The effect of sago as binder in the fabrication of alumina foam through the polymeric sponge replication technique

Influence of various binders to alumina foam substrate was investigated. The substrate was prepared by the polymeric sponge replication technique using different solid loading ratios and binder agents. The slurries used showed a shear thinning behavior. During replication, a sponge template was coated in alumina slurry, whilst excess slurry was removed manually. The resulting substrate have been studied via the Archimedes method, morphological and phase analysis, and compression test. The total porosities varied between each binder rose from 79.2% to 90.4% depending on their solid loading. The samples with natural binders had a bulky struts and fine surface, contrary to the PVA added samples. Upon compression test, PVA added samples destroyed in fragments whilst natural binders modified samples had a collapsed microstructure but still preserved its structural integrity. Comparison of experimental data and prediction value of Gibson and Ashby model show a quiet big gap between both values.