Evaluation of bulk defects area in friction stir welded 1080 aluminum alloy utilizing electrical resistivity measurements

In this study, the electrical resistivity measurements as an accessible technique for NDT inspection of FSWed sections were investigated. For this purpose, 1080 Aluminum plates were welded by the FSW technique. The welding parameters were optimized using the Taguchi L9 orthogonal design of experiments. The rotational speed, tool shape, tilt angle, and welding speed were taken into consideration as welding parameters. The soundness of welds was inspected by visual tests, radiography, and metallography observations. The electrical resistivity of welded sections was compared with the area of bulk defects. It revealed that there is a linear relationship between the electrical resistivity and the area of bulk defects. The acquired intercept of the linear equation was introduced as a reference point. The results showed that the area of bulk defects could be predicted by d=0.0001R−C an equation with good accuracy, and the joints with lower electrical resistivity than the reference point could be considered as a sound weld.