Principles of Tribology

About the Authors xxi Second Edition Preface xxiii Preface xxv Introduction xxvii Part I Lubrication Theory 1 1 Properties of Lubricants 3 1.1 Lubrication States 3 1.2 Density of Lubricant 5 1.3 Viscosity of Lubricant 7 1.3.1 Dynamic Viscosity and Kinematic Viscosity 7 1.3.2 Relationship between Viscosity and Temperature 9 1.3.3 Relationship between Viscosity and Pressure 10 1.4 Non-Newtonian Behaviors 12 1.4.1 Ree-Eyring Constitutive Equation 12 1.4.2 Visco-Plastic Constitutive Equation 13 1.4.3 Circular Constitutive Equation 13 1.4.4 Temperature-Dependent Constitutive Equation 13 1.4.5 Visco-Elastic Constitutive Equation 14 1.4.6 Nonlinear Visco-Elastic Constitutive Equation 14 1.4.7 A Simple Visco-Elastic Constitutive Equation 15 1.5 Wettability of Lubricants 16 1.5.1 Wetting and Contact Angle 17 1.5.2 Surface Tension 17 1.6 Measurement and Conversion of Viscosity 19 1.6.1 Rotary Viscometer 19 1.6.2 Off-Body Viscometer 19 1.6.3 Capillary Viscometer 19 References 21 2 Basic Theories of Hydrodynamic Lubrication 22 2.1 Reynolds Equation 22 2.1.1 Basic Assumptions 22 2.1.2 Derivation of the Reynolds Equation 23 2.2 Hydrodynamic Lubrication 26 2.2.1 Mechanism of Hydrodynamic Lubrication 26 2.2.2 Boundary Conditions and Initial Conditions of the Reynolds Equation 27 2.2.3 Calculation of Hydrodynamic Lubrication 28 2.3 Elastic Contact Problems 29 2.3.1 Line Contact 29 2.3.2 Point Contact 31 2.4 Entrance Analysis of EHL 34 2.4.1 Elastic Deformation of Line Contacts 35 2.4.2 Reynolds Equation Considering the Effect of Pressure-Viscosity 35 2.4.3 Discussion 36 2.4.4 Grubin FilmThickness Formula 37 2.5 Grease Lubrication 38 References 40 3 Numerical Methods of Lubrication Calculation 41 3.1 Numerical Methods of Lubrication 42 3.1.1 Finite Difference Method 42 3.1.2 Finite Element Method and Boundary Element Method 48 3.1.3 Numerical Techniques 51 3.2 Numerical Solution of the Energy Equation 54 3.2.1 Conduction and Convection of Heat 55 3.2.2 Energy Equation 56 3.2.3 Numerical Solution of Energy Equation 59 3.3 Numerical Solution of Elastohydrodynamic Lubrication 60 3.3.1 EHL Numerical Solution of Line Contacts 60 3.3.2 EHL Numerical Solution of Point Contacts 64 3.4 Multi-Grid Method for Solving EHL Problems 68 3.4.1 Basic Principles of Multi-Grid Method 68 3.4.2 Nonlinear Full Approximation Scheme for the Multi-Grid Method 69 3.4.3 V andWIterations 71 3.4.4 Multi-Grid Solution of EHL Problems 71 3.4.5 Multi-Grid Integration Method 73 References 76 4 Lubrication Design of Typical Mechanical Elements 78 4.1 Slider and Thrust Bearings 78 4.1.1 Basic Equations 78 4.1.2 Solutions of Slider Lubrication 79 4.2 Journal Bearings 81 4.2.1 Axis Position and Clearance Shape 81 4.2.2 Infinitely Narrow Bearings 82 4.2.3 InfinitelyWide Bearings 85 4.3 Hydrostatic Bearings 88 4.3.1 Hydrostatic Thrust Plate 89 4.3.2 Hydrostatic Journal Bearings 90 4.3.3 Bearing Stiffness andThrottle 90 4.4 Squeeze Bearings 92 4.4.1 Rectangular Plate Squeeze 93 4.4.2 Disc Squeeze 94 4.4.3 Journal Bearing Squeeze 94 4.5 Dynamic Bearings 96 4.5.1 Reynolds Equation of Dynamic Journal Bearings 96 4.5.2 Simple Dynamic Bearing Calculation 98 4.5.3 General Dynamic Bearings 100 4.6 Gas Lubrication Bearings 