An extensive investigation was carried out on the SR-FSW of 2219aluminium alloy with the thickness
of 6 mm, and the weld appearances, microstructure and mechanical properties of the SR-FSW joint has been analyzed.
The results indicated that the SR-FSW joint had excellent top and underside appearances without inner defects,
distortion and seam thinning if the parameters were carefully chosen. Typical macrosections of the joint were slightly
hourglass shpaed,and the width of the top and underside surface was slightly greater than the mid-thickness of the
joint. As analyzed, the macrosection of the joint was related with the change of the SRPT, heat production and heat
trasfer. The microstructure of the joint also consisted of nugget zone, thermal-mechanically affected zone, heat affected
zone, and within each zone, the microstructure was the same as C-FSW joint. The SR-FSW joint and C-FSW joint
had the similar hardness distribution with the typical “W” type, but the former had no anisotropic. The mechanical
property shown that the tensile strength of the joint can reach 318. 3 MPa, and the ductility can get to 5. 5%. The
fracture mechanisium of the joint was ductile fracture.