Radiative behavior of low-porosity ceramics: I—Development and applications of a physical optics modeling approach

Abstract

We propose a physical optics approach to compute the volume radiative properties and surface reflectivity of porous ceramics composed of a weakly absorbing solid matrix containing low fractions of heterogeneities (pores or particles). Our approach accounts for dependent scattering between heterogeneities that are small and close to each other compared to the wavelength, and only requires the 3D microstructure and complex refractive indexes of constituent phases as input. We performed numerical validation of our models on reference microstructures with known solutions, and showed that an accuracy of 5% is achieved. We then applied our approach to compute the spectral volume and surface radiative properties of tomography-reconstructed porous alumina samples of various porosities up to 30%. Microstructure-property relations are extracted from numerical results, and are compared to several analytical relations in order to assess their applicability in the studied material.