Sandeep Rathee, PhD, is an Assistant Professor in the Department of Mechanical Engineering at the National Institute of Technology, Srinagar, India. His research interests include friction stir welding/processing, additive manufacturing, composites, and hybrid manufacturing. Manu Srivastava, PhD, is an Assistant Professor in the Department of Mechanical Engineering at the PDPM Indian Institute of Information Technology, Design and Manufacturing, Jabalpur, India. Her research interests include additive manufacturing, friction-based AM, friction stir processing, advanced materials, manufacturing practices, and optimization techniques. J. Paulo Davim, PhD, is a Professor at the University of Aveiro, Portugal and a Fellow (FIET) of the Institution of Engineering and Technology, UK. His research interests include advanced manufacturing methods and materials.

• About the Editors xvList of Contributors xviiiPreface xxvAcknowledgements xxixList of Figures xxxList of Tables xl1 Friction Stir Welding: An Overview 1Farooz A. Najar, Shazman Nabi, Sandeep Rathee, and Manu Srivastava1.1 Introduction 11.2 FSW Working Principle 21.3 Weld Zones 31.4 Variants of FSW 41.5 Defects 101.6 Advantages and Limitations of FSW 111.7 Conclusion and Future Prospectus 12Acknowledgments 12References 122 Friction Stir Welding and Single-Point Incremental Forming: State-of-the-Art 15Hitesh Mhatre, Amrut Mulay, and Vijay Gadakh2.1 Introduction 152.2 Friction Stir Welding (FSW) 162.3 Single-Point Incremental Forming (SPIF) 182.4 FSW and SPIF 212.5 Summary and Outlook 22References 233 Friction Stir Brazing and Friction Stir Vibration Brazing 25Behrouz Bagheri and Mahmoud Abbasi3.1 Introduction to FSB 253.2 Variants of FSB 263.3 Two Case studies 273.4 Application of FSB and Its Variants in Industry 353.5 Summary and Future Directions 35References 364 Fundamentals of Friction Stir Processing 39Atul Kumar, Devasri Fuloria, Manu Srivastava, and Sandeep Rathee4.1 Friction Stir Processing (FSP): Background 394.2 Working Principle of FSP 394.3 Comparison with Other Severe Plastic Deformation (SPD) Techniques 424.4 Process Variables 434.5 Mechanisms of Microstructural Evolution During FSP 484.6 Critical Issues in FSP 494.7 Future Scope 50References 515 Role of FSP in Surface Engineering 55Setu Suman and Kazi Sabiruddin5.1 Introduction 555.2 Role of Surface Modification Techniques 565.3 Thermal Spray Technique 575.4 FSP – Solid-State Coating Process 585.5 Process Parameters of FSP: Surface Engineering 605.6 Inappropriate Characteristics of Surface Modification 615.7 Summary 63References 646 Surface Composite Fabrication Using FSP 67Baidehish Sahoo, Jinu Paul, and Abhishek Sharma6.1 Introduction 676.2 Reinforcement Incorporation Approaches 686.3 Effect of Process Parameters 716.4 Microstructural Evolution and Mechanical Properties 756.5 Strengthening Mechanisms 806.6 Defects 836.7 Summary and Future Directions 86References 867 Friction Stir Welding of Dissimilar Metals 93Narayan Sahadu Khemnar, Yogesh Ramrao Gunjal, Vijay Shivaji Gadakh, and Amrut Shrikant Mulay7.1 Introduction 937.2 Application Areas of Dissimilar Material Joining 947.3 Issues for Dissimilar Material Joining 947.4 FSW of Dissimilar Materials 957.5 Recent Developments in Tool Design and Tool Materials 1037.6 Parameter Optimization 1037.7 Common Defects that Occur in FSW of Dissimilar Metal Joining 1047.8 Future Recommendations for Dissimilar Metal Joining 105Acknowledgments 105References 1068 Friction Stir Welding of Aluminum