Table of Contents

Foreword v

Preface xvii

List of Contributors xix

1 Fibers for Ceramic Matrix Composites 1
Bernd Clauß

1.1 Introduction 1

1.2 Fibers as Reinforcement in Ceramics 1

1.3 Structure and Properties of Fibers 2

1.3.1 Fiber Structure 2

1.3.2 Structure Formation 3

1.3.3 Structure Parameters and Fiber Properties 4

1.4 Inorganic Fibers 7

1.4.1 Production Processes 7

1.4.1.1 Indirect Fiber Production 7

1.4.1.2 Direct Fiber Production 7

1.4.2 Properties of Commercial Products 9

1.4.2.1 Comparison of Oxide and Non-oxide Ceramic Fibers 9

1.4.2.2 Oxide Ceramic Filament Fibers 10

1.4.2.3 Non-oxide Ceramic Filament Fibers 11

1.5 Carbon Fibers 12

1.5.1 Production Processes 15

1.5.1.1 Carbon Fibers from PAN Precursors 15

1.5.1.2 Carbon Fibers from Pitch Precursors 17

1.5.1.3 Carbon Fibers from Regenerated Cellulose 17

1.5.2 Commercial Products 18

Acknowledgments 19

2 Textile Reinforcement Structures 21
Thomas Gries, Jan Stüve, and Tim Grundmann

2.1 Introduction 21

2.1.1 Definition for the Differentiation of Two-Dimensional and Three-Dimensional Textile Structures 23

2.1.2 Yarn Structures 23

2.2 Two-Dimensional Textiles 24

2.2.1 Nonwovens 24

2.2.2 Woven Fabrics 25

2.2.3 Braids 27

2.2.4 Knitted Fabrics 28

2.2.5 Non-crimp Fabrics 29

2.3 Three-Dimensional Textiles 30

2.3.1 Three-Dimensional Woven Structures 30

2.3.2 Braids 32

2.3.2.1 Overbraided Structures 32

2.3.2.2 Three-Dimensional Braided Structures 34

2.3.3 Three-Dimensional Knits 37

2.3.3.1 Multilayer Weft-Knits 37

2.3.3.2 Spacer Warp-Knits 37

2.4 Preforming 38

2.4.1 One-Step/Multi-Step Preforming 38

2.4.2 Cutting 39

2.4.3 Handling and Draping 39

2.4.4 Joining Technologies 40

2.5 Textile Testing 41

2.5.1 Tensile Strength 41

2.5.2 Bending Stiffness 41

2.5.3 Filament Damage 42

2.5.4 Drapability 42

2.5.5 Quality Management 42

2.6 Conclusions 43

2.6.1 Processability of Brittle Fibers 43

2.6.2 Infiltration of the Textile Structure 43

2.6.3 Mechanical Properties of the Final CMC Structure 44

2.6.4 Productivity and Production Process Complexity 44

2.7 Summary and Outlook 44

Acknowledgments 45

3 Interfaces and Interphases 49
Jacques Lamon

3.1 Introduction 49

3.2 Role of Interfacial Domain in CMCs 50

3.3 Mechanism of Deviation of Transverse Cracks 52

3.4 Phenomena Associated to Deviation of Matrix Cracks 53

3.5 Tailoring Fiber/Matrix Interfaces. Influence on Mechanical Properties and Behavior 55

3.6 Various Concepts of Weak Interfaces/Interphases 59

3.7 Interfacial Properties 61

3.8 Interface Control 64

3.9 Conclusions 66

4 Carbon/Carbons and Their Industrial Applications 69
Roland Weiß

4.1 Introduction 69

4.2 Manufacturing of C/Cs 69

4.2.1 Carbon Fiber Reinforcements 71

4.2.2 Matrix Systems 73

4.2.2.1 Thermosetting Resins as Matrix Precursors 73

4.2.2.2 Thermoplastics as Matrix Precursors 74

