Speaker
Description
The detection of subsurface defects in aluminum plates using infrared thermography addresses particularly stringent safety requirements in various industrial sectors, notably in civil aerospace construction and the automotive industry, where material reliability is a critical criterion. Such defects generally manifest as anomalies affecting both dimensional accuracy and geometric shape conformity.
The present work constitutes a contribution to the implementation of the thermal flash method in reflection mode, applied to the detection and thermophysical characterization of subsurface defects in aluminum plates. To this end, an experimental setup was designed and developed, incorporating a high-resolution infrared imaging system. This system enables the acquisition of thermogram sequences in the form of thermal images, representing the thermal state of the surface of the tested plate. Artificial subsurface defects of various geometric shapes and depths were intentionally introduced to evaluate the detection capability of the described method. Indeed, the use of advanced infrared image segmentation methods enables the estimation of local physical quantities characterizing each detected defect region, such as local thermal diffusivity, thermal contrast, the thermal barycenter, as well as the area and circularity of the defect surface. The obtained results are very encouraging and indicate the feasibility of developing a reliable system for the detection and characterization of subsurface defects in metal sheets.
