Gamma ray transmission technique applied to porous phase characterization of low-porosity ceramic samples

Abstract

The aim of this study is to apply gamma ray transmission (GRT), a non destructive technique, in the structural characterization of low-porosity ceramic samples. GRT technique is based on the attenuation that photons of an incident radiation beam undergo when passing through the material. With this technique the porosity of alumina (Al2O3) and boron carbide (B4C) ceramic samples, was determined. The equipment employed comprises a 241Am (Americium) gamma ray source (59.6 keV and 100 mCi), a 50.8 mm × 50.8 mm NaI (Tl) scintillation detector coupled to a standard Gamma Ray Transmission system and a micrometric automated table for sample movement. The porosity profile of the samples shows a homogeneous porosity distribution, within the spatial resolution of the employed transmission system. The mean porosity values determined for Al2O3 and B4C were 17.8 (±1.3 %) and 3.87 (±0.43 %), respectively. Statistical treatment of these results was performed and showed that the mean porosity values determined by Gamma Ray Transmission technique are the same as those supplied by the manufacturer.