Aerospace Materials and Material Technologies (eBook)

Dr. N. Eswara Prasad, FIE,FAPAS,FIIM, a B.Tech. (1985) and a Ph.D. (1993) in Metallurgical Engineering from Indian Institute of Technology (BHU), Varanasi, India, is an innovative and creative researcher and technologist. He is currently serving as Director, Defense Materials and Stores Research and Development Establishment (DMSRDE), DRDO at Kanpur, India.He has made significant and outstanding contributions to the Indian Defense Research and Development Organization (DRDO)ce;"> in the last 30 years in the fields of design, materials development and characterization, and airworthiness certified production of many advanced aerospace, aeronautical and naval materials and components. The extensive research work conducted  by him has resulted in the development and certified production of  (i) Al & Al-Li alloys for LCA, LCH  and  Indian Space Programme, (ii) Aero Steels, including Maraging and PH Steels for Indian Missile Programmes, (iii)  High strength and high temperature Ti Alloys, including -Ti alloys for LCA’s slat tracks and landing gear, (iv) Advanced  Ultrahigh Temperature materials - Mo & Ti Intermetallics, Monolithic Ceramics (Structural Alumina, Graphite and SiC), Carbon, Silica and SiC based Continuous Fibre-reinforced, Ceramic-matrix Composites (CFCCs) for cutting edge components, systems and technologies. Application of these materials in DRDO has been complemented by him by extensive fundamental research on tensile deformation, fatigue and fracture, correlations between chemical composition-processing-microstructure-texture-deformation, leading to first time scientific explanations on Property Anisotropy. In the last 6 years, Dr. Prasad has been instrumental in the concurrent development and production of several airworthiness certified materials and components of Aero and Naval steels, Al alloys, Ni-base Superalloys, Ti sponge and Special Ti alloys for Indian Defense, Indian Air Force, Indian Navy and ATVP – the Indian Submarine Program, which have resulted in realizing defense hardware worth more than Rs. 12 billion, out of which direct materials production of nearly Rs. 6.2 Billions through 180 provisional clearances and 11 type approvals of CEMILAC. Dr. Prasad’s prolific research resulted over 170 research articles in peer-reviewed national and international journals and conference proceedings, including 30 written/edited books and book chapters as well as 26 classified and unclassified, as also peer reviewed technical reports and a highly acclaimed first International Monograph on Al-Li Alloys in 2014. He has also authored nearly 90 confidential reports and more than 260 certification documents for DRDO. In recognition of his original contributions in the fields of Metallurgy and Materials Engineering, Dr. Prasad had received several national and international awards. He has been the recipient of YOUNG SCIENTIST AWARD (ICSA, 1991), YOUNG METALLURGIST (Ministry of Steel,1994), AvH’s Humboldt Research Fellowship (1998-99), Max-Planck-Institute (Stuttgart)’s Visiting Scientist (1998-99), Binani Gold Medal (IIM, 2006), METALLURGIST OF THE YEAR (Ministry of Steel, 2010), AICTE-INAE Distinguished Visiting Professorship at Andhra University and Mahatma Gandhi Institute of Technology (INAE, 2012-Till Date), IIT-BHU(MET)’s Distinguished Alumnus Award (2013) and the prestigious Dr. VM Ghatge Award of AeSI (in 2014).Dr. Prasad is a Fellow of Institute of Engineers (India) [FIE], Indian Institute