and Its Alloy 109Palani Sivaprakasam, Kolar Deepak, Durairaj Raja Joseph, Melaku Desta, Putti Venkata Siva Teja, and Murugan Srinivasan8.1 Introduction 1098.2 Fundamentals of FSW 1108.3 FSW of Aluminum and Its Alloy 1108.4 Influences of Process Parameters 1128.5 Testing and Characterization of FSW of Al and Its Alloy 1158.6 Additive Mixed Friction Stir Process of Al and Its Alloy 1188.7 Applications 1188.8 Conclusions 119References 1199 Mechanical Characterization of FSWed Joints of Dissimilar Aluminum Alloys of AA 7050 and AA6082 125Mohd Sajid, Gaurav Kumar, Husain Mehdi, and Mukesh Kumar9.1 Introduction 1259.2 Materials and Methods 1269.3 Results and Discussion 127References 13110 Sample Preparation and Microstructural Characterization of Friction Stir Processed Surface Composites 135Manu Srivastava, Sandeep Rathee, Shazman Nabi, and Atul Kumar10.1 Introduction 13510.2 Sample Preparation for Microscopic Analysis of Metals, Alloys, and Composites 13610.3 Etching 14010.4 Microstructural Evolution 141Acknowledgment 146References 14611 Microstructural Characterization and Mechanical Testing of FSWed/FSPed Samples 149Prem Sagar, Sushma Sangwan, and Mohankumar Ashok Kumar11.1 Introduction 14911.2 Microstructural Characterization 15211.3 Mechanical Testing 15911.4 Conclusions 162References 16212 Comparative Analysis of Microstructural and Mechanical Characteristics of Reinforced FSW Welds 165Tanvir Singh12.1 Introduction 16512.2 Friction Stir Welding (FSW) 16612.3 Reinforcing Materials-Based Fabrication of FSW Welds 16712.4 Joinability of Reinforced FSW Welds 16812.5 Metallurgical Characteristics of FSW Reinforced Welds 16912.6 Mechanical Behavior of Reinforced FSW Welds 17912.7 Conclusions 18412.8 Future Challenges 184References 18513 Summary of Efforts in Manufacturing of Sandwich Sheets by Various Joining Methods Including Solid-State Joining Method 193Divya Sachan, R. Ganesh Narayanan, and Arshad N. Siddiquee13.1 Introduction 19313.2 Sandwich Sheets 19313.3 Classification of Sandwich Sheet Structures 19413.4 Applications 19513.5 Fabrication Methods 19613.6 Summary 200References 20114 Defects in Friction Stir Welding and its Variant Processes 205Vinayak Malik and Satish V. Kailas14.1 Introduction 20514.2 General Defects in FSW 20514.3 Characteristic Defects in Friction Stir Butt and Lap Joints 20814.4 Distinctive Defects in Major Friction Stir Variants 20914.5 Solutions to Avoid Defects in Friction Stir-Based Processes 21214.6 Summary and Concluding Remarks 213Acknowledgment 213References 21315 Nondestructive Ultrasonic Inspections, Evaluations, and Monitoring in FSW/FSP 215Yuqi Jin, Teng Yang, Narendra B. Dahotre, and Tianhao Wang15.1 Introduction 21515.2 Ultrasonic Wave Behaviors in FSWed/FSPed Samples 21515.3 Common Ultrasonic Inspection and Evaluation Methods for FSWed/FSPed Samples 22415.4 Case Studies on Recent Novel Ultrasound Evaluation and Monitoring in FSW/FSP 23415.5 Roles and Potentials of Ultrasound in Future FSW/FSP 24215.6 Conclusion 243Acknowledgment 243References 24316 Applications of Friction Stir Welding 245Raja Gunasekaran, Velu Kaliyannan Gobinath, Kandasamy Suganeswaran, Nagarajan Nithyavathy, and Shanmugam Arun Kumar16.1 Introduction 24516.2 Application of FSW on Different Materials 24716.3 Industrial Applications of FSW 25216.4 Conclusion 255References 25617 Equipment Used During FSP 259Kandasamy Suganeswaran, Nagarajan Nithyavathy, Palaniappan Muthukumar, Shanmugam Arunkumar, and Velu Kaliyannan Gobinath17.1 Introduction 