Survey on influence of starch addition on gel casting of porous alumina bodies

The aim of this research is to study the influence of starch content and sintering temperature on microstructure, physical and mechanical properties of porous alumina bodies prepared by gel casting. Samples with 60.5, 63 and 65.5 wt% alumina and 7.5, 5 and 2.5 wt% corn starch, respectively, were ball milled 3 hours, casted into the molds and heated into drier (86 oC, 2 h) to gelatinization process. The dried samples were sintered 1h at 1400, 1450 and 1500 oC. After sintering, the samples properties were reported: bulk density 1.41-1.68 g.cm-3, open porosity 53.92-62.01% and Cold Crushing Strength (CCS) 0.98-3.82 MPa. Phase Analysis of the samples in 1500oC showed the peaks of α-alumina phase Also, Microstructural evaluation showed large pores remaining connected by small necks after starch burning out which caused interconnecting porosities and permeability increase.