Mechanics and Chemistry in Lubrication

Although it is widely recognized that friction, wear and lubrication are linked together in a single interdisciplinary complex of scientific learning and technological practice, fragmented and specialized approaches still predominate. In this book, the authors examine lubrication from an interdisciplinary viewpoint. They demonstrate that once the treatment of lubrication is released from the confines of the fluid film concept, this interdisciplinary approach comes into full play. Tribological behavior in relation to lubrication is then examined from two major points of view: one is mechanical, not only with respect to the properties and behavior of the lubricant but also of the surfaces being lubricated. The other is chemical and encompasses the chemistry of the lubricant, the surfaces and the ambient surroundings. It is in the emphasis on the interaction of the basic mechanical and chemical processes in lubrication that this book differs from conventional treatments.

Contents1. Introduction 1.1. What Is Friction 1.2. Friction and Wear 1.3. Tribology 1.4. Some Further Statements about Lubrication References2. Simple Hydrodynamic Theory: The Reynolds Equation in Two Dimensions 2.1. Beauchamp Tower's Bearing Experiments 2.2. A n Engineering Derivation of the Two-Dimensional Reynolds Equation 2.3. The Reynolds Equation in Use: The Plane Slider Bearing 2.4. Energy Losses in the Hydrodynamic Lubrication of Bearings 2.5. The Pivoted Slider Bearing: Design Variables 2.6. The Full Journal Bearing 2.6.1. Application of the Reynolds Equation to the Full Journal' Bearing 2.6.2. Friction in the Full Journal Bearing References Appendix 3. Some Advanced Aspects of Hydrodynamic Lubrication 3.1. The Classical Fluid 3.1.1. Stress Analysis of a Fluid 3.1.2. The Simple Visccus Fluid 3.2. The Navier-Stokes Equations 3.3. The Generalized Reynolds Equation 3.4. Squeeze Films 3.5. Elastohydrodynamic Lubrication 3.5.1. Elastohydrodynamic Theory 3.5.2. Some Elastohydrodynamic Solutions: Line Contact 3.5.3. Elastohydrodynamic Solutions for Point Contact 3.5.4. Experimental Observations of Elastohydrodynamic Lubrication References 4. The Nature and Properties of Liquids 4.1. The Properties of Liquids and Lubrication 4.2. Newtonian and Non-Newtonian Viscosity 4.3. Capillary Viscometry 4.3.1. Newtonian Flow through a Capillary 4.3.2. Non-Newtonian Capillary Flow 4.3.3. Sources of Error in Capillary Viscometry 4.4. Capillary Viscometers 4.4.1. The Cannon-Fenske Viscometer 4.4.2. Capillary Viscometry Under Pressure 4.5. Rotational Viscometry and Viscometers 4.5.1. The Couette Viscometer 4.5.2. The Cone-and-Plate Viscometer 4.6. Rolling-Ball and Falling-Sinker Viscometers 4.7. Orifice Viscometers 4.8. Influence of Temperature and Pressure on Viscosity 4.8.1. The Walther Equation and ASTM Viscosity-Temperature Charts 4.8.2. The Viscosity Index 4.8.3. Pressure and Viscosity 4.9. Theories of Viscosity and the Molecular Structure of Liquids 4.10. Compressibility and Bulk Modulus 4.11. The Role of Compressibility in Lubrication References 5. Gases as Lubricating Fluids 5.1. Fundamentals of Gas Film Lubrication 5.2. Gas-Lubricated Bearings 5.3. Properties of Gases References 6. Measurement of Fluid Film Thickness and Detection of Film Failure 6.1. Electrical Methods 6.1.1. Film Thickness by Electrical Resistance 6.1.2. Film Thickness by Electrical Capacitance 6.2. ODtical Interferometry 6.3. X-Ray Transmission 6.4. Summarizing Discussion of Film Thickness Measurement 6.5. The Meaning of Film Failure 6.6. Electrical Methods of Detecting Film Failure 6.7. Detection of Fluid Film Failure by Friction or by Examination of Surface Condition References 7. Friction: Phenomenology. Detection and Measurement 7.1. Basic Phenomenology of the Friction of Solid Bodies 7.2. Simple Behavioral Aspects of Static and Kinetic Friction 7.3. Experimental Arrangements for Detection and Measurement of Friction 7.3.1. Devices Utilizing Elastic Deflection 7.3.2. Dead-Weight Tangential Traction Devices 7.3.3. Inclined Plane Method for Static Friction 7.3.4. Damping of Oscillatory Motion References 8. Friction: Mechanisms and Analysis 8.1. A Simple Mechanism for the Friction of Solid Metallic Bodies 8.2. Extension of the Adhesive-Junction Model for Friction 8.3. Intermittent Motion in Frictional Sliding: Stick-Slip Oscillation 8.4. Frictionally Induced Quasiharmonic Vibration 8.5. The Nature of Static and Kinetic Friction 8.6. Sliding Speed and Friction 8.7.