25917.2 FSP Experimental Setup 26417.3 Microstructural Characterization 26717.4 Mechanical Behavior of Composites Based on Various Tool Shapes 27117.5 Mechanical behavior of Composites Based on Various Process Parameters 27217.6 Conclusion 273References 27318 Analysis of Friction Stir Welding Tool Using Various Threaded Pin Profiles: A Case Study 275Bommana B. Abhignya, Ashish Yadav, Manu Srivastava, and Sandeep Rathee18.1 Introduction 27518.2 Geometry Considered 27718.3 Results and Discussions – Analysis in ANSYS 27818.4 Conclusion 279Acknowledgement 281References 28119 Static Structural and Thermal Analysis of Honeycomb Structure Fabricated by Friction Stir Processing Route: A Case Study 283Nikhil Jaiswal, Umashankar Bharti, Ashish Yadav, Manu Srivastava, and Sandeep Rathee19.1 Introduction 28319.2 Modeling Details 28419.3 Result and Analysis 28619.4 Scope of the Case Study 29019.5 Conclusion 291Acknowledgement 292References 29220 Friction Stir-Based Additive Manufacturing 293Ardula G. Rao and Neelam Meena20.1 Additive Manufacturing: An Introduction 29320.2 Solid-State AM Processes 29520.3 Case Studies of FSAM on Different Materials 29920.4 Advantages of FSAM Over Other AM Techniques 30020.5 Advancements 30120.6 Limitations 30220.7 Conclusions and Future prospectives 303References 303Index 307

Sandeep Rathee, PhD, is an Assistant Professor in the Department of Mechanical Engineering at the National Institute of Technology, Srinagar, India. His research interests include friction stir welding/processing, additive manufacturing, composites, and hybrid manufacturing. Manu Srivastava, PhD, is an Assistant Professor in the Department of Mechanical Engineering at the PDPM Indian Institute of Information Technology, Design and Manufacturing, Jabalpur, India. Her research interests include additive manufacturing, friction-based AM, friction stir processing, advanced materials, manufacturing practices, and optimization techniques. J. Paulo Davim, PhD, is a Professor at the University of Aveiro, Portugal and a Fellow (FIET) of the Institution of Engineering and Technology, UK. His research interests include advanced manufacturing methods and materials.

• About the Editors xvList of Contributors xviiiPreface xxvAcknowledgements xxixList of Figures xxxList of Tables xl1 Friction Stir Welding: An Overview 1Farooz A. Najar, Shazman Nabi, Sandeep Rathee, and Manu Srivastava1.1 Introduction 11.2 FSW Working Principle 21.3 Weld Zones 31.4 Variants of FSW 41.5 Defects 101.6 Advantages and Limitations of FSW 111.7 Conclusion and Future Prospectus 12Acknowledgments 12References 122 Friction Stir Welding and Single-Point Incremental Forming: State-of-the-Art 15Hitesh Mhatre, Amrut Mulay, and Vijay Gadakh2.1 Introduction 152.2 Friction Stir Welding (FSW) 162.3 Single-Point Incremental Forming (SPIF) 182.4 FSW and SPIF 212.5 Summary and Outlook 22References 233 Friction Stir Brazing and Friction Stir Vibration Brazing 25Behrouz Bagheri and Mahmoud Abbasi3.1 Introduction to FSB 253.2 Variants of FSB 263.3 Two Case studies 273.4 Application of FSB and Its Variants in Industry 353.5 Summary and Future Directions 35References 364 Fundamentals of Friction Stir Processing 39Atul Kumar, Devasri Fuloria, Manu Srivastava, and Sandeep Rathee4.1 Friction Stir Processing (FSP): Background 394.2 Working Principle of FSP 394.3 Comparison with Other Severe Plastic Deformation (SPD) Techniques 424.4 Process Variables 434.5 Mechanisms of Microstructural Evolution During FSP 