of Metals [FIIM] and AP Akademi of Sciences [FAPAS]. Dr. R. J. H. Wanhill is emeritus Principal Research Scientist at the Netherlands Aerospace Centre, formerly the National Aerospace Laboratory NLR, in the Netherlands. He holds two Doctorates, one from the University of Manchester (1968) and the second from the Delft University of Technology (1994). He joined the NLR in 1970, and since then has investigated fatigue and fracture of all classes of aerospace alloys. He is co-author of the book ‘Fracture Mechanics’ (1984), which has run into a second edition; co-author with Simon Barter of the monograph ‘Fatigue of Beta Processed and Beta Heat-treated Titanium Alloys’, published by Springer in 2012; and co-author and co-editor for the book ‘Aluminium - Lithium Alloys: Processing, Properties and Applications’, editors N. Eswara Prasad, Amol A. Gokhale and R. J. H. Wanhill, published in 2014.From 1978 to 1996 Dr. Wanhill was head of the Materials Department of the NLR, and in 1979-80 adjunct professor of materials at Delft University of Technology. From 1997 to 2008 he was a Principal Research Scientist in the Aerospace Vehicles Division of the NLR. From 2008 to 2015 he has been emeritus Principal Research Scientist at the NLR. In 2002 the Board of the Foundation NLR awarded Dr. Wanhill the first Dr.ir.B.M. Spee Prize for outstanding contributions on aerospace materials. In October 2014 he was awarded an Honour Diploma by the Netherlands Aerospace Fund for his long-term contributions to scientific research and knowledge at the NLR, and use of this knowledge for aircraft failure analyses.  In recent years Dr. Wanhill has worked on the analysis of fatigue cracking in GLARE panels from the Airbus 380 MegaLiner Barrel test (presented at ICAF 2009) and, in collaboration with Dr. Simon Barter (Defence Science and Technology Group, DSTG, Melbourne). From November 2009 to May 2010 Dr. Wanhill was a Visiting Academic at the DSTG. The work there included (i) a collaborative report, book chapter, and presentation for the Royal Australian Air Force (RAAF) on fatigue life assessment of combat aircraft; (ii) a book chapter on stress corrosion cracking (SCC) in aerospace; (iii) two seminar presentations, on service failures and the MegaLiner Barrel GLARE cracking (see above); and (iv) preparation of a course on failure analysis, held twice at Auckland Technical University at the beginning of May 2010. This course has been adopted by the RAAF as part of its instruction material.Since 1994 Dr. Wanhill has been investigating fracture phenomena in ancient silver and iron, and has published eight peer-reviewed papers on this topic. The most recent papers have been published in the Journal of Failure Analysis and Prevention (2011), Metallography, Microstructure, and Analysis (2012) and the leading archaeological scientific journal Studies in Conservation (2013). Dr. Wanhill also gives annual lectures on ancient silver for a Master’s Degree course on conservation at the University of Amsterdam. Dr. Wanhill has been an author and speaker on several fatigue and fracture topics and also on fatigue-based design of aircraft structures. In 2012, Dr. Wanhill was a keynote speaker for the International Conference on Engineering Failure Analysis V, held in The Hague. He also had two additional contributions, with co-authors: “Validation of F-16 wing attachment fitting bolts” and “Five helicopter accidents with evidence of material and/or design deficiencies”. All three presentations have been published as papers in Engineering Failure Analysis in 2013. In 2014 he was a keynote speaker at Fatigue 2014, held in Melbourne. In 2015 he gave a Public Lecture at Materials Days 2015, Rostock, with the title “Materials and structural integrity: Milestone aircraft case histories and continuing developments”. This presentation has also been adopted by the RAAF as instruction material, and in written chapter form will be published in ‘The Reference Module in Materials Science and Engineering’.

