Influence of Surface Silica Impurities on the Sintering Behavior of Alumina Powders

摘要

The filtering, pressing and sintering behavior of an alumina powder with and without silica impurity on surface has been studied. When silica is removed from surface by HF-treatment and compactibility is considerably enhanced due to the different acidity/basicity nature of the OH of the hydroxyl layers. The silica impurity decreases the activation energy of the initial stage of sintering and grain boundary energy, improves the densification process and exerts a moderate inhibitor effect on the grain growth. (ERA citation 05:032589)