484.6 Critical Issues in FSP 494.7 Future Scope 50References 515 Role of FSP in Surface Engineering 55Setu Suman and Kazi Sabiruddin5.1 Introduction 555.2 Role of Surface Modification Techniques 565.3 Thermal Spray Technique 575.4 FSP – Solid-State Coating Process 585.5 Process Parameters of FSP: Surface Engineering 605.6 Inappropriate Characteristics of Surface Modification 615.7 Summary 63References 646 Surface Composite Fabrication Using FSP 67Baidehish Sahoo, Jinu Paul, and Abhishek Sharma6.1 Introduction 676.2 Reinforcement Incorporation Approaches 686.3 Effect of Process Parameters 716.4 Microstructural Evolution and Mechanical Properties 756.5 Strengthening Mechanisms 806.6 Defects 836.7 Summary and Future Directions 86References 867 Friction Stir Welding of Dissimilar Metals 93Narayan Sahadu Khemnar, Yogesh Ramrao Gunjal, Vijay Shivaji Gadakh, and Amrut Shrikant Mulay7.1 Introduction 937.2 Application Areas of Dissimilar Material Joining 947.3 Issues for Dissimilar Material Joining 947.4 FSW of Dissimilar Materials 957.5 Recent Developments in Tool Design and Tool Materials 1037.6 Parameter Optimization 1037.7 Common Defects that Occur in FSW of Dissimilar Metal Joining 1047.8 Future Recommendations for Dissimilar Metal Joining 105Acknowledgments 105References 1068 Friction Stir Welding of Aluminum and Its Alloy 109Palani Sivaprakasam, Kolar Deepak, Durairaj Raja Joseph, Melaku Desta, Putti Venkata Siva Teja, and Murugan Srinivasan8.1 Introduction 1098.2 Fundamentals of FSW 1108.3 FSW of Aluminum and Its Alloy 1108.4 Influences of Process Parameters 1128.5 Testing and Characterization of FSW of Al and Its Alloy 1158.6 Additive Mixed Friction Stir Process of Al and Its Alloy 1188.7 Applications 1188.8 Conclusions 119References 1199 Mechanical Characterization of FSWed Joints of Dissimilar Aluminum Alloys of AA 7050 and AA6082 125Mohd Sajid, Gaurav Kumar, Husain Mehdi, and Mukesh Kumar9.1 Introduction 1259.2 Materials and Methods 1269.3 Results and Discussion 127References 13110 Sample Preparation and Microstructural Characterization of Friction Stir Processed Surface Composites 135Manu Srivastava, Sandeep Rathee, Shazman Nabi, and Atul Kumar10.1 Introduction 13510.2 Sample Preparation for Microscopic Analysis of Metals, Alloys, and Composites 13610.3 Etching 14010.4 Microstructural Evolution 141Acknowledgment 146References 14611 Microstructural Characterization and Mechanical Testing of FSWed/FSPed Samples 149Prem Sagar, Sushma Sangwan, and Mohankumar Ashok Kumar11.1 Introduction 14911.2 Microstructural Characterization 15211.3 Mechanical Testing 15911.4 Conclusions 162References 16212 Comparative Analysis of Microstructural and Mechanical Characteristics of Reinforced FSW Welds 165Tanvir Singh12.1 Introduction 16512.2 Friction Stir Welding (FSW) 16612.3 Reinforcing Materials-Based Fabrication of FSW Welds 16712.4 Joinability of Reinforced FSW Welds 16812.5 Metallurgical Characteristics of FSW Reinforced Welds 16912.6 Mechanical Behavior of Reinforced FSW Welds 17912.7 Conclusions 18412.8 Future Challenges 184References 18513 Summary of Efforts in Manufacturing of Sandwich Sheets by Various Joining Methods Including Solid-State Joining Method 193Divya Sachan, R. Ganesh Narayanan, and Arshad N. Siddiquee13.1 Introduction 19313.2 Sandwich Sheets 19313.3 Classification of Sandwich Sheet Structures 19413.4 Applications 19513.5 Fabrication Methods 19613.6 Summary 200References 20114 Defects in Friction Stir Welding and its Variant Processes 