4.2.2.3 Gas Phase Derived Carbon Matrices 75

4.2.3 Redensification/Recarbonization Cycles 79

4.2.4 Final Heat Treatment (HTT) 80

4.3 Industrial Applications of C/Cs 82

4.3.1 Oxidation Protection of C/Cs 83

4.3.1.1 Bulk Protection Systems for C/Cs 83

4.3.1.2 Outer Multilayer Coatings 88

4.3.1.3 Outer Glass Sealing Layers 90

4.3.2 Industrial Applications of C/Cs 92

4.3.2.1 C/Cs for High Temperature Furnaces 97

4.3.2.2 Application for Thermal Treatments of Metals 102

4.3.2.3 Application of C/C in the Solar Energy Market 105

5 Melt Infiltration Process 113
Bernhard Heidenreich

5.1 Introduction 113

5.2 Processing 114

5.2.1 Build-up of Fiber Protection and Fiber/Matrix Interface 115

5.2.2 Manufacture of Fiber Reinforced Green Bodies 117

5.2.3 Build-up of a Porous, Fiber Reinforced Preform 118

5.2.4 Si Infiltration and Build-up of SiC Matrix 119

5.3 Properties 121

5.3.1 Material Composition 127

5.3.2 Mechanical Properties 128

5.3.3 CTE and Thermal Conductivity 130

5.3.4 Frictional Properties 131

5.4 Applications 131

5.4.1 Space Applications 131

5.4.2 Short-term Aeronautics 133

5.4.3 Long-term Aeronautics and Power Generation 133

5.4.4 Friction Systems 134

5.4.5 Low-Expansion Structures 135

5.4.6 Further Applications 136

5.5 Summary 137

6 Chemical Vapor Infiltration Processes for Ceramic Matrix Composites: Manufacturing, Properties, Applications 141
Martin Leuchs

6.1 Introduction 141

6.2 CVI Manufacturing Process for CMCs 143

6.2.1 Isothermal-Isobaric Infiltration 144

6.2.2 Gradient Infiltration 145

6.2.3 Discussion of the Two CVI-processes 146

6.3 Properties of CVI Derived CMCs 146

6.3.1 General Remarks 146

6.3.2 Mechanical Properties 148

6.3.2.1 Fracture Mechanism and Toughness 148

6.3.2.2 Stress-Strain Behavior 149

6.3.2.3 Dynamic Loads 151

6.3.2.4 High Temperature Properties and Corrosion 151

6.3.2.5 Thermal and Electrical Properties 153

6.4 Applications and Main Developments 153

6.4.1 Hot Structures in Space 153

6.4.2 Gas Turbines 155

6.4.3 Material for Fusion Reactors 156

6.4.4 Components for Journal Bearings 156

6.5 Outlook 161

7 The PIP-process: Precursor Properties and Applications 165
Günter Motz, Stephan Schmidt, and Steffen Beyer

7.1 Si-based Precursors 165

7.1.1 Introduction 165

7.1.2 Precursor Systems and Properties 166

7.1.3 Cross-Linking Behavior of Precursors 167

7.1.4 Pyrolysis Behavior of Precursors 169

7.1.5 Commercial Available Non-oxide Precursors 171

7.2 The Polymer Impregnation and Pyrolysis Process (PIP) 171

7.2.1 Introduction 171

7.2.2 Manufacturing Technology 173

7.2.2.1 Preform Manufacturing 173

7.2.2.2 Manufacturing of CMC 175

7.3 Applications of the PIP-process 180

7.3.1 Launcher Propulsion 180

7.3.2 Satellite Propulsion 182

7.4 Summary 184

8 Oxide/Oxide Composites with Fiber Coatings 187
George Jefferson, Kristin A. Keller, Randall S. Hay, and Ronald J. Kerans

