关键词: 镁铝尖晶石;固溶体;致密化;二氧化钛

Abstract: Magnesium aluminate spinel (MgAl2O4) was synthesized by solid-state sintering using low-grade magnesite and industrial α alumina fine powder as raw materials.The effect of TiO2 addition on densification behavior of magnesium aluminate spinel synthesized was discussed.The phase composition and microstructure of specimens were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The results show that the replacement solid solution of TiO2 addition and formed magnesium aluminate spinel is the significant mechanism to promote the densification of magnesium aluminate spinel synthesized by solid-state sintering.The generation of cation vacancy and the lattice defect of magnesium aluminate spinel are in favor of crystal growth of magnesium aluminate spinel under high temperature which obtains the purpose of densification by excluding pores due to the role of steric hindrance.The extent of densification of magnesium aluminate spinel gradually increases with the increasing in amount of TiO2 content which improves the sintering properties and microstructure of magnesium aluminate spinel effectively.

Key words: magnesium aluminate;solid solution;densification;titanium dioxide