205Vinayak Malik and Satish V. Kailas14.1 Introduction 20514.2 General Defects in FSW 20514.3 Characteristic Defects in Friction Stir Butt and Lap Joints 20814.4 Distinctive Defects in Major Friction Stir Variants 20914.5 Solutions to Avoid Defects in Friction Stir-Based Processes 21214.6 Summary and Concluding Remarks 213Acknowledgment 213References 21315 Nondestructive Ultrasonic Inspections, Evaluations, and Monitoring in FSW/FSP 215Yuqi Jin, Teng Yang, Narendra B. Dahotre, and Tianhao Wang15.1 Introduction 21515.2 Ultrasonic Wave Behaviors in FSWed/FSPed Samples 21515.3 Common Ultrasonic Inspection and Evaluation Methods for FSWed/FSPed Samples 22415.4 Case Studies on Recent Novel Ultrasound Evaluation and Monitoring in FSW/FSP 23415.5 Roles and Potentials of Ultrasound in Future FSW/FSP 24215.6 Conclusion 243Acknowledgment 243References 24316 Applications of Friction Stir Welding 245Raja Gunasekaran, Velu Kaliyannan Gobinath, Kandasamy Suganeswaran, Nagarajan Nithyavathy, and Shanmugam Arun Kumar16.1 Introduction 24516.2 Application of FSW on Different Materials 24716.3 Industrial Applications of FSW 25216.4 Conclusion 255References 25617 Equipment Used During FSP 259Kandasamy Suganeswaran, Nagarajan Nithyavathy, Palaniappan Muthukumar, Shanmugam Arunkumar, and Velu Kaliyannan Gobinath17.1 Introduction 25917.2 FSP Experimental Setup 26417.3 Microstructural Characterization 26717.4 Mechanical Behavior of Composites Based on Various Tool Shapes 27117.5 Mechanical behavior of Composites Based on Various Process Parameters 27217.6 Conclusion 273References 27318 Analysis of Friction Stir Welding Tool Using Various Threaded Pin Profiles: A Case Study 275Bommana B. Abhignya, Ashish Yadav, Manu Srivastava, and Sandeep Rathee18.1 Introduction 27518.2 Geometry Considered 27718.3 Results and Discussions – Analysis in ANSYS 27818.4 Conclusion 279Acknowledgement 281References 28119 Static Structural and Thermal Analysis of Honeycomb Structure Fabricated by Friction Stir Processing Route: A Case Study 283Nikhil Jaiswal, Umashankar Bharti, Ashish Yadav, Manu Srivastava, and Sandeep Rathee19.1 Introduction 28319.2 Modeling Details 28419.3 Result and Analysis 28619.4 Scope of the Case Study 29019.5 Conclusion 291Acknowledgement 292References 29220 Friction Stir-Based Additive Manufacturing 293Ardula G. Rao and Neelam Meena20.1 Additive Manufacturing: An Introduction 29320.2 Solid-State AM Processes 29520.3 Case Studies of FSAM on Different Materials 29920.4 Advantages of FSAM Over Other AM Techniques 30020.5 Advancements 30120.6 Limitations 30220.7 Conclusions and Future prospectives 303References 303Index 307

Sandeep Rathee, PhD, is an Assistant Professor in the Department of Mechanical Engineering at the National Institute of Technology, Srinagar, India. His research interests include friction stir welding/processing, additive manufacturing, composites, and hybrid manufacturing. Manu Srivastava, PhD, is an Assistant Professor in the Department of Mechanical Engineering at the PDPM Indian Institute of Information Technology, Design and Manufacturing, Jabalpur, India. Her research interests include additive manufacturing, friction-based AM, friction stir processing, advanced materials, manufacturing practices, and optimization techniques. J. Paulo Davim, PhD, is a Professor at the University of Aveiro, Portugal and a Fellow (FIET) of the Institution of Engineering and Technology, UK. His research interests include advanced manufacturing methods and materials.