Foreword by Prof. Dipankar Banerjee 7
Foreword by Prof. Indranil Manna 9
Series Editors’ Preface 11
About the Indian Institute of Metals 11
Genesis and History of the Series 11
Current Series Information 12
About This Book 12
Preface to Volume 1 14
Acknowledgements 16
Contents 18
About the Editors 21
Contributors 24
Metallic Materials 27
1 Magnesium Alloys 28
Abstract 28
1.1 Introduction 28
1.2 Classification and Designation 29
1.3 Physical Metallurgy of Mg Alloys 29
1.3.1 Role of Different Alloying Elements 30
1.3.1.1 Zinc (Zn) 30
1.3.1.2 Zirconium (Zr) 30
1.3.1.3 Aluminium (Al) 30
1.3.1.4 Rare Earth (RE) Elements (Nd, Ce, La, Gd, Pr) 31
1.3.1.5 Manganese (Mn) 31
1.3.1.6 Silver (Ag) 31
1.3.1.7 Silicon (Si) 31
1.3.1.8 Thorium (Th) 31
1.3.1.9 Transition Elements (Copper (Cu), Iron (Fe), Nickel (Ni), Cobalt (Co)) 32
1.3.1.10 Lithium (Li) 32
1.3.1.11 Yttrium (Y) 32
1.3.1.12 Beryllium (Be) 32
1.3.1.13 Calcium (Ca) 32
1.3.2 Precipitation Reactions in Mg Alloys 32
1.3.3 Strengthening in Mg Alloys 33
1.4 Aerospace Mg Alloys 33
1.4.1 Casting Alloys 36
1.4.2 Wrought Alloys 37
1.4.3 Welding and Machining 38
1.4.4 Recent Advancements in Mg Alloys 38
1.5 Mechanical Properties 40
1.5.1 Tensile Properties 40
1.5.2 Fatigue and Fracture Resistance 42
1.5.3 Creep and Oxidation Properties 43
1.5.4 Corrosion Behaviour 46
1.5.4.1 General Corrosion 46
1.5.4.2 Galvanic Corrosion 46
1.5.4.3 Stress Corrosion Cracking (SCC) 46
1.5.4.4 Corrosion Fatigue 47
1.5.4.5 Advances in Corrosion Protection Techniques 48
1.6 Global Scenario and Indian Programmes 48
1.7 Summary 49
Acknowledgments 49
References 50
2 Aluminium Alloys for Aerospace Applications 53
Abstract 53
2.1 Introduction 54
2.2 Classification and Designation 56
2.2.1 Wrought Alloys 57
2.2.2 Cast Alloys 57
2.2.3 Temper Designations 57
2.3 Age-Hardenable Aluminium Alloys 59
2.4 Effects of Alloying Elements 61
2.5 Mechanical Properties 64
2.5.1 Strength and Fracture Toughness 64
2.5.2 Fatigue 66
2.5.3 Fatigue Crack Growth 68
2.5.4 Corrosion Resistance 68
2.6 Typical Aerospace Applications of Aluminium Alloys 69
2.7 Indian Scenario 70
2.7.1 Gaps in Indian Aerospace Aluminium Technologies 72
2.7.2 Type Certification of Aluminium Alloys in India 73
2.8 Summary and Conclusions 73
Acknowledgments 75
References 75
Some Useful Data Handbooks 76
3 Aluminium–Lithium Alloys 77
Abstract 77
3.1 History of Alloy Development 77
3.2 Aircraft Structural Property Requirements 78
3.3 Physical Metallurgy of Al–Li Alloys 82
3.4 Processing Technologies 84
3.5 Mechanical Properties 85
3.5.1 Tensile Properties 86
3.5.2 Fatigue Properties 86
3.5.3 Fracture Toughness and R-curves 91
3.6 Corrosion and Stress Corrosion Cracking 91
3.7 Current Indian Scenario 93
3.8 Conclusions 93
Acknowledgments 93
References 94
4 Titanium Sponge Production and Processing for Aerospace Applications 97
Abstract 97
4.1 Introduction 97
4.2 Established Methods of Titanium Extraction 98
4.3 World Production of Titanium Sponge—Recent Developments 100
4.4 Indian Scenario on Titanium Sponge Production 101
