Reaction sintered zinc oxide incorporated magnesium aluminate spinel from commercial grade oxide reactants

Commercially available fused magnesia and reactive alumina sources were used to develop stoichiometric magnesium aluminate spinel by solid-state reaction sintering technique. Zinc oxide was used as a sintering additive up to 2 wt%. The mixture was compacted using a uniaxial pressure of 150 MPa into pellets and bars. The pressed product was sintered in the temperature range of 1200 to 1600 degrees C. The dilatometric method was used to evaluate spinel formation with varying amount of zinc oxide. Phase analysis and density study were conducted to study the sintered products. The increase in additive content was found to improve the density and spinel formation in the composition. The dilatometric study showed that addition of zinc oxide reduced the spinel formation temperature and also increased shrinkage at higher temperatures, indicating better sintering. The microstructural study showed dense and compact nature of spinel in the presence of ZnO. One thousand six hundred degrees celsius sintered products were used to study flexural strength and thermal shock resistance.