Modelling of the Thermal Radiative Properties of Oxide Ceramics

Abstract

A numerical model based upon a Monte Carlo Ray Tracing (MCRT) code was developed to predict the thermal radiative properties (reflectance, transmittance, emittance) of a family of virtual alumina ceramics with prescribed textural features. The numerical samples were constituted of polydisperse spherical pores [20–120 μm] embedded in a continuous and homogenous alumina matrix. The texture of the alumina ceramics were numerically settled, allowing, in our case, to fix their porosity, their volumetric surface and their radii size distribution. The MCRT code was applied at T = 300 K and T = 1300 K since, at the local scale, the complex indices of refraction of the alumina matrix were known. The comparisons of the emittance spectra of the numerical samples with the ones acquired by infrared emittance spectroscopy on a single crystal of alumina (T = 300 K and T = 1300 K) allow to discuss the effects played by the temperature and by each textural parameters.

Hybrid Methodology for Retrieving Thermal Radiative Properties of Semi-Transparent Ceramics

“…Thus, we focus this study in the semitransparent region, the region from the mid-infrared to the visible range, where light travels far under the material surface, and where the whole volume and topology of the material affect the light propagation. Indeed, texture, pore size and its distribution, are known to influence radiative properties of semitransparent materials. − …”