Influence of the Fe2O3 method of incorporation into the brucite (Mg(OH)2): a new processing route to obtain dense MgO-Fe2O3 ceramic composites

Abstract

The effect of adding microparticles of cations with oxidation state 3 + in doubly calcined brucite (Mg(OH)2) was studied to obtain dense MgO-Fe2O3 composites. Powders, consisting of brucite and Fe2O3 microparticles (with 1, 3, and 5 wt%), were mechanically mixed. Subsequently, the mixtures were calcined at 960 °C for 4 h. Afterward, green compacts were obtained by pressing and, then, sintering was conducted at 1600 °C for 4 h. Physical, chemical, and mechanical properties were determined in sintered samples. In addition, the morphology and microstructure were studied by SEM and XRD. The results revealed that the sample containing 5 wt% Fe2O3 exhibited a densified morphology with low porosity, as well as high cold crushing strength. This new processing route, considering brucite, as the starting material might be a potential candidate, due to the early ionic activation between cations of hematite to brucite, for obtaining dense MgO-Fe2O3 ceramic composites.