This volume presents fundamentals and the current status of friction stir welding (FSW) and solid-state friction stir processing of materials and provides researchers and engineers with an opportunity to review the current status of the friction stir related processes and discuss the future possibilities. Contributions cover various aspects of friction stir welding and processing including their derivative technologies. Topics include but are not limited to: Additive friction stir technologies Friction stir extrusion technologies High temperature applications Industrial applications Friction stir spot technologies Dissimilar alloys and materials Lightweight alloys Simulation, characterization, and non-destructive examination techniques.