8.1 Introduction 187

8.2 Applications 189

8.3 CMC Fiber-Matrix Interfaces 189

8.3.1 Interface Control 190

8.3.2 Fiber Coating Methods 191

8.3.3 CMC Processing 194

8.3.4 Fiber-Matrix Interfaces 195

8.3.4.1 Weak Oxides 195

8.3.4.2 Porous Coatings and Fugitive Coatings 197

8.3.4.3 Other Coatings 198

8.4 Summary and Future Work 198

9 All-Oxide Ceramic Matrix Composites with Porous Matrices 205
Martin Schmücker and Peter Mechnich

9.1 Introduction 205

9.1.1 Oxide Ceramic Fibers 206

9.1.2 “Classical” CMC Concepts 207

9.2 Porous Oxide/Oxide CMCs without Fiber/Matrix Interphase 208

9.2.1 Materials and CMC Manufacturing 210

9.2.2 Mechanical Properties 214

9.2.3 Thermal Stability 218

9.2.4 Other Properties 220

9.3 Oxide/Oxide CMCs with Protective Coatings 223

9.4 Applications of Porous Oxide/Oxide CMCs 226

10 Microstructural Modeling and Thermomechanical Properties 231
Dietmar Koch

10.1 Introduction 231

10.2 General Concepts of CMC Design, Resulting Properties, and Modeling 232

10.2.1 Weak Interface Composites WIC 232

10.2.2 Weak Matrix Composites WMC 237

10.2.3 Assessment of Properties of WIC and WMC 238

10.2.4 Modeling of the Mechanical Behavior of WMC 238

10.2.5 Concluding Remarks 243

10.3 Mechanical Properties of CMC 244

10.3.1 General Mechanical Behavior 244

10.3.2 High Temperature Properties 246

10.3.3 Fatigue 251

10.3.4 Concluding Remarks 255

Acknowledgment 256

11 Non-destructive Testing Techniques for CMC Materials 261
Jan Marcel Hausherr and Walter Krenkel

11.1 Introduction 261

11.2 Optical and Haptic Inspection Analysis 263

11.3 Ultrasonic Analysis 262

11.3.1 Physical Principle and Technical Implementation 263

11.3.2 Transmission Analysis 264

11.3.3 Echo-Pulse Analysis 265

11.3.4 Methods and Technical Implementation 266

11.3.5 Ultrasonic Analysis of CMC 267

11.4 Thermography 268

11.4.1 Thermal Imaging (Infrared Photography) 269

11.4.2 Lockin Thermography 271

11.4.3 Ultrasonic Induced Thermography 272

11.4.4 Damage Detection Using Thermography 272

11.5 Radiography (X-Ray Analysis) 273

11.5.1 Detection of X-Rays 273

11.5.1.1 X-Ray Film (Photographic Plates) 274

11.5.1.2 X-Ray Image Intensifier 274

11.5.1.3 Solid State Arrays 275

11.5.1.4 Gas Ionization Detectors (Geiger Counter) 275

11.5.2 Application of Radiography for C/SiC Composites 275

11.5.3 Limitations and Disadvantages of Radiography 277

11.6 X-Ray Computed Tomography 277

11.6.1 Functional Principle of CT 277

11.6.2 Computed Tomography for Defect Detection 279

11.6.3 Micro-structural CT-Analysis 280

11.6.4 Process Accompanying CT-Analysis 282

11.7 Conclusions 283

12 Machining Aspects for the Drilling of C/C-SiC Materials 287
Klaus Weinert and Tim Jansen

12.1 Introduction 287

12.2 Analysis of Machining Task 288

12.3 Determination of Optimization Potentials 290

12.3.1 Tool 290

12.3.2 Parameters 294

12.3.3 Basic Conditions 294

12.4 Process Strategies 295

12.5 Conclusions 300

13 Advanced Joining and Integration Technologies for Ceramic Matrix Composite Systems 30Mrityunjay Singh and Rajiv Asthana