102 4.6.1 Basic Equations of Gas Lubrication 102 4.6.2 Types of Gas Lubrication Bearings 103 4.7 Rolling Contact Bearings 106 4.7.1 Equivalent Radius R 107 4.7.2 Average Velocity U 107 4.7.3 Carrying Load PerWidthW/b 107 4.8 Gear Lubrication 108 4.8.1 Involute Gear Transmission 109 4.8.2 Arc Gear Transmission EHL 112 4.9 Cam Lubrication 114 References 116 5 Special Fluid Medium Lubrication 118 5.1 Magnetic Hydrodynamic Lubrication 118 5.1.1 Composition and Classification of Magnetic Fluids 118 5.1.2 Properties of Magnetic Fluids 119 5.1.3 Basic Equations of Magnetic Hydrodynamic Lubrication 121 5.1.4 Influence Factors on Magnetic EHL 123 5.2 Micro-Polar Hydrodynamic Lubrication 124 5.2.1 Basic Equations of Micro-Polar Fluid Lubrication 124 5.2.2 Influence Factors on Micro-Polar Fluid Lubrication 128 5.3 Liquid Crystal Lubrication 130 5.3.1 Types of Liquid Crystal 130 5.3.2 Deformation Analysis of Liquid Crystal Lubrication 132 5.3.3 Friction Mechanism of Liquid Crystal as a Lubricant Additive 136 5.4 Electric Double Layer Effect inWater Lubrication 137 5.4.1 Electric Double Layer Hydrodynamic Lubrication Theory 138 5.4.2 Influence of Electric Double Layer on Lubrication Properties 142 References 145 6 Lubrication Transformation and Nanoscale Thin Film Lubrication 147 6.1 Transformations of Lubrication States 147 6.1.1 Thickness-Roughness Ratio 147 6.1.2 Transformation from Hydrodynamic Lubrication to EHL 148 6.1.3 Transformation from EHL to Thin Film Lubrication 149 6.2 Thin Film Lubrication 152 6.2.1 Phenomenon ofThin Film Lubrication 153 6.2.2 Time Effect of Thin Film Lubrication 154 6.2.3 Shear Strain Rate Effect onThin Film Lubrication 157 6.3 Analysis ofThin Film Lubrication 158 6.3.1 Difficulties in Numerical Analysis of Thin Film Lubrication 158 6.3.2 Tichy's Thin Film Lubrication Models 160 6.4 Nano-Gas Film Lubrication 161 6.4.1 Rarefied Gas Effect 162 6.4.2 Boundary Slip 163 6.4.3 Reynolds Equation Considering the Rarefied Gas Effect 165 6.4.4 Calculation of Magnetic Head/Disk of UltraThin Gas Lubrication 166 References 169 7 Boundary Lubrication and Additives 171 7.1 Types of Boundary Lubrication 171 7.1.1 Stribeck Curve 171 7.1.2 Adsorption Films and Their Lubrication Mechanisms 172 7.1.3 Chemical Reaction Film and its Lubrication Mechanism 177 7.1.4 Other Boundary Films and their Lubrication Mechanisms 179 7.2 Theory of Boundary Lubrication 179 7.2.1 Boundary Lubrication Model 179 7.2.2 Factors Influencing Performance of Boundary Films 181 7.2.3 Strength of Boundary Film 184 7.3 Lubricant Additives 185 7.3.1 Oily Additives 185 7.3.2 Tackifier 186 7.3.3 Extreme Pressure Additives (EP Additives) 187 7.3.4 Anti-Wear Additives 187 7.3.5 Other Additives 187 References 189 8 Lubrication Failure and Mixed Lubrication 190 8.1 Roughness and Viscoelastic Material Effects on Lubrication 190 8.1.1 Modifications of Micro-EHL 190 8.1.2 Viscoelastic Model 191 8.1.3 LubricatedWear 192 8.2 Influence of Limit Shear Stress on Lubrication Failure 195 8.2.1 Visco-Plastic Constitutive Equation 195 8.2.2 Slip of Fluid-Solid Interface 196 8.2.3 Influence of Slip on Lubrication Properties 196 8.3 Influence of Temperature on Lubrication Failure 200 8.3.1 Mechanism of Lubrication Failure Caused