeric films directly on rubbing surfaces to reduce wear

A basic theoretical study of the temperature rise in sliding contact with multiple contacts