Effect of dynamic recrystallization on structural properties of friction stir welded dual-phase brass

Dual phase brass is a demanding material for various industries like medical, electronic, automotive, aerospace, and marine owing to its excellent corrosion resistant properties. Dynamic recrystallization (DRX) is a challenging phenomenon experienced in rolling operation, where strain-rate dependent behaviour is observed under the compressive loading, which causes recrystallization dynamically. During friction stir welding along with axial compressive force, rotating tool generates a combination of forces, namely transverse and shear deforming forces. These forces result from rotational and linear movement of tool and promote DRX within material. A combination of these forces causes the grain structure to recrystallize dynamically, enhancing its properties. Despite yielding favourable outcomes, the mechanism has not been investigated in detail. In present study, the distinctive variations in friction stir welding (FSW) process parameters were employed to identify the effect of DRX. Further, the detailed metallurgical evaluation was conducted along with its effect on the mechanical properties. The effect of DRX is evidenced in dual-phase brass in terms of grains and phase fraction enhancement that further enhances the mechanical properties of the weldments.