ABSTRACT
This chapter describes the fabrication of surface composites by friction stir processing (FSP) in detail. The stirring action of the FSP tool can be used to incorporate and distribute secondary phase particles in a metal in order to fabricate surface metal matrix composites. The mechanism behind the composite formation during FSP can be explained by considering the material flow during FSP. Excessive heat generation leads to an increase in the temperature at the processing zone close to that of melting point and leads to thermal softening of the work material. The level of thermal conductivity of the work material governs the amount of heat concentration at the processing zone along with the other processing parameters which further directly influence the recrystallization rate and the size of the zone that undergoes microstructure modification. Designing the geometrical features of the FSP tool is also crucial which directly influence the rate of heat generation.
