Determination of the porosity and pore size distribution of SiC ceramic foams by nuclear methodologies

Abstract

Two nuclear methodologies were used for porosity and pore size distribution determination of SiC ceramic foams. Thirty samples were analysed, six of each one of the following pore densities: 30, 45, 60, 80 and 100 pores per inch (ppi). The two nuclear techniques employed were X-ray microtomography and gamma ray transmission. For the microtomography technique, the spatial resolution of the images was 32 mm. For the gamma ray transmission methodology, a NaI (Tl) scintillation detector and Am-241 radioactive source were used. The gamma transmission technique was precise for porosity determination in relationship to the nominal values supplied for the sample manufacturer. The 30 and 45 ppi samples analysed by the microtomography technique present average porosities equivalent to the nominal porosity, and the other samples present an average of 4?6% smaller values. The 30 and 45 ppi sample two-dimensional images show voids inside the structural solid material of the ceramic.

Three-Dimensional Stochastic Modeling and X-Ray Microtomography Applied to Titanium Scaffolds: A Comparative Approach

“…Gaussian method generated a model for a 700 average autocorrelation function. However, some techniques take images from just one surface of the sample, cause of metallographic specimens preparation (section plane, polish and resin cold mounting) [11,12]. The method uses porosity and autocorrelation function data as parameters to generate the model.…”

Mechanical properties of PLA/PBS foamed composites reinforced by organophilic montmorillonite

“…In foaming process of thermoplastics, high melt viscosity is critical. Unfortunately, neither PLA nor PBS has sufficient melt viscosity . There are several ways to increase the melt viscosity of PLA, such as copolymerization, reaction extrusion, radiation crosslinking and nano‐particle blending .…”

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