Experimental and numerical study of simultaneous cooling with CO2 gas during friction stir welding of Al-5052

Present study investigates temperature distribution and final distortion of butt-joint Al-5052 plates using conventional and simultaneously cooling for friction stir welding, experimentally and numerically. Pursuant to the experimental results, cooling process reduced the distortion in the weldment by 60% in comparison with the conventional process. Finite-element model of the welding process was used by modifying the source term. By proposed model, good agreements between the experimental and numerical results were obtained. According to the numerical simulations, the maximum longitudinal residual stress had 50% reduction in comparison with the conventional process. Easy handling of CO2 gas and no infiltration in the nugget zone can be benefits of the proposed process.