Diffusivity measurement of semi-transparent media: model of the coupled transient heat transfer and experiments on glass, silica glass and zinc selenide

The aim of this theoretical and experimental study is to provide a complete methodology to estimate the intrinsic diffusivity of semi-transparent media from flash method experiments. A semi-analytical model describes the coupled conductive–radiative transient heat transfer in a slab. The relevance of the model used for the inversion is then investigated. Experimental results are presented for several semi-transparent samples: float glass, SiO2 and ZnSe. Measurements of rear face temperature are obtained by optical way (infrared detection) for a wide temperature range (293–700 K), for several radiation boundary conditions (black or gold coatings). The results are compared with those obtained through an other set-up and an other experimental procedure.