Shrinkage and properties of die pressed alumina produced from different granule sources

Abstract

The relationship between compaction pressure and binder content on the density, shrinkage, weight loss, as well as the physical and mechanical properties of 92% alumina were studied. Samples were produced by die pressing using spray dried granules with two different binder content. Properties in the green, presintered, and sintered states were examined. It was found that the compaction pressure and binder content affected the sintered shrinkage of the samples. The increase in compaction pressure increased the green density and decreased the shrinkage, but did not affect the mechanical properties considerably. The increase of binder content lead to increased weight loss and shrinkage. The sintered density, hardness and flexural strength were increased when binder content was increased. A microstructural evaluation showed a decrease in porosity with increased compaction pressure. Samples produced with increased binder showed less residual porosity, which was responsible for the improvement in the properties.