CYCLIC DEFORMATION IN OXIDES, CARBIDES AND NITRIDES : alumina, magnesia, yttria, sic, b4c... and si3n4

This book presents the fatigue properties of structural materials used for the production of ceramics. It explains the cyclic deformation and how failures occur by fatigue. Dislocations related to fatigue are examined. The way that fatigue induces structural changes in material undergoing cyclic deformation is explained as well. A special chapter considers the importance of environmental effects on fatigue. Surface treatment such as shot pinning, sand blasting and laser treatment are described. The book explains how design should be carried out considering all the major factors leading to reduced fatigue resistance. Preface—Cyclic Deformation in Oxides, Carbides and Nitrides 8 Contents 10 About the Author 16 1 Basic Concepts of Fatigue 18 1.1 S–N Relations 21 1.1.1 S–N Relation in Alumina 27 1.1.2 S–N Relation in Magnesia 30 1.1.3 S–N Relation in Zirconia 34 1.1.4 S–N Relation in Si3N4 40 References 43 2 Endurance Limit 44 2.1 Fatigue Strength in Alumina 49 2.2 In Yttria-Stabilized Zirconia (YSZ) 49 2.3 In SiC 53 2.4 In Si3N4 53 References 61 3 Stress Cycles 62 3.1 Introduction 62 3.2 Low Cycle Fatigue 63 3.2.1 Morrow’s Relation 63 3.2.2 Coffin—Manson Concept: (The Strain-Life Equation) 64 3.3 High Cycle Fatigue 68 3.3.1 Stress-Life (S–N) Method 68 3.3.2 Strain-Life (E-N) Prediction of Fatigue Failure 70 3.4 Very High Cycle Tests 71 References 74 4 Fatigue Life 75 4.1 Introduction 75 4.2 Strain Life 76 4.2.1 Strain Life in Alumina 78 4.2.2 Strain Life in Yttria Stabilized Zirconia (YSZ) 79 4.2.3 Strain Life in SiC 79 References 83 5 Strengthening (Softening) 84 5.1 Introduction 84 5.2 Hardening in Alumina 85 5.3 Hardening in Magnesia 89 5.3.1 Introduction 89 5.3.2 Strength of MgO 90 5.4 Hardening in Pure Zirconia 92 5.5 Hardening in Partially Stabilized Zirconia (PSZ) 94 5.5.1 Hardening in Yttria Stabilized Zirconia (YSZ) 96 5.5.2 Y-TZP Zirconia Fatigue Behavior in Water 96 5.6 Hardening in SiC 99 5.6.1 Damage in SiC/SiC 100 5.6.2 Hardening in Al/SiC 102 5.6.3 Hardening in C/SiC and C–C/SiC 112 5.7 Hardening in B4C 122 5.8 Hardening in Si3N4 126 References 132 6 Structural Features 133 6.1 Introduction 133 6.2 Hysteresis 134 6.2.1 Hysteresis in Alumina 134 6.2.2 Carbon/Al2O3 139 6.3 Hysteresis in Magnesia 141 6.3.1 Mechanical Hysteresis (Cyclic Indentation) 141 6.3.2 Magnetic Hysteresis 144 6.3.3 Hysteresis in MgO/C Composite 147 6.4 Hysteresis in Zirconia 150 6.4.1 Hysteresis—Zirconia Transformation 150 6.4.2 Stabilized Zirconia 153 6.5 Hysteresis in SiC/SiC 167 6.6 Hysteresis in Si3N4 168 6.6.1 PH-Sensitive Coating 168 6.6.2 Electrical Properties (Hysteresis in C-V Curves) 173 6.6.3 Inelastic Deformation in Monolithic Si3N4 173 6.7 The Mean Stress 174 6.7.1 The Mean Stress in Alumina 178 6.7.2 The Mean Stress in Y-STZ 179 6.7.3 The Mean Stress in Si3N4 182 References 185 7 Underloading, Overloading and Cumulative Damage 186 7.1 Introduction 186 7.2 Underloading 187 7.3 Overloading 189 7.4 Cumulative Damage 198 7.4.1 Cumulative Damage in Alumina 200 7.4.2 Cumulative Damage in Magnesia (MgO) 205 7.4.3 Cumulative Damage in Zirconia 207 7.4.4 Cumulative Damage in SiC/SiC 209 7.5 Variable Amplitude Loading 215 7.6 Experimental Observations 219 7.6.1 Partially Stabilized Zirconia (PSZ) 219 7.6.2 Si3N4 Under Variable Stress Amplitude 221 References 224 8 Structural Observations in Fatigued Specimens 225 8.1 Introduction 225 8.2 Progression Markings, (Beach Marks) and Striations 226 8.2.1 Yttria Stabilized Zirconia (YSZ) 229 8.2.2 Striations in SiC/SiC Composite 231 8.2.3 Striations in Si3N4 231 8.3 Wallner Lines in Alumina 233 8.4 Dislocation Structure 233 8.4.1 Introduction 233 8.4.2 Dislocations in Alumina 234 8.4.3 Dislocations in Magnesia 237 8.4.4 Dislocations in Yttria Partially Stabilized Zirconia (YSZ) 242 8.4.5 Dislocations in Yttria Fully Stabilized Zirconia 243 8.4.6 Dislocations in B4C 