4.4.1 Development of Kroll Technology at DMRL, Hyderabad 101
4.4.2 Development of Combined Process Technology at DMRL, Hyderabad 102
4.4.3 Quality Evaluation and Processing of Aerospace Grade Sponge 105
4.4.4 Commercial Production of Titanium Sponge at KMML, Chavara, India 107
4.4.5 Quality Assurance Program at KMML Sponge Plant 107
4.4.6 Type Certification of Titanium Sponge—The Approach 108
4.5 Properties of Ti Sponge 110
4.6 Concluding Remarks 111
Acknowledgments 111
References 112
5 Titanium Alloys: Part 1—Physical Metallurgy and Processing 114
Abstract 114
5.1 Introduction 114
5.2 Physical Metallurgy of Titanium Alloys 115
5.2.1 Crystal Structure 115
5.2.2 Elastic Properties 117
5.2.3 Deformation Modes 117
5.2.4 Slip Modes 118
5.2.5 Alloying Additions 119
5.2.6 Phase Transformations 122
5.3 Primary Processing: Melting and Consolidation 124
5.3.1 Vacuum Arc Remelting (VAR) 124
5.3.2 Cold Hearth Melting (CHM) 126
5.3.3 Melt-Related Defects 127
5.3.4 Conditioning and Homogenization 130
5.4 Secondary Processing 130
5.4.1 Forging 130
5.4.2 Rolling 132
5.5 Titanium Alloy Castings 133
5.6 Indian Scenario on Titanium Alloy Processing 135
5.7 Summary 136
Acknowledgments 137
References 137
Bibliography 138
6 Titanium Alloys: Part 2—Alloy Development, Properties and Applications 139
Abstract 139
6.1 Introduction 139
6.2 Titanium Alloy Developments and Applications 140
6.2.1 Commercially Pure Titanium and ?-Titanium Alloys 140
6.2.2 High Temperature Near-? Titanium Alloys 142
6.2.3 ? + ? Titanium Alloys 145
6.2.3.1 Processing and Microstructures of ? + ? Titanium Alloys 145
6.2.3.2 Mechanical Properties of ? + ? Titanium Alloys 149
6.2.3.3 Applications of ? + ? Titanium Alloys 152
6.2.4 ? Titanium Alloys 155
6.2.4.1 Introduction: General Characteristics 155
6.2.4.2 Processing and Microstructures 156
6.2.4.3 Mechanical Properties of ? Titanium Alloys 161
6.2.4.4 Applications of ? Titanium Alloys 164
6.3 Summary 167
Acknowledgments 167
References 167
Bibliography 170
7 Aero Steels: Part 1—Low Alloy Steels 171
Abstract 171
7.1 Introduction 171
7.2 Classification and Designation 172
7.3 Compositions of Low Alloy Steels 174
7.3.1 Ultrahigh-Strength Steels (UHSS) 174
7.3.2 Bearing Steels 176
7.4 Effects of Alloying Elements 176
7.4.1 Critical Transformation Temperatures 176
7.4.2 Formation and Stability of Carbides 176
7.4.3 Grain Size 178
7.4.4 Eutectoid Point 178
7.4.5 Hardenability 179
7.4.6 Volume Change 180
7.4.7 Resistance to Softening While Tempering 180
7.5 Strengthening Mechanisms 181
7.6 Melting of Low Alloy Steels 182
7.7 Fabrication of Low Alloy Steels 183
7.8 Heat Treatment 183
7.9 Surface Hardening of Steels 185
7.10 Engineering Properties 186
7.11 Indian Scenario 188
7.12 Summary and Conclusions 192
Acknowledgments 192
References 192
8 Aero Steels: Part 2—High Alloy Steels 194
Abstract 194
8.1 Introduction 194
8.2 Secondary Hardening Steels 195
8.2.1 Effects of Alloying Elements in Secondary Hardening Steels 195
8.2.2 Processing and Thermal Treatments 197
8.2.3 HP 9-4-X Steels 198
8.2.4 AF1410 Steel 200
8.2.5 AerMet Steels 201
8.2.6 Ferrium Steels 204
8.3 Maraging Steels 205
8.3.1 Effects of Alloying Elements in Maraging Steels 206
8.3.2 Processing and Heat Treatments of Maraging Steels 208
8.4 Precipitation Hardening (PH) Steels 209
8.4.1 Mechanical Properties of Typical PH Stainless Steels 210
8.4.2 Processing and Heat Treatments of PH Stainless Steels 211
8.4.3 Weldability of PH Stainless Steels 212
