Friction Stir Superplasticity for Unitized Structures

This book describes the fundamentals and potential applications of 'friction stir superplasticity for unitized structures'. Conventional superplastic forming of sheets is limited to the thickness of 3 mm because the fine grained starting material is produced by rolling. Friction stir superplasticity has grown rapidly in the last decade because of the effectiveness of microstructural refinement. The thickness of the material remains almost constant, and that allows for forming of thick sheets/plates, which was not possible before. The field has reached a point where designers have opportunities to expand the extent of unitized structures, which are structures in which the traditional primary part and any supporting structures are fabricated as a single unit. With advanced optimization and material considerations, this class of structures can be lighter weight and more efficient, making them less costly, as well as mechanically less complex, reducing areas of possible failure.
- Discusses how friction stir processing allows selective microstructural refinement without thickness change
- Demonstrates how higher thickness sheets and plates can be superplastically formed
- Examples are presented for aluminum, magnesium and titanium alloys
- Covers the production of low-cost unitized structures by selectively processing cast sheets/plates

Prof. Rajiv Mishra (Ph.D. in Metallurgy from University of Sheffield) is a Regents Professor at the University of North Texas and founder of Optimus Alloys LLC. He is a Fellow of ASM International. He is a past-chair of the Structural Materials Division of TMS and served on the TMS Board of Directors (2013-16). He has authored/co-authored more than 450 papers in peer-reviewed journals and proceedings and is principal inventor of four U.S. patents. His current Google Scholar h-index is 95 and his papers have been cited more than 43000 times. He has co-authored three books; (1) Friction Stir Welding and Processing, (2) Metallurgy and Design of Alloys with Hierarchical Microstructures, (3) High Entropy Materials: Processing, Properties, and Applications. He has edited or co-edited fifteen TMS conference proceedings. He was an associate editor of Journal of Materials Processing Technology and is the founding editor of a short book series on Friction Stir Welding and Processing published by Elsevier and has co-authored seven short books in this series. He is a recipient of TMS-SMD Distinguished Scientist Award in 2020 and TMS-MPMD Distinguished Scientist Award in 2024. He is an adjunct professor in the department of Materials Science and Engineering at North Carolina State University. Most recently, he has founded Optimus Alloys LLC for commercialization of research efforts and serves as the Chief Scientific Advisor. Optimus Alloys is focused on process-specific alloy design for additive manufacturing of high-performance components.

1. Introduction2. Friction stir microstructure for superplasticity 3. High-strain-rate superplasticity 4. Low temperature superplasticity 5. Superplasticity of cast alloy - an example6. Superplastic deformation mechanism7. Enhanced deformation kinetics8. Cavitation during superplasticity9. Abnormal grain growth10. Superplastic forming of friction stir processed plates11. Potential of extending superplasticity to thick sections12. Summary 13. References