Thermal Diffusivity Mapping of Solids by Scanning Photoacoustic Piezoelectric Technique

Quantitative thermal diffusivity mapping of solid samples was achieved using the scanning photoacoustic piezoelectric (PAPE) technique. Based on the frequency-domain PAPE theoretical model, the methodology of the scanning PAPE thermal diffusivity mapping is introduced. An experimental setup capable of spatial and frequency scanning was established. Thermal diffusivity mapping of homogeneous and inhomogeneous samples was carried out. The obtained thermal diffusivity images are consistent with the optical images in image contrast and consistent with the reference values in thermal diffusivity. Results show that the scanning PAPE technique is able to determine the thermal diffusivity distribution of solids, hence providing an effective method for thermal diffusivity mapping.