A review on effect of friction stir processing on the welded joints

Conventional fusion weld joint possesses coarse grain structure, inevitable defects which results in inferior weld properties. To overcome this, the welds are often repaired or processed with post welding treatments. Friction stir welding (FSW) being solid state process avoids issues related to the solidification of the conventional weld. FSW joint also exhibits the need for improved weld properties. The variant process of FSW, friction stir processing (FSP) modify the microstructure of material for property improvement. FSP can be used to modify welded joints which in addition to modify the microstructure. It also eliminates defects if followed to the fusion welding process. The friction stir processed (FSPed) weld joint is expected to exhibit improved mechanical properties and corrosion resistance. This paper review recent research trends related to the use of FSP for weld modification and its effect on weld properties. It also briefs the different welding processes and parameters used. The last section summarises the scope for FSP and its variants for weld modification.