Green properties of dry-pressed alumina compacts fabricated using sucrose as binder

Abstract

The green density and flexural strength of dry pressed alumina compacts fabricated using sucrose binder (0.6-10.8 wt%) was studied as a function of particle size of alumina powder and moisture content. An optimum binder content (7.2 and 8.4 wt% for fine and coarse alumina, respectively) was established in terms of achieving maximum green density and strength in the pressed compact. Maximum achievable green density of dried samples was 63% and 60% for fine and coarse alumina, respectively. The corresponding maximum strength was 12.5 and 7.52 MPa. Observed results have been co-related with the microstructure of green samples. Samples with sucrose content 3.6 wt% and above were strong enough for green machining. The high green strength of samples could be co-related to plasticizing effect of binder solution leading to maximum particle packing and binder-ceramic interaction, as was revealed by IR study. Samples with optimum sucrose content exhibited minimum porosity (5% and 18% for fine and coarse alumina respectively) after firing. © 2013 Elsevier Ltd and Techna Group S.r.l.