• About the Editors xvList of Contributors xviiiPreface xxvAcknowledgements xxixList of Figures xxxList of Tables xl1 Friction Stir Welding: An Overview 1Farooz A. Najar, Shazman Nabi, Sandeep Rathee, and Manu Srivastava1.1 Introduction 11.2 FSW Working Principle 21.3 Weld Zones 31.4 Variants of FSW 41.5 Defects 101.6 Advantages and Limitations of FSW 111.7 Conclusion and Future Prospectus 12Acknowledgments 12References 122 Friction Stir Welding and Single-Point Incremental Forming: State-of-the-Art 15Hitesh Mhatre, Amrut Mulay, and Vijay Gadakh2.1 Introduction 152.2 Friction Stir Welding (FSW) 162.3 Single-Point Incremental Forming (SPIF) 182.4 FSW and SPIF 212.5 Summary and Outlook 22References 233 Friction Stir Brazing and Friction Stir Vibration Brazing 25Behrouz Bagheri and Mahmoud Abbasi3.1 Introduction to FSB 253.2 Variants of FSB 263.3 Two Case studies 273.4 Application of FSB and Its Variants in Industry 353.5 Summary and Future Directions 35References 364 Fundamentals of Friction Stir Processing 39Atul Kumar, Devasri Fuloria, Manu Srivastava, and Sandeep Rathee4.1 Friction Stir Processing (FSP): Background 394.2 Working Principle of FSP 394.3 Comparison with Other Severe Plastic Deformation (SPD) Techniques 424.4 Process Variables 434.5 Mechanisms of Microstructural Evolution During FSP 484.6 Critical Issues in FSP 494.7 Future Scope 50References 515 Role of FSP in Surface Engineering 55Setu Suman and Kazi Sabiruddin5.1 Introduction 555.2 Role of Surface Modification Techniques 565.3 Thermal Spray Technique 575.4 FSP – Solid-State Coating Process 585.5 Process Parameters of FSP: Surface Engineering 605.6 Inappropriate Characteristics of Surface Modification 615.7 Summary 63References 646 Surface Composite Fabrication Using FSP 67Baidehish Sahoo, Jinu Paul, and Abhishek Sharma6.1 Introduction 676.2 Reinforcement Incorporation Approaches 686.3 Effect of Process Parameters 716.4 Microstructural Evolution and Mechanical Properties 756.5 Strengthening Mechanisms 806.6 Defects 836.7 Summary and Future Directions 86References 867 Friction Stir Welding of Dissimilar Metals 93Narayan Sahadu Khemnar, Yogesh Ramrao Gunjal, Vijay Shivaji Gadakh, and Amrut Shrikant Mulay7.1 Introduction 937.2 Application Areas of Dissimilar Material Joining 947.3 Issues for Dissimilar Material Joining 947.4 FSW of Dissimilar Materials 957.5 Recent Developments in Tool Design and Tool Materials 1037.6 Parameter Optimization 1037.7 Common Defects that Occur in FSW of Dissimilar Metal Joining 1047.8 Future Recommendations for Dissimilar Metal Joining 105Acknowledgments 105References 1068 Friction Stir Welding of Aluminum and Its Alloy 109Palani Sivaprakasam, Kolar Deepak, Durairaj Raja Joseph, Melaku Desta, Putti Venkata Siva Teja, and Murugan Srinivasan8.1 Introduction 1098.2 Fundamentals of FSW 1108.3 FSW of Aluminum and Its Alloy 1108.4 Influences of Process Parameters 1128.5 Testing and Characterization of FSW of Al and Its Alloy 1158.6 Additive Mixed Friction Stir Process of Al and Its Alloy 1188.7 Applications 1188.8 Conclusions 119References 1199 Mechanical Characterization of FSWed Joints of Dissimilar Aluminum Alloys of AA 7050 and AA6082 125Mohd Sajid, Gaurav Kumar, Husain Mehdi, and Mukesh Kumar9.1 Introduction 1259.2 Materials and Methods 1269.3 Results and Discussion 127References 13110 Sample Preparation and Microstructural Characterization of Friction Stir Processed Surface Composites 135Manu Srivastava, Sandeep Rathee, Shazman Nabi, and Atul Kumar10.1 Introduction 13510.2 Sample Preparation for Microscopic Analysis of Metals, Alloys, and Composites 13610.3 Etching 14010.4 Microstructural Evolution 141Acknowledgment 146References 14611 Microstructural Characterization and