8.5 Illustration of Martensitic PH Steels Diversity: Custom 455, 465 and 475 213
8.5.1 Processing and Heat Treatments of Custom 455, 465 and 475 Stainless Steels 213
8.5.2 Weldability of Custom 455, 465 and 475 Stainless Steels 216
8.6 Indian Scenario 216
8.7 Summary 218
References 218
Bibliography 219
9 Nickel-Based Superalloys 220
Abstract 220
9.1 Introduction 221
9.2 Classification of Nickel-Based Superalloys 221
9.3 Physical Metallurgy 223
9.3.1 Chemical Composition 223
9.3.2 Microstructural Constituents 225
9.3.3 Heat Treatment 226
9.3.4 Strengthening Mechanisms 228
9.4 Manufacturing Processes 230
9.4.1 Wrought Alloys 231
9.4.2 Cast Superalloys 233
9.5 Properties of Superalloys 235
9.5.1 Tensile Properties 236
9.5.2 Creep Resistance 237
9.5.3 Fatigue 238
9.5.4 Fatigue Crack Growth 240
9.6 Evolution of Advanced Nickel-Based Superalloys 241
9.6.1 First Generation Superalloys 242
9.6.2 Second Generation Superalloys 243
9.6.3 Third Generation Superalloys 243
9.6.4 Fourth Generation Superalloys 244
9.6.5 Fifth Generation Superalloys 244
9.6.6 Sixth Generation Superalloys 245
9.7 Concluding Remarks 246
Acknowledgments 246
References 246
10 Structural Intermetallics 250
Abstract 250
10.1 Introduction 250
10.2 Crystal Structures and Compositions of Selected Intermetallics 251
10.2.1 Nickel Aluminides 252
10.2.2 Titanium Aluminides 253
10.2.3 Iron Aluminides 254
10.2.4 Molybdenum Silicides 254
10.2.5 Niobium Silicides 255
10.3 Processing 257
10.4 Properties of Ni-, Fe-, and Ti-Based Aluminides 259
10.4.1 Property Surveys 259
10.5 Aerospace Applications 261
10.5.1 Silicides 261
10.5.2 Aluminides 262
10.5.3 Indian Scenario 264
10.6 Summary 264
References 264
11 Bronzes for Aerospace Applications 267
Abstract 267
11.1 Introduction 268
11.2 Bronzes 268
11.2.1 Effects of Alloying Elements 268
11.2.2 Aluminium Bronzes 271
11.2.3 Aluminium-Silicon Bronzes 273
11.2.4 Silicon Bronzes 273
11.2.5 Phosphor Bronzes 274
11.2.6 Beryllium Bronzes 274
11.2.7 Manganese Bronzes 276
11.2.8 High Leaded Tin Bronzes 277
11.2.9 Sintered Bronzes (Oil Impregnated Bronzes) 277
11.2.10 Aircraft Bronze (French Bronze) 278
11.2.11 Nickel-Silicon Bronzes 278
11.3 Processing of Bronzes 279
11.3.1 Melting Practices 279
11.3.2 Casting Practices 280
11.3.3 Hot-Working 281
11.3.4 Cold-Working and Annealing 282
11.4 Indigenous Development of Aluminium and Silicon Bronzes for Aerospace 283
11.5 Summary and Conclusions 286
Acknowledgments 286
References 286
12 Niobium and Other High Temperature Refractory Metals for Aerospace Applications 287
Abstract 287
12.1 Introduction 287
12.2 Niobium Alloys 290
12.2.1 Nb Alloys and Their Properties 290
12.2.2 Production Methods for Niobium 294
12.2.3 Melting and Refining of Niobium and Preparation of Nb-Based Alloys 295
12.2.4 Processing of Niobium 296
12.2.5 Applications of Niobium and its Alloys 297
12.3 Niobium-Silicide Based Composites 299
12.4 Other Refractory Metals 300
12.4.1 Tantalum and its Alloys 300
12.4.2 Molybdenum and Its Alloys 301
12.4.3 Tungsten and Its Alloys 303
12.4.4 Rhenium and Its Alloys 305
12.5 Indian Scenario 306
12.6 Summary 306
References 307
Composites 309
13 GLARE®: A Versatile Fibre Metal Laminate (FML) Concept 310
Abstract 310
13.1 Introduction 310
13.2 GLARE: A Family of Materials 311
13.3 GLARE Applications 312
13.4 GLARE Properties 313
13.4.1 Damage Tolerance (DT): GLARE Basics 314
13.4.2 Fatigue Evaluation: The MLB Test 315
13.4.3 Residual Strength 317
13.4.4 DT Certification of GLARE 319
13.4.5 Impact Resistance 319
13.4.6 Flame Resistance 320
