Processing of Alumina Powder into Ceramic Foam Materials by Impregnating Polyurethane Sponge with Bonded Ceramic Slurry

Ceramic foams have an interesting combination of properties, such as low weight,
high temperature stability, high permeability, high porosity, low thermal
conductivity, and low heat capacity. These properties have lead to a diverse range of
applications, such as metal melt filtration, ion-exchange filtration, heat exchangers
catalyst support, and refractory linings. Most of the production routes to such
materials are via expensive sol-gel or chemical vapor deposition (CVD) technique.
For that reason, the objective of this research is to develop a simple and economical
method to synthesize and subsequently characterize ceramic foam using Alumina
processed via powder routes, by an aid of Polyurethane (PU) sponge as template.
The fundamental components for the process are; ceramic (Alumina powder, Al2O3),
available foam (Polyurethane, PU-sponge) as a template, Carboxyl Methyl Cellulose
(CMC) as an organic binder, Sodium Meta Silicate (Na2O.SiO) as a sintering aid,
and distilled water (H2O) as a wetting agent. The process starts with selection of the
template from four different samples of PU sponge by using various analysis such as
TGA and SEM-EDS analysis. Next is the production of ceramic slurry by mixing the
optimum compositions of each material in a ball mill. The resulting slurry is then
impregnated into cut of the selected PU sponge in which a way that it carry a high
loading. Subsequent to that, the impregnated foam will undergo drying process to
remove the water before the organic additives were removed by calcination process.
The impregnated foam will then subsequently undergo firing and re-firing (sintering
process) with slow scheduled to get the foam microstructure and to burn out all the
remaining processing additives. The resulting ceramic foam will then be
characterized in terms of its porosity, pore structure, pore individual shape, density,
linear and volume shrinkages, crystallinity and crushing strength.