by Temperature 200 8.3.2 Thermal Fluid Constitutive Equation 201 8.3.3 Analysis of Lubrication Failure 202 8.4 Mixed Lubrication 203 References 207 Part II Friction andWear 209 9 Surface Topography and Contact 211 9.1 Parameters of Surface Topography 211 9.1.1 ArithmeticMean Deviation Ra 211 9.1.2 Root-Mean-Square Deviation (RMS) or Rq 211 9.1.3 Maximum Height Rmax 212 9.1.4 Load-Carrying Area Curve 212 9.1.5 ArithmeticMean Interception Length of Centerline Sma 212 9.2 Statistical Parameters of Surface Topography 213 9.2.1 Height Distribution Function 214 9.2.2 Deviation of Distribution 215 9.2.3 Autocorrelation Function of Surface Profile 216 9.3 Structures and Properties of Surface 217 9.4 Rough Surface Contact 219 9.4.1 Single Peak Contact 219 9.4.2 Ideal Roughness Contact 220 9.4.3 Random Roughness Contact 221 9.4.4 Plasticity Index 223 References 223 10 Sliding Friction and its Applications 225 10.1 Basic Characteristics of Friction 225 10.1.1 Influence of Stationary Contact Time 226 10.1.2 Jerking Motion 226 10.1.3 Pre-Displacement 227 10.2 Macro-FrictionTheory 228 10.2.1 Mechanical EngagementTheory 228 10.2.2 Molecular Action Theory 229 10.2.3 Adhesive FrictionTheory 229 10.2.4 Plowing Effect 233 10.2.5 Deformation Energy Friction Theory 235 10.2.6 Binomial FrictionTheory 236 10.3 Micro-FrictionTheory 238 10.3.1 "Cobblestone" Model 238 10.3.2 Oscillator Models 240 10.3.3 Phonon Friction Model 242 10.4 Sliding Friction 243 10.4.1 Influence of Load 243 10.4.2 Influence of Sliding Velocity 244 10.4.3 Influence of Temperature 245 10.4.4 Influence of Surface Film 245 10.5 Other Friction Problems and Friction Control 246 10.5.1 Friction in SpecialWorking Conditions 246 10.5.2 Friction Control 247 References 250 11 Rolling Friction and its Applications 252 11.1 Basic Theories of Rolling Friction 252 11.1.1 Rolling Resistance Coefficient 252 11.1.2 Rolling Friction Theories 254 11.1.3 Adhesion Effect on Rolling Friction 258 11.1.4 Factors Influencing Rolling Friction of Wheel and Rail 260 11.1.5 Thermal Analysis ofWheel and Rail 262 Shock 268 11.2 Applications of Rolling Tribology in Design of Lunar Rover 271 11.2.1 Foundations of Force Analysis for Rigid Wheel 271 11.2.2 Mechanics Model of a Wheel on a Soft Surface 275 11.2.3 Dynamic Analysis of Rolling Mechanics of Lunar Rover with Unequal Diameter Wheel 278 References 280 12 Characteristics andMechanisms of Wear 282 12.1 Classification ofWear 282 12.1.1 Wear Categories 282 12.1.2 Wear Process 283 12.1.3 Conversion ofWear 285 12.2 AbrasiveWear 285 12.2.1 Types of AbrasiveWear 285 12.2.2 Factors Influencing AbrasiveWear 286 12.2.3 Mechanism of AbrasiveWear 289 12.3 AdhesiveWear 290 12.3.1 Types of AdhesiveWear 291 12.3.2 Factors Influencing AdhesiveWear 291 12.3.3 AdhesiveWear Mechanism 294 12.3.4 Criteria of Scuffing 296 12.4 FatigueWear 298 12.4.1 Types of FatigueWear 298 12.4.2 Factors Influencing FatigueWear 300 12.4.3 Criteria of Fatigue Strength and Fatigue Life 303 12.5 CorrosiveWear 307 12.5.1 OxidationWear 307 12.5.2 Special CorrosiveWear 309 12.5.3 Fretting 309 12.5.4 Cavitation Erosion 310 References 312 13 Macro-Wear Theory 314 13.1 Friction Material 315 13.1.1 Friction Material Properties 315 13.1.2 Wear-Resistant