Torque and force perspectives on particle size and its effect on mechanical property of friction stir welded AA6092/17.5SiCp-T6 composite joints

Torque and force generated during Friction Stir welding play a major role in determining and controlling the quality of the final weld. This study combines role of torque and force on particle size in the weld zone. AA6092/17.5SiC(p)-T6 composite plates of 6mm thickness are welded at different tool rotational speed (TRS); 1000rpm, 1500rpm and 2000rpm and a fixed traverse speed of 2mm/sec and tilt angle of 2 degrees by using a taper pin tool. Fluctuations in the torque and force values was noticed at 2000 rpm which may be attributed mainly due to the evolution of a discrete stick-slip event at higher heat input and possible tool wear at higher TRS. The result shows a comparatively stable torque and force at 1500rpm. Particle size of 4.03 mu m and 4.99 mu m was observed in nugget zone (NZ) and Thermo-mechanically affected zone (TMAZ) respectively at 1500rpm which is very much smaller than the particles in base material (7.92 mu m). The effect of particle size in the weld zone was investigated in terms of the tensile strength. Better strength and elongation were achieved for the sample that possessed finer size particles among the welded samples.