Preparation of Dense and Fine-Grained Magnesium Oxide Polycrystals through Colloidal Processing

Abstract

To obtain a fine-grained MgO polycrystals, colloidal processing was conducted. The dispersed aqueous and non-aqueous suspensions of fine MgO particles were prepared. The suspensions were consolidated by slip casting and CIP treatment under 400 MPa and then the compacts were sintered at 1300-1600°C in air. It was difficult to consolidate large compact without cracks via nonaqueous colloidal processing. In case of aqueous colloidal processing, influence of the MgO hydration on the sintering was examined. Undoped MgO bodies were not densified fully even at 1600°C but densification was promoted by adding Fe₂O₃ or ZrO₂. Fine grained ZrO₂ dispersed MgO polycrystals were obtained.