Effect of preparation conditions on the sintering behaviour of alumina

In ceramic processing of alumina the role of impurities is very important. In order to incorporate them into the bulk material we often use the impreg nation method. This method offers several advantages, but we showed that it , has serious drawbacks: reduced sintering rate and final density. This was explained in terms of reduced green density of impregnated powders , caused by formation of "hard" aggregates. Possible effects of water and d ifferent acids are also discussed.