Mechanism 316 13.2 Wear Process Curve 317 13.2.1 Types ofWear Process Curves 317 13.2.2 Running-In 317 13.3 Surface Quality andWear 320 13.3.1 Influence of Geometric Quality 321 13.3.2 Physical Quality 323 13.4 Theory of AdhesionWear 324 13.5 Theory of EnergyWear 325 13.6 DelaminationWearTheory and FatigueWear Theory 327 13.6.1 DelaminationWearTheory 327 13.6.2 FatigueWear Theory 329 13.7 Wear Calculation 329 13.7.1 IBMWear Calculation Method 329 13.7.2 Calculation Method of CombinedWear 331 References 335 14 Anti-Wear Design and Surface Coating 337 14.1 Selection of Lubricant and Additive 337 14.1.1 Lubricant Selection 337 14.1.2 Grease Selection 340 14.1.3 Solid Lubricants 341 14.1.4 Seal and Filter 341 14.2 Matching Principles of Friction Materials 343 14.2.1 MaterialMating for AbrasiveWear 343 14.2.2 MaterialMating for AdhesiveWear 344 14.2.3 MaterialMating for Contact FatigueWear 345 14.2.4 Material Mating for FrettingWear 345 14.2.5 MaterialMating for CorrosionWear 345 14.2.6 Surface Hardening 346 14.3 Surface Coating 346 14.3.1 Common PlatingMethods 347 14.3.2 Design of Surface Coating 354 14.4 Coating Performance Testing 355 14.4.1 Appearance and Structure 355 14.4.2 Bond Strength Test 356 14.4.3 Hardness Test 360 14.4.4 Wear Test 360 14.4.5 Tests of Other Performances 361 References 362 15 Tribological Experiments 363 15.1 Tribological ExperimentalMethod and Devices 363 15.1.1 ExperimentalMethods 363 15.1.2 Commonly Used Friction andWear Testing Machines 364 15.1.3 EHL andThin Film Lubrication Test 365 15.2 Measurement ofWear Capacity 368 15.2.1 Weighing Method 368 15.2.2 Length Measurement Method 368 15.2.3 Profile Method 368 15.2.4 IndentationMethod 369 15.2.5 Grooving Method 371 15.2.6 PrecipitationMethod and Chemical AnalysisMethod 372 15.2.7 Radioactive Method 373 15.3 Analysis of Friction Surface Morphology 373 15.3.1 Analysis of Surface Topography 373 15.3.2 Atomic Force Microscope (AFM) 374 15.3.3 Surface Structure Analysis 375 15.3.4 Surface Chemical Composition Analysis 377 15.4 Wear State Detection 378 15.4.1 Ferrography Analysis 378 15.4.2 Spectral Analysis 379 15.4.3 Lubricant Composition Analysis 380 15.4.4 Mechanical Vibration and Noise Analysis 380 15.4.5 Lubrication State Analysis 380 15.5 Wear Failure Analysis 380 15.5.1 Site Investigation 380 15.5.2 Lubricant and its Supply System 381 15.5.3 Worn Part Analysis 381 15.5.4 Design and Operation 381 References 383 Part III Applied Tribology 385 16 Micro-Tribology 387 16.1 Micro-Friction 387 16.1.1 Macro-Friction and Micro-Friction 387 16.1.2 Micro-Friction and Surface Topography 388 16.1.3 Plowing Effect and Adhesion Effect 391 16.2 Micro-Contact and Micro-Adhesion 393 16.2.1 Solid Micro-Contact 393 16.2.2 Solid Adhesion and Surface Force 394 16.3 Micro-Wear 396 16.3.1 Micro-Wear Experiment 396 16.3.2 Micro-Wear of Magnetic Head and Disk 398 16.4 Molecular Film and Boundary Lubrication 401 16.4.1 Static Shear Property of Molecular Layer 401 16.4.2 Dynamic Shear Property of Monolayer and Stick-Slip Phenomenon 402 16.4.3 Physical State and Phase Change 404 16.4.4 Temperature Effect and Friction Mechanism 405 16.4.5 Rheological Property of Molecular Film 406 16.4.6 Organized Molecular Film 408 References 410 17 Metal