13.1 Introduction 303

13.2 Need for Joining and Integration Technologies 304

13.3 Joint Design, Analysis, and Testing Issue 304

13.3.1 Wettability 305

13.3.2 Surface Roughness 306

13.3.3 Joint Design and Stress State 306

13.3.4 Residual Stress, Joint Strength, and Joint Stability 307

13.4 Joining and Integration of CMC–Metal Systems 309

13.5 Joining and Integration of CMC–CMC Systems 314

13.6 Application in Subcomponents 318

13.7 Repair of Composite Systems 321

13.8 Concluding Remarks and Future Directions 322

Acknowledgments 323

14 CMC Materials for Space and Aeronautical Applications 327
François Christin

14.1 Introduction 327

14.2 Carbon/Carbon Composites 328

14.2.1 Manufacturing of Carbon/Carbon Composites 328

14.2.1.1 n-Dimensional Reinforcement 328

14.2.1.2 Three-Dimensional Reinforcement Preforms 329

14.2.1.3 Densification 333

14.2.2 Carbon/Carbon Composites Applications 335

14.2.2.1 Solid Rocket Motors (SRM) Nozzles 335

14.2.2.2 Liquid Rocket Engines (LRE) 337

14.2.2.3 Friction Applications 338

14.3 Ceramic Composites 338

14.3.1 SiC-SiC and Carbon-SiC Composites Manufacture 339

14.3.1.1 Elaboration 340

14.3.2 SiC-SiC and Carbon-SiC Composites Applications 340

14.3.2.1 Aeronautical and Space Applications 340

14.3.2.2 Liquid Rocket Engines Applications 341

14.3.3 A Breakthrough with a New Concept: The Self-Healing Matrix 343

14.3.3.1 Manufacturing of Ceramic Composites 343

14.3.3.2 The Self-Healing Matrix 344

14.3.3.3 Characterization 344

14.3.4 Representative Applications of These New Materials 347

14.3.4.1 Military Aeronautical Applications 347

14.3.4.2 Commercial Aeronautical Applications 349

15 CMC for Nuclear Applications 35
Akira Kohyama

15.1 Introduction 353

15.2 Gas Reactor Technology and Ceramic Materials 354

15.3 Ceramic Fiber Reinforced Ceramic Matrix Composites (CFRC, CMC) 356

15.4 Innovative SiC/SiC by NITE Process 358

15.5 Characteristic Features of SiC/SiC Composites by NITE Process 359

15.6 Effects of Radiation Damage 362

15.6.1 Ion-Irradiation Technology for SiC Materials 363

15.6.2 Micro-Structural Evolution and Swelling 364

15.6.3 Thermal Conductivity 366

15.6.4 Mechanical Property Changes 369

15.7 Mechanical Property Evaluation Methods 371

15.7.1 Impulse Excitation Method for Young’s Modulus Determination 372

15.7.2 Bulk Strength Testing Methods for Ceramics 373

15.7.3 Test Methods for Composites 374

15.7.4 Development of Materials Database 378

15.8 New GFR Concepts Utilizing SiC/SiC Composite Materials 379

15.9 Concluding Remarks 381

16 CMCs for Friction Applications 385
Walter Krenkel and Ralph Renz

16.1 Introduction 385

16.2 C/SiC Pads for Advanced Friction Systems 385

16.2.1 Brake Pads for Emergency Brake Systems 388

16.2.2 C/SiC Brake Pads for High-Performance Elevators 388

16.3 Ceramic Brake Disks 391

16.3.1 Material Properties 392

16.3.2 Manufacturing 394

16.3.3 Braking Mechanism 396

16.3.4 Design Aspects 398

16.3.5 Testing 401

16.4 Ceramic Clutches 403

Index 409

About the Author

Walter Krenkel holds the Chair of Ceramic Materials at the University of Bayreuth, Germany, where he also heads the Ceramic Composites Group at the Fraunhofer-Gesellschaft. He gained his PhD in aeronautics and aerospace from the University of Stuttgart, and was formerly Head of Ceramic Composite Structures and of the Center of Excellence Lightweight CMC Structures at the German Aerospace Center. He is a Fellow of the American Ceramic Society, and serves on the scientific and advisory boards of many international conferences, workshops and technology exchange forums worldwide.
Professor Krenkel`s research focuses on the development
and qualification of CMCs and other novel ceramics.