Porosity profile evaluation of ceramic samples using gamma ray transmission technique

Nowadays, there is a constant search for materials used in industry, medicine, biology among others, with better performance and lower costs. Therefore, the development of techniques to describe material characteristics is an important point on such researches. This paper shows results for seven SiO2 ceramic samples with permeability of (46.0 ± 9.2) mD, that have been analyzed using gamma ray transmission to characterize its structure. The samples had different sizes: four bricks with 10x1.9x5 cm and three cylinders with 3.6 cm high and 4.9 cm diameter size. The experimental array consisted of a moving XZ micrometric table for sample positioning, 241Am source (59.53 keV, 100mCi), Pb collimators, NaI(Tl) detector and compatible nuclear electronic chain. Experimental evaluation showed that the system has special resolution of 2.1 ± 0.1 mm. A millimetric scanning of the porosity was measured and calculated the average total porosity for each sample, which presented a good agreement with the values supplied by the manufacturer. The average porosity value obtained for brick samples was 29.76 ± 0.38% for R1 sample, 29.76 ± 0.25% for R2, 29.55 ± 0.35% for R3 and 30.54 ± 0.33% for R4. For the cylindrical samples it was 27.16 ± 0.20% for sample C1, 27.20 ± 0.15% for C2 and 26.55 ± 0.18% for C3. Each sample showed a high variation on the porosity profile, as can be seen through the relative difference between the higher and lower porosity value for each sample: 28.38% for R1 sample, 19.07% for R2, 24.85% for R3 and 25.78% for R4, 15.81% for C1, 13.67% for C2 and 19.15% for C3. (author)