Preliminary procedure for the assessment of probeless friction stir spot welds (P-FSSW) in dissimilar aluminum alloys by long pulsed laser thermography

This work presents a preliminary investigation into the quality assessment of Probeless Friction Stir Spot Welding (PFSSW) joints in dissimilar aluminum alloys using laser thermography. This innovative process based on friction stir spot welding, demonstred good capabilities for aluminum joints. To evaluate the quality of these innovative joints in a non-destructive way a long-pulsed laser thermography preliminary procedure has been proposed. The study compares thermographic assessments with conventional testing on two specimens: deemed acceptable and not. Results indicate that preliminary procedure based on laser thermography can effectively assess weld quality, estimating the size of welded zones with an error margin of 3% relative to ultrasonic test UT.The present work constitutes a preliminary step toward the ultimate goal of developing a thermographic procedure for the non-destructive evaluation of the mechanical strength of these joints using laser thermography, with a simplification of the equipment.