Forming Tribology 412 17.1 Mechanics Basis of Metal Forming 412 17.1.1 Yield Criterion 412 17.1.2 Friction Coefficient and Shear Factor 413 17.1.3 Influence of Friction on Metal Forming 414 17.2 Forging Tribology 416 17.2.1 Upsetting Friction 416 17.2.2 Friction of Open Die Forging 418 17.2.3 Friction of Closed-Die Forging 418 17.2.4 Lubrication andWear 418 17.3 Drawing Tribology 421 17.3.1 Friction and Temperature 421 17.3.2 Lubrication 422 17.3.3 Wear of Drawing Die 424 17.3.4 Anti-Friction of Ultrasound in Drawing 427 17.4 Rolling Tribology 429 17.4.1 Friction in Rolling 429 17.4.2 Lubrication in Rolling 432 17.4.3 RollerWear 434 17.4.4 Emulsion Lubricity in Rolling 434 References 435 18 Bio-Tribology 437 18.1 Mechanics Basis for Soft Biological Tissue 437 18.1.1 Rheological Properties of Soft Tissue 437 18.1.2 Stress-Strain Curve Analysis 437 18.1.3 Anisotropy Relationships 439 18.2 Characteristics of Joint Lubricating Fluid 440 18.2.1 Joint Lubricating Fluid 440 18.2.2 Lubrication Characteristics of Joint Fluid 441 18.3 Lubrication of Human and Animal Joints 443 18.3.1 Performance of Human Joint 444 18.3.2 Joint Lubricating Fluid 445 18.3.3 Lubrication Mechanism of Joint 446 18.4 Friction andWear of Artificial Joint 447 18.4.1 Friction andWear Test 447 18.4.2 Wear of Artificial Joint 448 18.5 Other Bio-Tribological Studies 451 Referencess 452 19 Space Tribology 453 19.1 Features of Space Agency and Space Tribology 453 19.1.1 Working Conditions in Space 453 19.1.2 Features of Space Tribology Problems 455 19.2 Analysis of Performances of Space Tribology 456 19.2.1 Starved Lubrication 456 19.2.2 Parched Lubrication 456 19.2.3 Volatility Analysis 458 19.2.4 Creeping 460 19.3 Space Lubricating Properties 462 19.3.1 EHL Characteristics of Space Lubricant 462 19.3.2 Space Lubrication of Rolling Contact Bearing 463 References 465 20 Tribology of Micro Electromechanical System 466 20.1 Introduction 466 20.2 Tribological Analysis Technique for MEMS 467 20.2.1 Measurement of Micro/Nano-Frictional Force 467 20.2.2 Stick-Slip Phenomenon 470 20.2.3 Measurement of Micro Adhesive Force 473 20.2.4 Factors Influencing Surface Analysis 473 20.3 Tribological Study of a Micro Motor 484 20.3.1 Lubrication of Micro Motor 486 20.3.2 Measurement of Frictional Force 487 20.3.3 Influence Factors 488 20.4 Wear Analysis of MEMS 491 20.4.1 Mechanism of MicroWear 492 20.4.2 MicroWear of Monocrystalline Silicon 494 20.4.3 MicroWear of Nickel Titanium Shape Memory Alloy 496 20.4.4 Analysis of Surface Bulging 501 References 507 21 Ecological Tribology 509 21.1 Zero Friction and Superlubrication 509 21.1.1 Phenomenon of Superlubrication 509 21.1.2 Mechanisms of Superlubrication 510 21.1.3 Discussion of Superlubrication 514 21.2 Green Lubricant 516 21.2.1 Introduction of Green Lubricants 517 21.2.2 Development of Green Lubricating Oil for Refrigeration 518 21.2.3 Application Tests 520 21.2.4 Biodegradation Test 521 21.3 Friction-Induced Noise and Control 523 21.3.1 Stick-Slip Model 523 21.3.2 Friction-Induced Noise of Wheel-Rail 524 21.3.3 Friction-Induced Noise of Rolling Contact Bearing 526 21.4 Remanufacturing and Self-Repairing 528 21.4.1 Remanufacturing 529 21.4.2 Self-Repairing 531 References 532 Index 535