Influence of cassava starch content and sintering temperature on the alumina consolidation technique

The influence of starch content and sintering temperature on the preparation of alumina bodies were studied. The process was water-based and cassava starch was used as consolidator, binder and pore former. Colloidal suspensions were prepared with three different starch concentrations and the ideal dispersant content and gel point were determined by rheological analysis. The wet samples were demolded after consolidation in silicone mold at 60 °C for 2 h. After the drying step the samples were sintered at 1200, 1400 and 1600 °C, showing open porosities between 13 and 55%, depending on the starch content on the precursor suspensions and sintering temperature. The pore structures were analyzed by SEM (scanning electron microscopy) and Hg porosimetry. Basically, the pore structures are dominated by large spherically shaped pores left by the starch particles, which are connected through small pore channels.