**Preface XI**


Chapter 7 **Lubrication and Friction of Porous Oil Bearing Materials 113** Yanguo Yin and Guotao Zhang

Preface

processing techniques.

Lubrication is critical in any application where moving parts are involved. As problems faced by the world increase in complexity, lubrication increases in importance while the conditions while lubrication is required under more extreme conditions of speed, tempera‐ ture, and stress. In addition, the materials to be lubricated have become more exotic and potentially reactive due to the increased stress and temperature requirements. In the near future, lubricants with different compositions will be necessary for various applications, in‐ cluding refrigeration due to the development of more environment-friendly refrigerants and aerospace due to the use of higher-performance alloys for bearings and machining to reduce hazardous waste generation, among others. The extreme conditions make the properties of both the lubricant base stock and the additives more important and have required the devel‐ opment of more exotic bearing materials, including composition, surface treatments, and

This book is divided into two sections: first, the chemistry of some lubricants and lubricant additives are examined. Typical lubricant base stocks do not have ideal lubricating properties for use in many applications, so a series of additives are formulated to improve these proper‐ ties. The chapters include both experimental and theoretical approaches to the decomposition of the lubricants and additives. Second, the lubrication of a variety of different substances is investigated in order to optimize lubricant properties for certain applications. It has become more apparent that the environmental effects and human health effects of degraded lubri‐ cants and additives are also important. Some of these studies are directed toward the develop‐ ment of more environment-friendly materials and lubricants for important applications. This

book covers some of the important research in the area of lubricants and lubrication.

**David W. Johnson** University of Dayton Dayton, Ohio, USA
