Influence of gelling additives in the green properties of Al_2O_3 bodies obtained by aqueous gel casting

摘要

The use of gelling additives, as polysaccharides, in colloidal processing provides adequate mechanical properties to the green bodies to be handled. In this work, Al_2O_3 gel casting is studied by using agar, agarose and carrageenan as gelling additives. The rheological behaviour of the gel casting slurries on cooling is studied. The green characteristics of the gel cast bodies prepared at different conditions are characterised in terms of density, microstructure and mechanical behaviour (bend strength, elastic modulus) at room temperature. A correlation between the obtained results is established and the best compositions and processing conditions are discussed.