13.4.7 Corrosion Resistance 320
13.4.8 Inspections and Repairs 321
13.5 GLARE and Other Candidates for Primary Aircraft Structures 322
13.6 Summary 324
Acknowledgments 324
References 325
14 Carbon Fibre Polymer Matrix Structural Composites 327
Abstract 327
14.1 Introduction 327
14.2 Types of Composites 329
14.3 CFRP Composites 330
14.3.1 CFRP Composite Matrices 330
14.3.2 CFRP Composite Fibres 332
14.3.3 CFRP Aerospace Components Production 333
14.3.4 Reference Guidelines for CFRP Materials and Processing 336
14.4 CFRP Properties 337
14.4.1 Specific Mechanical Properties and Practical Weight Savings and Costs 337
14.4.2 Impact Damage and Inspections 341
14.4.3 Repairs of CFRP Structures 344
14.5 Safety and Damage Tolerance of CFRP Components and Structures 345
14.5.1 Strength and Safety Definitions 345
14.5.2 Reduction Factors on Allowables 346
14.5.3 Testing to Determine Allowables 346
14.5.4 Damage Tolerance (DT) Allowables 348
14.5.5 Repair Issues: Validation 349
14.6 Developments Old and New 350
14.6.1 3D CFRP Components and Structures 350
14.6.2 Self-healing CFRPs 352
14.7 Current Indian Scenario (Contribution Partly by K. Vijaya Raju) 353
14.7.1 Light Combat Aircraft TEJAS 354
14.7.2 Light Transport Aircraft SARAS 354
14.8 Summary 356
References 356
Bibliography 359
15 C/C and C/SiC Composites for Aerospace Applications 360
Abstract 360
15.1 Introduction 360
15.2 Carbon Reinforcements 361
15.2.1 Carbon Fibre Reinforcements 361
15.2.2 Other Carbon Reinforcing Materials 363
15.3 Carbon Fibre Preforms 363
15.4 C/C Composites Processing 365
15.4.1 Chemical Vapour Impregnation (CVD/CVI) 367
15.4.2 Liquid-Phase Impregnation Process 369
15.5 Properties of C/C Composites 369
15.5.1 Mechanical Properties of C/C Composites 370
15.5.2 Thermal Properties of C/C Composites 371
15.6 Example Applications of Aerospace C/C Composites 371
15.6.1 C/C Composite Brake Pads 371
15.6.2 C/C Nozzle and Throat 372
15.6.3 C/C Combustion Chamber 374
15.7 C/SiC Composites 374
15.7.1 C/SiC Fibre/Matrix Interface/Interphase 375
15.7.2 Oxidation 376
15.8 C/SiC Composite Processing 377
15.8.1 Chemical Vapour Impregnation (CVD/CVI) 377
15.8.2 Polymer Infiltration and Pyrolysis (PIP) 377
15.8.3 Liquid Silicon Infiltration (LSI) 378
15.9 Properties of C/SiC Composites 379
15.10 Applications of Aerospace C/SiC Composites 380
15.10.1 Thermal Protection Systems (TPS) and Hot Structures for Space Vehicles 380
15.10.2 Jet-Vanes for Rocket Motors 381
15.10.3 C/SiC Nozzles and Components for Rocket and Jet Engines 381
15.10.4 C/SiC Composite Nozzle Throats 382
15.11 Indian Scenario for C/C and C/SiC Development 383
15.12 Summary 384
Acknowledgments 384
References 384
16 Ceramic Matrix Composites (CMCs) for Aerospace Applications 387
Abstract 387
16.1 Introduction 387
16.2 CMC Constituents 388
16.2.1 Ceramic Matrices 388
16.2.2 Ceramic Reinforcements 390
16.2.3 Interfaces 391
16.3 Toughening by Fibre Reinforcement/Crack Bridging 393
16.4 Processing of CMCs 395
16.5 CMCs Properties 397
16.6 Aerospace Applications 401
16.7 Summary 403
Acknowledgments 403
References 403
17 Nanocomposites Potential for Aero Applications 406
Abstract 406
17.1 Introduction 406
17.2 Metal Matrix Nanocomposites (MMNCs) 407
17.2.1 Strengthening Mechanisms 407
17.2.2 Synthesis and Processing 409
17.2.3 Current Developments in Lightweight MMNCs 411
17.3 Polymer Matrix Nanocomposites (PMNCs) 411
17.3.1 Reinforced Strengthening 414
17.3.2 Fabrication of PMNCs 417
17.3.3 Current Challenges in PMNCs 418
17.4 Ceramic Matrix Nanocomposites (CMNCs) 419
