The aim of this study is to present an overall view of friction stir processing (FSP), including the method, the state-of-the-art regarding current
studies, and possible applications. FSP is a solid-state thermo-mechanical processing method. It can be used to produce defect-free,
recrystallized, homogeneous, fine grained microstructures. Structures can be processed at specific locations, through-section or to a desired
depth, or entirely. The benefits obtained with FSP include elimination of casting defects and refinement of microstructures resulting in improved
strength, ductility, resistance to corrosion and fatigue, and formability (including high strain rate superplasticity). Alsosurface composites
can be produced by FSP.