Microstructural characterization of TiO2 ceramics substrates using image analysis software ImageJ

Resumo

In this work the clusters size and porosity of TiO₂ ceramics substrates were quantified. The ceramics analyzed were prepared by two techniques: slip-casting and compaction, starting from an aqueous suspension of commercially available TiO₂ (Rutilo RKB-2, B’Herzog) with organics additives. The ceramics were sintered at temperature of 1100 and 1150^oC/1h. The microstructure of the ceramics and the clusters of the atomized suspensions in the spray dryer were analyzed in scanning electron microscopy (SEM-HITACHI TM 3000). The image analysis software ImageJ was used to treat images to removing noise and highlight the regions of interest in the analysis. The porosity was determined from analysis of five different images using the following algorithm, as suggested in the standard ASTM E 1382-97 [1]: Unsharp Masks Filter; Median Filter; Threshold Command. The average clusters size was determined using Ferret Diameter [2], from analysis of five different images, reaching the count of 1126 clusters. It was used same algorithm above, just applying at the end, the Overlay/Masks command to highlight the clusters contour. 

Applying methodology described for determination the average clusters size, the value of 7.174 µm ± 0.984 was obtained (Figure 2). The results showed that the digital image processing was effective in the analysis of microstructure of ceramic substrates, as well as, for determination of particle size in micrometric scale. The porosity determined by images analysis considers in addition to the open pores, also the closed pores.