17.4.1 Types of Reinforcement/Strengthening Mechanisms 419
17.4.2 Fabrication of CMNCs 421
17.5 Characterization of Nanocomposites 422
17.6 Future Aerospace Applications 422
17.7 Conclusions 423
Acknowledgments 423
References 423
Special Materials 427
18 Monolithic Ceramics for Aerospace Applications 428
Abstract 428
18.1 Introduction 428
18.2 Mechanical Properties 429
18.2.1 Strength Properties 429
18.2.2 Fracture Toughness 429
18.2.3 Thermal Shock Resistance 430
18.2.4 Creep and Creep Crack Growth 430
18.2.5 Mechanical Property Improvements via Toughening Micro Mechanisms 431
18.3 Ultrahigh-Temperature Ceramics for Aerospace Applications 432
18.3.1 Alumina Ceramics 434
18.3.2 Zirconia Ceramics 434
18.3.3 Silicon Nitride Ceramics 435
18.3.4 Silicon Carbide Ceramics 437
18.3.5 Molybdenum Disilicide (MoSi2) Ceramics 438
18.3.6 Carbon Ceramics 439
18.4 Emerging Monolithic Ceramics for Aerospace Applications 440
18.4.1 Titanium Boride Ceramics 440
18.4.2 Zirconium Boride Ceramics 442
18.5 Indian Scenario 444
18.6 Summary 444
Acknowledgments 444
References 445
19 Nano-enabled Multifunctional Materials for Aerospace Applications 451
Abstract 451
19.1 New Challenges for High Performance Aerospace Materials 451
19.2 Definitions 452
19.3 Examples of Functional Materials 452
19.4 Studies of Functional Materials and Potential Aerospace Applications 455
19.5 Nanomaterials and Structures for Aerospace: An Overview 455
19.6 Specific Assessments of Some Nanostructural Materials 456
19.6.1 Carbon Compounds 456
19.6.2 Ablative Applications 458
19.6.3 Sensor Films (Spacecraft) 460
19.6.4 Superhydrophobic coatings 460
19.7 Update of Nanofunctional Materials Research 461
19.8 Summary 462
Acknowledgments 462
References 462
20 MAX Phases: New Class of Carbides and Nitrides for Aerospace Structural Applications 466
Abstract 466
20.1 Introduction 466
20.2 Physical Metallurgy of MAX Phases 467
20.2.1 Polymorphism of MAX Phases 467
20.3 Synthesis Procedures 469
20.3.1 Synthesis of Thin MAX Phases 469
20.3.2 Synthesis of Bulk MAX Phases 470
20.3.3 Synthesis of MAX Phases in Commercially Viable Bulk Forms 470
20.4 Properties of MAX Phases 473
20.4.1 Physical Properties 473
20.4.2 Chemical Properties 473
20.4.3 Mechanical Properties 474
20.5 Applications 474
20.6 Summary and Conclusions 475
Acknowledgments 475
References 475
21 Shape Memory Alloys (SMAs) for Aerospace Applications 477
Abstract 477
21.1 Introduction 477
21.2 SME Mechanisms 478
21.2.1 SMA Behaviour 480
21.3 SME Alloys 481
21.3.1 Properties of Commercial SMAs 482
21.3.2 Ni–Ti Alloy Variants 483
21.4 Aerospace Applications of SMAs 484
21.4.1 Overview 484
21.4.2 Actual and Potential Applications in Aircraft 485
21.4.3 Applications in Spacecraft 487
21.5 Concluding Remarks 489
References 489
Bibliography 491
22 Detonation Sprayed Coatings for Aerospace Applications 492
Abstract 492
22.1 Introduction 492
22.2 Detonation Spraying 493
22.2.1 The Spraying Process 493
22.2.2 Equipment Characteristics 494
22.3 DSC Technology Compared with Other Thermal Spray Techniques 494
22.4 DSC Coating Applications in Aerospace 496
22.4.1 Tungsten Carbide/Cobalt (WC–Co) Coatings 496
22.4.2 Modified Tungsten Carbide/Cobalt (WC–Co–Cr) Coatings 500
22.4.3 Cr3C2–NiCr Coatings 501
22.4.4 Abradable Coatings 502
22.4.5 Thermal Barrier Coatings (TBCs) 502
22.4.6 Coating Refurbishments 503
22.5 Other Coating Processes 503
22.6 Summary and Concluding Remarks 506
Acknowledgments 507
References 508
23 Piezoceramic Materials and Devices for Aerospace Applications 510