251 8.4.7 Dislocations in Si3N4 253 References 255 9 Work Hardening (Softening) 256 9.1 Introduction 256 9.2 The Effect of Stress Amplitude 257 9.2.1 The Effect of Stress Amplitude in Alumina 259 9.2.2 The Effect of Stress Amplitude in Zirconia 262 9.2.3 The Effect of Stress Amplitude in Partially Stabilized Zirconia 264 9.2.4 The Effect of Stress Amplitude in Si3N4 268 9.3 The Effect of Strain Amplitude 274 9.3.1 Introduction 274 9.3.2 Effect of Strain Amplitude in SiCf/SiCm 275 9.3.3 Effect of Strain Amplitude in Si3N4 278 9.4 The Effect of Grain Size 280 9.4.1 The Effect of Grain Size in Alumina 281 9.4.2 The Effect of Grain Size in Y-TZP 285 9.4.3 The Effect of Grain Size in 8 mo% Y-TZP (Fully Stabilized) 290 9.4.4 The Effect of Grain Size in SiC 295 9.4.5 The Effect of Grain Size in Si3N4 298 9.5 The Effect of Temperature 303 9.5.1 The Effect of Temperature in Alumina 303 9.5.2 The Effect of Temperature in Yttria Fully Stabilized Zirconia 307 9.5.3 The Effect of Temperature in Partially Stabilized Zirconia 310 9.5.4 The Effect of Temperature in Yttria Partially Stabilized Zirconia 315 9.6 The Effect of Temperature in SiC 319 9.6.1 The Effect of Temperature in SiC/SiC 324 9.7 The Effect of Temperature in Si3N4 329 References 332 10 Fatigue Fracture 334 10.1 Introduction 334 10.1.1 Fracture in Alumina 336 10.1.2 Fracture in Magnesia 339 10.1.3 Fracture in Zirconia 344 10.1.4 Fracture in Partial Stabilized Zirconia (MgO) 348 10.1.5 Fracture in Yttria Partial Stabilized Zirconia 352 10.1.6 Fracture in SiC 356 10.1.7 Fracture in Si3N4 359 10.2 Temperature Effect on Fatigue Fracture 366 10.2.1 Introduction 366 10.2.2 Temperature Effect on Fatigue Fracture in SiC 367 10.2.3 Temperature Effect on Fatigue Fracture in Si3N4 369 References 372 11 The Notch Effect 374 11.1 Introduction 374 11.2 Notch Effect in Alumina 375 11.3 Notch Effect in 3% Y-Zirconia 378 11.4 Notch Effect in 3% MgO-Zirconia (Partially Stabilized) 381 11.5 Notch Effect in SiC 384 11.6 Notch Effect in Si3N4 388 References 396 12 The Effect of Environment 398 12.1 Introduction 398 12.2 The Effect of Environment in Alumina 399 12.2.1 In Moist Air and Dry Environment-N2 399 12.2.2 In Vacuum and Water Vapor 402 12.2.3 In Hydrogen 407 12.3 The Effect of Environment in Yttria Stabilized Zirconia (Y-TZP) 409 12.3.1 In Water 409 12.3.2 In Air 413 12.4 Effect of Environment in SiC 418 12.4.1 In Air 418 12.4.2 In Steam and Laboratory Air 420 12.5 Effect of Environment in Si3N4 424 12.5.1 In Water 424 12.5.2 In Air 428 12.5.3 In Vacuum 435 12.5.4 In Nitrogen 437 References 440 13 Surface Treatment 441 13.1 Introduction 441 13.2 Shot Peening Alumina 442 13.3 Shot Peening in Yttria Partially Stabilized Zirconia (PSZ) 448 13.4 Shot Peening in Si3N4/SiC Composite 451 13.5 Sandblasting 455 13.5.1 Introduction 455 13.5.2 Sandblasting in Alumina 456 13.5.3 Sandblasting in Yttria 460 13.6 Laser Treatment 463 13.6.1 Introduction 463 13.6.2 Laser Surface Treatment of Alumina 465 13.6.3 Laser Surface Treatment of Yttria Stabilized Zirconia (YSZ) 470 13.6.4 Laser Surface Treatment of SiC 473 13.6.5 Laser Surface Treatment of Si3N4 479 13.6.6 Laser Surface Treatment of Si3N4/SiC 481 References 488 14 Cyclic Deformation in Nanostructures 489 14.1 Introduction 489 14.2 Cyclic Deformation in Nanostructure (NS) Alumina 490 14.3 Cyclic Deformation in Nanostructure Yttria 492 14.4 Cyclic Deformation in Nanostructure SiC 496 14.5 Cyclic Deformation in Nanostructure Si3N4 499 References 504 15 Static Fatigue 505 15.1 1 Introduction 505 15.2 Static Fatigue in Alumina 506 15.3 Static Fatigue in Yttria-Stabilized Tetragonal Zirconia (Y-TZP) 506 15.4 Static Fatigue in SiC 511 15.5 Static Fatigue in B4C 514 15.6 Static Fatigue in Si3N4 515 References 521 16 Thermal Fatigue 522 16.1 Introduction 522 16.2 Thermal Fatigue in Alumina 523 16.3 Thermal Fatigue in YSZ 524 16.4 Thermal Fatigue in Boron Carbide (B4C) 530 16.5 Thermal Fatigue in Si3N4 534 References 540 Index 541