Non-destructive investigation of aluminum alloy hemmed joints using neutron radiography and X-ray computed tomography

Methods for the non-destructive analysis of aluminum alloy hemmed joints for automotive applications were investigated to visualize the void size, volume fraction and shape within the adhesive fill. These defects can adversely affect the performance of hemmed joints by decreasing fatigue strength and corrosion resistance. Thermal neutron radiography and X-ray computed tomography were applied to visualize the voids. The void fraction within the adhesive fill was determined from the neutron images with the use of an image analysis thresholding method.