Abstract 510
23.1 Introduction 510
23.1.1 Origin of Piezoelectricity 511
23.1.2 Piezoelectric Charge Coefficient (D) 512
23.1.3 Notation of Axes 512
23.1.4 Structure of PZT 513
23.1.5 Piezoelectric Effect—Importance of Poling 513
23.2 Preparation of Piezoelectric Powders 515
23.2.1 PZT Materials 515
23.2.2 PMN Materials 516
23.2.3 PZT–PMN Materials 517
23.2.4 PMN–PT Materials 517
23.3 Fabrication of PZT Devices 517
23.3.1 Fabrication of Multilayered Stacks 517
23.3.2 Amplified PZT Actuators 522
23.3.3 Ring Actuators 522
23.4 Aerospace Applications of PZT ML Stacks 523
23.4.1 Shape and Vibration Control 523
23.4.2 Structural Health Monitoring (SHM) 524
23.5 Other Applications 525
23.5.1 Piezo Energy Harvesting 525
23.5.2 Piezo Fuel Injection Systems 525
23.6 Conclusions 525
Acknowledgments 526
References 526
24 Stealth Materials and Technology for Airborne Systems 528
Abstract 528
24.1 Introduction 528
24.2 History of Stealth Technology 529
24.3 Threat Perception and Analysis 530
24.4 Multispectral Stealth 531
24.4.1 Visual Stealth 532
24.4.2 Infrared Stealth 533
24.4.3 Radar Stealth 534
24.4.3.1 Radar Cross-Section (RCS) 534
24.4.3.2 RCS Reduction 534
24.5 Radar-Absorbing Materials and Structures (RAMS and RAS) 536
24.5.1 Radar-Absorbing Materials (RAMs) 536
24.5.2 Classification of RAMS 537
24.5.2.1 Magnetic Absorbers 537
24.5.2.2 Dielectric Absorbers 538
24.5.2.3 Conducting Polymers 539
24.5.2.4 Nanomaterials 539
24.5.3 Radar-Absorbing Structures (RAS) 540
24.6 Plasma Stealth 541
24.7 Acoustic Stealth 541
24.8 Counter Stealth 542
24.9 Currently Available Stealth Aircraft 542
24.10 Summary 543
References 544
25 Paints for Aerospace Applications 547
Abstract 547
25.1 Importance of Paints for Aerospace Applications 547
25.2 Selection of Paint Formulations for Aerospace Applications 549
25.3 Paint Application Areas in Military Aircraft 550
25.3.1 Airframes 550
25.3.2 Radomes 553
25.3.3 Gear Boxes 554
25.3.4 Fuel Tanks 554
25.3.5 Stored Aircraft Weapons 555
25.4 Special Functional Paints 556
25.4.1 Camouflage Paint Schemes 556
25.4.2 Radar Signal Absorbing Paints (RAPs) 558
25.4.3 Fluorescent Paints 558
25.4.4 Anti-Skid Paints 559
25.4.5 Hydrophobic Paints 560
25.4.6 Infrared (IR) Paints 561
25.4.7 Intumescent Paints 562
25.4.8 Miscellaneous Paints 562
25.5 Properties, Testing and Analysis of Paints 562
25.5.1 Chemical Analysis 563
25.6 Ageing of Paints 564
25.6.1 Outdoor Weathering 564
25.6.2 Accelerated Weathering 564
25.7 Airworthiness Certification of Paints 565
25.8 Volatile Organic Compound (VOC) Regulations 566
25.9 Paint Monitoring 567
25.10 Some Important New Developments 567
25.11 Indian Scenario 568
25.12 Conclusions 568
Acknowledgments 568
References 568
26 Elastomers and Adhesives for Aerospace Applications 571
Abstract 571
26.1 Elastomers 571
26.1.1 Introduction 571
26.1.2 Varieties of Elastomers 572
26.1.3 Elastomer Compounding 572
26.1.4 Vulcanising 573
26.1.5 Elastomer Types and Properties [8–10] 574
26.1.6 Elastomer Aerospace Requirements 582
26.1.7 Aerospace Applications of Elastomers 585
26.2 Adhesives 586
26.2.1 Introduction 586
26.2.2 Advantages of Adhesive Bonding 586
26.2.3 Mechanisms of Adhesive Bonding 587
26.2.3.1 Adhesion 587
26.2.3.2 Adherend surface 587
26.2.4 Surface Treatment of Substrates 587
26.2.5 Adhesive Type and Properties 588
26.2.6 Adhesive Joint Design [47, 48] 589
26.2.7 Aerospace Applications of Adhesives 590
26.3 Indian Scenario 592
26.4 Conclusions 592
Acknowledgments 592
References 592