Influence of Various Consolidation Techniques on the Green Microstructure and Sintering Behavior of Alumina Powders

Submicrometer alumina powders, of both standard and narrow particle-size distributions, were consolidated by dry-pressing and colloidal-forming techniques. The resulting green compacts were characterized in terms of pore-size distribution, green density, shrinkage behavior, and sintered density. The interrelationships between powder characteristics, green compact microstructure, and sintering behavior are discussed. There are distinct differences between the characteristics of compacts that were directly consolidated from powder suspensions and those that were dry pressed. Dense microstructures can be achieved at low temperatures using narrow-sized, well-dispersed powders with colloidal-forming techniques.