Mechanical Testing of FSWed/FSPed Samples 149Prem Sagar, Sushma Sangwan, and Mohankumar Ashok Kumar11.1 Introduction 14911.2 Microstructural Characterization 15211.3 Mechanical Testing 15911.4 Conclusions 162References 16212 Comparative Analysis of Microstructural and Mechanical Characteristics of Reinforced FSW Welds 165Tanvir Singh12.1 Introduction 16512.2 Friction Stir Welding (FSW) 16612.3 Reinforcing Materials-Based Fabrication of FSW Welds 16712.4 Joinability of Reinforced FSW Welds 16812.5 Metallurgical Characteristics of FSW Reinforced Welds 16912.6 Mechanical Behavior of Reinforced FSW Welds 17912.7 Conclusions 18412.8 Future Challenges 184References 18513 Summary of Efforts in Manufacturing of Sandwich Sheets by Various Joining Methods Including Solid-State Joining Method 193Divya Sachan, R. Ganesh Narayanan, and Arshad N. Siddiquee13.1 Introduction 19313.2 Sandwich Sheets 19313.3 Classification of Sandwich Sheet Structures 19413.4 Applications 19513.5 Fabrication Methods 19613.6 Summary 200References 20114 Defects in Friction Stir Welding and its Variant Processes 205Vinayak Malik and Satish V. Kailas14.1 Introduction 20514.2 General Defects in FSW 20514.3 Characteristic Defects in Friction Stir Butt and Lap Joints 20814.4 Distinctive Defects in Major Friction Stir Variants 20914.5 Solutions to Avoid Defects in Friction Stir-Based Processes 21214.6 Summary and Concluding Remarks 213Acknowledgment 213References 21315 Nondestructive Ultrasonic Inspections, Evaluations, and Monitoring in FSW/FSP 215Yuqi Jin, Teng Yang, Narendra B. Dahotre, and Tianhao Wang15.1 Introduction 21515.2 Ultrasonic Wave Behaviors in FSWed/FSPed Samples 21515.3 Common Ultrasonic Inspection and Evaluation Methods for FSWed/FSPed Samples 22415.4 Case Studies on Recent Novel Ultrasound Evaluation and Monitoring in FSW/FSP 23415.5 Roles and Potentials of Ultrasound in Future FSW/FSP 24215.6 Conclusion 243Acknowledgment 243References 24316 Applications of Friction Stir Welding 245Raja Gunasekaran, Velu Kaliyannan Gobinath, Kandasamy Suganeswaran, Nagarajan Nithyavathy, and Shanmugam Arun Kumar16.1 Introduction 24516.2 Application of FSW on Different Materials 24716.3 Industrial Applications of FSW 25216.4 Conclusion 255References 25617 Equipment Used During FSP 259Kandasamy Suganeswaran, Nagarajan Nithyavathy, Palaniappan Muthukumar, Shanmugam Arunkumar, and Velu Kaliyannan Gobinath17.1 Introduction 25917.2 FSP Experimental Setup 26417.3 Microstructural Characterization 26717.4 Mechanical Behavior of Composites Based on Various Tool Shapes 27117.5 Mechanical behavior of Composites Based on Various Process Parameters 27217.6 Conclusion 273References 27318 Analysis of Friction Stir Welding Tool Using Various Threaded Pin Profiles: A Case Study 275Bommana B. Abhignya, Ashish Yadav, Manu Srivastava, and Sandeep Rathee18.1 Introduction 27518.2 Geometry Considered 27718.3 Results and Discussions – Analysis in ANSYS 27818.4 Conclusion 279Acknowledgement 281References 28119 Static Structural and Thermal Analysis of Honeycomb Structure Fabricated by Friction Stir Processing Route: A Case Study 283Nikhil Jaiswal, Umashankar Bharti, Ashish Yadav, Manu Srivastava, and Sandeep Rathee19.1 Introduction 28319.2 Modeling Details 28419.3 Result and Analysis 28619.4 Scope of the Case Study 29019.5 Conclusion 291Acknowledgement 292References 29220 Friction Stir-Based Additive Manufacturing 293Ardula G. Rao and Neelam Meena20.1 Additive Manufacturing: An Introduction 29320.2 Solid-State AM Processes 29520.3 Case Studies of FSAM on Different Materials 29920.4 Advantages of FSAM Over Other AM Techniques 30020.5 Advancements 30120.6 Limitations 30220.7 Conclusions and Future prospectives 303References 303Index 307