Fabrication of Translucent Magnesium Aluminum Spinel Ceramics

Abstract

A precursor for magnesium aluminum spinel powder, composed of crystalline ammonium dawsonite hydrate (NH 4 Al(OH) 2 CO 3 ·H 2 O) and hydrotalcite (Mg 6 Al 2 (CO 3 )(OH) 16 ·4H 2 O) phases, was synthesized via precipitation, using ammonium bicarbonate as the precipitant. The precursor was characterized by differential thermal analysis/thermogravimetry, X‐ray diffractometry, and scanning electron microscopy. Reactive spinel powder, which could be densified to translucency under vacuum at 1750°C in 2 h without additives, was obtained by calcining the precursor at 1100°C for 2 h.